Taris Jewell | 27/04/2022 20:45:42 |
22 forum posts | hi guys I'm after a strange one. my old Colchester master seems to use a left-hand acme thread 3/4 x 10tpi. and I don't really want to try and make that so I didn't know if anyone in the UK sold some. many thanks for any help |
Hopper | 27/04/2022 22:10:12 |
![]() 7881 forum posts 397 photos | Moore International and others in the current thread on Boxford leadscrews. |
Nigel Graham 2 | 27/04/2022 23:29:17 |
3293 forum posts 112 photos | Have you tried HPC Gears? I bought from them when I made a new lead-screw for my Myford ML7. (I fitted a second-hand, early-pattern screw-cutting gearbox that needs the screw cutting short to end just inside the wall of the box. Rather than risk an un-useable machine if I made a complete dog's dinner of things or the gearbox failed, and treating the lathe to a new screw anyway, I have kept the original lead-screw and other parts carefully as spare / reversion parts.
|
Stueeee | 28/04/2022 09:11:18 |
![]() 144 forum posts | Might be worth taking a look at this website: **LINK** |
Dave Halford | 28/04/2022 10:57:20 |
2536 forum posts 24 photos | I think HPC is the only imperial leadscrew stockist in the UK |
Hopper | 28/04/2022 11:09:14 |
![]() 7881 forum posts 397 photos | ABSSAC UK mentioned in the other thread list them. Surprisingly they quote a maximum accuracy error of 6 thou per foot for their precision screws. Makes all the arguing over metric thread approximation change gears on forums rather moot then. |
Dave Halford | 28/04/2022 14:30:01 |
2536 forum posts 24 photos | Please put a link on, all I see in the catalogue is metric. |
Nigel Graham 2 | 28/04/2022 14:51:09 |
3293 forum posts 112 photos | Try this one: www.hpcgears.com/n/products/linear_motion/leadscrews/leadscrews.php It is they I used, but note that "standard range" might not include your specific choice, and having it made probably won't be cheap. |
old mart | 29/04/2022 19:23:40 |
4655 forum posts 304 photos | Stueee's link to Kingston engineering shows their data sheet 3, but unfortunately their easily available ACME 10 tpi is only 1/2" not the op's 3/4". The 3/4 x 8 ACME is available in rod and nuts, a possibility if the dial graduations could be changed. There are a great many more suppliers over in the USA, but unless you know somebody living there it can be difficult and expensive to ship things to the UK. |
Nigel Graham 2 | 29/04/2022 19:31:51 |
3293 forum posts 112 photos | That's exactly what I bought from the HPC catalogue: 3/4 X 8 tpi LH ACME... You don't need import it!. |
Nigel Graham 2 | 29/04/2022 19:53:22 |
3293 forum posts 112 photos | OOOps, I beg your pardon. I misread the notification. You want 10TPI. Not the 8 I needed. I've looked it up again: www.hpcgears.com/pdf_c33/2.8-2.9.pdf, and no, the only listed 10TPI thread is 0.5" dia. So back to Old Mart's question of whether you can change the handwheel dial, perhaps make a graduated ring to fit over the existing one? |
Taris Jewell | 29/04/2022 20:32:44 |
22 forum posts | hi, thanks for all replies I've emailed a few different people and it seems £250 is the best price which is more than I'm willing to pay. I'm interested to know some more about changing the handwheels if anyone can recommend a thread or a supplier of good metric hand wheels then I can use any thread I want. i would probably use a metric trapezoidal lead screw if possible. now failing that I am planning on making the lead screw myself as I see no reason to why I can't and I should save £200 and learn a new skill |
Weary | 29/04/2022 20:57:20 |
421 forum posts 1 photos | I know that you wanted a UK supplier, however, a forum member on MECH sourced an acme screw-thread (albeit different to your requirement) from Roton Products in the US and had very good service from them. So ,maybe worth considering? Here is Roton Products info' , & Here is the relevant MECH thread. Kingston Engineering in the UK got a mention as a good supplier in the UK in that MECH thread. Don't know if you have tried them, so here is their site.
Edited By Weary on 29/04/2022 21:04:38 |
Michael Gilligan | 29/04/2022 21:19:51 |
![]() 23121 forum posts 1360 photos | Posted by Hopper on 28/04/2022 11:09:14:
ABSSAC UK mentioned in the other thread list them. Surprisingly they quote a maximum accuracy error of 6 thou per foot for their precision screws. Makes all the arguing over metric thread approximation change gears on forums rather moot then. . Surely any serious argument is about approximations much worse than that ^^^ MichaelG. |
Michael Gilligan | 29/04/2022 21:53:13 |
![]() 23121 forum posts 1360 photos | Actually … that’s rather a disappointing spec. from ABSSAC UK Go Compare : **LINK** https://www.helixlinear.com/blog/acme-screws/what-puts-the-precision-in-precision-acme-lead-screws/ MichaelG. |
Taris Jewell | 29/04/2022 22:27:11 |
22 forum posts | michael it was abssac that quoted me £250 they don't stock them they can just custom make it ill email some more people over the weekend and see |
Michael Gilligan | 29/04/2022 22:38:02 |
![]() 23121 forum posts 1360 photos | Posted by Taris Jewell on 29/04/2022 22:27:11:
michael it was abssac that quoted me £250 they don't stock them they can just custom make it ill email some more people over the weekend and see . That makes Hopper’s quoted spec. all the more disappointing, Taris ! … I wonder how much Helix charge MichaelG. |
Hopper | 29/04/2022 23:56:24 |
![]() 7881 forum posts 397 photos | Posted by Michael Gilligan on 29/04/2022 21:19:51:
Posted by Hopper on 28/04/2022 11:09:14:
ABSSAC UK mentioned in the other thread list them. Surprisingly they quote a maximum accuracy error of 6 thou per foot for their precision screws. Makes all the arguing over metric thread approximation change gears on forums rather moot then. . Surely any serious argument is about approximations much worse than that ^^^ MichaelG. Martin Cleeve's book Screwcutting on the Lathe lists compound gearing with standard set of change gears to cut metric threads on an 8 tpi leadscrew lathe with errors ranging from 1 in 3000 down to 1 in 8000 and that never seems to be good enough for some model engineers who insist on 127 tooth gears etc. But even 1 in 3000 is only 4 thou per foot. 1 in 8000 is thou and 'arf. |
Hopper | 30/04/2022 00:54:14 |
![]() 7881 forum posts 397 photos | And when you think of it, even 6 thou per foot is not much total error. That's plus or minus a quarter of a thou per inch. Pretty good for a mass produced item. You'd have to go to an expensive ground thread to fo much better. Edited By Hopper on 30/04/2022 00:55:43 |
Kiwi Bloke | 30/04/2022 01:18:17 |
912 forum posts 3 photos | It's good to see that Halifax Rack & Screw are still going, and now also have a branch in USA. Don't know whether they will still talk to Joe Public, but they were friendly a couple of decades ago... Good luck. |
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