neural revolt
Plastic
- Joined
- Apr 2, 2020
Yes, yes same old problem.
It's a Maximat Super 11 (I have seen the other threads, they don't answer my question) and I detected some taper in it by machining a long piece of stock at two ends, about 30cm apart. About .02mm.
Now here's my dilemma.
The instruction book walks you through an alignment procedure that relies on two thick steel block/plate (one for tail one for head stock) you are supposed to make (lathe didn't come with these to me) and install under the cabinet top plate with two bolts coming from above to clamp the lathe at one point underneath the head stock and one point at the tail stock. Now, at the head stock you are supposed to drill and tap the plate for two bolts to come up from underneath, through the cabinet top and pushing up against the headstock casting feet on either side of the clamp down bolt. These two bolts are used to adjust for twist in the bed, I guess.
Now, that is fine, I get it, but my cabinet doesn't have the two holes these two screws are supposed to poke through the cabinet top and the whole lathe is in such a pristine condition I can't bring myself to start putting holes in it.
Another detail, just in case. My cabinet (the original factory Emco) has two thick (50x5mm) flat reinforcing bars running (welded every 10cm or so thin side on) under the top plate on the head stock side to give it some rigidity I suppose (it's all obviously factory) but like I said, no holes for these two adjusting screws. I mention this because I am not sure all cabinets are the same (after all mine doesn't have the two holes or provision for adjustable feet as pictured in the manual).
So I made these two blocks from 25mm thick steel, but only used the clamping bolts through as yet.
I put the cabinet on some sturdy frames with adjustable feet just to keep it off the ground and leveled everything as best I can (no machinist super duper level here). I used a precision digital level (or three) and I get consistent readings along the bed, all at 0 (with whatever precision these things have - my guess is pretty good but not prefect).
I just wanted to see if I had any twist to worry about before I started drilling or coming up with a solution.
Well, it seems I do. I detected some taper in it by machining a long piece of brass stock at two ends, about 30cm apart (tail stock is properly aligned). About .02mm, thinner at tail stock end.
Adjusting the feet on the frames I made (there's eight of them) works brilliantly to move the whole lathe in the desired position, but it does nothing to twist. So I loosened all the bolts in the stand/cabinet, chip tray, etc. just to see if that makes any difference, but it doesn't. Measured with all these loose/tightened up everything comes up the same so I would say the twist is not imparted by the stand pulling the lathe this way or that.
The cabinet is made of pretty thick steel (3mm), but I would say the way the lathe is bolted down (two bolts, one at either longitudinal end) doesn't lend itself to correcting twist so I'd say I need to use the twist correcting method suggested in the manual.
Now as I said, I would like to avoid drilling the cabinet, so I was thinking of getting a thick steel plate (say 25mm or so) to run underneath the full length of the lathe from head stock to tail stock and sandwich that in between the lathe and cabinet and put the two adjusting bolts at the head stock end through that. Not sure how I would get at the heads to make adjustments, maybe mill some pockets in the sides of this plate so I can put a spanner on or some such, but that's detail.
And yes, I am aware that some random piece of (most likely cold rolled) steel will come with its own twist, but I hope the adjustability I gain with the two bolts will be enough to take that out plus I also expect rigidity to increase a little bit (not that I noticed any problems with the kind of hobby work I do).
And I forgot to say, the ways have absolutely no sign of wear. As in they look like the lathe has never been used.
What do people think about this idea?
It's a Maximat Super 11 (I have seen the other threads, they don't answer my question) and I detected some taper in it by machining a long piece of stock at two ends, about 30cm apart. About .02mm.
Now here's my dilemma.
The instruction book walks you through an alignment procedure that relies on two thick steel block/plate (one for tail one for head stock) you are supposed to make (lathe didn't come with these to me) and install under the cabinet top plate with two bolts coming from above to clamp the lathe at one point underneath the head stock and one point at the tail stock. Now, at the head stock you are supposed to drill and tap the plate for two bolts to come up from underneath, through the cabinet top and pushing up against the headstock casting feet on either side of the clamp down bolt. These two bolts are used to adjust for twist in the bed, I guess.
Now, that is fine, I get it, but my cabinet doesn't have the two holes these two screws are supposed to poke through the cabinet top and the whole lathe is in such a pristine condition I can't bring myself to start putting holes in it.
Another detail, just in case. My cabinet (the original factory Emco) has two thick (50x5mm) flat reinforcing bars running (welded every 10cm or so thin side on) under the top plate on the head stock side to give it some rigidity I suppose (it's all obviously factory) but like I said, no holes for these two adjusting screws. I mention this because I am not sure all cabinets are the same (after all mine doesn't have the two holes or provision for adjustable feet as pictured in the manual).
So I made these two blocks from 25mm thick steel, but only used the clamping bolts through as yet.
I put the cabinet on some sturdy frames with adjustable feet just to keep it off the ground and leveled everything as best I can (no machinist super duper level here). I used a precision digital level (or three) and I get consistent readings along the bed, all at 0 (with whatever precision these things have - my guess is pretty good but not prefect).
I just wanted to see if I had any twist to worry about before I started drilling or coming up with a solution.
Well, it seems I do. I detected some taper in it by machining a long piece of brass stock at two ends, about 30cm apart (tail stock is properly aligned). About .02mm, thinner at tail stock end.
Adjusting the feet on the frames I made (there's eight of them) works brilliantly to move the whole lathe in the desired position, but it does nothing to twist. So I loosened all the bolts in the stand/cabinet, chip tray, etc. just to see if that makes any difference, but it doesn't. Measured with all these loose/tightened up everything comes up the same so I would say the twist is not imparted by the stand pulling the lathe this way or that.
The cabinet is made of pretty thick steel (3mm), but I would say the way the lathe is bolted down (two bolts, one at either longitudinal end) doesn't lend itself to correcting twist so I'd say I need to use the twist correcting method suggested in the manual.
Now as I said, I would like to avoid drilling the cabinet, so I was thinking of getting a thick steel plate (say 25mm or so) to run underneath the full length of the lathe from head stock to tail stock and sandwich that in between the lathe and cabinet and put the two adjusting bolts at the head stock end through that. Not sure how I would get at the heads to make adjustments, maybe mill some pockets in the sides of this plate so I can put a spanner on or some such, but that's detail.
And yes, I am aware that some random piece of (most likely cold rolled) steel will come with its own twist, but I hope the adjustability I gain with the two bolts will be enough to take that out plus I also expect rigidity to increase a little bit (not that I noticed any problems with the kind of hobby work I do).
And I forgot to say, the ways have absolutely no sign of wear. As in they look like the lathe has never been used.
What do people think about this idea?