Model Engine Maker

Engines => From Kits/Castings => Topic started by: Jo on October 29, 2020, 11:42:57 AM

Title: Model Heinrici Engine
Post by: Jo on October 29, 2020, 11:42:57 AM
Last year as a Christmas present I was given a rather nice set of Heinrici castings to fondle and then return to their custodian  :pinkelephant: . As I have been under the weather for the last couple of months and struggling to think straight Surus thought that I needed a bit of encouragement so has let me have the castings back for a short while before he expects them to be returned as a completed engine ...


For those of you who were following along last year you will know that I am the custodian of Mr Westbury's air cooled prototype of this model: http://www.modelenginemaker.com/index.php/topic,9446.0.html  During that restoration the castings for this engine arrived although I was originally  told a Porkie by Surus about what they were  Graham quickly correctly identified them as a set of Andy Spooner's Heinrici castings for which he would be the supplier as he has the patterns.

The other supplier of the Heinrici Castings is Reeves who supply castings from the earlier version of the Westbury Heinrici design and Chipmaster has one of these models mounted on his own base.



A bit of gentle casting fettling is probably not a bad idea to help me get back into the workshop  so lets start with the base... However I keep wondering if Surus has an ulterior motive in letting me have these castings as he has confirmed that the space vacated by the Heinirici castings should be just about big enough  :noidea:

Jo
Title: Re: Model Henirici Engine
Post by: Admiral_dk on October 29, 2020, 12:30:38 PM
I hope you have a great time working on this engine Jo - looking forward to progress  :cheers:
Title: Re: Model Henirici Engine
Post by: Jo on October 29, 2020, 02:27:23 PM
Thanks Per  :)

The base casting is the first challenge on this engine. It represents a very expensive casting as I seem to recall Graham said it needed 3 cores to cast it. As proven on my re-build of the original engine an alternative is to make the base out of bar stock. If this was done it would reduce the cost of this casting set greatly.

This is a very difficult casting to hold but thankfully there is very little machining needed. First up I needed to get the base flat: It is not a good idea to try clamping it upside down on the milling table to mill the bottoms of the feet as there will be too much flex  :paranoia: Instead I worked out which two feet were 'long' and used a feeler gauge under the other two feet to find I only needed to remove 0.8mm. With the two high feet marked up with black ink they were rubbed on a surface plate to show up the high points and the offending areas where the ink had been removed hand filled down a bit. Blacken, check on the surface plate, file and repeated until the base sat flat.

The next thing I should mention is this is a very tall casting and it just fitted on Tgs table with enough spare head room to use our big facing cutter on it. The hole in the top of the casting had already been bored so I accepted its placement (which I later found was not central  :facepalm2: ) and used it to position the four bolting down bolts. The original drawings do not show the base and you may think " I know I will use a nut and bolt to hold the  engine down that will be much easier so it needs to be clearance size but Stop, stop, stop, lets first look underneath the base casting - Yes there is a nasty tapered surface under there so the fastening down will have to be either by studs and nuts, or with bolts threading into the base . The drawings show the holes as 1/4" which really dates from the original 1940's design for 1/4 Whit bolts with huge heads. I have chosen to drill 4.1mm and tap the holes 2BA which is more than adequate and it means the bolts will have smaller heads  ;)

A quick prime and it is looking base like and that is about all I can cope with for now  :-[

Jo
Title: Re: Model Henirici Engine
Post by: Alyn Foundry on October 29, 2020, 03:26:36 PM
Hi Jo.

I'll be following along with interest, although I have the patterns an engine was never built here.

A slight correction to your post....

The base had two cores. A very large one that used the inside of the pattern itself as a corebox and a second smaller one for the chimney exhaust. The problem was that it needed 3 moulding boxes to cast. The " intermediate " box, between Cope and Drag had to be made to match the height of the base pattern.

I guess you've noticed the R.L.E. flywheels??

Cheers Graham.
Title: Re: Model Henirici Engine
Post by: Jo on October 29, 2020, 03:32:41 PM
Thanks for the correction Graham  :)

Yes I had noticed the RLE flywheels: I need to work out what to do with them, they both will need modifying: one needs a crank and the other the pulley  :thinking:

Jo
Title: Re: Model Henirici Engine
Post by: Jasonb on October 29, 2020, 03:36:02 PM
Are your flywheels aluminium Jo? They look to be the same coloure as the rest of the castings with no sign of a special coating though I suppose a bit of zinc could have been added to the mix.
Title: Re: Model Henirici Engine
Post by: Jo on October 29, 2020, 03:38:52 PM
Yes they are standard home cast Aluminium which means it is what every was available at the time but the base seems to machine ok so who every cast them knew what they were doing.

Jo
Title: Re: Model Henirici Engine
Post by: Dave Otto on October 29, 2020, 03:55:33 PM
Hi Jo

Always good to see another hot air project, I will be following along.

Dave
Title: Re: Model Henirici Engine
Post by: Jo on October 29, 2020, 04:25:31 PM
Thanks Dave,

Yes the Stirling engines are always a nice easy model engine to make. This one is a good size so there is nothing small and fiddly to confuse me  ::)

Jo
Title: Re: Model Henirici Engine
Post by: Jo on November 05, 2020, 04:23:38 PM
The platform has had its top and bottom faces skimmed flat and taken to 11mm thick.

Using a point in the collet to approximate the locations of edges the DRO was set to put the centre of the bore in an appropriate place on the casting and this is now the datum for all the other measurements.

The mounting holes, the vertical hole for the air and a feature was added, before using a boring head to take the main hole out to 50.8mm.

To remove the feature a small plug was made and loctited in and once painted no one will ever know   :-X

Jo
Title: Re: Model Henirici Engine
Post by: Jo on November 08, 2020, 02:51:13 PM
The casting set came with an Alloy power cylinder, which will need a liner. It also seems to be designed to screw into the base rather than use the two holes I have already drilled in the platform  ::) . As the Cast Iron I have from which I could make the liner is big enough to make the power cylinder in one I may as well make one from solid.

While I had the power hacksaw going I also cut off a piece to make the liner for the cylinder jacket.

The cylinder jacket is a big aluminium casting which had a couple of sprue marks on it which were easily machined/filed off ready to enable the top and bottom to be machined flat. Because of the nature of casting both of these surfaces were domed so it was necessary to use the side of the casting to square up the top. Because I do not want to machine the sides flat but keep their natural cast look a couple of business cards were added between the vice jaws and the casting - these both aid the holding of the casting and prevent any marks from the vice  ;) Both the top and bottom surfaces were taken down the same amount so that the casting walls are the same thickness.

Having centred up the casting ready for the boring bit brain fade set in  :disappointed: so I will leave it there for now before I go wrong  :-\

Jo
Title: Re: Model Henirici Engine
Post by: Alyn Foundry on November 08, 2020, 04:18:31 PM
Hi Jo.

Good to see you making some " swarf " again!

When Andy first built this engine he was working for an Automotive supplier and also had access to secondhand parts.

