Making a alternative type parting tool
Steviegtr | 13/09/2022 22:46:34 |
![]() 2668 forum posts 352 photos | I always sort of had problems parting off with the myford lathe. It is not uncommon. I eventually made a rear mounted version of my own design. For some it will be a too long a series to watch. But for others it may give a little insight of how i went about it. Beware it's 3 video's long , but works just as intended now. I show at the end parting some mild steel bar. Since then i got more ambitious & tried a larger 25mm piece of stainless. Also using more steady force. It works perfectly. The cost was very little A bought blade & some inserts + a piece of mild steel bar EN1A i believe. For anyone wanting to have a peek, it's here. Steve. Edited By Steviegtr on 13/09/2022 22:48:57 |
Chris Crew | 14/09/2022 08:34:48 |
![]() 418 forum posts 15 photos | I had second thoughts about the comment I made, so deleted it. Edited By Chris Crew on 14/09/2022 08:38:44 |
Steviegtr | 14/09/2022 17:10:13 |
![]() 2668 forum posts 352 photos | Posted by Chris Crew on 14/09/2022 08:34:48:
I had second thoughts about the comment I made, so deleted it. Edited By Chris Crew on 14/09/2022 08:38:44 Thanks Chris. Back to the Zoo now. HaHa. Take care. Steve. |
Harry Wilkes | 14/09/2022 18:18:46 |
![]() 1613 forum posts 72 photos | Watched the vids well done, like many I had trouble parting so I looked in the box's of bit's that came with my lathe found a Myford rear parting off tool post problem gone ! H |
Howard Lewis | 16/09/2022 15:01:41 |
7227 forum posts 21 photos | Made a rear toolpost for my ML7, and had no more parting problems. (Ruined an inserted carbide parting tool in the front post! ) Having upgraded to something larger, one of the first jobs was to make a four way indexing rear toolpost, to take the OLD HSS parting blade (With Zero top rake ) So good that I now use power feed tom part off! If you can, fit and use a rear toolpost Howard |
Steviegtr | 16/09/2022 15:05:23 |
![]() 2668 forum posts 352 photos | Posted by Howard Lewis on 16/09/2022 15:01:41:
Made a rear toolpost for my ML7, and had no more parting problems. (Ruined an inserted carbide parting tool in the front post! ) Having upgraded to something larger, one of the first jobs was to make a four way indexing rear toolpost, to take the OLD HSS parting blade (With Zero top rake ) So good that I now use power feed tom part off! If you can, fit and use a rear toolpost Howard I'm glad you posted this as I wondered if using the power feed was plausible. Steve. |
Howard Lewis | 16/09/2022 15:13:04 |
7227 forum posts 21 photos | The good thing about using power feed is that the feed is constant and consistent, so ,there should ,be no fear of letting the tool rub, or of over feeding and having a dig in. If no power feed is available, the skill to feed steadily, and not too fast, needs to be acquired. (One of the first things that I was taught in the Training School ) One advantage of the rear toolpost is that with the tool, being inverted, the swarf falls out, with less fear of clogging the cut. Howard Edited By Howard Lewis on 16/09/2022 15:14:52 |
Steviegtr | 16/09/2022 15:15:07 |
![]() 2668 forum posts 352 photos | Thanks for that Howard Steve |
David George 1 | 16/09/2022 21:45:12 |
![]() 2110 forum posts 565 photos | I have made a rear toolpost from a casting base and mild steel top clamps for a blade and tip. Never been a problem since I made it and I can slide it in and out to suit diamiter of job. David |
not done it yet | 16/09/2022 23:28:26 |
7517 forum posts 20 photos | Posted by Steviegtr on 16/09/2022 15:05:23:
I'm glad you posted this as I wondered if using the power feed was plausible. Steve. Just make sure that when the cutter reaches the centre, if cutting a solid bar, that the cross slide still has some travel. If not, you will likely break something - cross slide power feed drive, feed nut threads or something else. |
Steviegtr | 17/09/2022 00:16:59 |
![]() 2668 forum posts 352 photos | That was my thinking. Maybe for now I will do it manually. I already sprained the leadscrew with the front parting tool fiasco. It's getting eased now but was stiff for a while. Steve. |
Steviegtr | 17/09/2022 00:17:43 |
![]() 2668 forum posts 352 photos | Posted by David George 1 on 16/09/2022 21:45:12:
I have made a rear toolpost from a casting base and mild steel top clamps for a blade and tip. Never been a problem since I made it and I can slide it in and out to suit diamiter of job. David Looks good David. Steve. Edited By Steviegtr on 17/09/2022 00:18:15 |
John Rutzen | 17/09/2022 09:20:11 |
411 forum posts 22 photos | I have a rear parting toolpost I made for my Harrison M250 but I find that it isn't dig-ins that are the problem. What happens is that a bit of swarf welds itself in the cut , jamming everything up. So I am very cautious about parting off, I keep my hand on the clutch lever all the time so I can stop it quickly if it goes wrong. |
Alan Jackson | 17/09/2022 10:19:19 |
![]() 276 forum posts 149 photos | How about doing this, it can be mounted on the front side if the chuck is screwed on or the rear side if the chuck has a bolted or camlock mounting. https://www.youtube.com/watch?v=S8HvS13L7MU Alan |
Tony Pratt 1 | 17/09/2022 11:02:22 |
2319 forum posts 13 photos | Posted by John Rutzen on 17/09/2022 09:20:11:
I have a rear parting toolpost I made for my Harrison M250 but I find that it isn't dig-ins that are the problem. What happens is that a bit of swarf welds itself in the cut , jamming everything up. So I am very cautious about parting off, I keep my hand on the clutch lever all the time so I can stop it quickly if it goes wrong. What cutting oil or coolant do you use? Tony |
Chris Crew | 17/09/2022 14:34:00 |
![]() 418 forum posts 15 photos | "So I am very cautious about parting off, I keep my hand on the clutch lever all the time so I can stop it quickly if it goes wrong". May I suggest that may well be your problem. You have to be a little fearless when parting-off, once the tool starts cutting you have to keep it cutting, use plenty of coolant/lubricant and if you are parting-off a larger diameter don't be afraid to retract the tool and increase the speed as the diameter decreases. Plunge the tool in to start cutting again. You really should be laughing at parting off on a lathe like the Harrison 250. |
Howard Lewis | 17/09/2022 17:21:20 |
7227 forum posts 21 photos | Agreed! I always lubricate by some means (A steady drip, of soluble oil syphon fed from an overhead bottle, or ordinary lub oil applied frequently with a brush. And NEVER let the tool rub, keep it cutting. My parting tool has Zero Top Rake. My sliding power feed is 0.0022"/rev so the cross feed is probably 0.0045" or 0.0011" per rev (Not sure which ) but it works for me. Howard Edited By Howard Lewis on 17/09/2022 17:21:57 |
John Rutzen | 17/09/2022 17:33:28 |
411 forum posts 22 photos | Yes, maybe I need to arrange a constant coolant drip, I just apply water soluble stuff with a syringe. Its difficult to keep it in the cut because it gets flung out. I think I don't use it much because it's a faddle to clean the machine tray and I don't like it being oily. I've never dared to part off under power feed! Edited By John Rutzen on 17/09/2022 17:34:55 |
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.