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Builds, Repairs, Show Your Machines! => Technical Tips, Builds, and Help => Topic started by: Jon Cameron on January 09, 2020, 04:08:19 pm

Title: 2" Durham and North Yorkshire traction engine
Post by: Jon Cameron on January 09, 2020, 04:08:19 pm
Hello everyone,

Firstly hope you all had a great Christmas and wish you all well for 2020.

I've been absent for a while and a lot has changed at home, a house move, new job, (again), hopefully a little more settled now.  Anyhow onto the post.

I was lucky enough to aquire a 2" Durham and north yorkshire traction engine for a very modest sum, it is far from been built to an excellent standard. When I first got it I looked over it and then started to take measurements and look over the parts I have.

Lists of issues that have been found are as follows
• wheels not running true to axle bores
• timing belts stuck on wheels with evostick adhesive
• front axle was not correctly centred before machining, meaning axle ends have large flat spots on them.
• Front perch fork seems stiff in the perch bracket so may need lapping or remachining
• smokebox has been silver soldered internally to seal the smokebox
• chimney base on smokebox not centred, it was machined incorrectly then bodged
• smokebox doesn't fit on the boiler, as the front tube plate has bulged the outer shell where it has been tapped in before silver soldering.
• The hornplates don't measure parralel, on investigation this is because the sides of the outer Firebox aren't parralel, and slightly taper to the top.
• the castings for the axles and crankshaft need their bearings remachining as it was bored oversize to accommodate the above
• the rear wheels same as the fronts with timing belts stuck on and rims not running true to the bores.

So on reflection not quite so lucky.......🤔

Having had the ME write up for sometime I have all the plans available and spured on the purchase of this miniature traction engine.

Having got moved into a new house I have an average sized garage which compared to the 6x4' rickety wooden shed is luxury. I will be setting the workshop up before continuing much further with this thread, however arrangements have already been made to have the boiler initially hydraulic tested to working pressure. This will ensure there are no leaks in tubes or the main soldered joints.

If all goes well with this then I will proceed to try and rectify first the issues that lead from the boiler, the bulge in the tube plate, and skimming the mounting bushes on the sides of the boiler to half overall dimensions from the centre line of the boiler. This will mean the hornplates will be able to sit vertically instead of tapered. Then I can move onto sorting the other bits out.

After a conversation with another chap who has built a Durham, he said he had a spare unmachined cylinder casting. And the bonus bit he said I could have it if I could pick it up. Sadly we are at opposite ends of the country (uk) so it means I'll have to arrange a courier to collect it. But far cheaper than paying for the fuel or even paying for a new one at over £100. So my head has been thinking of how to machine it on the myford ML4 and I think I have an idea which will involve a fixture plate attached to the vertical slide (bought some more tooling too), and the casting bolted to this through tapped holes in the top of the cylinder for the regulator chest. I can then machine the rear face of the cylinder, the bore and the mounting all in one setting, turn the vertical slide around and machine the front cylinder face. Then mounting on an expanding mandrel on the vertical slide I will be able to machine the valve face and make any corrections to the valve ports if required.
Doing it this way will ensure that four of the five major machined surfaces will all be parralel to each other. Or at true 90° (for the cylinder ends).

Anyhow still paint to strip and a workshop to set up so will be back again soon with an update on how the hydraulic test goes.....
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Title: Re: 2" Durham and North Yorkshire traction engine
Post by: txlabman on January 09, 2020, 08:06:36 pm
Happy New Year Jon!

Good to see you posting again.

This looks like a great project. I am looking forward to following this rehabilitation.

Cheers,
Charlie
Title: Re: 2" Durham and North Yorkshire traction engine
Post by: Nick on January 10, 2020, 01:09:29 am
Heck of a project, but the kids will enjoy that one  8)
Title: Re: 2" Durham and North Yorkshire traction engine
Post by: jkbixby on January 10, 2020, 07:33:40 am
Looks like another great project Jon so will be following closely - and glad to see you're here posting.
Title: Re: 2" Durham and North Yorkshire traction engine
Post by: Hero on January 10, 2020, 11:48:06 am
That should keep you out of mischief for a while!
Title: Re: 2" Durham and North Yorkshire traction engine
Post by: Jon Cameron on February 11, 2020, 04:33:26 am
A good look at the horn plates and the castings for the crankshaft, has revealed what I already suspected, that I will have to make new ones the machining is pretty poor quality to none existent. After feeling quiet dismayed by it all I thought I would see if I was flogging a dead horse, and plugged the boiler up to see if it would actually hold water, and didn't have any prevalent leaks. thankfully I can say that the boiler held up and even after been left overnight with hot water in it there was no signs of water under the engine in the morning, so signs are promising for a hydraulic test.

 The next question I have for you all, given the castings are so badly machined and I will be making new horn plates anyway, (they aren't parallel in any axis), would it be easier to fabricate the second shaft and rear axle/suspension bearing or machine a casting. I have yet to work out how to machine inside the rear axle bearing holder, other than with a really small long series end mill. So for me building up would seem easier on this part. unless any of you have any ideas on how to machine inside it? woodruff cutter would be too larger a diameter to get fully to the top of the slot.
Title: Re: 2" Durham and North Yorkshire traction engine
Post by: Jon Cameron on September 16, 2020, 07:40:36 pm
Hello,

So the house took longer to sort to our liking than I thought, and I've only just got around to setting up the garage as a workshop.

Has it really been 9 months, my word I should have my arse kicked.

I got myself a large metal bench the other day, and this has increased space to be able to work. So with the lump of box section, angle, and sheet that is my bench, I dragged it into position and laid all the parts out. Although this will be a long haul, I need to do some bits until I get my ML4 up and running how I want it. So trying to muster up some motivation. I set about with the wheels, clearing all the gunk off the rim with a mixture of files, emery cloth, and scotch brite to get rid of the rubber, metal set, and epoxy glue that the previous owner had applied.
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Once its cleaned up ill get them in primer, so they don't corrode, then its onto making some tyres. I think its 1/16" less for every 1" circumference, for a tight fit, the rubber can then be profiled to a nice round corner shape, and hopefully will look like a vulcanised tyre, and also stay put when in use. The rears below will also have the same treatment.
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The front axle is a bit of a no brainer, it wasn't set up between centres for machining so its a bit lopsided, also two flats where there should be a nice round profile is no good, so a new lump of steel acquired from the scrap bin at work, and ill be turning and milling a new axle happily soon, for free
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Need to buy some ME taps and dies for the boiler, then also mill the stays parallel with the boiler. I also need to get round to finish assembly of my ML4, so I can actually turn something.
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Title: Re: 2" Durham and North Yorkshire traction engine
Post by: txlabman on September 30, 2020, 09:27:23 am
It is great to see you making progress on this project Jon.

Your new workshop looks bigger than the old one.

I am looking forward to future updates.

Regards,
Charlie
Title: Re: 2" Durham and North Yorkshire traction engine
Post by: Jim on September 30, 2020, 05:39:38 pm
Must be terrific to be out of the 6x4 shed, that was a feat what you managed to shoehorn into that little shed!