His suggestion to me at the time was to use a telescopic shock absorber for the hot and cold end of the displacer cylinder and also suggested the use of an empty deodorant spray canister as the displacer piston.

By cutting the top off the shock absorber/damper and gently removing the bottom eye he then screw cut a thread on the upper, open end of the hollow tube that screwed into the water jacket casting that you now have in the vice of your milling machine.

I'm just relaying some information for your interest because as we all know there's many a way to get to the destination.

Cheers Graham.
Title: Re: Model Henirici Engine
Post by: Jo on November 08, 2020, 04:27:01 PM
Thank you Graham,

I am not sure if I would want to cut the top off of a spray can  :paranoia:   Hydraulic tubes can be very useful when making model so I appreciate Andy recycling those  :ThumbsUp: I have a piece of tube for making the displacer and brought a piece of stainless exhaust repair section for the hot end.

The aluminium castings are very nice to machine I suspect Andy may have been using old alloy wheels to supply his metal for casting.

Jo
Title: Re: Model Henirici Engine
Post by: Alyn Foundry on November 08, 2020, 06:27:37 PM
Hi Jo.

I wasn't suggesting you go hacking at an aerosol can under pressure but use a properly emptied one. What Andy did was to then drill out the little plastic valve in the top and Epoxy resin the Brass displacer rod in place whilst being held vertically. Using this method made for an extremely lightweight displacer piston.  ;)

I wouldn't know what Aluminium he was using at the time but your guess is quite possible. I've suddenly realised I'm remembering dialogue from over 30 years ago too. Andy was a serious collector of hot air engines I'm pretty sure the engine you're building would have been directly scaled from an Hienrici in his collection.

Cheers Graham.
Title: Re: Model Henirici Engine
Post by: Dave Otto on November 08, 2020, 06:54:36 PM

I've suddenly realised I'm remembering dialogue from over 30 years ago too. Andy was a serious collector of hot air engines I'm pretty sure the engine you're building would have been directly scaled from an Hienrici in his collection.

Cheers Graham.

Something that I have wondered about, on this engine that Jo is building and the Westbury Heinrici engine that I have castings for. Are these replicas/ models of an actual engine or just someones interpretation? It seems that all the photos you find the Heinrici engines are all beta configuration except for only the smallest one which is alpha? also these engines all seem to have a round water jacket instead of the square one, like on Jo's engine and also the Westbury engine.

Just wondering if anyone had some insight on these differences?

Dave
Title: Re: Model Henirici Engine
Post by: Jo on November 08, 2020, 07:29:27 PM
This model is based on an original Heinrici engine which was owned by Mr H. A Taylor that was used to drive a roots blower for a petrol-air gas generator.

The engine was lost in September 1941 when the ME offices in Kingsway were bombed. However before this happened the engine was drawn up and the blue prints were later published in Model Engineer in Volume 83 (I do not have a copy of these  :wallbang: ) This original design of the Heinrici engine was mostly made of cast Iron and is still available from Reeves in the UK.

In 1964  :NotWorthy: Mr Edgar Westbury took the earlier design and modified it to make it easier to machine and so that the model makers could use Aluminium alloy that they could cast themselves in their back gardens. Aluminium was used for all the main parts except the working cylinders, where sliding wear is involved. Mr Westbury also modified some of the parts to make them easier to machine for the home machinist, while keeping the visual appearance of the engine. The Alyn Foundry castings for this model are thus true to Mr Westbury's intention for this later model in that it is made of Aluminium :)

Jo
Title: Re: Model Henirici Engine
Post by: Dave Otto on November 08, 2020, 07:39:53 PM
Thanks Jo

So if I understand correctly both your model and the Westbury one are from the same original engine? My castings are all iron except for the water jacket; the stand is fabricated from sheet steel.
It is still interesting me that you never see a photo of this style engine, i.e. Alpha style with a square water jacket;  if anyone has a link to one I would love to see it?
I purchased my castings from a friend many years ago, I'm not sure where he got them.

Dave
Title: Re: Model Henirici Engine
Post by: Jasonb on November 08, 2020, 07:55:07 PM
I think the square hopper ones are known as the "HA" type, see this one on Smokstak

https://www.smokstak.com/forum/threads/heinrici-hot-air-engines.160400/

Looks like Jo will be needing to stick some alphabetti spaghetti to here hopper. Also looks like it may have screws retaining the cylinder
Title: Re: Model Henirici Engine
Post by: Jo on November 08, 2020, 07:58:28 PM
This is one of the original Model casting sets: https://www.ebay.co.uk/itm/Hot-air-engine-model-castings-by-Edgar-Westbury-Heinrici-style-stationary-engine-/333773900953?_trksid=p2047675.l2557&ssPageName=STRK%3AMEBIDX%3AIT&nma=true&si=zE485OOYr8G9F2KhcAMRfmfmBJ8%253D&orig_cvip=true&nordt=true&rt=nc

Jo
Title: Re: Model Henirici Engine
Post by: Bob on November 08, 2020, 08:02:58 PM
This is a very interesting engine. Gerd Maier has very extensive documentation on Heinrici engines and thinks that Heinrici did not make any engines with square section cooling chambers as features in the Westbury engine. Gerd suggests that "A front view and a side view are not sufficient to determine the shape of an object; a top view is required to define if this body is round or square. It was in the 1990s when Heinrici two-cylinder copies (I call them fakes) were made by the dozen in a small workshop in Southern England. I suppose that they were following the two drawings reprinted above. These were made by Edgar T. Westbury, based on an original 1.18" watercooled HA model lost during the war. Since there was no plan view, copies with an asymmetric and square engine baseplate (instead of a round one) were produced. Moreover, instead of the maker's name embossed on the cooling-jacket a square plaque HEINRICI /MOTOR was bolted onto an inappropriate cast-iron HL-type base. Other copies, embossed SCHURAT, are known" To quote from Gerd's CD on Heinrici prototypes.

I have always thought it a bit odd as at first glance it has the form of Heinrici's concentric (beta configuration) engines but it is in fact a gamma configuration engine. There seems to be a gap in the market for a medium size model of a Heinrici concentric engine that is somewhat closer to the prototype then ETW's engine.

Bob
Title: Re: Model Henirici Engine
Post by: Jasonb on November 08, 2020, 08:12:06 PM
I'm tempted to get the drawings for this one, he does not sell the castings anymore but drawings are supposed to be available

http://www.de.heinrici-heissluftmotor.de/assets/applets/Seiten_aus_mim_05_08.pdf
Title: Re: Model Henirici Engine
Post by: Jo on November 08, 2020, 08:43:33 PM
Since there was no plan view, copies with an asymmetric and square engine baseplate (instead of a round one) were produced.

There is a plan view but of course there is a platform above the cooling jacket which the two A frames mount onto so unless the shape was shown as hidden detail the fact it should have been round would have been lost. A round jacket could be turned up out of a piece of square Ali and the Water pipe bosses added after.

Jo
Title: Re: Model Henirici Engine
Post by: Jasonb on November 08, 2020, 08:47:18 PM
Strange that the Smokstak link I posted is by Gerd where he shows a square HA yet the copied text by Bob seems to contradict that?

