Member postings for old mart

Titanium is naturally silver colour, but can be anodised at different voltages to give lots of different colours.

If you still get problems after checking out all the suggestions, try facing off a bit of bar with an ordinary tool to make sure the cross slide is square to the spindle axis. Locking the saddle if you can when parting is recommended.

As already mentioned, sharp tooling is the way to go. If you are intending to use carbide, then the polished inserts made for aluminium, often called H01 grade will work well. If you have to drill a bar, a sharp drill, slow speed, high pressure and plenty of lubricant, soluble oil being preferred. Titanium conducts heat slower than most metals, so you must not allow it to get hot if possible. After drilling a pilot hole, let it cool down before enlarging the hole. Tube would be the best option if you can get some of the right size. If you can get tube, make a plug to go in the part within the chuck jaws so you can get it nice and tight without distorting it.

At 600 rpm the pointer would oscillate ten times a second and be hard to read. The slower the better. I rarely use the one I bought, but would turn the spindle by hand first to be sure the eccentricity was not out of the pointer range. A point to remember is that the figures on the dial only represent an exact distance when the probe in use is the right length and angle.

The plastic locking ring on mine is split and comes off easily.

Edited By old mart on 03/07/2021 17:56:51

My 7 X 12 mini lathe has a fuse amongst the controls which used to trip when drilling. I changed from 1A to 1.5A and it is ok now, I hope I haven't overdone the rating.

We had a volunteer at the museum who ran a 2Kw electric heater through a partially unwound extension reel and the inner 12 feet had to be removed as it had started to melt. He had been an aircraft electrician, so he should have known better.

I was concerned with the RCD's when setting up the 0.75 Kw VFD, but it has not tripped so far.

Edited By old mart on 03/07/2021 17:37:48

1" plywood is extremely strong, and spread across several joists would be plenty. Get a sheet of external type, marine ply is very expensive.

We have three righthand and two lefthand holders for TNMG 16 inserts. One of each hand has an aluminium insert in it which is also good for fine finishing cuts on steel. I find that the cheap Chinese Drillpro brand for steel works very well. As Vic says, you get six edges as long as you don't knock the whole end off an insert. We have Sandvik, Seco, Kennametal, Iscar, Tungalloy and others bought cheaply on ebay. WNMG in 6 and 8 sizes are also good with six edges like TNMG. Try the cheap H01 grade if you are thinking of getting some for aluminium.

Edited By old mart on 03/07/2021 12:50:10

Lathes UK may have something, they do reprints of manuals.

I did this years ago, not to tune the engine, but to lower the compression ratio when unleaded petrol came in. I did it by hand with a die grinder, fortunately the head was aluminium. Th match the volumes, with the valves and plugs in place. a piece of perspex with a hole in it covered each combustion chamber in turn, and a syringe was used with oil to get within 1/4CC each.

For a strimmer, be sure to get one that advances the line/s automatically when you tap the head on the ground. I ditched the posh one and went back to Black & Decker because of this .

It's a good job you mentioned the insert, I have been transfering rubbish from the bin into a bin bag, searching, and found it after 1/4 hour. I now have 5, 6 and 8 tpi ACME inserts. I would like to make a better nut for the drill mill X leadscrew, but have not been able to find 2.5mm trapezoidal inserts.

The whole spindle must be bigger diameter, as the common Myford spindle thread is 1 1/8" which is 31.75mm.

If you have a digital meter, set it to 20 megohms and test that black plastic, it is very unlikely to be a conducting grade, but, being black, it could be antistatic, there is a remote possibility.

Edited By old mart on 30/06/2021 18:54:55

Welcome to the forum, Guy, what you are up against is the great difficulty of turning a round groove which is one of the most difficult things to do without chatter. I have tools using round inserts of diameters from 6mm to 20 mm, but have never succeeded in getting the required finish in a turned groove. I would think that your best bet is finding a bearing that is near the size and getting the races ground as there will be some wall thickness available for modifications. I buy bearings from Simply Bearings, you might find they have something.

**LINK**

The threading bar arrived back safe and sound along with a nice letter and some money, which was unexpected, but much appreciated. I will spend the money on tooling for the museum. Now I will have to get on with using the bar myself, very easy as the thread on the Tom Senior's knee is anticlockwise. Keep us updated with the mill repairs.

It must be good, a steam engine from a smoke free home.

As there is very little difference between 3mm pitch and 8tpi, you should measure the leadscrew not the nut, and over at least 30 pitches. 8TPI IS 0.125" and 3mm is 0.1181", only 0.0069" difference per pitch.

I just saw your 20=2.5", definately 8tpi.

Edited By old mart on 28/06/2021 20:51:31

Back again, the thread was from 20-6-2019 in manual machine tools, "my version of a locking device for threaded spindles" There were no replies on this forum, but I had also posted on The home shop Machinist in the USA.

I cannot find the thread, but if you can access my album, the basic pictures are from the 3rd to the 8th.