The Workshop Progress Thread 2019

[JasonBModerator @jasonb]

That's Right Ron, some models tend to use upturned cap heads screws but I put a fine straight knurl on some 4mm steel and then reduced turned the end down for a M2.5 thread before using a 3mm ball mm nose cutter to make the recess. I'll be making all my own period fixings, the cap heads are just easy during construction.

The reason these engines did not have a throttle was they often went into tether boats where you had no control of the engine just dropped the boat into the water running and timed it to see how fast it could complete a set number of loops, at this sort of period they were getting around 50mph out of the top ones.

Michael, the whole of the old magazines make interesting reading as they cover many subject and the adverts are as interesting or more so than the articles. Page 626 of the 1936 edition has the article about making the castings.

The fuel tank turned up today along with some spares so that jamjar Maytag engine could be a possibility. I'm sure the postie must think I'm getting into jam making as I also bought some 8oz Mason jars for another engines vapour tank.

[Jim NicParticipant @jimnic]

At long last I have completed Stew Hart’s Overcrank engine. I knew when I started that it was a step up from anything I’d done before but thanks to Stew’s excellent drawings (which I believe were not originally drawn with publication in mind) and a bit of thought and common model engineering sense the result is shown below.

And a vid:

It has taken the best part of a year but I’m pleased with it. Thanks to Stew for the drawings.

Jim

[JasonBModerator @jasonb]

That has turned out very well, nice slow runner too.

[mechman48Participant @mechman48]

Another fine model Jim, nice runner too .

George.

[Mogens KildeParticipant @mogenskilde92996]

A very nice engine – absolutely great job

Thank you for sharing !

[Neil WyattModerator @neilwyatt]

Lovely model Jim, congrats to you and well done to Stew for the original design!

Neil

[geoff walker 1Participant @geoffwalker1]

Hi Jim

Lovely job mate, there's a lot going on with that engine, and only a year to make. I wouldn't be halfway there

Well done

Geoff

[Jim NicParticipant @jimnic]

Thanks for the kind comments gents.

A little bit of a mod to do on my Grasshopper Beam engine pipework then its on to the next project – a Muncaster designed Double Acting Oscillator using the cylinder casting kindly given to me by Geoff Walker. This engine will present me with its own challenges as I am not good with castings having only used them on a Stuart Models 10V and my Grasshopper Beam (which did not turn out well with several of the castings being discarded after my attempts on them!). I have the barstock materials on order, the cylinder casting and some drawings so I'm committed now.

Jim

[John HinkleyParticipant @johnhinkley26699]

Not really workshop progress, but progress nevertheless, albeit with the continuing saga of my gearbox design. I had all but completed the internals, when I found that I'd messed up the gearchange mechanism, such that I'd ended up with the 4th and 5th gear gate in the middle! After a bit of head-scratching (and not a little profanity), I got it sorted with a bit of a re-design of the two offending selector forks and their associated rods. The "finished" design is illustrated below :

Anticipating starting to cut metal soon, I've emailed Abbey Castings to ascertain whether they can cast the selector forks in bronze for me, in a "raw" state, ready for me to machine to finished size, but have yet to receive a reply. Perhaps they are on holiday? I'll try ringing on Monday.

John

[Mark Gould 1Participant @markgould1]

John,

I am amazed to think you are designing a gearbox, i only vaguely undertand them! looking forward to seeing the progress, do you plan to take any phtotos to share with us?

Mark

[John HinkleyParticipant @johnhinkley26699]

Mark Gould 1,

To be fair, I have leaned very heavily on the expertise of Mr. Hewland; the design being based on the 5-speed version of the FT200 gearbox that they produce. I have chosen my own gear ratios to suit the scale of the model and it is intended to be a demonstration of the principles of gearbox operation, not necessarily to be fitted to an engine. At least, not in the immediate future – but never say never. I'll take a number of photos of the progress if I consider them to be significant to the build and put them with the others in the album, along with the brief notes which accompany them. From time to time I may well stick a couple in this thread, too.

If I can get into 3D printing, I will try to design a casing to hang it all in, but for the moment my ambition is to support the gubbins on perspex or similar plates so that the workings can be observed. We'll see – literally!

For some idea of size, the input and output shafts are 190mm long and the gears are 1.5MOD, the largest being a shade over 60mm in diameter.

Thanks for your interest.