Gerd's website http://www.stirlingmaier.com/dcomp.htm
Title: Re: Model Heinrici Engine
Post by: Dave Otto on November 09, 2020, 12:35:23 AM
Thanks for all the information guys, interesting topic.
Bob, I guess I have my alpha and gamma engine configuration backwards.

Dave
Title: Re: Model Heinrici Engine
Post by: Jo on November 09, 2020, 10:08:17 AM
Having reviewed the cooling jacket casting this morning I can confirm that the core is circular rather than as I feared square. This means that it would be possible to machine the jacket round if sufficient information was available to be able to define the correct shape (diameter and the water bosses).

Because the jacket is separate from the base it would still need a square flange at the bottom which would correspond with the raised square area on the platform in order to bolt it down. A square flange at the top could be left to bolt the cover and the A frames down to it.

Jo
Title: Re: Model Heinrici Engine
Post by: Jasonb on November 09, 2020, 10:28:36 AM
If you went with a round jacket would you also go for a completely different stand? Looking at the line up Dave posted yesterday the only one with the cylinder at the side is the smallest and that has a different type of stand, unless an image can be found of one with the square stand.

Do we know if Westbury made it to a specific scale or is it 1:1 ? what is the bore of his?
Title: Re: Model Heinrici Engine
Post by: Jo on November 09, 2020, 11:09:20 AM
I am not currently intending on rounding the jacket as I believe Andy Spooner would have aimed to make a good reproduction as he was a collector of Stirling Engines. The fact that Andy put so much time and trouble into the patterns/cores for the base tells me he was determined to get that right so there is no reason to assume any of the remainder is wrong.

Do we know if Westbury made it to a specific scale or is it 1:1 ? what is the bore of his?

It is full sized: it has a 30mm bore same as the original Heinrici engine.

Jo
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on November 09, 2020, 11:29:22 AM
Good morning All.

I'm attempting to contact Andy later as an old collector friend is still in touch. We might as well get it from the " horses mouth " so to speak.

Cheers Graham.

PS. This photo is from a Dutch collector who recently posted it on the Small power ( Facebook ) engine group.
Title: Re: Model Heinrici Engine
Post by: Jo on November 09, 2020, 12:23:33 PM
If you are talking to Andy, Graham maybe you could see if he would tell you the history of this set of his/your castings. I would also like to know how well his ran with the Ali flywheels. And if he has a pic of his original that would be the icing on the cake  :embarassed:

Jo
Title: Re: Model Heinrici Engine
Post by: Bob on November 09, 2020, 05:07:01 PM
Hi Dave

People get quite confused by the alpha, beta and gamma configurations of Stirling engines. I am not sure if the terminology is very helpful but I suppose using Greek letters adds an air of academic respectability. The gamma configuration has separate power cylinder and displacer chamber that are linked by a tube. This configuration gives a lot of flexibility for the linkage so for example the power cylinder and the displacer chamber can be at 90 degrees to one another and both work from a single crank pin (As the Stirling 90 described by Anthony Mount in Historic Engines worth Modelling Vol 1) or the two chambers can be parallel to one another and the linkage uses two crank pins 90 degrees apart (Typical of Heinrici HA) or by the use of a bell crank linkage (as used by T E Haynes in his engine described in Model Engineering for Schools Book 2 Incidentally this engine has been described by others  in the model engineering world but without giving Mr Haynes his due recognition) The downside of the gamma configuration is the dead space due to the air in the transfer pipe and possible restriction of the pressure pulse between the displacer chamber where it is generated and the power cylinder.

The beta configuration has the power cylinder coaxial with the displacer chamber and in the best designs the stroke of the power piston overlaps with the swept volume of the displacer. There are lots of engines that work like this such as the Rider Ericsson pumping engine and the Heinrici HL type. From my observations at Stirling rallies and exhibition stands beta engines outperform gamma engines and I have always attributed this to the reduction in dead volume and the free flow of air between the working cylinder in the displacer chamber.

The enigma is the alpha engine. These should be the best engines in terms of specific power output and the ones that have been well documented do indeed run very well and produce a lot of power for their size. That being the case why in over 10 years of exhibiting Stirling engines at model engineering shows and rallies have I only ever seen one alpha engine running? The alpha has two pistons set 90 degrees apart and the cylinders are connected by a transfer pipe that often incorporates a regenerator. In full size the Haywood Tyler engine is an example of an alpha engine. I suspect some Haywood Tyler models are actually gamma configuration engines rather than true alpha engines.

Rather contentiously, is an alpha engine just a gamma engine with a big fat displacer rod the same diameter as the bore of the displacer chamber??

Bob
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on November 09, 2020, 05:57:43 PM
Hi Jo.

Your set of castings is Andy's interpretation of the E T Westbury design. On the square water jacket you might notice a rather steep angle of draught around each water outlet? This was done to make the " draw " from the sand mould easier to accomplish.

Andy has let all his engines go apart from a couple of his favourites, a Robinson and a very early LT ignition Bamford, sorry no pictures either.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Dave Otto on November 09, 2020, 06:19:48 PM
Hi Dave

People get quite confused by the alpha, beta and gamma configurations of Stirling engines. I am not sure if the terminology is very helpful but I suppose using Greek letters adds an air of academic respectability. The gamma configuration has separate power cylinder and displacer chamber that are linked by a tube. This configuration gives a lot of flexibility for the linkage so for example the power cylinder and the displacer chamber can be at 90 degrees to one another and both work from a single crank pin (As the Stirling 90 described by Anthony Mount in Historic Engines worth Modelling Vol 1) or the two chambers can be parallel to one another and the linkage uses two crank pins 90 degrees apart (Typical of Heinrici HA) or by the use of a bell crank linkage (as used by T E Haynes in his engine described in Model Engineering for Schools Book 2 Incidentally this engine has been described by others  in the model engineering world but without giving Mr Haynes his due recognition) The downside of the gamma configuration is the dead space due to the air in the transfer pipe and possible restriction of the pressure pulse between the displacer chamber where it is generated and the power cylinder.

The beta configuration has the power cylinder coaxial with the displacer chamber and in the best designs the stroke of the power piston overlaps with the swept volume of the displacer. There are lots of engines that work like this such as the Rider Ericsson pumping engine and the Heinrici HL type. From my observations at Stirling rallies and exhibition stands beta engines outperform gamma engines and I have always attributed this to the reduction in dead volume and the free flow of air between the working cylinder in the displacer chamber.

The enigma is the alpha engine. These should be the best engines in terms of specific power output and the ones that have been well documented do indeed run very well and produce a lot of power for their size. That being the case why in over 10 years of exhibiting Stirling engines at model engineering shows and rallies have I only ever seen one alpha engine running? The alpha has two pistons set 90 degrees apart and the cylinders are connected by a transfer pipe that often incorporates a regenerator. In full size the Haywood Tyler engine is an example of an alpha engine. I suspect some Haywood Tyler models are actually gamma configuration engines rather than true alpha engines.

