Member postings for old mart

I would favour a slow cure epoxy, like traditional Araldite, not one of the 1 hour type. The leather would need to be sanded down on the glue side to attempt to remove any traces of dressing from the belt. Using leather from a belt that has been holding trousers up is risky, as they are dyed and treated with no regard to using them with glue in a future life. The metal would ideally be shot blasted with alumina to key it, but coarse abrasive papers will have to do for most people. Degreasing the metal before gluing is vital for adhesion. If the thickness was fairly even, then pieces glued on radially with gaps between them might not need any machining, just let them bed in with use.

Bristol made three cylinder radials, probably sleeve valve. They look strange alongside 5,7 and 9 models.

They are so much better than a compound, but are unlikely to resolve down to single minutes of angle. You were lucky with that taper, it is always useful to have the mating part at hand to offer up for fine adjustments. I got a Morse Taper right after about three fine adjustments, with care, you can feel whether the front or back touches first.

If the die is not split, it is only good for cleaning up an existing thread. If the die is split, the die holder has to have a big enough bore to allow the die to be expanded by the central screw, for the first pass. Then the first screw is backed off a bit and the other two screws done up lightly on the die for the second pass. The quality of dies varies from excellent to christmas cracker, you may have the latter and could be trying to accomplish the impossible.

I wouldnt weld the arbor onto the boring head, I would do it up tightly and drill and tap a hole for a grub screw across the joint. Then you could get it apart at a later date if required

If ends are to be brazed into the tube, then chrome moly tubing like Reynolds 531 would be best. The molybdenum in the alloy prevents cracking caused by the heat of brazing.

With a small reamer, I would rather use a pin vise than a tap wrench. The hole size depends a lot on the size of the shaft if a gear is to be pinned to it. I have seen tapered drills, but not in sizes smaller than 1/8".

Edited By old mart on 28/11/2020 14:30:03

What model Myford is it? I don't recognise the bed. Now I know, thanks to lathes UK.

Edited By old mart on 27/11/2020 21:13:20

The solid carbide cutters can be used dry on steel, but oil might help the finish. You will have to proceed using several passes, reducing the depth as the ammount cut increases each time. Very careful lining up will be needed, I have had frequent lop sided results from rounding cutters. All of my rounding off has left tool marks, on cast iron, steel and aluminium which did not matter to me, but you may have to do some hand finishing.

ARC do HSS ones, they look like the solid carbide type.

https://www.arceurotrade.co.uk/Catalogue/Cutting-Tools/Corner-Rounding-End-Mills/4-Flute-HSS-Corner-Rounding-End-Mills

Edited By old mart on 27/11/2020 20:46:05

Edited By old mart on 27/11/2020 20:48:33

I don't remember seeing a Myford with a hammered paint finish.

I use CT90, but 3in1 would be better than dry. CT90 is probably intended for steel pipe threads in plumbing.

They probably supply the tools with the same hand as most people would use them vertically. You could lock the threads and run the machine in reverse, if it has that capability.

There may be more than one drawback to changing the standard backplate for your ISO/DIN adaptor. When you produce the 1 1/2" register and thread in the adaptor and fit it to the spindle, the front will require machining to get it to run true. All backplates fitted to threaded spindles are machined in situ. The only advantage of your adaptor that I can see is being able during assembly, to provide a positive locking to the thread to ensure the lathe is safe to use in reverse. The locking could be permanent as long as it did not interfere with removal of the spindle from the headstock.

160MM chucks are much bigger than 5" / 125mm chucks, in weight as well as length. There will be a sacrifice in overall length between centres as well as a small stiffness loss.

When I was in plating, nickel was never removed electrolytically. A commercial stripping solution called Ni Plex was used. This was for nickel and decorative chrome on steel. I don't know about a brass base, though.

If the plating will peel off, it will be nickel, that thickness of chrome would not be ductile at all and would crack off.

Edited By old mart on 27/11/2020 19:33:41

I used to use them regularly, just use cutting fluid, keep turning, but use very little axial force. It is easy to push too hard and increase the cut rate and the chance of snapping the reamer. The hole should be large enough for the reamer end to enter easily. The imperial reamers should be 1:48 taper and so should the pins, don't use metric pins.

Edited By old mart on 27/11/2020 19:19:15

Corner rounding milling cutters would do the job, but you would need a solid carbide one with that steel. I have a small solid carbide one which came in a job lot, four flute and about 3mm rad.

I bet there are lots of interesting sites like this, keep up with the links, everybody.

A left handed 12mm indexable lathe boring bar might do, unless your size is 1/2". The flats on the bar might be a problem, though.

You have a mill, just put a flat on a bit of silver steel and silver solder a carbide insert to it pointing in the direction required. Something like a basic TPUN would do.

From the photos, particularly the first, it looks like there will be very little left of the inner part of the screws when they are cut to clear the 50mm bore. The remaining flanges are all that will hold the jaws and the screws in the chuck.