Sophie Beam Engine

I am getting a bit ahead of myself here but this will be my next project after the Stirling engine is finished.

1. How do I make the main pillar ? Would you make this as one piece or three pieces ?

2. How to get the smooth taper on the flywheel/main beam connecting rod ?

Sophie Beam Engine from Bengs

Link to Bengs added by JasonB

Edited By Brian John on 30/01/2016 10:05:33

Edited By JasonB on 30/01/2016 13:41:24

The column is probably cast to shape but if not then its just a case of uurning various diameters.

Have a search for "fishbelly" as I did a post about how to do them, may have been Garry's my little engine thread.

The column is not cast to shape.

I cannot find ''fishbelly''. Is this done freehand ? Can you post a link please ?

Edited By Brian John on 30/01/2016 11:20:46

You may find, the taper is two tapers joined end to end at the thick part with a radiused bit in the middle. Turn one taper and then flip end to end (Between centres), turn second at same setting and join with a file.

Regards Ian.

.

**LINK**

Read the posts from 11-1-2014 in this thread I did some sketches to show the steps involved in fishbellying a rod.

If the column is not cast then its just a case of holding a bit of round bar in your chuck with some tailstock support and turning the various diameters and then either using cocave or convex tools or eveb a file to add the mouldings This is one I did out of steel that is about 8" long, sorry no in progress photos.

I have also put a link to Bengs' site into your first post so people can see more details of teh kit.

Edited By JasonB on 30/01/2016 13:42:25

Jason : So you used a file to add the mouldings ? I could not see how it might be done with a lathe tool. Thank you for the links. I now understand how the fishbelly is made : more freehand work. So I am going to have to buy a smooth single cut file from somewhere.

Edited By Brian John on 31/01/2016 06:11:33

IT could all be done with a file but better to do the basic shaping with a lateh tool first, think of it like a small version of that rounded piston end that you did. Its quite easy to grind up a shaped tool like this and if used on both sides would produce a half round and then just blend with a file.

I don't have any single cut files but manage perfectly well so save your money.

Having built one Stirling engine (''Laura'' from Bengs), I am interested in building another. How does this ''John'' Stirling engine compare in complexity with their Sophie Beam engine ie. which would appear to be the most difficult to build ?

**LINK**

Edited By Brian John on 03/03/2016 06:20:47

It looks to me that Sophie would be the bigger challenge..so go for it..... and even better do it from bar stock to make it more of a challenge (specially without a mill lots of filing)

Brian, I'd say go for it, it looks a nice little motor. From what I read on the link there's 10 pages of drawings, and 4 pages of instructions, in German, hope they have a translation.

Ian S C

If you adapt a Peatol / Taig vertical slide to fit to your lathe Brian you will be able to mill lots of small things. It usually not too difficult to fit. It comes with a flat base and 2 holes running through it. That may allow it to be done as it comes. If not it's easy to fasten a bit of aluminium plate to the bottom. It's a very rigid vertical slide. Not sure if they do a metric version though but imperial would only be a minor inconvenience.

The "vice" they use is interesting too. Replacement parts are easy to make. The nice thing about it is that it can be machined to create steps etc while in place so alignment can be perfect. A bit of brass shim can be used to prevent things from being marked via the clamping screws.

John

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You mean this ?

**LINK**

http://www.ebay.com.au/itm/Taig-1220-Milling-Attachment-Allows-Mill-Work-To-Be-Done-On-A-Lathe-SHIPS-FREE-/191810635569?hash=item2ca8ce0731:g:h~oAAMXQ4uJSHBem

Edited By Brian John on 04/03/2016 11:28:56

That I can vouch for!

Neil