Model Engine Maker

Engines => From Kits/Castings => Topic started by: Jo on October 22, 2019, 02:26:29 PM

Title: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 22, 2019, 02:26:29 PM
Back in the last Millennium or even earlier (early 1980's  ;) ) I can recall my friend Adam Harris who runs Camden Miniature Steam Services showing me a very expensive set of castings for a 3" Scale Rider-Ericsson Hot-Air Pumping Engine. While being very desirable I  was not allowed   to buy expensive castings by my EX-husband  :cussing: ).

Roll on 30 or so years and my young Apprentice was caught buying a set of said castings on Flea-bay  :) There had been a bit of a concern about the arrival of said castings as the seller thought he could post them using parcel-farce for £2.80 Thankfully the fact that it probably cost ten times that did not stop them arriving today or Surus pouncing on the delivery driver  :facepalm2:

I have been allowed to unpack them for him and we have a set of Adam's Rider Ericsson castings  :pinkelephant: Ok so we are missing the bronze bits and the cylinder liner but hey these casting sets are now over £750 or were when Adam sold them last so it looks like we might have a good buy   

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 22, 2019, 02:37:16 PM
Lets start with a bit of history:

John Ericsson patented his Hot Air Pumping Engine in 1890, the year such engines were first commercially produced. They were very successful for general pumping duties where their low power was not a drawback and the fact they had no boiler and could run on virtually anything was a positive advantage. The prototype of this model is an eight inch engine, the size refers to the bore, and in full size it could pump around 500 gallons an hour.

Adam Harris is not the designer of this model engine, he runs a very good book supply company (yes I know the name Camden Miniature Steam Services does not sound very book like  ::) ) and the drawings and a build article for this engine are in the American book "Steam and Stirling - engines you can build".

I know that Myers in USA does an excellent set of castings for a 1/4 scale Rider-Ericsson but these are not them  :hellno: No these are Adam's own and the one major omission in the UK set of castings is the lack of a casting for the firebox

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: b.lindsey on October 22, 2019, 02:44:23 PM
Looks like a nice set of castings Jo. One comment which applies to the Myers set as well...replace the tubing for the displacer piston and cylinder liner with stainless tubing unless you want to run antifreeze as a coolant in the case of the cylinder liner. The displacer piston can be subject to condensation as well and therefore some rust if not done with stainless (or perhaps aluminum).

Bill
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 22, 2019, 04:27:22 PM
 :thinking: I was thinking of making the cylinder liner out of cast Iron bill. I am not sure were I might get a piece of Stainless tube that sort of size.

What I thought was the Displacer cylinder is not it is too large a diameter so I will need to find something else for that as well. The drawings suggest a piece of copper tube but that is unlikely to be easy to find. I did find a piece of welded steal tube that could possibly be turned down to make that out of.

The displacer piston it came with looks like it has been used before  :headscratch:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 22, 2019, 04:32:42 PM
Bit of my Scooby exhaust should do the trick.  ;)

If you grind down the seam on the inside you can buy a whole range of stainless exhaust pipe in short lengths. What is the diameter you need?
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: b.lindsey on October 22, 2019, 04:33:21 PM
I was just saying that any part that comes in contact with water like the cylinder liner, or condensation like the displacer piston will rust over time. Steel or cast iron will work of course but you would need to mix antifreeze in the water or you will be pumping dirty brown water.

Bill
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Alyn Foundry on October 22, 2019, 05:41:49 PM
Hi Jo.

Your reference to commercial production of the hot air engine, was the date of 1890 for Ericsson?

AE and H Robinson were making hot air engines commercially from 1881.

The Alyn foundry Robinson patterns and production rights were bought from a gentleman named Andy Spooner, who also sold me the rights to a side by side water cooled Hienrici. His " trick " was to use scrap automotive shock absorbers for the cylinders and when emptied of oil the body makes a nice displacer piston too.

Cheers Graham.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Chipmaster on October 22, 2019, 05:55:36 PM
I agree with Bill and Jason. I used a cast iron cylinder liner in my Rider Ericsson and could see corrosion was going to be a problem, as soon as I ran it the water turned murky brown so I used ForLife engine coolant. Fortunately a friend gave me a gallon years ago, it costs about £30 for 5 litres now.
As Jason said you should be able to obtain stainless steel tube from car exhaust fabricators for the displacer and its cylinder.

Andy
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 22, 2019, 06:23:34 PM
Just looked at what stainless tube I have on the shelf and the seam is almost non existent, I was thinking of my ERW stocks which have more of a seam.

As a bonus it comes with those numbers on it that you can understand
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 22, 2019, 06:27:01 PM
Thanks guys,

The date was a direct quote from both the article and Adam's sales literature Graham.


I'm going to have to look into options for the liner and the displacer cylinder when I am next allowed to see these castings.  Someone is currently installing them in his casting store with the promise that I will see them again on Thursday evening  :wine1:

I had noted that I can get 250mm long stainless tube locally for about £10 a bit, I wasn't sure if it was seamless. I don't want seamed tube for a cylinder liner  :hellno: but it will work for the hot end.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Admiral_dk on October 22, 2019, 09:49:06 PM
Nice castings Jo - I'm guessing that both you and Surus will have a lot of happy hours (at different times) from them  :cheers:

Quote
I don't want seamed tube for a cylinder liner  :hellno:

As the only thing I remember doing to with a seamed tube, is cutting them with a saw / cutter, for length and turning a thread on each end - I guessing here .... The seam has a different hardness and this is a pain in the proverbial when trying to be working on the thickness in a lathe (in- / out- side)  :thinking:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 23, 2019, 08:48:33 AM
Thanks Per,

Having a hard weld line down the side of the bore would leave a slight ridge which I cannot see even Honing taking out so best go with a seamless tube. I have about a metre of 60mm diameter Cast Iron so I am tending towards that unless I can find a piece of hydraulic tubing the right size.


A very nice man  :embarassed: sent me a set of paper patterns for the missing firebox. This box needs to be bent up and welded out of thin steel sheet. Having reviewed it I decide to modify the pattern slightly and add welding tabs.

I looked everywhere for a piece of 1.2mm steel to make a firebox out of but all I had was a piece of aged 1mm. The starting point required the removal of the brown protective coating. This the allowed me to spray it with spray mount and stick the pattern on it. I had been warned that cutting the pattern out would be difficult but as I had been using the Hagner successfully on the Triple cladding I decided to try using that. And other than breaking 6 blades  :Doh: we had success.

The corners need to be bent with a 16mm radi, to achieve this I used a piece of 28.6mm diameter steel and angle Iron clamped in the vice. This bent fairly well by hand except the ends which were a bit short so they had to be tapped over using a hammer.

So we have the outline of the firebox. Now I need to decide how to join it up: spot weld, rivet, arc weld, Tig Weld, or silver solder :noidea:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: b.lindsey on October 23, 2019, 02:23:17 PM
Nice work on the firebox Jo. The myers plans also show a  fabricated firebox though they were apparently not updated once the cast firebox was added to the kit.