Rather contentiously, is an alpha engine just a gamma engine with a big fat displacer rod the same diameter as the bore of the displacer chamber??

Bob

Thanks Bob!

Dave
Title: Re: Model Heinrici Engine
Post by: Jo on November 09, 2020, 06:27:17 PM
Your set of castings is Andy's interpretation of the E T Westbury design. On the square water jacket you might notice a rather steep angle of draught around each water outlet? This was done to make the " draw " from the sand mould easier to accomplish.

Thanks Graham,

I will be building it as a copy of Westbury's design of the Heinrici so that it can go with the Air cooled Heinrici Engine that came from Westbury's own engine collection. I will work on the assumption that the two ali flywheels will be heavy enough as my Rider-Ericsson runs ok with an Ali wheel.

Jo
Title: Re: Model Heinrici Engine
Post by: Jasonb on November 09, 2020, 06:32:11 PM

It is full sized: it has a 30mm bore same as the original Heinrici engine.

Jo

So which is the correct bore? Westbury's one from reeves is 1" presumably his best guess at what would have been a 26mm bore or your engine which has a 30mm bore.

Or did Andy scale it up a bit to suit an old shock absorber he had going spare?

EDIT, Ignore that Reeves describe it as 1" but drawing is 1 3/16" which is close enough for 30mm
Title: Re: Model Heinrici Engine
Post by: Jo on November 10, 2020, 12:32:00 PM
The water jacket has been bored and the four mounting holes drilled 4.1mm using a long series drill. Then on to the cover: this is a square shaped casting that needs turning - it can be mounted up in a four jaw independent chuck but even easier the four jaw self centring chuck  :)

I have modified the design as I have chosen to add a bronze bush in the centre of the cover as I am not sure an aluminium cover is not going to wear and the hole will become oval. The cover was bored and a piece of bronze loctitied in before completing the machining.

I found a tipped tool supplier who could provide me round tipped tools of 6mm, 8mm, 10mm and 12mm diameter using one of these tool the curved surface was turned.

The top surface also has a curved feature. These tipped tools cannot be used to form this as they do not have sufficient clearance so I had to go back to using one of my old bits of HSS and even then the groove is only 4mm deep not the 6mm shown on the drawing.

I now have three parts with three different diameters which are joined together using the liner so it must be time to turn that up

Jo
Title: Re: Model Heinrici Engine
Post by: Roger B on November 10, 2020, 05:06:32 PM
That's some rather nice metal sculpting  :praise2:  :wine1:
Title: Re: Model Heinrici Engine
Post by: JULIUS on November 10, 2020, 07:29:52 PM
Jo

I have attached some drawings of the Heinrici model which I made years ago
These drawings are in imperial measurements.
I hope they might help. If you look on my disc it is under project number 05A-05-00

Julius
Title: Re: Model Heinrici Engine
Post by: Jo on November 10, 2020, 07:47:11 PM
Thank you Roger  :)

And Thank you Julius, I had noted that your design has a round cylinder jacket which is something we were discussing yesterday

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on November 11, 2020, 04:05:41 PM
A small drill was used to start the hole through the piece of Cast Iron bar. (I tried not to think about all those piston rings I was wasting  :wallbang: ) Then my small hole precision boring bar was employed to open it up so the cover fitted in the hole. Then holding one end then the other it was turned such that the bottom would fit in the platform, the bottom/middle would fit into the lower part of the water jacket before turning round and machining top to fit the top of the water jacket and finishing off by using a round turning tool to undercut the middle.

This undercut is supposed to help with assembly but you have to be careful on such large diameters is is amazing just how little off square you need to be with a liner for everything to lock solid as you try pushing it in  :ShakeHead: Talking of locking solid: Straight of the lathe I decide to assemble everything, first dropping on the top cover which promptly locked in place solid  :wallbang: Of course the cast iron had been a little warm straight of Big C and as it cooled is shrank and it would have only taken one piece of dirt :facepalm: Having encouraged the cover off I used a brake liner hone to take off a nats whisker from the top bore and it is now fitting nicely again.

I finished off by assembling everything. It was only once I came inside I started wondering if I had the liner the correct length  :thinking: It looks long in that pic. I'll check in the morning - it is easily corrected if needed  ;)

Jo
Title: Re: Model Heinrici Engine
Post by: Roger B on November 11, 2020, 04:58:26 PM
I take the cores out of cylinders etc. with a hole saw. With my low powered machines it is much quicker than step drilling and boring and you save most of the material  :)
Title: Re: Model Heinrici Engine
Post by: Jo on November 11, 2020, 05:13:24 PM
Thanks Roger,

Sadly this lump was 85mm long and my hole saws (which I have been known to employ like you did  ;) ) do not have the required depth  :-\

Jo
Title: Re: Model Heinrici Engine
Post by: Roger B on November 11, 2020, 07:56:02 PM
Yup, that's just over the limit  :( I have done 80mm for the horizontal engine and the diesel.
Title: Re: Model Heinrici Engine
Post by: Jasonb on November 11, 2020, 08:03:53 PM
The trick is when you drill the second end bore away some of the "plug" so that the holesaw can meet the cut from the first side ;)
Title: Re: Model Heinrici Engine
Post by: crueby on November 11, 2020, 08:07:06 PM
Never tried using a hole saw like that - does it take a special type for cutting metal, or will the normal hardware store ones work well enough?
Title: Re: Model Heinrici Engine
Post by: Roger B on November 12, 2020, 07:38:03 AM
I use Bosch Bimetallic ones from the local shop. They work well on cast iron but can tend to clog up with swarf on alumuinium. I haven't tried on brass or steel.
Title: Re: Model Heinrici Engine
Post by: Jo on November 12, 2020, 03:15:13 PM
Having checked my stores I might be ok for Cast Iron the size that that core would have been  :)

Most of the power cylinder is plain turning the same as the liner. The more interesting bits are the taper and getting the holes in the end and the two sides parallel to those holes. Once the taper is in place the only way to hold the cylinder will be through the bore on a mandrel. So I decided before turning the taper to hold the parallel side of the cylinder and drill for the two mounting screws and then mill the two flats. As an after thought I think it would be easier for someone else to drill the two holes then turn the taper before milling the two flats  ;)

I then mounted the cylinder on a mandrel and turned the taper. The centre "washers" on either end would have gotten in the way to turn the curved top edge so I mounted the cylinder (with the two flat sides) in one of Mr Silky's oversized 5C collets with end support and turned a pretty curve  ::)

The then tried it on the platform to find the platform profile and cylinder did not match so having milled a bit off the platform I am now adding a bit to either side so that it meets the profile of the cylinder, I'll finish sorting it out tomorrow   :wine1:

Jo

Title: Re: Model Heinrici Engine
Post by: Jo on November 14, 2020, 01:25:19 PM
The power cylinder has been honed to provide a smooth inside surface using my delapena honing machine.

