Rexvalter VF-118 lathe (was: old Myford Ml7)

[slim_boy_fat]

Scenario - you are doing a cut on a long bar on auto feed. While it's cutting you decide to get ready for the next process & without thinking you reach across the spinning bar to get the chuck off the tool board. Next thing you know you are meeting the surgeon who had the task of trying to reattach your arm after the lathe ripped it off!

We all need one of these........ https://www.ebay.co.uk/itm/Lathe-Ac...e=STRK:MEBIDX:IT&_trksid=p2055119.m1438.l2649

 

[MrFluffy]

I'm not sure I would put a tool board behind a lathe, too dangerous. Scenario - you are doing a cut on a long bar on auto feed. While it's cutting you decide to get ready for the next process & without thinking you reach across the spinning bar to get the chuck off the tool board. Next thing you know you are meeting the surgeon who had the task of trying to reattach your arm after the lathe ripped it off!

But I would agree that a splashback is essential, especially given the immaculate condition of your workshop!

Ive had my lathe tooling on a board behind the machine for 15 years now. Never once have I been dumb enough to even be tempted to reach across and lift a chuck off its position to change on a machine already set up for doing a job. Taper tooling for the tailstock yes, who doesnt hot swap that when needed and thats off to one side, but chucks and faceplates etc with their two handed lifts? Even my toolpost blocks sit on the wall mount until the machine is powered off, let alone out of gear. If I need a few different ones for a job, they sit in the tray at the tailstock end.
Think I'd class that under darwin award material if someone told me it happened to them, and maybe its time to get a rubber room and a jacket to stop them cutting themselves, certainly not own anything as dangerous as a metal workshop...

Splashguards, well, theyre great, and good for protecting the celing, in fact after one particular incident I now have a dirty marker that divides my whole workshop into two along the axis of the chuck

 

[DennisCA]

This lathe came with a tool tray that mounts behind the headstock. I removed it as I am keeping the lathe against the wall. Not sure were to put it, doesn't fit on the tool wall either.

I am thinking of how to store the quick change tool posts, I think a simple french cleat will work best, just hang them on that.

 

[GW8IZR]

My workshop, the one with spinny round stuff is tiny and I have to use all manner of places to store stuff. I believe its safe enough as you just adapt. For example I have the same standing place to use the lathe as the mill, take a step sideways and I'm at the pillar drill, turn 180 degrees and there is the bench and vice. You just have to adapt and its safe 'cos unlike a factory you only need to do one thing at a time.

 

[addjunkie]

I keep chucks face plate, steadies etc big stuff on a board raised about 6 inches up under the machine bed. Small stuff i keep on a tray mounted ontop of the far right of the splash guard. But going forward, ive an old clarke rool cab the will roll nicely between lathe and mill, because no matter what I do need some where to put mic, vernier, cupa, glasses etc in easy reach. The head stock isnt the place.

 

[DennisCA]

Does anyone have any idea on how to remove the secondary shaft on this lathe? The manual did not say. There are two set screws on each side and the bigger gear seems to be able to slide, so I figured the bearing would be tapped out from right to left, but it doesn't seem to want to move more than a little, and I don't want to hit too hard. I wanted to try and remove the secondary shaft to see if the noise it makes is from the gears. I am quite certain it's what it is, but I want to make sure it's not the bearings.

 

[Turbo]

Before you start stripping anything try spraying some anti-fling chain lube on the left-hand set of gears & see if the noise changes, being careful not to get any on the belts! The large gear on the right looks like plastic so you could try some silicon oil or grease on that set of gears.

If you want to remove the shaft it may come out the rhs of the casing. Is outer diameter of the small gear smaller than the outer dia of the bearing? If so the whole shaft may drive out from the large gear side, taking the small gear & rhs bearing with it & leaving the large gear in the casing.

 

[DennisCA]

I'll have to see about finding some stuff like that, don't go into town every day, or even every week.

Took a video just now, checking the run-out on the spindle contact surface, dunno if that is acceptable, also don't know if the crappy mount might be doing it, you can also hear what it sounds like:

 

[Pete.]

