Author Topic: Model Heinrici Engine  (Read 8979 times)

Offline Charles Lamont

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Re: Model Heinrici Engine
« Reply #90 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.)

Online Jo

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Re: Model Heinrici Engine
« Reply #91 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
Enjoyment is more important than achievement.

Offline Alyn Foundry

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Re: Model Heinrici Engine
« Reply #92 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 ??

Offline Jasonb

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Re: Model Heinrici Engine
« Reply #93 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
« Last Edit: December 15, 2021, 08:42:12 PM by Jasonb »

Offline Alyn Foundry

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Re: Model Heinrici Engine
« Reply #94 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.

Offline Jasonb

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Re: Model Heinrici Engine
« Reply #95 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

Offline Alyn Foundry

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Re: Model Heinrici Engine
« Reply #96 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....

 

She runs a treat !!

Merry Christmas.

Offline Jasonb

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Re: Model Heinrici Engine
« Reply #97 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?

Offline Admiral_dk

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Re: Model Heinrici Engine
« Reply #98 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

Offline Jasonb

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Re: Model Heinrici Engine
« Reply #99 on: December 23, 2021, 08:48:02 PM »
If you watch on Youtube the description mentions the electric pump.

Offline Alyn Foundry

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Re: Model Heinrici Engine
« Reply #100 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.

Offline Jasonb

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Re: Model Heinrici Engine
« Reply #101 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

Offline Alyn Foundry

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Re: Model Heinrici Engine
« Reply #102 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.

Offline Jasonb

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Re: Model Heinrici Engine
« Reply #103 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 ;)

Offline Alyn Foundry

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Re: Model Heinrici Engine
« Reply #104 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.