Bill
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 23, 2019, 02:38:22 PM
I've bored out quite  a bit of ERW steel tube with a weld seam and not found it a problem when using carbide inserts, though that won't cure the rust issue.

Then again, hundreads of hit and miss engines about that are water cooled and run iron liners and cast iron water jackets. Just swill a bit of tank sealer or similar about inside if you are worried or pump mineral oil.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Bluechip on October 23, 2019, 03:04:41 PM
T

I looked everywhere for a piece of 1.2mm steel to make a firebox out of but all I had was a piece of aged 1mm.


Jo

Hi Jo

That bit of steel sheet I was babbling about t'other night has been found ....  eventually ...   :facepalm:

It's approx. 460mm x 420mm x 0.8mm  .....  :shrug:

So it's now yours.   :ThumbsUp:

Unfortunately it's covered in blue paint and appears to be rust free.  So apologies for the amount of prep. it will need before use ...  :embarassed:

Dave
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 23, 2019, 03:15:27 PM
Thanks Dave  :)

Still deciding how to join up the box. A quick practise with my new welder was vaporising the steel plate as was my old welder  :facepalm:

I think it is going to be rivet together then chalk with either silver or if cool enough soft solder.


I have been pointed at a supplier of the required Stainless steel tube. I'll let you know when I recover from the shock of the price  :lolb:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 24, 2019, 02:46:27 PM
It looks like I have found a suitable bit of stainless tube for the displacer cylinder  :)

I have also been taking the firebox about as far as I want to go before putting on the band round the middle which is used to mount it onto the engine. The three side joins had three rivets each put in to hold things together. Then the box was silver soldered together. It was a high silver solder I used which doesn't run very much hence the lumps  :facepalm2:

The important thing is it is together without too many problems. And I even managed to keep the part of the paper template with the positioning of the fire hole and the arch at the bottom, thankfully I had centre popped the centre of the hole for the chimney before burning off the paper.

Its Thursday and it looks like I will be allowed to fondle the Rider-Ericsson castings this evening :wine1:  :pinkelephant:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on October 24, 2019, 04:47:43 PM
Looking forward to more pictures of those castings, Jo!
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 24, 2019, 06:26:36 PM
We have to be patient Bent. Trying to rush someone has known the entire casting set to be hidden in the back of the cupboard for a few months and I am at a disadvantage if I try bribery as the grocery delivery driver only has one box of Snickers Icecream on board so I have to pace admitting to them  :wallbang:


The flywheel Bracket has an odd one: it uses a needle bearing without an inner to the race  :headscratch: To be able to do this it says you have to get a super hard dowel (which are too short  :facepalm: ) There is plenty of space in there for a real needle roller or even to use a bronze bush. I wonder what the original had  :noidea:

The only feature I have found so far is that the bore for the power cylinder is short. I assume by the amount that was turned off the top. I'll need to check the consequences of this  :thinking: It might not be as simple as shortening the liner.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 24, 2019, 06:32:36 PM
I thought it was quite common to run needle rollers on a hardened shaft with just the drawn cup on the outside.

It is possible to buy hardened inner rings that you could loctite onto a shaft

You can get 1/2" dowels upto 4" long

Also saw some 2 1/4" x 10g seamless steel tube on e-bay if you want that for the liner
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 24, 2019, 06:44:25 PM
I was going to use silver steel so could just harden it  :noidea:

Also saw some 2 1/4" x 10g seamless steel tube on e-bay if you want that for the liner

So lets have the link  :stickpoke:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 24, 2019, 06:47:58 PM
Dowel pins, Zoro is part of Comwell, or you could just use a bit of 1/2" HSS

https://www.ebay.co.uk/itm/Kennedy-1-2x3-Inch-Plain-Dowel-Pin/132456053728?hash=item1ed6fefbe0:g:YCgAAOSwmcNdWsmm

Tube, do short lengths. Probably as close as you will easily get to 2" bore

https://www.ebay.co.uk/itm/STEEL-TUBE-COLD-DRAWN-SEAMLESS-2-1-4-OD-X-10SWG-57-15MM-X-3-05MM-EN10305-1/223154073434

Though you will have to open your purse :Lol:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 24, 2019, 06:51:59 PM
or 3 1/2" long pins so you can cut off the tapered end

https://www.ebay.co.uk/itm/Kennedy-1-2x3-1-2-Inch-Plain-Dowel-Pin/142644328260
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 24, 2019, 06:56:13 PM
My usual supplier who knows a thing or two about bearings just happens to do 11/16 OD x 1/2 ID and even suggests running them direct on a hardened shaft.

https://www.arceurotrade.co.uk/Catalogue/Bearings/Needle-Roller-Bearings
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 24, 2019, 08:51:23 PM
I can see that you find it easy to spending the pennies JB.  ::) My other supplier may be able to supply a bit of tube for me   :naughty:

Jo

P.S. You don't need a hardened shaft if you are using cheap Chinese sourced bearings  ;)
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 25, 2019, 07:02:25 AM
So you will just be running them straight against the rust then :wallbang:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 25, 2019, 07:53:20 AM
Heat treatment of most metals causes an oxide layer to form on the surface of the metal which most of us clean off  ::)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 25, 2019, 07:59:13 AM
Or better still use a ground dowel pin as cleaning off that oxide from a bit of something you harden will reduce the diameter & quenching will possibly distort the rod and then you will be moaning that you have another wobbly flywheel either from a loose fit of the bearings or bent shaft :facepalm:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: ketan swali on October 25, 2019, 12:57:04 PM
Hi Jo,

Looking at your drawing, it suggests 2 x B88 - Torrington. The original B88 is a drawn cup needle roller bearing, with a full complement of needle rollers. ARC used to get them way back from Torrington when it was part of IR, then kept on being passed to current ownership by KOYO. Originally, when they were not available as a caged bearing. Later they were, and what ARC currently offers, is BA88 which is a caged version of B88, in IKO Japan brand:
https://www.arceurotrade.co.uk/Catalogue/Bearings/Needle-Roller-Bearings/Needle-Roller-Bearings-Imperial
The image you see on that page is a good representation of what we have currently in stock for BA88.

Some fitting notes:

- Drawn Cup NRBs get their support from their housing. As they come, if you put the bearing on a 1/2" shaft, it will rattle. You will need to measure the OD of the bearing, and make the hole in the casting about a thou to a thou and a half smaller. For hard casting material, usually a thou smaller, for soft casting material, more.. but there is no exact measure. Once you press fit the bearing into the housing, the needles will compress (for want of word) onto the 1/2" shaft, and hopefully, if you have done it right, the bearing will not rattle on the shaft. This is a common mistake made by fitters, be they new or experienced, when specifically fitting drawn cup NRBs.... commonly the cause of slippage on DCNR Clutch bearings like RC02 fitted to lubricator boxes?.

- Ideally, make a mounting mandrel to press fit the bearing in. See attachment for general guidance.
- When press-fitting, press on the drawn cup on the side which has the bearing details stated on it. This side/edge of the drawn cup is hardened.
- For the shaft, ideally you need something hard for the needle rollers to run on. dowel pins are fine. You may also get away with silver steel to some extent (I think Nevel Evens used this often). Alternatively, you may be able to find a hardened inner ring with an OD of 1/2".

