Member postings for old mart

Parallel od sockets are available, I have two, 1" and 2" for MT2. Capstan lathes use them. The taper part of the drill is not as hard as the rest and if you can hold them using the centre at the end of the tang to steady them you can turn down the taper. I turned parallel shanks on some of the smaller MT3 drills, and one of the volunteers took a MT3 26mm drill home to turn as his lathe could just pass about 28mm through the spindle.

About three years ago, I noticed somebody selling an item which was radioactive without mentioning that fact to any potential buyer. Complaining to ebay got nowhere and all I got from the seller was abuse and told to mind my own business.

I wondered about that bullwheel, but it may be from a newer lathe than an ML4.

Superb quality, could you show us the machines you used in making it?

 I have used a Taylor Hobson many years ago, and even made a little rotary table for it to engrave instrument dials, and pressure gauge dials.

You could also use a die grinder with 3 and 6mm collets in a similar setup.

Edited By old mart on 04/01/2021 19:11:19

Edited By old mart on 04/01/2021 19:15:13

I have bookmarked the ABSSAC link from JohnF as I was interested in the 1 x 5 ACME and will probably check whether LH is available and for the price of a couple of feet. It would be for the Tom Senior knee which I have tooled up to make nuts for when the CO19 allows.

I agree that rigidity will be a problem, but cutters up to 6mm would probably be usable. A bracket across the gooseneck would help.

The museum's Smart & Brown model A has a 3mm pitch cross slide leadscrew with two long bronze nuts and as the machine is imperial, the scale is now 0-118 instead of the original leadscrews 8tpi 0-125. Backlash is set at 0.001".

Edited By old mart on 04/01/2021 18:35:00

Taper pins don't usually have holes in them, but roll pins always do. I would make a drift that was close to the hole diameter, and hold a heavy metal block with a 1/4" hole against it while tapping at the pin. Use a small hammer and gradually increase the power. A roll pin won't take much moving.

If the glass is laminated, avoid soaking it and use cool water, not luke warm. Any separation of the balsam will start at the outside edges and you will have to live with any that is present. Don't be tempted to clean the edges of the plate.

Edited By old mart on 04/01/2021 17:46:46

That would seem to confirm my 65 tooth tooth bull gear. If the diameter of the damaged one is posted, then a possible donor gear might be possible.

That would work if you intend to produce your own alloy, of you could use phosphor bronze and just melt that. SAE 660 gunmetal is leaded and is the one to avoid, I have soft soldered it with great success, but not only does the lead make wetting the surface difficult, but the lead vapour given off is unhealthy when brazing or silver soldering. Google the types of bronze available first if you are going to buy it.

Ok, with just the lathe you must have been doing some milling to get this far.

Think about tilting the work to the 8 degrees and then using a small cutter, say about 3mm diameter. It will leave an indentation, but that will not affect the way the clamping works at all.

Look closely at Phil P's second picture.

Edited By old mart on 03/01/2021 20:48:37

Edited By old mart on 03/01/2021 20:50:13

Phil P's drawing of his quick change blade holder shows the standard angle, 75 (15) degrees.

Getting the op's 8 degrees is just as easy assuming he has a mill.

Edited By old mart on 03/01/2021 18:27:41

As Thor has mentioned, ARC has inperial size er25 collets and it would be best to get e few in the exact sizes to complement your metric collets.

The gear would not have to be made from the original cast iron, unhardened steel, or even aluminium would work. The bull gear on the Atlas 12 x 24 we are working on at the museum is made of zamak, a zinc alloy like the mazak we have here in Blighty.

Pewter has lead in it.

I believe that the gear has 65 teeth (please confirm that) and if the diameter was measured, there is just a chance that one of the changewheels made by Myford could match and have a new boss made . It might not be quite the same thickness, but wouldn't have to carry much power

There are people advertising gears made to pattern, I have no idea how expensive they are.

A 1/2hp three phase motor and VFD from the inverter drive supermarket with a remote switch with all the controls would cost about £200. A similar capacitor run motor single phase would be around £50 and a capacitor start motor would be about £75.