The piston was turned from a piece of 35mm diameter Cast Iron bar. The drawings implies a fairly thick skirt but my experience has shown that thinner is better. the outside of the piston has a few grooves to act as cavitation seals. The piston fit is such that it will slide down the power cylinder if both are cleaned with brake fluid but with any oil on either is sufficient for it to not slide  :) .

The piston yoke is made of a piece of its-so-hard-why-did-I-keep-it stainless. Both turning the outside and milling the slot made twirls of swarf that were rather hot  :paranoia: Surprisingly it was happy enough to be threaded with a die  :headscratch: For now I have left the thread over long so I have the option of putting a nut on the other end if there is sufficient space - if there isn't I will turn it off later.

I need to think about the remaining ali bits as I am not convinced that Ali makes a good bearing surface for the Gudgeon pin or the crankshaft. I'm off to look at that original engine  :thinking:

Jo
Title: Re: Model Heinrici Engine
Post by: Twizseven on November 14, 2020, 02:53:43 PM
Jo,

Its looking good.  Not sure how you work at the speed you do.  :praise2:

Colin
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on November 14, 2020, 03:12:20 PM

I need to think about the remaining ali bits as I am not convinced that Ali makes a good bearing surface for the Gudgeon pin or the crankshaft. I'm off to look at that original engine  :thinking:

Jo

Hi Jo.

Well.... The Japanese motorcycle industry changed a lot of engineering practices that we held so dear here in the UK.   ;)

Obviously a lot depends on the Aluminium Alloy but a good " polished " surface and reasonable lubrication should be fine for your engine.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Jo on November 14, 2020, 03:35:37 PM
And I have a lot of little aero engines that have Ali conrods that rely on just good lubrication  :thinking:

However how many "four hundred fours" had rattily cams, due to the lubrication needing to be better  ::)

Jo
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on November 14, 2020, 03:53:08 PM
You have a point Jo, but from my own experience back to my days spent at North Wales Motorcycles most problems were due to poor maintenance. Sadly regular oil changes weren't on the list for many owners.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Jasonb on November 14, 2020, 04:12:08 PM
Are those Conrods not made out of 2014 (HE15) which has some copper in it to help smooth the ride. Not sure of what's in old alloy wheels :thinking:

For the short amount of running it's likely to get may not be worth the worry unless you are thinking of adding a few fan blades to keep you cool next summer :)
Title: Re: Model Heinrici Engine
Post by: Jo on November 16, 2020, 12:32:48 PM
The flywheel castings are too large a diameter to fit above the Power cylinder and too wide as the connecting rod will be offset too far  :Doh: If I increase the height of the A frames by leaving 8mm thick on the bottom rather than the 6.35mm shown on the drawings I can gain 3.2mm on the available Space for the flywheel. Even so the maximum diameter is going to have to be under 165mm and the flywheel casting started out at 168mm diameter.

Width wise: the central boss on the flywheel can be taken down to 19mm wide which will fit onto the available space on the crankshaft but I don't want the flywheel rubbing on the A frame so a bit of clearance will be needed. Having checked the clearances on the connecting rod so long as the flywheel is above the bottom of the A frame then the rim can be wider than shown on the drawing. The flywheels are started out at over 22mm wide but this is going to come down when I turn them smooth.

Lets see what happens..  :thinking:

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on November 19, 2020, 04:01:04 PM
Four holes were drilled and reamed in a piece of steel at the correct spacing to make the webs for the crank. A bit of hand filing to shape them up then a bit of loctite to join it all together to make the crankshaft. I have not added the spacers on the outside of the webs as I intend on adding that later  ::)

The crankshaft goes on top of the two A frames. Which need's a hole drilled and reamed for the crankshaft and the bottoms of the feet milled at the correct distance from the crank hole.

Now we can do the flywheels: Mounted on the outside of the three jaw the outside surface can be turned and the front face. While it is all set up the hole for the crankshaft can also be drilled and bored.

When fitted all together it is found the flywheels are: too big a diameter, too wide and look wrong  :toilet_claw:

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on November 19, 2020, 04:08:01 PM
After a bit of thinking and looking at the other engine I decided to reduce the flywheels to 152mm diameter so the outside rim is level with the base of the A frames and to reduce the width of the flywheels to 17.5mm as shown on the drawings.

Of course the problem now is that you cannot hold the flywheel and guarantee getting everything true unless it is dialed up on a face plate   :wallbang:  As the wheel was over width I could turn the outer diameter and the face leaving a bit to protect Mr Silky's faceplate and then wander over to Big C and hold the flywheel by the outside in his small chuck to turn the other face to take things to the correct width.

The flywheel has come down a lot in comparison with the original but it looks a bit better  :thinking: It is going to need a bit of extra weight.

Jo

Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on November 19, 2020, 04:32:54 PM
They look nice Jo.   :ThumbsUp:

I notice that you've managed to loose the " gas pocket " too.

Before worrying about their weight I'd be inclined to carry on as you might be surprised how little is needed, particularly with there being two of them.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: ettingtonliam on November 19, 2020, 06:36:01 PM
Jo
I'm building the Alyn Robinson hot air engine. I've never built a hot air engine before, and was not sure what fit would be needed for the piston in the cylinder. I saw your comments above for the fit of the piston, and by far cruder methods than yours have managed to get it so that it drops under its own weight with a dry piston and cylinder, but just slides down slowly when oiled. It took me several hours to take off the last half thou or so to convert a stiff push fit into a free sliding fit!
I was disappointed to find that if I blocked the cylinder outlet at the governor end, the piston didn't stay put with the air cushion under it. Then I realised I'd drilled and tapped the piston head for the gudgeon housing---.
Title: Re: Model Heinrici Engine
Post by: Jo on November 19, 2020, 06:57:30 PM
Thank you Graham, I won't write the flywheels off until I have tried running the engine with them.

Hi Richard,

I saw your comments above for the fit of the piston, and by far cruder methods than yours have managed to get it so that it drops under its own weight with a dry piston and cylinder, but just slides down slowly when oiled. It took me several hours to take off the last half thou or so to convert a stiff push fit into a free sliding fit!

Yes it takes second to post about doing it but a bit longer to get the fit right  ;)

Quote
I was disappointed to find that if I blocked the cylinder outlet at the governor end, the piston didn't stay put with the air cushion under it. Then I realised I'd drilled and tapped the piston head for the gudgeon housing---.