In the late 1980s, Mr. Torrington had made many legal challenges on Chinese factories.  Slowly after the year 2000, the current group which owns Torrington, have plenty of JVs with Chinese factories. :-)

Good Luck Jo.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: ketan swali on October 25, 2019, 01:06:13 PM
Also read this for fitting guidance:
https://www.ikont.com/catalogs/needle-roller-bearing-series/5508_3_E_TA.pdf

Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: ketan swali on October 25, 2019, 03:38:49 PM
The boys on the Stirling Hot Air Engine stand always liked to use ball raced bearings, without any seals, or shields, removing almost all of the lubrication, to reduce as much of the friction as possible, in their assembly.

So, just out of curiosity Jo, is there a possibility you could consider similar?... example 4 x SR1212ZZ after removing the metal shields?
https://www.arceurotrade.co.uk/Catalogue/Bearings/Ball-Bearings-Imperial/12-Bore
in which case, the OD bore in casting would need to be 'slightly' bigger, or

Metric 4 x 6701-2RS after removing the rubber seals?
https://www.arceurotrade.co.uk/Catalogue/Bearings/Ball-Bearings-Metric/12mm-Bore
in which case, 12mm shaft to be considered, and the OD bore in casting would need to be 'slightly' bigger.

Keep in mind, the original full complement of rollers in B88 would have created the most amount of friction. The above method would mean that you could use whatever unhardened material you want for the 1/2"/12mm shaft, and have lower friction.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on October 25, 2019, 03:46:54 PM
Interesting info Ketan, I wonder if just two would do? From previous experience your balls are quite smooth. ;)

hMioASP3vpgt=7s
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 25, 2019, 05:53:36 PM
Thanks for your input Ketan,

A friend has found some English  8) made needle bearings and I have ordered a 101.6mm  :lolb: dowel so I will give those a go  :ThumbsUp:

Jo

Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: ketan swali on October 25, 2019, 07:39:22 PM
Jason,

Looking at your you tube video, it would suggest that two may do fine. The ball raced bearings I mentioned are thin/slim sectioned, so I suggested four after looking at the original B/BA88 widths which are double the width of the slim ball bearings I suggested.

Jo,

Glad you got it sorted. The English made (presumed to be made in England) are they B/BA88s?.... if so, would you mind having a look on the bearings to identify who the maker is please?. Just interested to know for my own knowledge. If it is marked RHP... then it was probably made by FLT in Poland or just near the end of the war in England for a limited period. If it is marked INA, they are based in Sutton Coldfield but didn't make these in the U.K.. They were made by their plant in Kindsbach (not sure of spelling) - Germany, which changed hands between FAG, INA and Torrington.... and then there were fakes or copies made in Italy, Russia and China, marked ENGLAND or Germany... but still good and some bad. Torrington only made these in the U.S. and Germany. So I am a little puzzled about the English made for this particular bearing.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Chipmaster on October 25, 2019, 10:12:25 PM
Hi Jo,
For the power cylinder you could consider a Westwood cylinder liner, have a look at WCL !A on their list with a semi finished bore of 50.17mm (Less 1.00mm for final finishing in bore) and it's 177.8mm  ~ 7" long. As you know I used a Westwood liner for my Rider Ericsson.

https://westwoodcylinderliners.co.uk/products/browse-by-size/

I donít know what they cost but cast iron is so much easier to machine, hone and lap.

Andy
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 26, 2019, 08:32:09 AM
Thanks Andy, I've sent them an enquiry. The alternative is that one of the model traction engine companies has seamless steel tube available which you only pay pro-rata on length and no cutting fee :)

Ketan I will find out the manufacturer when I pick them up. I suspect they are ex-fast jet production line as funded on cost plus by the tax payer so unlikely to be a cheap make  ::)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: ketan swali on October 26, 2019, 12:13:34 PM
Thanks Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on October 29, 2019, 02:16:31 PM
That dowel turned up (with four extras I didn't order  :headscratch:) and it is 12.7mm diameter and 4 1/2" long   :Doh: Mr Silky had a look at it for me and turned it down to the required initial length of 101.6mm using a Sumitomo tipped carbide tool. When it comes to assembly I might get him to reduce it further.

I can report that the case hardening is good and is about 1mm thick  :ThumbsUp: and the sparks did fly when machining through it. The centre is a little softer. 

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 04, 2019, 06:13:24 PM
Latest on the liner: No response from Westwood  :disappointed: But a very lovely man has picked up a suitable bit of seamless steel tubing that can be machined and I have borrowed a Delapena hone of the right size so Smelly can hone it for me  :ThumbsUp:

In the meantime I have continued on assembling Numero Uno of the Triples  :toilet_claw: So exciting.

To break the monotony I decided to bore the flywheel bracket for the needle rollers that I picked up. These are Koyo bearings made in USA  :headscratch: The book of words suggests mounting the bracket on a faceplate and boring to fit the bearings  :headscratch: Ok I'm game. With a 6.7mm spacer under the centre boss everything mounted nicely and both sides of the centre boss ran true  :) Because of the accuracy required for fitting the bearings properly I made a go/no go gauge marked up with too small, too big and the measurements that are acceptable and used this to aid the boring.

I'll have to have a think about how to hold the bracket to machine the other side. My reference surfaces are the bore and the machined face  :noidea:

Jo

Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on November 04, 2019, 06:23:10 PM
These are Koyo bearings made in USA  :headscratch:

Why head scratching, I thought Ketan explained it.

Torrington used factories in Germany and US to make these type of bearings, Koyo bought out Torrington and still use the same factories.

Not English as you said.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 04, 2019, 06:30:34 PM
He said nothing about Koyo buying anyone out :ShakeHead:

Not English as you said.

You didn't expect my supplier to admit to any makes other than English, German or Swiss did you?  :lolb:


I am still short of a bit of 19mm square to make the water pump out of: My supplier weighed his in  :wallbang:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: scalemodel on November 05, 2019, 10:42:40 AM
Hi jo
Im abit late coming to the table but I'm so glad you have started this engine as ive got one on the bench part built which I want to finish off.
I started my engine 15 years ago when after building some stuart engines wanted something with a fire in it. Unfortunately my mind turned to model traction engines and the the rider got put in the cupboard, 15 years on 2 traction engines down I'm now worn out and skint, my mind has turned back to models I can pick ie model hit and miss engines and want to get my rider finished

Jonathan
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 05, 2019, 01:18:54 PM
Welcome Jonathan, I will have to see if I can build your enthusiasm to build your model  :) Did you know it is possibly the last ever Southern Counties Traction Engine Group meeting at the end of the month  :( You are welcome to come along it is held just south of Newbury.


I have been avoiding fitting the Triples making some more swarf and clamped the bracket to a plate to machine the bosses to height and to skim off the bottom of the feet/bracket.

