Member postings for old mart

Simply Bearings do a 15 x 28 x 4 needle type thrust bearing, the loss of length could be made up buy using the race plates from the other bearings.

I have had a beta of the new edge for months now and are not too pleased with the mass of adjustments that can be made to it. Some make difficulties where none existed before, such as my preference of not keeping any passwords and not being logged into anything when the browser is closed down. For security, I prefer to log in every time. I had been running the beta alongside the previous edge until this week when an "upgrade " killed off the old one.

My laptop and another pc have also had the new version added this week. I won't be syncing them with this new edge.

The average basic user will never be able to take advantage of the better security, while the setting up is so convoluted.

You could make sure the thrust bearings have plenty of room radially on the shaft and in the housing, or replace them with the needle type which have flat races.

I bought a couple of the type posted by Steve Neighbour, and find them very good, especially with button oilers. They have good pressure. They have had semi synthetic 5W40 and slideway oil in them for nearly a year now and the plastic still seems oil proof. One has a bendy spout.

If the problem is a regular one, then it might be worth finding out of the tungsten carbide brazed grit hole cutters come in the size you use. At least they could cut through the skin, giving the HSS ones a chance.

I must have missed the Howard Lewis post mentioning the Myford leadscrew pitch. There is your answer, Myford spares are far easier to get hold of than any other make, and the modifying them to fit is by far the easiest option.

The four jaw is the most versatile, so I would vote for it to have the indexed backplate.

Gearboxes come in lots of ratios, these are right angle types: **LINK**

Sad to say, your pictures look great until you compare them with the view through a real telescope, even a cheap one.

Gerry, have you read how big those oilite bushes are?

Don't feel too sorry for the fellow, he obviously has so much money that his garage is full of cars which are about as much use as a chocolate teapot in 70mph limits. Back in the days when I had a 200cc Honda Benley which did 70 flat out, I overtook 50 times as many supercars as ever overtook me.

Most people have only one lathe, so major modifications of this nature are just dreams.

Do it outside and tell the fire brigade first. If you live in a town, you risk being fined for having a fire.

If the dial slips on its shaft, then put a washer under the head of the screw. Don't fix it so that it cannot be moved when required. 

The bellows came from that organisation that should not be mentioned any more. Perhaps putting in "lathe leadscrew cover" into a search engine would do.

Edited By old mart on 26/06/2020 20:34:45

Edited By old mart on 26/06/2020 20:37:13

If 80 divisions is required, then make a leadscrew and nut of 12.5 tpi, it will be perfect. To do that, you need a lathe which will do 25 tpi, and double the leadscrew speed.

It did cross my mind that a twin start thread of two 24tpi either Whitworth or 60 degree form would be easier to produce a in the limited space. Of course, a new leadscrew would also have to be made at the same time. Just making a new nut will highlight the uneven wear on your leadscrew.

Doing the maths, I was surprised to find that for 12tpi, the dials would have to have 83.3333 divisions per turn, that is total madness if thousandths of an inch were needed.

When we overhauled the apron of the model A, I decided to fit those telescopic spring leadscrew covers and now the leadscrew is clean and oily, and the new nut will last as long as the machine, also the constantly connected threading dial, with its 24 divisions will not suffer from dirt in its little bronze gear.

The cheap mini diamond files in wallets will score carbide easily, get the cheapest out there. The ideal length would be about 1mm of plain shank projecting when the collet is tightened.

The temperature has gone down now (21:10) to a mere 27.7C.

The threading indicator top with the printing should turn with the gear, but be possible to slacken off the central screw to get it lined up with the datum on the casting. The datum will be a simple paint radial mark, yours probably goes where the top edge gets wider at 12 o'clock when it is fitted to the lathe. The dial must not slip relative to the gear, unless you are adjusting it. This type pivot to disengage the gear from the leadscrew to avoid unwanted wear when you are not threading.

Edited By old mart on 25/06/2020 21:14:18

The Tom Senior light vertical has three sizes of these oilers on the same machine. I have loads of spares now The diameter is the same as the hole, but you need to know whether it is imperial, or metric, the clue usually lies in the machines origin.