Member postings for old mart

I googled "steam locomotive valve gear" and amongst the results was this:

**LINK**

Lots of different Loctites is exactly what industry requires for their very specific needs. Hobbyists are only a fraction of a percent of their sales and do not count.

To be sure what they are a simple test with a multimeter would give equal resistance each way round with filament bulbe and different readings with a diode.

I would agree with Chris Evans, en16t or en24t, they are chrome moly and strong all round.

Medium strength would be 243. If you google loctite, there is a lot of information available.

Zyltech have despatched the leadscrew using UPS and it is expected by the end of the month, good going so far, I will let you know more when it arrives.

The round column mill at the museum has leadscrews on the X and Y axes of 2.5mm TR pitch, and only recently was I able to get some er16 inserts in that non preferred pitch, from China.

Try first with an AA cell and if nothing happens both ways round, then two in series. If that still does not work, you could try with bridging your car battery.

Loctite 263 is the first choice for threads from 1/4", 6mm upwards. Smaller threads might break before being unscrewed and would require a weaker product such as 243 and 222 for the smallest threads. 290 is like penetrating oil and can be used on fasteners after they have been assembled, which can be handy. 270 came to mind first, but it seems to have been superceeded.

Edited By old mart on 08/05/2023 14:46:41

Edited By old mart on 08/05/2023 14:50:10

The leadscrew from the USA is longer and includes a nut for a similar price to the HPC one. This is probably because ACME is still much more common there than trapezoidal. I had not seen their advert before, and after making the slightly longer leadscrew, maybe in two parts, there will be plenty left over which is saleable. I noticed that Tracey Tools have the 1/2 x 10 ACME taps for sale, but the new Atlas nut we already have should fit the new leadscrew and combined with the new one, I will be able to design a superior antibacklash for the cross slide.

As you mention, a quality conventional thread would be a very good substitute leadscrew as even if the pitch error was greater than a dedicated leadscrew. With a cross slide it is normal to measure frequently and only move a short distance at a time which means even an error of 0.005" in the whole stroke, say 5" would only be 0.00025" in 1/4 inch. Of course the usual thread for cross slides is left handed, not so easy to get hold of.

Edited By old mart on 08/05/2023 12:18:16

I bought one of the ARC versatile 5" vises as it opens much wider than the 100mm Bisons. It is at the limit of what both mills can accomodate, the large round column mill and the Tom Senior light vertical. Also, the rear flange has been removed to allow about 20mm extra Y axis movement. It came with the rotary base which is not normally fitted, but can come in useful at times.

Thanks, the 10tpi was what I had hoped, and the link from NDIY is interesting. I generally avoid ebay USA sellers because of the postage and possible duty payable. I suppose the duty would not be payable on the carriage rates. The Atlas 12 x 24 will be staying at the museum because the powers that be got cold feet in case the old Smart & Brown dies with no backup lathe. So I would like to make a new cross slide leadscrew for it. The existing one is 1/2" x 10 LH ACME and because of slightly uneven wear in the leadscrew threads, my antibacklash solution has to be spring loaded. This comprises a new nut combined with the old worn one with a spring between them. Because of the length of both nuts and the fairly short length of thread on the leadscrew, one of the nuts runs of the end of the thread in both directions. Even with a perfect unworn leadscrew, the antibacklash would still have this shortcoming. A new leadscrew could have more thread at each end and still work. The Atlas design of cross slide also leaves much to be desired because of its shortness, If I made a replacement, it would be 2" longer.

Update, I have taken a chance and ordered 24" which includes one nut, total cost £ 44, I hope.

Edited By old mart on 07/05/2023 19:09:50

Probably a later type like the Super 7 with an imperial thread, and with the longest length of thread available.

I foundthe micrometer listings in the Mitutoyo catalogue, you might be able to see the type you want.

**LINK**

Can anybody tell me what the thread pitch, size and length of an imperial Myford cross slide leadscrew is? I am interested in the longest available length of thread.

It looks good, but I have overspent on Lidl 20V cordless tools in the last week. A cordless strimmer, about 70% as powerful as a mains one, A cordless jet wash, I wanted a less powerful one and this one runs at about 275psi, and a cordless chainsaw, works a treat cutting up 5" diameter trees.

BA has not changed at all, neither have any of the other thread standards. -

I hve bought from APT also and have never been dissapointed.

 I would be wary of imperial marked collets, it is likely that one marked 1/4", for instance is merely a 6-7mm. If you want to get imperial collets you could try the USA, they still use imperial, but postage could be super high.

Edited By old mart on 02/05/2023 20:37:24

Edited By old mart on 02/05/2023 20:37:50

This lathe uses a camlock spindle and may not have any backplates to attach a flange mount collet chuck. With the MT5 socket, the prospect of 5C worth looking into, or at least er32. I just googled MT5 to er32 and there were multiple hits, so these would be your best bet as you already use er32 on the mill.

Edited By old mart on 01/05/2023 21:04:52

Edited By old mart on 01/05/2023 21:07:48

I saw about half a dozen of the £12.99 tool kits in the big Lidl at Weston Super Mare today, I already have lots, so gave them a miss.