The other side of the feet seem to need about 5mm taken off so before I do that I am checking the alignment  :thinking: The centre of the cylinder seems to be 11.3mm over from the flywheel boss and 5.65mm ish over from the side of the bracket that clamps on the side. Time to go and measure again.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 05, 2019, 02:52:37 PM
Still thinking about it...

I have taken 2.4mm off of the back of the top bracket to bring it level with the back of the flat face on the cylinder. Then I decided to press in the bearings. Only to find that all the needles had jammed solid and where sitting at a slight angle after  :paranoia:

Having poked the shaft in and jiggled it about a bit I would swear the bearings were not moving they must be solid  :headscratch: All the dimensions were correct. I checked again 30 seconds later and they were all free and sitting square and supporting the shaft beautifully  :noidea:

While I am thinking about where to put the holes in the bracket I spotted that the raised bit on the casting around the bottom of the cylinder is all over the place  :disappointed: that will have to be sorted and I need to decide studs or bolts around the bottom of the cylinder :thinking: Lets have a measure up on the platform.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 06, 2019, 04:22:20 PM
While I am still not firing on all cylinders I found that that wobbly bit around the base of the cylinder was annoying me so the platform was mounted up in a vice and zeroed up on the hole for the cylinder. Using a 6mm ball end milling bit mounted in my boring head with Tgs head running in reverse that nasty wobbly edge was machined off. A small diameter abrasive drum on my Foredom was used to blend the new machined surface into the main platform surface  :)

I also drilled and tapped the three mounting holes for the platform to let it mount on the legs. I need to work out were the other mounting hole goes  :thinking: and I will need some studs  ::)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 07, 2019, 06:14:05 PM
I am pleased to say I have done the studs for the bottom of the cylinder and the three for the legs but still need to think more about something for the fourth mounting.

this set of castings did not come with the Bronze links so I have been raiding the come-in-handy shelf and found some bits of brass to make the links out of. The starting point for these is to drill and ream the holes. I often recall when I started making model engines that starting with the holes seemed strange but it all comes together in the end  :wine1:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 08, 2019, 03:45:46 PM
A piece of scrap aluminium was drilled and tapped for the centres of all  the rod ends and a set of clamping/filing buttons made. These buttons are 12.7mm OD, with a 6.35mm boss that goes into the hole in the rod, the hole for the bolt is smaller in this case for a 2BA allen screw.

While there is plenty of flat surfaces to clamp on to, it is time to mill the slot in the forked end and taking the other end to width but leaving most of the metal still on the top and bottom for shaping later

The two sides can then be evenly taken down by clamping the rod onto the aluminium jig while it is mounted horizontally. Flipping the Aluminium vertically allows the top and bottom to be brought down before unscrewing it from the jig and using the buttons to help with rounding the ends. Having cleaned out the holes with a reamer again a quick check on the engine to see what it looks like  :)

Hopefully the remainder will be just as trouble free.  :wine1:

Jo

Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: mike mott on November 08, 2019, 04:04:43 PM
Good afternoon Jo, I noticed in the last picture the hex stock bolts, are you making your own bolts and if so who is the supplier of the small size hex stock that you are using. in my neck of the woods we have a metal supermarket and they only stock .250 across the flats I would like to find a decent supplier of small steel hex without breaking my limited funds (retirement income is very low) I like the way you machine up the brass rod as well.

Mike
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 08, 2019, 04:17:04 PM
Thanks Mike,

Yes I am making my own bolts. Those are not small however they have 8.5mm A/F heads and I am using some of my extensive collection of bits of hex bar that came out of the old technical collage when it closed. Normally I machine my fastners out of round 303 Stainless bar and cut the hex myself but this is such a large engine that I can use some of the big stock material.

I am not sure where you would buy any small hex in Canada, maybe one of the other members would know. In the UK we struggle to find the old imperialous or BA sizes any more but metric sizes are easy to find.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: mike mott on November 08, 2019, 05:07:31 PM
Thanks Jo.

Mike
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 10, 2019, 04:35:10 PM
I have finished roughing out the links, just a bit of polishing to go  ::)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on November 10, 2019, 05:02:59 PM
Looking good though a nice blast with beads in your cabinet could look better than bling and polish.

Were the ones on the original engines brass/bronze or just iron castings?
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 10, 2019, 05:21:57 PM
They look to be polished cast bronze:

Kj8krCrRLRs
Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on November 10, 2019, 05:30:59 PM
Yes looks like Bronze, wonder if the factory just painted the lot and it's just the restored ones that get buffed up?

You going to make one of those nice wooden tubs too :LittleDevil:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 10, 2019, 06:30:43 PM
I was thinking about using a beer barrel  :DrinkPint:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on November 10, 2019, 06:53:46 PM
That would look the part, can you get them about 150mm tall? I think these days they are called cans ;D. Last time I saw one that small it was attached to a St Bernard

Or are you going to have a go at coopering? Could probably turn one from a log and just put some grooves down the sides to look like the staves and a few hoops to get the look.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Elam Works on November 10, 2019, 09:52:16 PM
Quote from: Jo
I was thinking about using a beer barrel


Well this might be over-scale, 10 x 7 dia. in the old imperial system. What was in it was less memorable than the novelty packaging, which is still around decades later as a part washer can. No doubt someone is still packaging beer in these mini-keggers; might require a little recon and research at the off-license. Also might need some volunteers to carry away the contents, especially if it is cheap and nasty like Badger.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 12, 2019, 04:44:17 PM
Thanks Doug, That casket looks about the same size as the one we emptied last year. I think both might be a bit big.

I am still working towards finding where to bolt down that bracket for the flywheel so I need to be able to find the centre of the cylinder that means it would be a good idea to make the beam pivot  ;)

I have made my two bearing blocks out of brass which is not a good bearing material  :disappointed: So machined them as a pair I have fitted mine with  oillite bearings. This has the advantage that I probably won't need to oil the bearing in my lifetime  :)

With the blocks then the beam support can be machined and the bearings fitted to it. The one area that is easy to miss is that the bottom studs must have a bit of extra material removed above the bottom clamping surface so that there is sufficient space for the securing nuts to rotate.

I found a piece of rusty old stuff, it was horrible :facepalm2: I think it had been chain drilled out of the centre of something but in it I found the top collar for the Displacer Cylinder  :cartwheel:

Another family shot for those of you who are watching quietly in the background  :cheers:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Dave Otto on November 13, 2019, 12:24:20 AM
Coming along nicely Jo!

I'm curious about the size and scale of your engine, you are calling it a 3" engine; is this the bore size?
It seems that from the photos it is more like the size of the 1/4 scale 2" engine from Myers?
The 3" engine from Myers is a large model at 25" tall to the top of the 13" flywheel.
The legs on your engine seem to be shaped differently that the US versions, is this just the way they were modeled or were the original engines different in England than the US?

Dave
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 13, 2019, 07:38:58 AM
Thank you Dave,

I am calling it a 3" engine as that is what the supplier Camden Miniature Steam Services calls it. In the UK a 3" engine means a 3" to the foot i.e. a 1/4 scale engine. I know that Rider Ericsson sold their engines based on the bore size so a 8" engine had an 8" bore so in their parlance this would be a 2" engine  :headscratch: which would be confusing for a UK audience. This model is a 1/4 scale model of the engine at the Henry Ford Museum as documented in "Steam and Stirling - engines you can build", the original engine had a 3 7/8" stoke this one has a 1" stroke.

