JP Santos | 23/09/2018 15:39:09 |
49 forum posts 9 photos | Hi all ! I decided to upgrade my little southbend lathe to something with a few more capabilites and ended up with this Boxford at a very good price. Everything works as it should and I'm looking forward to give a go at screw cutting. However.. she has a huge amount of backlash on the cross slide... I think the backlash on the cross slide is the most important as when turning any material, it jumps back.. ok you could work taking in account this, but is not ideal... Is there a away to fix all this? I see all the videos on youtube where people set there work pieces, then turn dials to zero it and cut thous of an inch at the time perfectly, and I would like to do that, but with all this play I won't be able to... I have taken some photos and also done a video so it's easy to see what I'm talking about as I'm pretty rubbish with the technical terms. If there was anyone local to Newbury, Berkshire that would be willing to help me I have some bits I could trade? I have a milling attachment for a myford (was hoping it would fit the boxford but doesn't look like), a spare Boxford model C Apron and a lead screw... btw, I use the lathe on my old harleys that range from 1951 to 1976. thank you! Edited By JP Santos on 23/09/2018 15:39:58 Edited By JP Santos on 23/09/2018 15:41:04 |
Dave Halford | 23/09/2018 16:28:31 |
2536 forum posts 24 photos | My Rockwell Delta 10" is just like that, however when you wind it to it's extremities of travel the backlash disappears which points to the lead screw rather than the nut being the culprit. Make sure you source the right bit :O) |
Neil Wyatt | 23/09/2018 16:33:55 |
19226 forum posts 749 photos 86 articles | That isn't a worn nut, it's badly adjusted where the spindle goes through the fixed bearing, you can see the handle and dial moving back and forth. No wonder it jumps, winding in you will push it forwards and it will slip straight back when it starts cutting. You need adjust the handle/dial assembly and get rid of that slop. Neil |
JP Santos | 23/09/2018 17:45:47 |
49 forum posts 9 photos | Thanks for the replies gents. I just went over to the garage to check it. Neil, you are correct, the handle and dial move back and forth, I took it out and seems like it's due to a little gap here where I'm pointing with the allen key... perhaps put a little shim there? But, besides that backlash there, also seems there's more. Thanks for your replies and suggestions. |
Kettrinboy | 23/09/2018 19:30:25 |
94 forum posts 49 photos | Once the handwheel /dial assembly is adjusted properly so that there is no movement there the crosslide will probably still move slightly due to wear in the screw and nut , on some lathes the nut is split so that you can close it slightly to take up wear , I suppose 10 to 20 thou of backlash is pretty common on a well used lathe that's about what my Harrison L5 shows but this has a split nut so I could improve it when I get round to it, how much play is too much , I would say over 60 thou is getting towards the top end of what I would live with , but with no split nut or any way to split it and close it a bit , your only recourse is a new screw and nut or a good secondhand one. regards Geoff Edited By Kettrinboy on 23/09/2018 19:31:01 |
JP Santos | 23/09/2018 19:55:04 |
49 forum posts 9 photos | Sorry to sound massively dumb here, how do I adjust the wheel/dial aseembly? I have a spare saddle and top slide for a Boxford and I think that one is pretty tight, so I'll see how difficult is to swap the lead screw and nut... where would one go to buy new parts for it please? thanks! JP |
Bazyle | 23/09/2018 20:29:56 |
6956 forum posts 229 photos | Right there's a few points that you need to get to know. The backlash comes from two areas, the fit of the nut on the screw and the setup of the bearing as you have found. |
Martin 100 | 23/09/2018 20:33:03 |
287 forum posts 6 photos | You are not looking in the right area. Look instead at the handwheel end of the cross slide screw. Unscrew the chromed slotted 'nut' (anticlockwise with something that doesn't damage the slot) Now undo the hex socket grubscrew that holds the handwheel to the cross slide screw. Now fit the handwheel to remove all slack, tighten the grub screw Refit the slotted nut. As for spares, you are out of luck for that area of the lathe because that type of cross slide / dial was discontinued in the early 1960's |
JP Santos | 23/09/2018 21:01:45 |
49 forum posts 9 photos | Evening gents!! Just got back in from the garage after reading your posts, it's sorted! So I first done the adjustment on the dial, by undoing the grub screw (luckily I work on Harleys so it's all imperial here) on the dial side, by pushing the dial forward while pulling on the handle, then done the grub screw back in and the slop on the dial/handle was completely gone. However.. there was still the backlash on the cross slide.... Started to taking it apart thinking I could use the whole lead screw and nut... wrong! the lead screw being from a model C doesn't have the gear that engages on the apron to give the auto cross slide... thanks for the help on directing me where to look. Next thing to look at is at certain speeds I have quite a lot of gear noise, I can't remember for sure but I think it's when at the higher speeds, if I engage the auto feed lead screw gears, it's quite noisy.. What kind of lubricant can I use on all the gears? gearbox and on the side? or should it be grease? |
Bazyle | 23/09/2018 21:06:44 |
