Pete. | 08/07/2020 01:09:39 |
![]() 910 forum posts 303 photos | I've been restoring a small benchtop mill from the 1940's, there is quite a lot of backlash in the x and y, I'm going to fit new leadscrews and nuts. The current screw is 5/8, so a trapezoidal 16mm will be a suitable replacement. I can only find one supplier for a T16 leadscrew and nuts, and it's a 4mm lead, ideally I'd prefer a 3mm lead, does anyone know any suppliers? The one I found is called 'accu' and they only seem to have a 4mm lead. Any help much appreciated thanks. |
Thor 🇳🇴 | 08/07/2020 06:10:27 |
![]() 1766 forum posts 46 photos | Hi Pete, T16 with a 3mm pitch might not be easy to find, usually 3mm pitch go to T14. I found one in the US, this supplier lists T16 with 3mm pitch, may be expensive to get delivered to Europe though. Thor |
not done it yet | 08/07/2020 08:09:30 |
7517 forum posts 20 photos | Bornemann comes up on my ‘puter as a bespoke supplier. Would not be cheap, but likely no worse than importing from the US? HPC Gears says ‘specials can be manufactured to order’. |
John C | 08/07/2020 09:17:56 |
273 forum posts 95 photos |
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Mike Woods 1 | 08/07/2020 09:27:06 |
41 forum posts 1 photos | I wonder if any of the Warco, Chester, Sieg, Amadeal or Axminster lathes or milling machines use this T16 x 3mm format. If so, the perhaps you could buy a spare part from one of the suppliers and modify to suit? Both my lathe and mill are in storage at the moment, otherwise I would measure them, but I am sure that the lathe is T16 x 3mm x 500mm. Mine is a Chester 920, so has a keyway over its entire length for a feed worm gear, other lathes which use half nuts for both feed and threading would not have that. Also, what is used on the remanufactured Myfords? Maybe others with ready access to their machines could offer some advice. Just a thought. Edited By Mike Woods 1 on 08/07/2020 09:30:22 |
John Haine | 08/07/2020 09:27:50 |
5563 forum posts 322 photos | Was the original 1/8" pitch? 3 mm is an awkward number for dials. 2.5 mm would surely be better? Why 16 mm? You can get 3 mm in smaller size. |
john fletcher 1 | 08/07/2020 09:29:21 |
893 forum posts | If you do a search for lead screws , I think you might find some thing like Humber Engineering or Hull Engineering, both ring a bell but can't be sure. Some time ago some here ,spoke of an engineering company in the Hull area who stock lead screws and he was a satisfied customer. John |
Chris Evans 6 | 08/07/2020 09:32:47 |
![]() 2156 forum posts | Not sure of your pitch but I have bought from Automotion Components in the past. |
William Chitham | 08/07/2020 09:59:52 |
156 forum posts 56 photos | Posted by John Haine on 08/07/2020 09:27:50:
Was the original 1/8" pitch? 3 mm is an awkward number for dials. 2.5 mm would surely be better?
For some reason 2.5mm pitch screws are vanishingly rare which is a shame since that is what I need for a Boxford crosslide. W. |
Sandgrounder | 08/07/2020 10:26:33 |
256 forum posts 6 photos | Posted by john fletcher 1 on 08/07/2020 09:29:21:
If you do a search for lead screws , I think you might find some thing like Humber Engineering or Hull Engineering, both ring a bell but can't be sure. Some time ago some here ,spoke of an engineering company in the Hull area who stock lead screws and he was a satisfied customer. John There is a firm in Hull called Kingdton Engineering who make leadscrews http://www.kingston-engineering.co.uk/products.php John |
Niels Abildgaard | 08/07/2020 11:40:23 |
470 forum posts 177 photos | These people also has nuts (Mutter) and trapez 16 * 3.