Adam at Camden did not have access to the original engine so he based his patterns on the drawings in the book with a few modifications to make the patterns/castings easier to work with.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on November 13, 2019, 08:20:28 AM
It's a bit of an unusual way to do it in the UK as generally only traction engines and road steam subjects use that convention of inches to the foot with stationary engines using fractional scales. So just like in the book most people in the UK would describe it as 1/4 scale.

Though they did list it as  3" scale not just 3" so less likely to be related to bore.

Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Dave Otto on November 13, 2019, 01:30:57 PM
Thanks Jo

That clears it up for me. :)
I have castings for both the 2" (1/4 scale) and 3"(3/8 scale) engines. The 3" castings are from Myers and the 2" castings are old enough that they were from Norbert Keely the guy that originally did them way back. I think Clarence Myers acquired the patterns for the Rider-Ericsson and also the Essex fan from Norbert. Need to find time to work on them someday.

Dave
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 14, 2019, 04:25:04 PM
Strikes me you have a lots of sets of castings Dave that need to be converted into models. Maybe I should send Surus over to check you are treating them correctly.  :pinkelephant:


A little bit more on the engine. A set of studs made for the beam Support and the bottom of the support has been shaped up. The drawings suggest that the cylinder should be shaped back to match this support  :noidea:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on November 14, 2019, 06:22:50 PM
Nice progress, Jo.  :popcorn:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 15, 2019, 07:24:15 PM
Thanks Bent  :)

I am still working towards being able to bolt down that bracket.... so next I need to do the beam, which will locate the crankshaft. The beam was banana shaped  :facepalm2: Having milled some flats on the sides I found that there was a 1.3mm off set between the ends of the beam and the centre features.

The reference is the pivot so first up find the pivot's centre (checking the two ends fit reasonably on the beam) and set up to bore it. This could them be used to face the two ends, one of which is slightly further out than the other and with the banana shape the tool caught the ribbing  :Doh: Before taking down the two edges either side of the oval hole.

Next a bit of hole drilling.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 19, 2019, 03:14:36 PM
The beam was mounted onto a plate to enable two holes in the beam end to be reamed, the slot for the piston rod to cut, the side ribs to be milled straight and for the top and bottom ribs to be thinned.

The casting around the piston rod slot was a bit uneven so was filled to bring it up then smoothed down with a hand file and some emery.  The beam could be milled to make the ribs at the top and bottom thinner but I have already taken about 4mm off so I will leave it there for now  :) .



Thanks to Muddled Engineer for the visit today  :-*. Surus made a big fuss over him and even let him look through his casting collection   :headscratch: I think it was a ploy to see if Eric had any more casting sets that he thought Surus needed...It was found that he still needs a Stuart 6A and the 600 :pinkelephant:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Admiral_dk on November 19, 2019, 08:22:04 PM
Nice progress with the beam and engine Jo  :cheers:

Still following along  :popcorn:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on November 20, 2019, 05:58:05 PM
Jo, do you use something like JB-Weld (steel-filled epoxy) for your Aluminum backfill repairs?

After doing some of the machining on my fan project, the castings "sprung" and some of the holes ended up moving.  Am debating repairing them, or using clamps to de-spring the parts before bolting them together... :noidea:

Also may want to patch/smooth some of the casting pores and pits before painting, and not sure what would hold up better under heat?
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 21, 2019, 02:33:30 PM
Thank Per  :)

Hi Bent, that is standard plastic epoxy filler as used on cars. Sometimes it is worth using JB Weld if I need something that can take a lot of temperature. I have also been given a tub of epoxy metal filler which I have not opened yet. While you may think of the top of a stove as being very hot relatively it isn't I doubt it will boil water and if it is hotter your fan will quickly overheat....


The power piston centre casting was also missing  :-\ So I made it up from some brass bar. I could have used a 25.4mm diameter bar and turned it down for the main body of the centre but chose to just stick on a collar of the wider diameter to save my sparse metal stocks  :paranoia: The two bosses are for the bottom of the links and these have been made by drilling the centre of a piece of brass 4mm (just under 2BA tapping size) and then using the side of a milling cutter the diameter of the body of the piston centre to scallop out the inner curves.

The piston centre bar can now be drilled 4mm at the appropriate point for the centre of the bosses, a suitable piece of brass tube inserted: I drilled a bit of brass 2.8mm here to take a 6BA screw to hold the bosses on. Having dampened the joints and dipped the damp bit in some flux it is ready to be silver soldered together.

Once silver soldered it can have the bottom of that 25.4mm diameter turned again to make sure it is true and the 1/2" by 26TPI thread cut using a die. The last bit being to add a bronze bush in the centre with Loctite to provide the sliding surface for the displacer rod.


 :thinking: I think we are ready to attach that flywheel bracket... With all the links in place it is obvious that the flange where it mounts to the cylinder casting needs a bit taken off. Once that is done the two holes for the mounting bolts can be drilled out 3.2mm (4BA tapping) and now I need to transfer those holes onto the cylinder so I need a 3.2mm diameter centre punch to poke down the two holes to mark the centres.

Jo


Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 21, 2019, 04:03:58 PM
Having turned a point on the end of a bit of steel this has been successfully used as a transfer punch  :cartwheel: while on a roll I also did the two at the bottom of the bracket and added a countersunk screw to provide the other leg mount.

A quick family shot and then in for an evening of fondling   :mischief:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on November 21, 2019, 09:02:11 PM
Nice work Jo!  :popcorn:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 22, 2019, 02:04:42 PM
Thanks Bent  :D


The next casting the displacer yoke is horrible:- nothing proved to be square or parallel  :-\ So the first step was to locate the holes and that the ones on the end of the two arms went in at the correct distance from the edge of the casting and that the other two holes were square to them  :paranoia:

With the holes in place the edges of the two arms could be taken to width. then it was time to do a lot more measuring. As I suspected the main yoke part was offset from the ends of the two arms  :facepalm: Luckily there was just enough on one side of the arms to get it back in the centre.

It is now coffee time while I contemplate how to continue with this yoke  :noidea:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on November 22, 2019, 06:11:14 PM
Would've like to see that drilling setup, were all the holes made in one go?  :noidea:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: ChuckKey on November 23, 2019, 01:17:53 AM
With the holes in place the edges of the two arms could be taken to width. then it was time to do a lot more measuring. As I suspected the main yoke part was offset from the ends of the two arms
A decent alloy (or gunmetal) casting is unlikely to mind a bit of careful bending to correct the geometry.

(I was recently staggered by the ductility of a full-size loco cylinder drain cock after the loco struck a fallen tree. The body of the almost new gunmetal casting had been twisted 30, maybe 45 degrees relative to the mounting flange and there was no cracking evident on a cursory inspection.)

