Guy Lamb | 03/02/2019 12:30:58 |
109 forum posts | Please forgive me if I've posted this in the wrong section, though it is in question form but, could someone suggest where I could look for a printable chart of screw cutting gear ratios for my Myford ML7 ? My machine didn't have a table on the inside of the guard as is usual practice. Trawls on'tinterweb have been fruitless Guy |
Chris Evans 6 | 03/02/2019 12:39:23 |
![]() 2156 forum posts | I am not a Myford man but a search on here should come up with spread sheets giving you what you need. It has been discussed several times. |
Roderick Jenkins | 03/02/2019 13:01:07 |
![]() 2376 forum posts 800 photos | Guy, These are from Bradley's Series 7 Manual:
HTH, Rod Edit: Forgot to add the setups Edited By Roderick Jenkins on 03/02/2019 13:08:04 Edited By Roderick Jenkins on 03/02/2019 13:08:55 |
Vic | 03/02/2019 13:38:26 |
3453 forum posts 23 photos | Well done Rod, that’s a comprehensive answer! |
Brian Oldford | 03/02/2019 13:51:24 |
![]() 686 forum posts 18 photos | Or try http://metal.duncanamps.com/software.php
|
John Purdy | 04/02/2019 22:37:15 |
![]() 431 forum posts 252 photos |
Guy I found that the chart in the gear cover was hard to read with the lighting in my shop so I printed it out 8 1/2 x 11, laminated it, and it hangs on the wall behind the lathe were I can read it while standing it front of the lathe. I have it as a PDF file and can send it to you if you pm me your e-mail address. You can then print it out and laminate it. John |
Lambton | 05/02/2019 09:06:28 |
![]() 694 forum posts 2 photos | Guy. Mau I suggest that you obtain a genuine Myford handbook for your lathe. Obtainable from "new" Myford or even as a PDF from the net. The handbook tells you all you really need to know about using and maintaining the lathe. Eric |
Neil Wyatt | 05/02/2019 11:47:43 |
![]() 19226 forum posts 749 photos 86 articles | You could buy Brian's book and rip the pages out, but he would probably come around and confiscate your lathe as punishment Neil |
norm norton | 05/02/2019 14:46:46 |
202 forum posts 10 photos | I love the last line in the chart showing what you need for 569 TPI (!!!) Can't think of an immediate use for that.. Out of interest, what is the finest thread used on a practical object that is known of? Norm |
not done it yet | 05/02/2019 15:10:12 |
7517 forum posts 20 photos | Only the last line? I reckon the last 15 lines are likely never used for threading! Anyone on here cutting threads of more than 60tpi? Question might be: Is 1.8 thou per rev a small enough increment for all power feed uses? I would have though it would be - at least for most jobs. |
Bob Mc | 05/02/2019 15:13:54 |
231 forum posts 50 photos | Micrometer...?
|
John Purdy | 05/02/2019 17:50:11 |
![]() 431 forum posts 252 photos | The last half dozen or so lines on the inch chart are intended as fine feeds. I only added the TPI out of curiosity! 120 TPI is UNF 000 and 160 is 0000 but obviously a thread of 569 TPI is a little over the top and not much practical use, at least for the kind of work we do! John Edited By John Purdy on 05/02/2019 18:05:18 |
mark costello 1 | 05/02/2019 21:13:57 |
![]() 800 forum posts 16 photos | What would be the thread depth for 569 tpi? Where can I get a tap? |
SillyOldDuffer | 05/02/2019 21:31:36 |
10668 forum posts 2415 photos | Posted by norm norton on 05/02/2019 14:46:46:
I love the last line in the chart showing what you need for 569 TPI (!!!) Can't think of an immediate use for that.. Out of interest, what is the finest thread used on a practical object that is known of? Norm My best offer is 508tpi on a micro-adjuster. I found this on the Kozak website: Our imperial sized matched set micro positioning adjustment screws and unbraked bushings deliver precision smooth movements in the most demanding OEM applications. These matched sets provide the smoothest and most precise movements in the industry with sub micron resolution not commonly found in direct drive hardware offering 127 TPI (.0079" per rev.), 200 TPI (.005" per rev.), 254 TPI (.0039" per rev.), and 508 TPI (.0019" per rev.), taking ultra fine to new industry levels. Not sure how standard the threads are - they also say 'Note: Kozak Micro cannot guarantee that our screws and bushings will be compatible with screws and bushings sold by other manufacturers. ' Dave |
Michael Gilligan | 05/02/2019 21:55:03 |
![]() 23121 forum posts 1360 photos | Oh, of course ... 508tpi is [very nearly] 0.05mm pitch I was surprised to see how moderately-priced they are ! MichaelG. . Edited By Michael Gilligan on 05/02/2019 21:55:36 |
Mike Poole | 05/02/2019 22:34:44 |
![]() 3676 forum posts 82 photos | Posted by mark costello 1 on 05/02/2019 21:13:57:
What would be the thread depth for 569 tpi? Where can I get a tap? I think you might have to make one, at least the gear train has already been worked out for you Mike |
norm norton | 06/02/2019 09:56:06 |
202 forum posts 10 photos | Posted by John Purdy on 05/02/2019 17:50:11:
The last half dozen or so lines on the inch chart are intended as fine feeds. Very rude of us John to find humour in your fine feed numbers and I apologise for starting it. What you have listed is a perfectly logical way of showing the fineness of feed. But I like that idea that at 569 TPI my Myford Series Seven might do better than the 'world's finest known thread' of 508 TPI. I might have a try, should I sharpen the 60 degree Whitworth tool first? |
Brian Wood | 06/02/2019 11:00:22 |
2742 forum posts 39 photos | Posted by Neil Wyatt on 05/02/2019 11:47:43:
You could buy Brian's book and rip the pages out, but he would probably come around and confiscate your lathe as punishment Neil Sacrilege indeed, but it would be your lathe I would impound for the suggestion !! Brian |
Michael Gilligan | 06/02/2019 11:37:44 |
![]() 23121 forum posts 1360 photos | Posted by norm norton on 06/02/2019 09:56:06:
... should I sharpen the 60 degree Whitworth tool first?
.
... but you might check the angle. MichaelG. |
John Purdy | 06/02/2019 20:20:55 |
![]() 431 forum posts 252 photos | Norm Yes your tool will have to be very sharp. The theoretical tip radius for a 569 TPI Whitworth thread is only .000247" and the flat on a 60deg. tool for a UN thread is .000225" wide! Good luck measuring that, at least with our normal measuring kit. About all you could do is to sharpen it to as fine a point as you can and as the theoretical thread depth for a sharp Whitworth thread is only .00173' and a 60 deg. one is .0016 there wouldn't be much of a tip load! John
Edited By John Purdy on 06/02/2019 20:38:11 |
Please login to post a reply.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
Sign up to our newsletter and get a free digital issue.
You can unsubscribe at anytime. View our privacy policy at www.mortons.co.uk/privacy
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.