You are not the only one who has done that  ::)

Jo
Title: Re: Model Heinrici Engine
Post by: Roger B on November 20, 2020, 11:29:38 AM
Those modified flywheels look somewhat more in keeping  :)  :ThumbsUp:  :wine1:
Title: Re: Model Heinrici Engine
Post by: Jo on November 22, 2020, 03:35:51 PM
The power cylinder connecting rod was clamped flat to a jig with a 3.2mm thick packing piece under the small end. as the rod is slightly off centre I decided to take the 0.8mm and 0.5mm off the same side and then bore for the pins. The pins are a simple turning exercise but I modified the big end pin to have two washers of bronze to prevent rubbing.

the piston carrier thread had to be made shorter so it did not hit the bottom of the power cylinder and it was necessary to pilot drill through to the bottom of the power cylinder so that the piston can go up and down to allow for round and round testing shortly. To do that will require the displacer cylinder and the A frames to be bolted down  ;)

I also investigated the displacer rod that came with the set  :headscratch: the end that goes round the displacer rod is only 13mm wide where as the drawing imply it should be 16mm. I have thought about this and have a cunning plan  :naughty:

Jo



Title: Re: Model Heinrici Engine
Post by: samc88 on November 22, 2020, 03:42:52 PM
Looking good

Sent from my G3121 using Tapatalk

Title: Re: Model Heinrici Engine
Post by: Admiral_dk on November 23, 2020, 07:54:59 PM
Great to see that you had some good time in the workshop Jo and nice result too  :cheers:
Title: Re: Model Heinrici Engine
Post by: Jo on November 26, 2020, 04:46:33 PM
Thanks for following along Guys  :)

Having removed another unintended feature  :ShakeHead: The four jacket studs have been made and two nice bolts for the power cylinder.

Work has begun on the displacer connecting rod. initially I was confused by the fact the engine came with two rods but it became apparent that the intention was to cut a cap from one and use the other  :) A slitting saw was used to cut off the required bits and they have been joined using two set screw as shown on the drawing  :thinking:

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on November 29, 2020, 04:00:18 PM
The displacer rod has been drilled and reamed and a bit of fettling done.

While the slitting saw is out I have also split the A-frame bearings which allows me to adjust the bearings. As Graham likes to talk about the skipping man here is the one on this Heinrici:

HT2a1PMWg8Q
 It does remind me of a kiddies toy  ::)

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on December 01, 2020, 03:01:53 PM
The displacer rod is just a piece of old printer stainless which has had two flats milled on either side to reduce the width down to 4.75mm so it can fit into the slot on the rod.

The displacer itself is made from a piece of stainless Exhaust repair. Fractionally bigger and thicker than shown on the drawings but adequate. I decided on making this fit with a flange rather than a screw thread which is likely to gum up in use   :-\ The flange is a piece of come-in-handie-no-idea-where-I -got-it-from bronze, the top turned to fit the jacket liner and the bottom turned to fit onto the exhaust piece, with a 1mm spacer left between the two to ensure the stainless does not drop through when silver soldered.

I chose to drill the mounting holes in the flange and drill/tap the ones in the platform before doing the silver soldering.

I first silver soldered on the end plate, then the flange. I learnt on the Rider-Ericsson it is easier to hand file the end plate round once silver soldered rather than trying to turn it  ::)

Only the displacer left now  8)

Jo
Title: Re: Model Heinrici Engine
Post by: Admiral_dk on December 01, 2020, 10:15:25 PM
Looks like you had a really good day in the shop Jo  :ThumbsUp:
Title: Re: Model Heinrici Engine
Post by: Jo on December 02, 2020, 03:24:28 PM
Thanks Per  :) , I seem to be feeling better of late so I hope to be back on the Halls shortly.


The Displacer has been made out of a gummy old bronze relief valve top, a piece of brass tube and the centre of a piece of brass I trepanned out of something  :noidea: I should have used a piece of brass for the top rather than doing the recycling but the only piece I could have taken it out of was a piece of 50mm diameter and it seemed too much of a waste  :paranoia:

The recycled piece of bronze was turned up and threaded before checking the clearance on the bottom of the top cover. At 20mm it seemed a bit big but a calculation on showed it would be the same 20mm under the displacer at the other end  :ThumbsUp:

The tube was shortened so that the finished displacer would be 140mm long and first the piece of plate then the bronze top silver soldered into place. After cleaning up you can still see something of the original fluting on the piece of bronze but it will be hidden inside so no one will ever know  :-X

All the bits are made other than the gaskets. I still need to slit the power piston rod and drill through to the displacer cylinder and sort out the water tank and plumbing and then we should be there   :wine1:

Jo

Title: Re: Model Heinrici Engine
Post by: Roger B on December 02, 2020, 05:02:40 PM
Looking good  :ThumbsUp:  :ThumbsUp:  :)  :wine1:

Does your 'come-in-handie-no-idea-where-I -got-it-from bronze' piece have a thread in the bore? I think I have something similar in my come-in-handie-no-idea-where-I -got-it-from bronze drawer section  ;)
Title: Re: Model Heinrici Engine
Post by: Jo on December 02, 2020, 05:07:14 PM
thanks Roger,

The piece of bronze: Yes, it did  ;)

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on December 03, 2020, 02:19:11 PM
I have squared up the cylinder and its head so the two of them match, then drilled and tapped the two water holes for the fittings. Cut some gaskets and fitted them.

The last job for today was to loctite the liner to the jacket. This is now sitting on the night storage heater so it is warm enough for the loctite to go off. Once that is set I can think about drilling through the engine platform into the bore of the liner with everything secured together.

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on December 04, 2020, 11:25:55 AM
Graham and I have been discussing the rather heavy displacer. So I decided to weight it with and without the rod  :o Looking at Westbury's original engine it has balance weights on the crank and opposite the pin. To get some idea of the sort of weight I could achieve I checked a pair of old Triple balance weights  :thinking:

While I think about that I decided to drill through for the air way from the main cylinder to the power cylinder.

Balance weights  :thinking:  :thinking:

Jo
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 04, 2020, 12:35:07 PM
So why does the model one need counter balance weights when the originals don't seem to have them?

Is the material being used the the displacer thicker than originally used?

Seems a shame to spoil the original look of the engine buy adding weights so could a thinner wall tube be found or given that a small pully was used to take off a drive there is no reason that the aluminium flywheel rims need to be left bare except for bling. Could pockets be machined into the rims and filled with lead, the opposite side could have a similar pocket filled with a bit of PU foam and smoothed over with filler.
Title: Re: Model Heinrici Engine
Post by: Jo on December 04, 2020, 02:53:39 PM
So why does the model one need counter balance weights when the originals don't seem to have them?

Don't know I am sure Graham will explain all to us  ::)


The last exciting bit was splitting the con rod big end using a slitting saw  :paranoia:

Initial round and round testing has shown that it needs more round and round testing as the power cylinder is a little sticky when the piston gets to the top. Having applied a little heat I can confirm that there seems to be a bit of a push there but it is all getting hot so it needs its cooling tank .

The problem is what to use as a cooling tank  :noidea: And then a bit of plumbing is needed  :thinking: Before a magic finger  :)

Jo
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 04, 2020, 03:53:07 PM
Oh my goodness Jo, just over 2 Kg....  :o

Ok, edit time. The decimal point was rather obscure initially until I blew the photo up a bit. Perhaps not as bad as I first thought.

 ( I don't think the engine will develop enough " puff " for that amount of weight. )

I've attached a photo of the Robinson displacer piston and rod assembly, you can see why this engine runs as well as it does.

We need to think of a material that is both lightweight and heat resistant, after all, we're only " displacing " the air from one end to the other. No sealing required.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Jo on December 04, 2020, 04:05:19 PM
Oh my goodness Jo, just over 2 Kg....  :o

That is just over 200 grams  ::)

The rod weighs 50 grams.. so the displacer is only 3/4 of the weight.