 Anyway, you seem to have got away with it this time.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 23, 2019, 07:39:31 AM
Sorry Bent I forgot to take a pic of holding the casting by the side of the "C" shaped bit and packing under the flat bit while drilling the holes  :-[ I drilled three holes like that offsetting the tapped hole at the end of the arm relative to the end profile of the arm, then turned it over and used coordinate drilling and checking the offset from the end of the arm to locate the second threaded arm hole. It was not fun  :ShakeHead:

With the holes in place the edges of the two arms could be taken to width. then it was time to do a lot more measuring. As I suspected the main yoke part was offset from the ends of the two arms
A decent alloy (or gunmetal) casting is unlikely to mind a bit of careful bending to correct the geometry.

I have many times adjusted a casting by a quick tweak in the vice with an encouraging implement. I did consider it on this one but on this casting one arm was actually slightly longer than the other so I am assuming the pattern was offset as well. Bending it "straight" would have meant that the short arm would have had the screw hole right on the end of the metal and needed filler to build up the profile of the missing arm  :paranoia:


I suspect I will be spending a lot more time on this casting before I am happy with what it looks like.  :noidea:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 24, 2019, 12:03:58 PM
A piece of stainless was found for the displacer cylinder which was 5 mm too short  :facepalm: But I think I can loose this shortfall in the base casting  :-X

The bottom of the tube has to be filled and I chose to cut a bit off of a piece of plate and to turn it round. With the three pieces available it was time to silver solder it up. I started by spacing the ring up off the bottom of the tube by 6mm using 4 8 nuts and silver soldering it in place. It was the thin cap that gave me most trouble and took three attempts  :facepalm: the first attempt left such a big hole that it pretended to be a watering can. The second left a little black line that did not have any solder on the inside so I poked it with a scalpel and it went through  :Doh:

Finally the displacer cylinder was complete and it was time to look at mounting it to the platform. At this point the difference in the diameters of the hole in the platform and the end of the displacer was HUGE  :o

The platform was mounted up in a vice and the centre of the hole found. This allowed the 6 holes to mount the displacer cylinder to be drilled and tapped. With the displacer cylinder in place it was time to pop the displacer piston in and look at all the clearances: which also look big. The good news was that the horrible looking piston that came with the engine once cleaned up proves to be made to the drawing but I am not sure I am happy with the clearance  :noidea:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Roger B on November 24, 2019, 12:36:30 PM
I like your live centre for cutting the disc for the end of the displacer cylinder  :ThumbsUp:  :ThumbsUp:  :wine1:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 24, 2019, 03:17:58 PM
Thanks Roger, I needed an extra washer as the point was a bit long.


Back to the yoke, what a pain, shaping it up was a bit like playing twister  :Doh: I managed to form the two bosses on the arms by supporting it with a spacer between the arms and providing a centre on one of the button screws. Then the rotary table helped form the other two but the shape of the yoke was not easy and it still hit the body of the BCA on either end. Thinning down of the flat arm had to be done in a vice...

Finally a bit of filing and use of a sanding drum in the Foredom left me with a possibly acceptable yoke  :) . Which even mounted on the engine allowing a bit of round and round/up and down testing: 

XWj9akgI7jQ
Ok so the displacer piston is rubbing  :facepalm2: but as it is not connected up yet that was to be expected.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 25, 2019, 04:43:27 PM
The Displacer Piston Rod End is a round knob. To make one of these we have to dig out our ball end turner. For those of you who may not have used one of these lets go through how to set up and use one:

The end of the rod need an undercut just beyond where the ball is going, for this part the drawing is perfect and gives us a 11.1mm diameter at the back end of the ball.  (Mr Silky is a collet lathe, this means his nose is the ideal shape for ball turning, if you use a standard chuck you will have to stick the metal you are turning your ball on further out to gain clearance for the ball turner. )

We now need to mount our ball turner on the tool post. The tip of the cutting edge has to be right in the middle of the bar, to set this we can position the tool on the top of the bar - this also sets the radius of the cutter for cutting the ball. Now we wind the saddle along and we bring it up and touch the tool on the end of the bar - this now positions the saddle for cutting the ball and we are going to lock the saddle. We now wind out the cutting tool and can start using the ball turner handle to pass the tool over the bar cutting our ball. Simples  ;D

The ball on its stub can now be held to have two flats milled and the central bore drilled and reamed (or bored if like me you don't have a reamer the right size  ::) ). The last trick is the ball is still on its stub.... so we can used the stub to hold the ball inside the collet to drill and tap the hole in the stem of the rod end before parting it off.

My engine now has a brass knob on it  :embarassed:

Jo

Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on November 25, 2019, 05:40:50 PM
Lovely work Jo.  I was admiring the time and effort to put the circular bosses on the yoke piece...then you go and whip out a brass knob... :embarassed: :lolb:

Didn't know I wanted a ball cutter until now, that's a neat bit of kit.  Oh and your explanation for the yoke drilling makes sense, I too get too busy to take pictures sometimes.

Is the ball end practical or just decorative?  Still trying to picture the linkage for the displacer (from the photo back on page 1 of this log), I assume the hoop that attaches to the yoke can also pivot around the yoke ends?
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 25, 2019, 05:55:57 PM
Thanks Bent  :)

Is the ball end practical or just decorative?  Still trying to picture the linkage for the displacer (from the photo back on page 1 of this log), I assume the hoop that attaches to the yoke can also pivot around the yoke ends?

The Ball end was on some of the original engines. From what I understand the engines varied.. a lot  :facepalm:

The hole through the ball is for the pivot which bolts to the two arms (Displacer Piston Rod Yoke) which have two pivots on their ends which pivot around the yoke ends  :thinking: It might be easier if I make those two arms tomorrow as it is much easier to see than to say.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on November 25, 2019, 07:11:13 PM
I follow your description, sounds like what I thought Jo (pivot at the ball, pivot on the yoke ends, so that the displacer piston rod moves through a fixed sleeve up at the top of the cylinder?)
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 26, 2019, 11:16:58 AM
That is about right Bent  ;)

I have just finished off the top pivot. It has been made out of 304 Stainless, so that it is relatively hard but will not corrode and damage the brass pivot. It is a piece of round bar which has had two flats milled onto it and had two threaded holes for the vertical links.

Now it is time for those long vertical links. The first thing I have noted is that one of the measurements is wrong and while most of the engines I have seen are all different... I will be deviating from the drawings to make ours more authentic  :)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 26, 2019, 04:32:49 PM
The displacer piston rod yoke (two long arms) are made in three pieces: a steel part to join to the pivot through the brass ball, a length of 4.76mm square steel and I have chosen to make the bottom loops out of brass. These three pieces need to be silver soldered together to make the arms yoke.

The top steel part began as a 12.7mm by 4.76mm length of steel which had two holes drilled in it for the two bolts. Then I sawed it in two and packed it with two pieces of 1.6mm to enable it to be held in a collet and turned to 11.1mm diameter. Over to the mill and the two sides had scallops taken out of the sides before milling a slot for the square bars.

