Author Topic: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine  (Read 4402 times)

Offline Jo

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #15 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
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Offline Jo

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #16 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
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Offline bent

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #17 on: October 24, 2019, 04:47:43 PM »
Looking forward to more pictures of those castings, Jo!

Offline Jo

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #18 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
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Offline Jasonb

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #19 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
« Last Edit: October 24, 2019, 06:39:59 PM by Jasonb »

Offline Jo

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #20 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
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Offline Jasonb

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #21 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:

Offline Jasonb

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #22 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

Offline Jasonb

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #23 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

Offline Jo

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #24 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  ;)
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Offline Jasonb

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #25 on: October 25, 2019, 07:02:25 AM »
So you will just be running them straight against the rust then :wallbang:

Offline Jo

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #26 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
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Offline Jasonb

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #27 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:

Offline ketan swali

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #28 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.
« Last Edit: October 25, 2019, 01:02:00 PM by ketan swali »
Ketan at ARC.

Offline ketan swali

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Re: Camden 3" scale Rider-Ericsson Hot Air Pumping Engine
« Reply #29 on: October 25, 2019, 01:06:13 PM »
Ketan at ARC.