Doesn't really matter, fit the backplate and face it off. The face of the backplate will run true and since it will seat at the same spot every time it will always run as true as the limits and condition of the machine allow.

 

[Richiew]

Nothing to worry about. One thousandth of an inch =0.0254mm and I think the movement on your metric DTI is about half of that which is fine for a hobbyist.
Your three jaw chuck will do well to get within 3 thou run out anyway.

 

[Pete.]

The problem with that face runout is that it will cause runout in the part to become greater as the distance from the chuck increases. Chuck jaw runout caused by scroll wear/clearance should measure largely the same along the part until the wear becomes chronic.

 

[addjunkie]

Does anyone have any idea on how to remove the secondary shaft on this lathe? The manual did not say. There are two set screws on each side and the bigger gear seems to be able to slide, so I figured the bearing would be tapped out from right to left, but it doesn't seem to want to move more than a little, and I don't want to hit too hard. I wanted to try and remove the secondary shaft to see if the noise it makes is from the gears. I am quite certain it's what it is, but I want to make sure it's not the bearings.

I assume in the video that is running with the back gauge engaged. Doesnt actually sound that bad. Check there is some clearence in the gears in the end cover, many folks asemble that lot a little tight. Try running it at the highest speed and machine a piece of bar, mic both ends see what its like.

How is the large gear secured to the shaft. It will be pinned or grub screwed somewhere to stop it moving laterally too far, from memory last i took something similar apart, i had to remove this, cant remember if it was a screw, pin, dowel tapered. But once out the shaft knocked out, towards yhe end that had a bearing cover one, to retain it.

 

[DennisCA]

If by back gauge you refer to the secondary shaft, then yes it is always engaged no matter how I turn the clutch. And the gears inside the cover on the left side of the head stock, I disconnected those so only the two shafts in the spindle moved, and it made no difference in the sound.

I wasn't able last night to determine how the large gear was secured to the shaft. Kinda leaving it alone for now, works best if I stop on something and look at it later, then I might have an aha moment.

 

[Pete.]

The manual didn't tell me jack about this, but what is the purpose of the 2nd shaft?

Going by the swarf that's collected on the left hinge I would say that there's a good chance that your noise is caused by bits of swarf hammered into the teeth of the big black gear and it's mating pinion.

If I had to guess at how it disassembles this is how it looks to me - the shoulder on the right side of the big gear means that the gear is probably pressed against that shoulder and drive taken by a keyway. The shoulder, the smaller gear on the other end of the shaft and the shaft bushing in the front of the headstock all look similar size so it's likely that the shaft will drift out towards the front leaving the big gear behind.

 

[DennisCA]

Hey that worked! You were right it did went out that way and the gear had a keyway. Put the shaft and gears in an ultrasonic cleaner with degreaser, the big gear isn't metal either, I thought it was but it's some kind of dark plastic type material.

Anyway with the shaft removed the sound is still there, but only with the clutch engaged on the left side, if it is not engaged at all, or on the right side, there's no noise. So it seems the clutch is the noise maker.

 

[DennisCA]

There, cleaned and degreased, now to oil them up and reassemble. I also cleaned all the loose change wheels while I was at it.

 

[Pete.]

With the selector (not a clutch) engaged to the left you're putting drive to the spindle. With it not engaged the spindle should not be turning, the belt pulley should be free turning on the spindle so that points to the spindle bearings as the source of the noise.

Given the amount of grease that's been pumped through the rear bearing I would suspect that the rear bearing has been full of hard-dried grease and someone has tried to shut it up by stuffing a load of new grease through it. Same could be true for the front bearing and in fact the kick you're seeing in the dial gauge might suggest the same. Sorry to say it but if that was my machine the spindle would be coming out and the bearings inspected.

 

[DennisCA]

Actually the spindle turns with the selector held in the middle too. But I suppose the spindle's coming apart to make sure.

 

[Pete.]

That will just be by friction. It shouldn't be driving when it's not engaged.

 

[RichardM]

If it's underdrive with an intermediate shaft as Boxford underdrives. My old one was a lot quieter after I changed the bearings on the intermediate shaft.