Two pieces of square bar are needed which have a 25mm ID bend on the end. It is easy to bend this round another bar cold but it  will be necessary to leave it over length so that it can be clamped for bending. Once cut to length the two ends can be silver soldered on and it cleaned up.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on November 26, 2019, 04:39:27 PM
A similar process is used to machine up the other end of the yoke except that these are filed round after silver soldering on the end of the rods.

Having put the yoke on the engine it became apparent that it is no longer possible to do any more round and round testing without adding the cylinder liner or the power piston as that acts as the guide for the piston rod  :(

So four pics of the crankshaft in each position to show the position of the arms and to check nothing jams up  :)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on November 26, 2019, 05:55:50 PM
Getting both pieces to come out square and true after silver soldering is the tricky part...for me  :Lol: 

Still following Jo. :popcorn:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 01, 2019, 01:07:11 PM
I have been given a barrel to go with my engine  :thinking: And a piece of seamless steal tube and a bit of Brass. So I can now finish off the engine  :whoohoo:

Thank you Dave  :-*

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on December 01, 2019, 01:24:13 PM
Do you have to empty the Barrel first or did Dave helpfully do that for you?
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 01, 2019, 01:31:07 PM
Dave was very generous in this regards ;)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Bluechip on December 01, 2019, 02:15:06 PM
Do you have to empty the Barrel first or did Dave helpfully do that for you?

That barrel has been loooooong ago emptied ...   I remember where and when and by whom it was emptied .....

The place was RAF Eastleigh  Nairobi  Kenya.

Time was Christmas Day 1964

Rob. C, Roy. S, Phil. V and me .... The first 3 names abbreviated to protect those who were undeniably guilty ...   ;D

Dave

Edit:  Actually 1964  -- corrected   :old:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on December 02, 2019, 05:18:07 PM
Rats, was hoping to help empty the barrel.

But, Jo will have to refill it when testing, presumably with the same liquid as originally held?  Dibs on being pump testing assistant... :wine1:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 03, 2019, 03:44:33 PM
Time to make a start on the liner. Dave very generously came up with a piece of seamless steel tube. The scale on the outside made me think it might be a bit tough and I was right  ::)

Having faced the two ends then got under the scale I machined a short smooth bit to use with the fixed steady. The fixed stead clamped in place carefully had each of the arms adjusted to just rub the metal surface before a smear of anti-rubbing was applied.

The inside of the tube proved to be as scaly as the outside and even once underneath that it is a bit tough. This is actually not a bad thing for a liner. However I noticed down the end of the bore I could hear a hard bit and having bored the liner out to 50.35mm and taken it down to "have a look" and :facepalm2: there was a mark.

Not a problem, Smelly got to work and honed out the liner to 50.4mm and all the marks have vanished and the bore has a very nice cross hatching on it  :wine1:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on December 03, 2019, 08:43:28 PM
Jo, does the liner get press fitted to the cylinder body or glued in?  Asking because it's obviously easier to hone before fitting, but do you worry about distortion due to press fitting?
 :headscratch:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 03, 2019, 08:58:52 PM
The original designer Larry Kazyak in his description said that on his first engine he did a 4 thou press fit but recommended on subsequent engines he used a "good grade of epoxy cement". So my plan is to use JB Weld  ;)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Vixen on December 03, 2019, 09:58:27 PM
The original designer Larry Kazyak in his description said that on his first engine he did a 4 thou press fit but recommended on subsequent engines he used a "good grade of epoxy cement". So my plan is to use JB Weld  ;)

Jo

If you use JB weld or a slightly more flexible epoxy, you will need a generous clearance for most of the glued length to get a durable seal. An external fillet alone will not last too long

Just thinking

Mike
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on December 04, 2019, 07:09:47 AM
I'd go with Loctite 648 which is the high temp one, use that on all the hit & miss engine liners, more likely to wick into the joint.

As mike says making the lower hole a bit smaller and stepping the OD of the liner by the same amount allows it to go in most of the way easily.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Vixen on December 04, 2019, 08:29:10 AM

As mike says making the lower hole a bit smaller and stepping the OD of the liner by the same amount allows it to go in most of the way easily.

Jason, I did not say that, that was your idea. I only recommended a generous clearance for the glue line.

Mike
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 04, 2019, 09:02:33 AM
I will be going with Frazer's recommendation of a sliding fit on both joints and Loctite.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Vixen on December 04, 2019, 09:32:00 AM
 :ThumbsUp: :ThumbsUp: :ThumbsUp:
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 06, 2019, 11:23:03 AM
The outside of the liner was machined to a sliding fit by holding the liner between two bungs. Then taken to length using the same two bungs  ::) Then back to Big C to machine a taper on the top edge.

Before fitting the liner I remembered I had to drill one last hole in the cylinder for the other water connection. While it says 1/16th pipe I am going with 1/4" 26 TPI brass thread.

Having first thoroughly degreased both surfaces which will form the seal with brake cleaner, I first liberally coated the bottom surfaces with loctite before doing the same to the top and sliding the liner in. The excess has been wiped off and it has now been left to go off above the night storage heater while I look at starting the next bit  :)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on December 06, 2019, 01:12:14 PM
That seems a big substitute thread, I would have thought 5/16" or 3/8" at the most if not using BSP but wanting the same look of the OD :headscratch:

1/2" or M12 x 1 is more what I would us ein place of 1/4BSP.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 06, 2019, 02:22:40 PM
Typo  ::)

The piece of Ali has now been mounted up in a collet the other way round and had a 12.7mm hole bored in it for 26mm deep and I have just finished boring a 36.6mm diameter hole 17.8mm deep in it and decided it was coffee time.

I wonder if I have any shortbread to go with my cuppa or possibly a Jaffa cake  :noidea:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Bluechip on December 06, 2019, 03:03:44 PM

I wonder if I have any shortbread to go with my cuppa or possibly a Jaffa cake  :noidea:

Jo

Still got some left ???   ::)   Getting very frugal of late ....  :headscratch:

Just had a ghastly shock .... new car is CHEAPER to insure than the one I have now for some reason   :o . Must be the end of the world ...  :thinking:

Dave
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 06, 2019, 03:22:40 PM
Just had a ghastly shock .... new car is CHEAPER to insure than the one I have now for some reason   :o . Must be the end of the world ...  :thinking:

Maybe they don't know it has a Lithium battery on board  :headscratch:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Bluechip on December 06, 2019, 03:28:44 PM
Just had a ghastly shock .... new car is CHEAPER to insure than the one I have now for some reason   :o . Must be the end of the world ...  :thinking:

Maybe they don't know it has a Lithium battery on board  :headscratch:

Jo

They do. They match it to the Reg. Number. It has been registered and they know it's a hybrid   ..... half Scalextric, half SUV....  ;D

Dave
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 06, 2019, 05:04:44 PM
Maybe you should let them know that it will be used to carry a set of Chuk 1 Castings early next year and Surus has got wind of the potential delivery  :facepalm:  :pinkelephant:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Bluechip on December 06, 2019, 07:15:46 PM
Maybe you should let them know that it will be used to carry a set of Chuk 1 Castings early next year and Surus has got wind of the potential delivery  :facepalm:  :pinkelephant:

Jo

Whose 'them'  :noidea:  The insurers ??  Baffled  :headscratch:  What's the castings got to do with them ?? 