6956 forum posts 229 photos | Part 2 Here's a useful diagram but it is really annoying that they don't tell you the threads of fixings. That's it for adjustment. The nut is not split for taking up wear. The screw itself will become worn in the middle over time so that provides another source of problems. Southbend did expect there to be backlash and if you read their instruction manual " know your lathe" there is an instruction to set the tool height above centre line contrary to the normal instruction, This upsets the purists but is very sensible on all lathes when done with some thought. Above centre there is a component of force on the tool outward which ensures the backlash is taken up. |
JP Santos | 23/09/2018 21:11:42 |
49 forum posts 9 photos | Thanks for that, I did find that diagram earlier, at least is good to know that if that backlash comes back I can buy a new lead screw and nut.... I will have a read on the "know your lathe manual" - it was given to me by the previous owner of my south bend lathe when I bought it. Never got to read it in details as the little lathe was in pretty good condition and I used it for basic jobs. The Boxford now will allow me to explore more the world of lathes, specially looking forward to some screw cutting. |
Bazyle | 23/09/2018 21:26:08 |
6956 forum posts 229 photos | Part 3 but on other topics a Boxford owner needs to know. The screw in the middle of the star wheel that engages the feed clutch is******* left hand thread********. The grubscrew on the right of the apron that holds the halfnut engagement lever in place has another gubscrew deep down the hole, The backgear lever on the front has a brass slipper running in a groove in the bull wheel. Check this isn't worn as the pin it pivots on will score the groove. Oil the groove even if not using backgear. The clutch is not there to let you walk away and let the saddle thump the saddle stop which will move if you do. You adjust it to just not slip and keep your hand on the feedwheel letting it run through your fingers. As you come close to the stop you grip the wheel and slow the saddle slipping the clutch so it gently touches the stop. Don't use grease or motorbike chain oil on changewheels as it holds dust and swarf. Use normal thin oil and use it occasionally to wash off the crud. Ditto in the apron, QCGB and leadscrews. Way oil for the ways. The apron probably leaks so put a dish under it. |
JP Santos | 24/09/2018 13:16:20 |
49 forum posts 9 photos | Hi again, thanks for the last post, I shall take note of that advice/tips on a note pad and keep it handy.
really appreciate the help given yesterday. many thanks! JP |
Jeff Dayman | 24/09/2018 13:56:02 |
2356 forum posts 47 photos | There are a large number of spare parts available in the US for South Bend lathes, which your Boxford is based on. You might be wise to join Practical Machinist website in USA who have a sub forum for South Bend. The guys there can probably answer any questions you may have. |
Bazyle | 24/09/2018 14:11:51 |
6956 forum posts 229 photos | Oh I forgot to mention one of the big gotchas being differences between SB and Boxford. The spindle nose diameter and tpi is the same except the SB is UNC and the Boxford is Whitworth so the facepates etc don't fit. |
thaiguzzi | 26/09/2018 10:10:14 |
704 forum posts 131 photos | Posted by Bazyle on 23/09/2018 21:26:08:
Part 3 but on other topics a Boxford owner needs to know. The screw in the middle of the star wheel that engages the feed clutch is******* left hand thread********. The grubscrew on the right of the apron that holds the halfnut engagement lever in place has another gubscrew deep down the hole, The backgear lever on the front has a brass slipper running in a groove in the bull wheel. Check this isn't worn as the pin it pivots on will score the groove. Oil the groove even if not using backgear. The clutch is not there to let you walk away and let the saddle thump the saddle stop which will move if you do. You adjust it to just not slip and keep your hand on the feedwheel letting it run through your fingers. As you come close to the stop you grip the wheel and slow the saddle slipping the clutch so it gently touches the stop. Don't use grease or motorbike chain oil on changewheels as it holds dust and swarf. Use normal thin oil and use it occasionally to wash off the crud. Ditto in the apron, QCGB and leadscrews. Way oil for the ways. The apron probably leaks so put a dish under it. I was going to reply, but Bazyle has said everything and more perfectly. +1. Keep the grease for your Harleys, it has no place on or near a lathe. Nice Shovel in the background by the way.... |
JP Santos | 26/09/2018 10:28:38 |
49 forum posts 9 photos | Thank you |
thaiguzzi | 27/09/2018 15:56:01 |
704 forum posts 131 photos | Posted by JP Santos on 26/09/2018 10:28:38:
Thank you Yeah i know, very very nice. |
JP Santos | 29/09/2018 12:07:06 |
49 forum posts 9 photos |
Hi all again, was going to open a new thread to discuss something else, but probably not worth as it probably has a simple answer, so I'll try on this one instead. I see on youtube videos people setting their workpiece, then the cross slide and then they zero it by turning the graduated dial. I think this is very useful in order to know how much you taking out of your piece and keep consistency, but on my Boxford I can't rotate the dial, unless I undo the grubscrew - which I think it's not the correct way? Is there a way to convert my boxford to have those graduated dials where I can turn it to zero?
thanks in advance |
Clive Brown 1 | 29/09/2018 14:52:03 |
1050 forum posts 56 photos | On my ME10, the dials are friction loaded. Under the grub-screw is a small spring and a brass disc pressing on the shaft.The friction pressure is controlled by adjusting the grub-screw,(hope my memory is correct). Sounds as if your grub-screws are over-tight. Try slackening them. It's also possible that your springs and pads are missing. Hope that helps, Clive |
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