Hello,

I'm slowly getting to see where all the issues are with a 2" durham project that I bought, unfortunately there has been many shortcuts, and parts left as "that'll do".

I've possibly mentioned all this elsewhere on the forum but as a recap, the issues ive found so far are as follows.

• Boiler stays project too far from the boiler sides and are not all parallel.
• boiler end that slots into the smokebox doesn't fit it looks as if the front tube plate was just too big and it has bowed the front end slightly. (about 1/32" so it is slightly larger dia at the front that 5"
• The boiler inner firebox bottom hasn't been clipped back so is of varying lengths needs filing back to 5/16" all around from the foundation ring
• The stays have already been drilled from the hornplate but as the hornplates don't sit flush im worried the stays are not drilled square for when the stays are trued up.
• The hornplate don't sit parallel or in line with each other so the holes are slightly out.
• the 2nd and hind axle casting, has had the holes drilled for attaching to the hornplates ad hock, and these need plugging and redrilling,
• The same axle holes seem slightly oversize by 1/64", (need to measure them properly with a bore gauge.
• The The front axle wasn't centred properly so the round axle ends actually have two flats in them.
• The chimney base is not sat on the smokebox in line with the perch bracket (tilted chimneys never look good.

I'm sure there's others not listed above but that's certainly a list to get on with. I've decided the hornplates will be scrap and may be used in the durham but not in the same form as they are now. The only thing I can trust on the boiler for reference is the barrel between the front plate and the firebox. I intend on using a parallel clamped to the back of the firebox and in line with the centre pop top and bottom, (assuming this is the reference for centreline). The boiler can then be set up in a mill on some Vee block, or just packing, and the stays milled to size with a machinist jack to the front and rear of the firebox. ( a lttle tooling project). The inner firebox bottom will be draw filled to get it to a scribed line on the copper. as I believe machining here could cause some serious issues with weeping. currently the boiler holds water without leaks but has not been subject to hydraulic yet, as if im right the machining on it will null and void the hydraulic cert as its modification to the outer shell.

Anyhow moving on as that's yet to come and ill see what feedback I get from here on the above.

I started to look at the 2nd and hind axle casting last night, I have made the axleblocks a good fit in the pockets, by using a marker pen and then sliding them up and down, and gently filing back where the blocks rubbed. whereas before they hardly moved, they are now free to move up and down. the mating face with the hornplates was all over, looks like it had been milled but in places the mill had gone a thou deeper and left swirly patterns on it. I draw filled the centre between the two axle bushes, to gain a datum for the rest, using a set square and a light to gauge where the high spots where, and draw filing, I have one side pretty much complete and level on the mating face.

Now the first question, what id like to know is the holes that haven't been drilled well on the casting, been a bronze casting can I mill them over size then plug and silver solder them together. before using a drilling template to redrill them and what solder and flux would be needed, these are right next to the firebox so soft solder I assume is out the question.

Second question how tight should the axles be within the bearing block and the 2nd shaft journal? 5/8" for the 2nd shaft, 3/4" for the rear axle. the rear axle I assume been sprung will require some form of movement to stop the rear axle locking solid when going over rough ground. If these are too loose I plan to over bore and solder a plug in same as above.

I don't have the serviet propane torch yet, and rather than buy new castings, I figured buy the torch and appropriate burner, and mend these instead for the same kind of money.

Jon

Edited By Jon Cameron on 13/05/2020 10:24:15

Hello,

Dispite little interest, i'll continue my postings and hopefully as it progress it may be useful or of interest to someone else. 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.

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.

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

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.

Set about the rear wheels, removing the timing belts that had been used as tyres. These had been stuck on with what looks like some kind of epoxy glue. However it's brittle in places, so I suspect that it would have fallen off on first use, anyhow I didn't like the exposed threads of the belts, so stripped them back.

After a lot of hard work, the glue was gone leaving just the surface of the rim.

Two wheels free from their timing belts.
Next job is to strip the paint off the rear wheels. Then get them in primer and make some new tyres for them all.

Jon

Edited By Jon Cameron on 17/09/2020 12:29:33

Edited By Jon Cameron on 17/09/2020 13:11:27