Signed by a 'Confused old Codger'

Dave
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 07, 2019, 03:11:16 PM
"Them" is the insurers: I think I may have mentioned that Surus has taken to pouncing on the post lady or any delivery drivers when ever castings are due to be delivered :facepalm2: Their screams of terror is a clear indication that they tried delivering something and he got there first....

Maybe I shouldn't have mentioned this before you try to dropping off the castings for me in your nice new vehicle  :-X

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Bluechip on December 07, 2019, 06:39:59 PM
"Them" is the insurers: I think I may have mentioned that Surus has taken to pouncing on the post lady or any delivery drivers when ever castings are due to be delivered :facepalm2: Their screams of terror is a clear indication that they tried delivering something and he got there first....

Maybe I shouldn't have mentioned this before you try to dropping off the castings for me in your nice new vehicle  :-X

Jo

They will be delivered to yourself with my usual decorum.    :LittleAngel:

'Dropping off'  indeed. Perish the thought that I should be so wanton ....  ::)  Rest assured I shall treat your property with the same contempt care as if it were mine own.  ;D

Dave  .. ( At the moment trying to gouge Red Oxide Primer out from under his fingernails ....  I'd forgotten how gobby the damn stuff is      :rant: ).
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 10, 2019, 02:53:31 PM
Having roughed out the piston I decided to mill out the slots for the two bolts on the power piston centre. This was a bad move: Only after turning the outside to size and adding the cavitation grooves did I remember I should have also drilled the tapping holes for the six screws that will hold on the brass Top Ring.


A slightly thicker than shown on the plans piece of brass sheet was found and had six clearance holes for the screws added. This then allowed the offcut of brass to be attached to the piston so it could have its outside turned and the inside bored. Before milling the slots for the power piston centre bolts. Having done the final machining of the power piston it could finally be turned round and the indent for the nut added.


Somewhere along the lines the piston seems to have grown and it now does not want to slide in the cylinder  :headscratch: This is not a problem it just provides a bit of material to conduct the lapping with.


I was trying to work out why the power piston had that odd brass plate: It seems to have originally been used to hold in place a leather cup ring but on the model it would cause too much friction so the recommendation is to use Teflon plumbing packing. I decided I would order some silicon "O" rings of 51mm diameter to see if they proved to be better  :noidea:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 12, 2019, 10:52:52 AM
The outside of the piston was a little too tight so I mounted it on its centre and rubbed a stone on the outside of it until it once again slide nicely into the cylinder. Of course the piston being aluminium it clogs up the stone so that need to be cleaned off as does the oily gritty mess caused by the lapping before assembling everything.

The power piston is held in place with a nut which uses a pin spanner but as I don't have one the right size two drills in the holes and a tommy bar between does just as well ;)

So looking at the fit:

2dd7R23gBNs
 :thinking: That will do for now, it will wear in with use.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 12, 2019, 01:29:08 PM
To position the Displacer piston in the right place the instructions say it should be 2.5mm below the power piston when the beam is level  :headscratch:  I decided if I first level up the beam and then put a G clamp on the displacer piston rod, I could remove the piston assembly and would know where the power piston needed to be relative to the displacer rod when mounting the displacer piston while tightening it up  :ThumbsUp:

At this point I decided to try putting some heat under the hot end (displacer cylinder) to see if anything happened. I used my usual candle power... Candles have the advantage that they do not make lots of noise but still provide sufficient heat. What this proved was the Hot end had a leak  :wallbang:

So it was necessary to repair it with some more silver solder and after some coffee and remembering to add a gasket I can give it another twirl over the candle :)

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 13, 2019, 11:04:16 AM
You will recall yesterday was trying to run the engine on a candle. Having thought about it the displacer piston is a huge piece of cold steel and I thought it is probably cooling the hot air before it can do any good at the power end, so I decided to try a gas burner to apply a bit more heat. A couple of seconds later and I heard a pop and the plate came off the end of the hot cylinder  :toilet_claw:

This morning I have silver soldered it back on and I will have to think further on the displacer piston cooling before it warms up problem  :thinking:

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: scc on December 13, 2019, 11:33:28 AM
Oh dear :thinking:   A facet of engineering that I'm ashamed to say  I know nowt about.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on December 13, 2019, 04:07:17 PM
How big a gas burner did you use :o

Or was it just a poor solder joint to start with, you need tenacity 5 or HT 5 for stainless as easyflow won't remove the chrome oxide that forms on the SS
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Alyn Foundry on December 13, 2019, 04:24:47 PM
What I was concerned about is the why it " popped " off? Surely the pressure should have started to move the power piston in an upward direction?

Cheers Graham.
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: bent on December 13, 2019, 04:35:26 PM
Wouldn't think you could develop much pressure, the fit's not that tight?  Could be thermal expansion of the end cap created enough shear to break the braze/solder joint?  Break out the Tig welder?
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Vixen on December 13, 2019, 04:54:47 PM
Hello Jo,

I cannot be sure from the photo, but the silver solder joint looks to be very crystalline and therefore structurally weak. You can get that sort of effect if the silver solder melts with the torch flame before the rest of the cylinder is up to red heat. It can also be caused by a flux which is not aggressive enough to clean all the oxides off the surfaces. Try to get the surfaces red hot to melt the solder rather than the flame. The solder should flash into the joint when the temperature is right.  As a matter of interest which grades of silver solder and flux are you using?

Mike
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 13, 2019, 06:22:56 PM
The hot end is only 1mm thick so it takes very little to get it red hot, which is above the temperature of the silver solder joint. Soldering up used B6 and Tenacity No 5 which is the flux I always use on stainless the existing silver solder was very well attached.

The book of words says it takes 10 to 15 mins for the engine to heat up prior to trying to run it: I assume this is to do with warming up the displacer cylinder... So will be going back to using candle power.. The heat shield may help to keep the heat in.

Jo
Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jasonb on December 13, 2019, 06:33:29 PM
If you got it red hot then whatever burner you used was way too aggressive, if using your Sievert then just crack the knob open and play a gentle almost orange flame under the engine not a full blast. Small camping burner would be ideal or a ceramic burner both with a fine regulator.

Some hot water through the plumbing will help warm it up if you can't wait that long.

Title: Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
Post by: Jo on December 13, 2019, 09:29:02 PM
Have you seen my other Stirling engines run JB  ::)

 IyDsfIYnyRw
 I am expecting the same out of this one the problem is that the displacer piston is thicker than the displacer cylinder so that while the outer one warms up the inner one does not at the same rate and, as I have learnt, trying to heat it up faster with these high efficient surfaces is not a good idea  :hellno:

Any way I was trying a quick run without any plumbing: The plumbing is there to cool the power cylinder not warm the displacer piston which is what is required. One of the next jobs is the water pump but I am thinking about modifications to it so it might take longer than just bashing it out..

Jo