Jo
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 04, 2020, 04:11:27 PM
Oh my goodness Jo, just over 2 Kg....  :o

That is just over 200 grams  ::)

The rod weighs 50 grams.. so the displacer is only 3/4 of the weight.

Jo

Thanks Jo, I've edited my post....
Title: Re: Model Heinrici Engine
Post by: Jo on December 04, 2020, 04:15:57 PM
 ;)

I'm going to fit a cooling tank and then see if it will run before I modify anything

Jo
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 04, 2020, 04:45:37 PM
;)

I'm going to fit a cooling tank and then see if it will run before I modify anything

Jo

That's definitely the best approach Jo.   :)

Cheers Graham.

Title: Re: Model Heinrici Engine
Post by: Jasonb on December 04, 2020, 05:23:54 PM
I see from the bit of drawing hiding behind Jo's displacer that its shown as 20g which is 0.91mm, i've got similar diameter brass tube with a 0.45mm wall so that's an immediate 50% weight reduction and the couple of mm over dia that Jo's tube looks to be (42 vs. 39) would have added about 5%

If you went over to 0.5mm wall aluminium tube and end plates you could get it down even more, I've seen Heinricis with them made of this and would bring the weight without rod down to about 60g.

As for the rod could it be a tube or smaller diameter?
Title: Re: Model Heinrici Engine
Post by: Jo on December 04, 2020, 06:07:21 PM
Before I change anything I am going to see if, with the cooling system fitted, it will run.

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on December 06, 2020, 03:18:36 PM
With the two water adapters fitted and a quick lash up of a tank it was time to see if it would run. Having first unintentionally washed the bench I then decided it was best if both water pipes were fitted rather than leaving one off to get rid of any air bubbles.  ::)

On applying some heat another bubble started forming on the upper water fitting and this bubble went in and out when the engine went round and round  :wallbang: This means only one thing :facepalm: A Water leak  :toilet_claw:

Having disassembled it there are not many choices as to where the leak could be  :disappointed: and yes there it is  :wallbang:  :wallbang:

The jacket was heated up to get the Loctite to let go and the liner gently tapped out with a hide mallet. I am assuming that the aluminium jacket expanding did not help the seal so I will try something different to seal it tomorrow :thinking: In the mean time it needs to cool.

Jo
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 06, 2020, 03:23:11 PM
You could just blow compressed air through it for initial testing then finally seal it all up once you know there will not be any mechanical alterations to make.

Plenty of O ring seals on the one I have just posted about :)
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 06, 2020, 03:30:26 PM
I know, you know that this can be a major problem where " dissimilar " metals are used Jo.

The solution would be either to use an " O " ring at the bottom end or perhaps easier to use a more flexible sealant like Silicon Rubber.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Jo on December 06, 2020, 03:44:09 PM
The solution would be either to use an " O " ring at the bottom end or perhaps easier to use a more flexible sealant like Silicon Rubber.

Thanks Graham, I was considering both of those  ;) I will need to clean up the Loctite first and I think a protective layer of high temperature clear lacquer might be applied to the outside of the liner.

I wonder if the liner could be aluminium  :thinking:

Jo
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 06, 2020, 05:18:05 PM


I wonder if the liner could be aluminium  :thinking:

Jo

Indeed it could Jo.

If I recall correctly Andy just used nearly the whole length of a an old shock absorber that was carried right through the water jacket and on down to the hot end. A single " O " ring ( at the bottom end of the water jacket ) allowed for its expansion.

This method made construction of the engine very easy and reduced the sealing issues to an absolute minimum.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Jo on December 22, 2020, 10:23:22 AM
The one item missing on this design is a pully to drive anything. I thought originally I may have been able to use this to provide a sort of crankshaft counterweight but the pulley I tried doing it with proved to be made of horrible stuff  :disappointed: So I remade it in aluminium and drilled the six spokes to enable it to be screwed on the side.

Having made it I found it went wobbly, wobbly  :facepalm2: A quick skim of the face of the spokes and it now goes round and round without wobbly, wobbly  :)

After various attempted designs at balancing the weight of the displacer I think the appropriate one is what my original half scale Westbury engine has so that is going to be the next job.

Jo
Title: Re: Model Heinrici Engine
Post by: Dave Otto on December 22, 2020, 01:34:19 PM
Looks good Jo!
Any closer to going round and round with a fire?

Dave
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 22, 2020, 01:41:24 PM
If you went with a hub mounted 3 step pully like the originals had then if made from iron or steel you could hollow out an eccentric hole at the back of the pulley which would help with balance. With a bit of cunning the modified hub could be made from a mix of aluminium on one side and steel on the other to add more hidden counter balance.
Title: Re: Model Heinrici Engine
Post by: Jo on December 22, 2020, 01:50:49 PM
Hopefully once the crankshaft balance problem is solved Dave :)


I'm finding it hard to spend long in the workshop as I normally have the radio on and all I am hearing is of peoples Christmases that have been ruined (because we have been told at the last minute the freedom that the Government had offered have been taken away and worse constraints put in place instead  :toilet_claw: ) and all of those poor (mainly EU) lorry drivers stuck on the roads down to and all around Dover because France has closed the boarders due to the UK doing sequencing of the Covid virus and identifying a new more virulent one, which looks like it is already all over the continent any way  :rant: I've had enough of this Pandemic  :-[

Jo
Title: Re: Model Heinrici Engine
Post by: Jo on December 22, 2020, 01:51:44 PM
If you went with a hub mounted 3 step pully like the originals had then if made from iron or steel you could hollow out an eccentric hole at the back of the pulley which would help with balance. With a bit of cunning the modified hub could be made from a mix of aluminium on one side and steel on the other to add more hidden counter balance.

That's what I looked into originally doing but have a better plan  ::)

Jo
Title: Re: Model Heinrici Engine
Post by: Charles Lamont on December 22, 2020, 08:45:57 PM
Jo, you are listening to the wrong channel. I normally listen to Radio 3 in the shop (unless it is ****ing lieder). Much better to work to than worrisome talk.

(For the benighted, Radio 3 is the BBC classical music station, with some weekend gems like Sound of Cinema, and Jazz Record Requests that for many years have enlivened my sacrosanct Saturday afternoon in the workshop.)
Title: Re: Model Heinrici Engine
Post by: Jo on December 24, 2020, 12:18:14 PM
I think you might be right  :)

On with the new crankshaft: A couple of balance weights and some new arms/shafts. The outsides of the weights turned to 60mm diameter.

The resulting crankshaft is rather heavier than the original - hopefully in the right place.

the engine is back together so a bit of flicking is in order.

Jo
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 15, 2021, 07:37:51 PM
Hi Jo.

Im bumping this thread as Ive decided to push ahead with the patterns for this particular model that I bought the rights to 20+ years ago.

