Member postings for Durhambuilder

So to bring this to a conclusion: I opted for 48T and 24 T in 0.8 module which matched the 72/36 T 48 dp within a few thou. Ali express delivered the cutters from China in about 10 days and with the postage were £24 for the two required. Just be careful when ordering, their cutter numbering system appears to be a reverse of what we’re used to over here. Photo in album. A big thank you to everyone that responded.

Oh my word, what a great set of responses, Thank You all.

To answer some questions albeit in no particular order:

The engine is the Jerry Howell Farm Boy, so far it’s looks as if it will be a great little engine.

Some builders have used 76/38 tooth mod 0.5 which appear to work, another builder was caught out using 32DP due to the larger overall diameter of the bigger gear catching other parts of the valve gear. I wonder if there would be a similar issue with MOD 0.8?

HPC do the gears in steel, ideally I need the smaller one in steel and the larger one in brass.

The tooth cutting depth for 48DP is about 45thou so the teeth are really quite small, I don’t know how critical the tooth profile is given the limitations of a home workshop in these small sizes.

I don’t think the pressure angle matters as long as they are both the same.

I like Jason’s idea for meshing gears, given the limited demonstration use my engine will get I’m tempted to give it a go with just the No 3 cutter. The softer brass gear may just ‘wear in’.

Simon that’s a really kind offer to loan a cutter, I’ll give it some thought and drop you a PM later.

Once again Thanks All.

I’m really struggling to find a number 2 48DP gear cutter to cut a 72 tooth gear. I also need a number 3 to cut a 36 tooth and those appear to be easily available. What problems might my encounter using a number 3 to cut 72 teeth, it’s for a slow running hit and miss engine.

Just be aware when scaling, things can get very big very quickly. A 1” x 1” x 1” cube is one cubic inch, a 2” x 2” x 2” cube is eight cubic inches, ie eight times the volume/ mass ! If you want a 3d object twice the size each dimension should be multiplied by 1.26.

Currently building a 5“ Tom Rolt as drawn by Don Young. I’m going to use ptfe or similar for the piston valves rather than DY’s forced fit iron ones. Should I use round ports in the valve liners to minimise risk of damaging the ptfe bobbins or should I stick to square ports? Cheers.

You can swap within the same group eg a 4.5kg butane can be swapped for a 6kg propane.

https://www.calor.co.uk/gas-bottles/refills-and-returns/refills

Sievert every time, get a starter kit and add burners as required.

https://www.gasproducts.co.uk/blow-torches/sievert-gas-blow-torch-kits/sievert-general-purpose-gas-blow-torch-kit.html

Calor gas cylinders can be found quite cheaply at car boot sales and the like, don’t worry about size or condition once you have the cylinder you just swap it with the size you prefer at your local calor dealer.

Appears to screw in to item four the bottom collar, I wonder if it should be 5/8 or 7/8 and not just 8?

Kaolin wool blanket (CUP Alloys) is probably the stuff you’re after; for my boilers however I used a pumice chimney liner, see my album.

There is the 3” Ray Prime Atkinson waggon as supplied by Reeves which would be a fair bit larger than the 2” Clayton, don’t think it top fired though.

26swg brass will dent very easily, For my locos I’ve used stainless steel cut from a ‘pound shop’ bathroom pedal bin.

I bought my chipmaster about 5yrs ago and love it, variator is still smooth as silk through the entire speed range. One of the easier lathes to move as well albeit a bit weighty, there are a pair of holes in the bed designed to push a bar through and you lift from there, the wide base also makes it a lot less top heavy and more stable when moving. I moved mine about 60 miles with a 1 tonne plant trailer and an engine crane to lift off and on.

I’ve clad my previous two boilers with thin stainless steel having bought a couple of cheap pedal bins for the purpose.
Just need to be careful you can get a big enough piece out of them whilst avoiding any holes, there is also the benefit that you get a nice rolled edge at one end. From memory the 4.5” dia boiler was done using an 8” round bin which cost about a fiver.

Welcome aboard, I have a Chipmaster in Frome so not too far away. Unfortunately I can’t help with your wiring, mine is run off of a phase converter.

My Dore Westbury is the one in the photos on Tony Griffiths site, **LINK**, this has the original power feed option but I can truthfully say I’ve never used it whilst milling!

That doesn’t look like a Boxford top slide to me, probably off of a bigger lathe.

Sell whatever scrap you can, beg borrow or steal to raise your budget to £2000 and buy the myford 254 in the classifieds, no connection with the seller but looks a cracking buy and fully tooled up.

Edited By Durhambuilder on 26/03/2021 11:56:38

Jensen healey 1972-1976

https://www.scmes.co.uk/images/Technical%20Information/SafetyValves/Small/Safety%20Valve%20Details%20All%20Doc%20&%20Valves%20off%20web.pdf

try this

Looks a good deal but just be careful, that lathe has ‘sold’ twice on eBay in the last couple of months. Photo has been cropped but definitely the same photo, bisley drawers alongside and metal strip on floor.