Member postings for steve de24

Thanks Jason

Jason,

thanks for describing how to broach a D shaped hole, I've wondered how they do that with prop drivers. Are the broach's cutting edges made from the intersection of radial and cylindrical surfaces or do you need to machine relief angles? Is the silver steel heat treated before use to cut aluminium?

Regards, Steve

Hi Gary,

I'm also following this thread and your progress. As a fellow newcomer I'm learning a lot from the help you are receiving from the more experienced on the site - thanks guys, much appreciated.

Steve

Blackcat,

I use a Jacobs drill chuck with a 3/8 inch x 24 tpi thread mounted on a 0MT arbour on my small Cowells lathe and I'm very happy with it..

However can I suggest that if using a commercially produced arbour requires you to re-cut the taper (so that the threaded end is close to the that part of the taper which fits into the tailstock) then don't bother. Assuming you don't have a taper turning attachment, the difficult part of the job is setting the lathe up to cut a well fitting taper (not so much difficult as fiddly trial and error requiring a lot of patience). Having put the effort in to cut a good fitting taper then I'd make my own arbours, in fact I'd make a lot from 5/8 and 3/4 dia steel bar (or whatever meets your needs). I'd also make some from smaller diameter silver steel for future use as extra centres.

The total cost of the material, plus the cost of a 3/8 inch x 24 tpi die, will be about the same as the commercially produced arbour.

What lathe do you have?

Steve

Foe a drawing of the Sherline 0MT taper take a look at **LINK**

Both the Cowells and the Sherline use half length 0MT tapers. The difference being that the Cowells use the thin end of the taper (from 6.4mm dia to 8mm dia) while the Sherline uses the fat end (from 8.1mm dia to 9.2mm dia). A full 0MT taper in the Cowells tailstock looks like Rod's photo.

Thanks to Neil Wyatt and John Baguley for their valve timing explanations. This newcomer found them interesting reading.

Steve

Stew,

Nice work, I'm impressed how well it runs on 5 psi. What size bolts are holding the con-rod together?

Steve

Dan, take a look at :-

**LINK**

I hope it helps, regards, Steve

John, Thanks for the info; for my needs all I have to remember is PB1 and Colphos. Steve

I've noticed that at model shows there seems to be 2 main types material sold as 'bronze'. The first is very copper coloured and the second a pale brass colour. This confused newbie would like be grateful if someone can explain what they are likely to be and what uses they are best suited for. Thanks in advance, Steve