Weve had a Reeves version on the shelf for a similar time, bought as a non runner. With number 3 son off for the Christmas period we had a little play. The displacer piston was ridiculously heavy so weve got a small deodorant aerosol canister fitted with a 1/4 Brass rod to the conrod. A PTFE bush pressed into the original 3/8 hole and reamed to the smaller diameter. Needless to say it will only run for a few minutes before the heat is conducted through to the cold end. Obviously some form of thermal barrier is needed to stop or at least retard this from happening.

Im in contact with a Dutch lady who has an amazing collection of Heinrici engines, she sent me a photo of the version that was replicated. Note the round footprint.

Im wondering if the same principle I used on my half scale Robinson, the large O ring would work having the hot end sort of floating?

Thoughts ??
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 15, 2021, 08:29:13 PM
Is that when running without any water flow? Would casting in iron help the problem?

It's a shame your pattern is split on the diagonal as it would look good with some writing cast into the side.

Now you have got me  :thinking: about how easy it would be to machine off the bottom of the Westbury one and replace with a circular disc, add the raised pads for cylinder and the one where one of their little circulating pumps could be fitted on the opposite side like in your photos which may help the heating problem. Then the stands is an easy fabrication from ERW tube and a couple more round discs
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 16, 2021, 11:31:49 AM
Hi Jo.

Did you manage to get this particular model to run?

Hi Jason.

Yes, just the water jacket filled with cold water. Theres a small window in between applying the heat to the engine and then the temperature equalising. At this moment just a couple of minutes. Obviously a cast Iron cold end would take much longer before it heated up and stopped the engine.

Im hoping that the following might be a solution to the problem.

We make the hot end nearly mechanically isolated from the cold end water jacket. We make a large diameter flange thats Silver soldered onto the open end. This flange has a partial O ring groove machined into it. A corresponding, partial groove is also done on the underside of the cold end casting. A suitable 6 mm cross-section Silicon or Viton O ring is used to both register and seal the two halves. Making the flange of a large diameter and the mounting holes near the outside edges means that the heat has to travel much further before finally being transferred through the mounting studs and nuts.These could also be made small to further reduce the conduction. In addition this flange could be a snug fit into the base casting/fabrication to further absorb the wasted heat.

The O ring separator works exceptionally well on my half scale Robinson replica.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 16, 2021, 01:06:24 PM
I used a couple of washers cut from car exhaust manifold gasket on my smaller Robinson which may be another option.

The drawings for the Heinrici that I built also had a close fitting "Skirt" that went around the hot end and had a spout that directed the warm air up the chimney therefore also stopping the bottom of the casting getting so hot as the heat is concentrated on the hot end. Will e-mail you a bit of the drawings also did you get my e-mail from Sunday regarding P Mk11
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 23, 2021, 07:22:05 PM
With nothing more than oversizing the crankshaft ends, reboring the flywheels and an empty aerosol deodorant can for the displacer piston....

 FE6fXQAL6vk
She runs a treat !!

Merry Christmas.
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 23, 2021, 07:25:23 PM
If that's all it needed why has it taken you 20yrs to do :LittleDevil:

Looks to be running well now, could do with a cast base though and a lick of paint ;)

Did you fit the O ring "insulator" in the end?
Title: Re: Model Heinrici Engine
Post by: Admiral_dk on December 23, 2021, 08:43:03 PM
She runs very well  :ThumbsUp:

The cooling water is that just the thermo action that circulates it ?

Thank you and a very happy Xmas to you too  :cheers:

Per
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 23, 2021, 08:48:02 PM
If you watch on Youtube the description mentions the electric pump.
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 24, 2021, 11:26:04 AM
If that's all it needed why has it taken you 20yrs to do :LittleDevil:

Looks to be running well now, could do with a cast base though and a lick of paint ;)

Did you fit the O ring "insulator" in the end?

Hi Jason.

By now I think youll realise there was always one too many irons in the fire always that next project.  :) :)

Paint ? Thats another taboo subject lol. I do, however have a batch of cast Iron bases on order and am reliably informed theyll be ready in the new year. Theyve already run a couple of samples to find the best way of casting them.

No, not this time because the sealant the original builder used was so tough I think we might have broken something trying to disassemble it. Using a good cooling system was enough to ensure satisfactory running. Although the video is short we left the engine running continuously for a good hour or so before finally turning off the gas.

To close Id like to say that these particular models will definitely run but the fit and finish has to be meticulous. Too tight wont do at all, too loose and the noise is almost deafening. The term Goldilocks zone springs to mind.

Thanks for your comments Per.  :ThumbsUp:

Now to celebrate my 29th wedding anniversary.  :wine1:

Cheers.
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 24, 2021, 04:18:42 PM

To close Id like to say that these particular models will definitely run but the fit and finish has to be meticulous. Too tight wont do at all, too loose and the noise is almost deafening. The term Goldilocks zone springs to mind.

No doubt helped by the use of cast iron flywheels as Mr Westbury originally intended rather than the aluminium ones on Jo's example and also no need to modify the crank webs with counterbalance weights so keeping the engine truer to the originals.

Now all you need to do is knock up a pattern and a few castings for a nice little water pump with Heinrici's swiveling drive to save having to get the fish tank pump out. Make sure you keep one of those base castings for yourself as it looks like there is a fair bit of interest in them, were you having then done in iron or Aluminium?

J

Enjoy your celebrations
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 24, 2021, 04:32:55 PM
Well.

How does a proper replication sound? I wonder if the base could be machined on a 3-1/2 swing lathe? Im talking about the whole main casting in the correct shape. Steps could be taken to make the casting useless for faking an original version.

The base? I still have the original sample, under the bench, that was cast at Rhuddlan foundry 22 years ago.  ;)

Iechyd da.

Graham.
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 24, 2021, 04:48:25 PM
I suppose a lot will depend on the particular 3.5" lathe. The traditional Myford with it's gap may well be able to handle it if you machined it with the top facing the tailstock but not a modern 7 x 16. That is assuming the circular base is larger than 7" what does your lady friend say it measures? It would make sense if it could be done on a 3.5" lathe as that would keep the market as wide as possible.

I did get asked about machining one of the reeves castings some time ago by someone who could not swing it but don't recall what size machine they had.

Then again with a lot of people having mills would a flycutter or face mill and a boring head do the job?

Looks like her one already has a pad for a pump so you are half way there and you know where to find a good pattern maker for the pump ;)
Title: Re: Model Heinrici Engine
Post by: Alyn Foundry on December 24, 2021, 06:31:34 PM
Were looking at 168 mm or 6.61 inches.

The problem will be that you wont be able to offset the casting to bore the cylinder on a 3-1/2 machine. Your suggestion of using a milling machine boring head would be the obvious alternative.

Suitable markings on the core box would leave un removable data on the inside of the water jacket to identify a replica too.

Im thinking a new thread might be a good idea starting in the new year.

Cheers Graham.
Title: Re: Model Heinrici Engine
Post by: Jasonb on December 24, 2021, 06:43:29 PM
Casting on an angle plate or vertical slide would allow you to bore on the lathe with the advantage of power feed.

Yes a new thread would be best.