John

[duncan webster 1Participant @duncanwebster1]

Today I finished the latest batch of signals, and I'm hoping it's the last. This makes 13 I've made, but it does add to the enjoyment of driving little puffers, and helps to avoid running up the back of the train in front when he has run out of chuff just round a blind bend.

Next step AWS to tell the drivers to stop messing with the fire and look at the signals!

Edited By duncan webster on 12/09/2019 15:15:27

[Nick Clarke 3Participant @nickclarke3]

Something to physically attract their attention instantly perhaps?

(From Akira Kurosawa's film 'Throne of Blood' – Macbeth retold with samurai)

[John HinkleyParticipant @johnhinkley26699]

Well, I couldn't resist the temptation. Following my post above, I've set to and cobbled together a casing for the gearbox. It involved a few changes to the internals, mind you, to prevent some of the insides ending up outside, or part way through the walls. Here's what I've done so far:

I think I'll need a 3D printer for that!

John

[JasonBModerator @jasonb]

If you do print it find some clear filament, would be a shame to hide all that work

[John HinkleyParticipant @johnhinkley26699]

Jason,

I did try to get a picture to give the effect you are suggesting, utilising the "shaded and all edges " view facility, but the internals are so complicated, it looks a real mess. Having thought about it while typing this, I'll try a "normal" view of the guts and a transparent view of the casing and attempt to combine the two. If it works, I'll post it here.

John

[JasonBModerator @jasonb]

John, I think Atom should also have "part colour" from that you can set the opacity of any part, in this situation just the case parts would need doing. I find this quite handy when checking an assembly as you can move say a crankshaft and check inside the crankcase to see if anything is going to hit as all the parts rotate.

Although not a fan of multi coloured drawings you could also show the selector forks in a bronze colour and the case in a lighter shade of grey to the gears and shafts.

[John HinkleyParticipant @johnhinkley26699]

That worked, Jason. Here's the result, at 50% translucency:

I'll stop posting for the moment. I feel I've monopolised this thread for long enough!

John

[JasonBModerator @jasonb]

Got a few more bits done on the '36 midget

Cut the crank webs to form counterbalance weights with a 10mm ball nose cutter

Hardened and tempered the cam lobes and set then onto the camshaft with 648, as the indexer was on the mill I used that and a square to set the angle. Once done pushrods and springs were completed

Then did a bit of screwing, starting with a plug for the oil level hole

Followed by some M3 and M2.5 ones with a fillister style head.

[GoCreateParticipant @gocreate]

5" Lion build.

Finally, after what seems endless hours and problems with weeping bushes I have a water tight boiler on the third hydraulic test, held 160psi for 15 minutes.

It's not pretty but it's water tight.

I received a great tip, after the boiler was finished off course, when making the threaded bushes drill and tap them with a blind hole then, when you test the boiler you don't need to fit blanking plugs, once the boiler is tested successfully finish drilling and tapping the threaded bushes.

I have done the boiler first as this was the biggest challenge, so pleased I can now get on with the frames and wheels etc.

Nigel

Edited By tractionengine42 on 27/09/2019 15:18:30

[Brian HParticipant @brianh50089]

Looks good Nigel, hopefully will encourage others who may think that boilermaking is a 'black art'!

Brian

[JasonBModerator @jasonb]

With the bracket for the ignition contacts completed ( see CNC thread) I made up the rest of the parts for that.

And also knocked up an exhaust pipe.

[Jim NicParticipant @jimnic]

I have made a start on Muncaster’s Double Acting Oscillating engine.

First off I gathered some bits of metal:

Then, since I hadn't figured out how to go about any other parts I made the flywheel, which still needs a bit of car body filler around the spoke ends to add a bit more realism.

Then I took delivery of the engine frames from Model Engineer’s Laser.

I had these lasered because I’m getting lazy in my old’ish age and could easily see me messing up forming the bowed feature halfway up and having to make more than one attempt.

Now I'm going to have to get my thinking head on and tackle the cylinder.

Jim

Edited By Jim Nic on 01/10/2019 14:51:51

[JasonBModerator @jasonb]

Off to a good start Jim.

[Richard S2Participant @richards2]

Reached a point where the repetition of making spokes for the wheels of the 1inch scale Water Cart is over-

I can relax a bit now I've set the spokes to hubs fixings before more work on the hubs detail and fix to the rims-

Spokes are set into recesses in the hubs and fixed with 10ba countersunk screws.

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