The Post Man Cometh.

[Nick GrantParticipant @nickgrant21535]

Looking beautiful, that shade of red really sets it off

[Nick_GParticipant @nick_g]

Posted by Nick Grant on 10/03/2015 15:03:58:

that shade of red really sets it off

It's Humbrol Crimson No.20 if you are interested.

I wanted something different from Brunswick green. It's a great colour but it seems 95% of Stuart engines get painted with it.

Nick

[Nick_GParticipant @nick_g]

.

Last weekend I started the Y shaped conrod. Did not get as far as I would have liked. But what I did manage to get done I was happy with.

Managed to get a bit more done today and it's progressing.

I first made the center / cross piece of the conrod. (with the center 'beefed' up a bit from the drawing) The ends have to be dropped to 1/4" to locate into the rods risers.

Next was the 2 risers. These are made from 1/2 x 5/16 bar. The center section of each is turned round and then a 'fish belly' taper to each end.

A short video of the interrupted cut can be seen here :- **LINK** (sounds like an old motorboat)

As recommended by the ever informative Jason the holes at each end of the bar was done before the turning.

Then the 'fish bellies' were done with the compound set at 1 degree and blended in with a file and emery paper.

Ends were trimmed to remove the center drill and live center pockets and milled on each side.

A bit of dressing with a file and they are starting to look the part.

I also decided to add a small brass bushing that has the 1/8th hole in to the top.

So just some polishing and the bottom center riser made and I will then be close to blast off. Unless we have a Houston type 'problem'.!

Nick

[Michael GilliganParticipant @michaelgilligan61133]

Looking Good, Nick

MichaelG.

[JasonBModerator @jasonb]

Have you deviated from the drawing re the bottom ends for a good reason or chickened out of making them round

Look good all the same and the fish bellies turned out well

J

[Nick_GParticipant @nick_g]

Posted by JasonB on 21/03/2015 21:01:41:

or chickened out of making them round

I think Moused out would be a better description.

Nick

[Michael GilliganParticipant @michaelgilligan61133]

I hadn't even noticed

… presumably they should look like the ones pictured here.

MichaelG.

[Nick_GParticipant @nick_g]

Posted by Michael Gilligan on 21/03/2015 21:14:52:

… presumably they should look like the ones pictured here.

MichaelG.

It's an optical illusion.

Mine are right. – Even the drawing is wrong.!!!! –

Nick

[Jeff DaymanParticipant @jeffdayman43397]

Great work Nick, well done. JD

[JasonBModerator @jasonb]

Actually thats a nice little feature on the one Michael linked to, the oil cup and through bolt to make it look a bit more like a split bearing with strap, wedge and cotter which would only have been on teh ends where there is rotation, the goint to the cross piece being static

Now if you would like me to tell you how to make ends like this just ask

[Nick_GParticipant @nick_g]

Posted by JasonB on 22/03/2015 07:32:55:

That's a very interesting part Jason and beautifully fabricated and constructed. What is it from.?

I would imagine very innovative for its day and you can see how this would have been produced in a Blacksmiths shop of the era.

Nick

[JasonBModerator @jasonb]

Scaled up and fabricated version of Anthony Mounts Benson Engine, few pics here does a similar job to your part but up the other way.

[Neil WyattModerator @neilwyatt]

It's looking very good Nick,

> very innovative for its day

Pretty much standard practice, actually.

The challenge is making the narrow key-sots in the rod ends. One trick is to drill the ends hollow so you only have to slot two thin walls, not right through.

Neil

Not quite as pretty as Jason's:

Here oneI made earlier:

[Nick_GParticipant @nick_g]

.

The conrod Was assembled with loctite and pinned through the joints with silver steel.

Getting serious now! Gaskets were made and the ones for the cylinder ends were assisted with the use of the PCD function of the mill DRO.

The crank pin was made out of EN24 – The last piece.!

Final assembly began.

.

And here she is. …………….. Finito.!!!!!!!!

So that's my first build done.

Need to put it on a nice base and build or buy a boiler so that it is actually a steam engine and not a compressed air engine.

What to build next.???? Decisions, decisions, decisions eh.

I would also like to thank the members of this forum that have assisted me in getting this far. Both those that have contributed directly to this thread and other information that I have picked up elsewhere on this site made by others. I would not have been at this stage without you. ………. Cheers guy's.!

Best regards, Nick

[JasonBModerator @jasonb]

Very nicely done Nick, look forward to the video of it running on air.

Nice touch adding the oiler and extended bearing to the big end

[Nick_GParticipant @nick_g]

Posted by JasonB on 29/03/2015 17:46:02:

look forward to the video of it running on air.

Oooops. Forgot to post that bit.

Here you go. :- **LINK**

Nick

[Neil WyattModerator @neilwyatt]

Lovely job, Nick.

Neil

[paul raynerParticipant @paulrayner36054]

fantastic job

paul

[ChrisHParticipant @chrish]

Just watched the video – booootiful!

Well done Nick, lovely model, you've done yourself proud.

Chris

[Michael GilliganParticipant @michaelgilligan61133]

Nick,

Sweet slow-running, on a whiff of Air

= Evidence of a very nice job.

Well done, Sir !!

MichaelG.

[GaryMParticipant @garym]

Great work Nick. Runs very well. Even though I've not posted much in the last few months, I've been following your build with interest.

Gary

[Nick_GParticipant @nick_g]

.

Thanks for the kind words guy's.

To buy or build a boiler. That is the next question.?

I have done quite a bit of soft soldering over the years but the skill of silver soldering and the required equipment is something I possess neither of. – Is jumping in a the deep end of making a boiler a good place to start to learn this skill I am wondering.?

Any advice will be welcome.

Many thanks again, Nick

[NJHParticipant @njh]

Nick

In my, albeit limited, experience silver soldering is not difficult. It requires scrupulous cleanliness in the joint areas and a reasonably close fit of the components to be soldered. Heat to get the component parts warm and a little extra heat applied to the cleaned and fluxed joints when applying the solder to get it to run. Sure, have a practice on some scrap copper sheet first and you will see how easy it is and will quickly gain confidence. Good fitting joints are needed – you don't want to try filling holes and gaps with silver solder and, just to reiterate, cleanliness is vital.

Apart from the method and amount of heat required I don't think it's much more difficult than soft soldering.

I do like the James Coombes and my current project of the " Trapezium Connecting Rod Engine" is similar in many respects – I may actually finish it one day !

Regards

Norman

 

 

Edited By NJH on 30/03/2015 18:03:53

Edited By NJH on 30/03/2015 18:08:44

[Nick_GParticipant @nick_g]

.

Another thread had prompted me to make this post after all this time.

Although I have another project 'on-the-go' presently. (which I have neglected this last couple of months) I do think a 2 X scale of the James Coombes on the size of and perhaps using the cylinder etc. of the major beam would be a most impressive model.

Would require the fabrication of the base, flywheel and the cross head guides, but certainly 'do-able'.

Only issue for me would be that my lathe can only turn 10 1/2" so flywheel would be a problem without using my friends lathe.

Nick

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