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old mart | 08/07/2020 13:09:32 |
4655 forum posts 304 photos | If you are replacing both leadscrews, check to see if they are right and lefthanded. If they are and you want to save money by buying one length of leadscrew, you will have to decide which axis will turn in the opposite direction to before choosing. I fitted a 3mm pitch leadscrew to the Smart & Brown model A at the museum to replace the worn out 8tpi one, and made a dial with 118 divisions on it instead of the original 125. This was because the rest of the lathe was imperial. With both leadscrews on your mill metric, you might just as well go with 120 divisoins, for 0.025mm steps. If you end up with 4mm pitch screws, then dials with 160 divisions would give the 0.025mm steps. Edited By old mart on 08/07/2020 13:15:16 |
Pete. | 09/07/2020 03:02:16 |
![]() 910 forum posts 303 photos | Thanks for all the suggestions, I will take a look at all of them when I have 5 minutes. The screw on there is a 5/8" 10tpi that I believe is 1/8" lead, replacing it with a 4mm lead isn't the end of the world, it just allowed for slightly smaller divisions with a 3mm. The company I originally found that does a Tr16 x 4mm works out about £50 - £60 which is pretty reasonable. I'll have a look at some of the suggestions and see what the prices are and leave a note here for anyone else who might have a similar problem. Thanks to all |
Michael Gilligan | 09/07/2020 07:27:53 |
![]() 23121 forum posts 1360 photos | Posted by Pete. on 09/07/2020 03:02:16:
[…] The screw on there is a 5/8" 10tpi that I believe is 1/8" lead … . Sorry, Pete ... I don’t understand that statement ^^^ MichaelG. |
JasonB | 09/07/2020 07:40:30 |
![]() 25215 forum posts 3105 photos 1 articles | Indeed, 10tpi will be 0.100" lead which allows for the handwheel to have a handy 100 divisions. Personally I would avoid half mm pitches or uneven ones and go for 2 or 4mm pitch as it makes it easier to count the number of turns. 2mm should do on a small benchtop machine and allows a handwheel to have quite small divisions and is a lot closer to your existing 2.54mm pitch than 4mm. Not such an issue if fitting a DRO. 4mm pitch would also need a bit more effort to turn, lack feel and be a bit harder to set to an exact position as you will have less rotation for a given amount of movement. Edited By JasonB on 09/07/2020 07:49:08 |
Andy Carlson | 09/07/2020 08:28:42 |
440 forum posts 132 photos | Imperial ACME screws can be had, certainly from HPC Gears in Chesterfield and Kingston Engineering in Hull so the first question is whether you actually want to change it to a metric pitch. Also check whether each screw is right or left handed before investigating prices and availability. |
old mart | 09/07/2020 18:46:50 |
4655 forum posts 304 photos | Having minimum backlash is a huge advantage, and while the mill is in bits, it would be worth seeing if there is room to incorporate backlash adjustment. Also, if fitting DRO's is a likelyhood, then the actual pitch wont matter as you will never be looking at mechanical scales. |
colin vercoe | 09/07/2020 20:11:09 |
72 forum posts | Halifax Rack and Screw company, if they are still in operation. |
Pete. | 10/07/2020 01:04:13 |
![]() 910 forum posts 303 photos | Posted by Michael Gilligan on 09/07/2020 07:27:53:
Posted by Pete. on 09/07/2020 03:02:16:
[…] The screw on there is a 5/8" 10tpi that I believe is 1/8" lead … . Sorry, Pete ... I don’t understand that statement ^^^ MichaelG. Sorry, I'd had long day when I wrote that, I'm not surprised you didn't understand it, I don't. It's a 5/8" leadscrew, 10 turns of the dial moves the table 1" which would make the lead closer to 2.5mm? |
Pete. | 10/07/2020 01:08:29 |
![]() 910 forum posts 303 photos | Posted by JasonB on 09/07/2020 07:40:30:
Indeed, 10tpi will be 0.100" lead which allows for the handwheel to have a handy 100 divisions. Personally I would avoid half mm pitches or uneven ones and go for 2 or 4mm pitch as it makes it easier to count the number of turns. 2mm should do on a small benchtop machine and allows a handwheel to have quite small divisions and is a lot closer to your existing 2.54mm pitch than 4mm. Not such an issue if fitting a DRO. 4mm pitch would also need a bit more effort to turn, lack feel and be a bit harder to set to an exact position as you will have less rotation for a given amount of movement. Edited By JasonB on 09/07/2020 07:49:08 You're right, after some consideration, 2mm lead would be much better. |
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