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Help with new lathe ways not straight... ughgh!

Is the lathe properly leveled? Would seem odd that its only twisted at the end, but it could depend on how stiff it is at that section vs how its supported.
 
The observation I saw in the video is, the surface he has the test indicator running on, that surface may be at fault. That surface could have been milled and a step left, or it was planed on a worn-out machine. I doubt that surface was ground at the same time the ways were ground. It may have been parallel and co-planer when setup and ground, and the operator knew this setting it up for grinding, too. Why finish grind that surface? It doesn't do anything for the saddle riding on the ways next to it. I suspect his ways are fine after this observation of the video. Just my opinion.
 
The observation I saw in the video is, the surface he has the test indicator running on, that surface may be at fault. That surface could have been milled and a step left, or it was planed on a worn-out machine. I doubt that surface was ground at the same time the ways were ground. It may have been parallel and co-planer when setup and ground, and the operator knew this setting it up for grinding, too. Why finish grind that surface? It doesn't do anything for the saddle riding on the ways next to it. I suspect his ways are fine after this observation of the video. Just my opinion.
The lathe is brand new. The surface I indicated off was ground with the Vway. It's literally the same part of the way, just the vertical section. The saddle tapers in on the way, it's clearly twisted or hasn't been machined straight. Technician is coming out tomorrow.
 
The lathe is brand new. The surface I indicated off was ground with the Vway. It's literally the same part of the way, just the vertical section. The saddle tapers in on the way, it's clearly twisted or hasn't been machined straight. Technician is coming out tomorrow.
I think he's questioning that you are measuring against a non-reference surface. It doesn't mean you are wrong about errors, just that the side of a Vway cannot be depended on to make the conclusion you came to. It is clear that you believe that it should be usable as a reference, but it can't unless the manufacturer explicitly says they have ground it to be used as that. The consensus here is that it is unlikely that they have ground it for that usage and the errors you are seeing are not conclusive. When the engineer comes to look at this for you I hope you will understand this point and are open to how he is going to validate any error. The Vway itself, or a precision fixture held in the headstock are going to tell a fuller story. I hope this works out for you.
 
I think he's questioning that you are measuring against a non-reference surface. It doesn't mean you are wrong about errors, just that the side of a Vway cannot be depended on to make the conclusion you came to. It is clear that you believe that it should be usable as a reference, but it can't unless the manufacturer explicitly says they have ground it to be used as that. The consensus here is that it is unlikely that they have ground it for that usage and the errors you are seeing are not conclusive. When the engineer comes to look at this for you I hope you will understand this point and are open to how he is going to validate any error. The Vway itself, or a precision fixture held in the headstock are going to tell a fuller story. I hope this works out for you.
I see your point. I really don't have enough indicators to go on, I can only measure of the saddle, and off the chuck/workpiece/test bar. I get what you are saying now and probably responded when I was full of frustration and I apologise for coming off gruff. Certainly not my normal personality. :D

I'll post his conclusions tomorrow, hopefully we can sort this out! :D
 
If the lathe cuts straight and then to a taper then certainly there is something wrong and the manufacturer /warranty should fix it. The bed is hardened. I am not saying that you are wrong about the measurement, just that the saddle does not ride on that side, but does ride on the top/sides of the V..
The bed width is stated .960, (I think), does it measure to be that, or at least straight?
Is the machine made like a replaceable way machine with the bed ways bolted in? If so could the machine have been poorly assembled, or banged around at shipping and knocked out of whack/or burned when grinding the error side...but out of whack for a short distance would be very odd.
If one looks at photo #29, that gives some/ a rough idea of how the bed is made.
*Again it should be the vendor or manufacturer who should fix it.

RE: QT Op: Technician is coming out tomorrow. "Good."
A good thread and I am anxious to find the results
 
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I see what Matt is saying and what Tyrone is. I have also seen the lousy fit of those gaps. They screw them down to the lousy surface and pin it. Then grind it assembled. I bet the bottom of that lathe bed is lousy too. So when it was ground it had a burr or low spot. It's apart. Stone off the obvious burrs, assemble it leaving out the pins, Measure and align it like Matt says. get it as good as you can and if it needs stoning, stone it. I have also seen where a tool room foreman screwed one up trying to fit one. Some of these supposed machinists are crude as hell, I was called to fix his F up. I had to scrape the bottom and then shim it to get it to align properly. There are no easy answers here gentlemen.
 
In my defence I‘ve only ever worked with companies that installed lathes that had been made by reputable, mainly European, makers. Home shop style lathes don’t really exist in the UK, apart from the “ Myfords “. If you want something bigger there were plenty of “ Harrison “, “ Colchester “ or even “ DSG’s “ to go around. So I expect a pretty high standard of machining and finish. To be honest I never came across more than a couple of Chinese made lathes and they were of the larger CNC type so they were built to reasonable standards.

Regards Tyrone.
 
In my defence I‘ve only ever worked with companies that installed lathes that had been made by reputable, mainly European, makers. Home shop style lathes don’t really exist in the UK, apart from the “ Myfords “. If you want something bigger there were plenty of “ Harrison “, “ Colchester “ or even “ DSG’s “ to go around. So I expect a pretty high standard of machining and finish. To be honest I never came across more than a couple of Chinese made lathes and they were of the larger CNC type so they were built to reasonable standards.

Regards Tyrone.
Tyrone, you are lucky to not have had to service modern manual equipment.
Our local machinery repair guy had to rebuild and re design parts of a brand new Summit lathe’s apron a few years back. The seller took no responsibility as they were just a reseller.
The OP may run into the same issue with the firm that sold him the taper cutting lathe.
 
Will be interested to hear what the Tech says.
The surface you were indicating is clearance and although its nice to see zeros, it wouldn't affect the passage of a well fitted carriage riding sound ways. If it were me id level the machine, check the carriage for yaw, indicate the gap on the sliding surfaces and if all's well move onto head alignment. It'll no doubt be adjustable on your machine.
'Good for the price' might mean just that. Focus on what matters and leave the indicator on the shelf for what don't.

GL
 
I would have thought this would have been asked before now...

You say in the first post that the lathe is cutting a taper of 0.1 mm in the last 30mm of the cut. You do not say what material you are cutting, how it is being held, what its diameter is, if it is solid or a tube, what it is being cut with, or if the .1 mm difference is on the diameter or the radius.

There are a lot of things which can produce a taper near the headstock. The video shows a piece of small diameter stock in the chuck, and a carbide insert tooling. Carbide insert tooling requires more force than HHS to cut. This pushes the work away from the bit, and bends the shaft being turned away from the bit- unless it is being supported by a tailstock center or a properly adjusted follow rest. Because the stock pushes away, the cut is not as deep, and the diameter is larger than anticipated. As the cutting bit approaches the headstock, the shaft cannot flex away from the bit as much, and cuts deeper, resulting in a greater reduction in diameter. The result is that the work diameter is reduced near the chuck. The lathe has cut a taper near the headstock- and it has nothing to do with the ways.

To compare the relationship between the carriage over just the bed and the bed /gap section: Take some large diameter stock- solid or tube with endcaps- and turn it between centers. Make your own temporary headstock center using some scrap stock held in the chuck so you know it is on axis. Leave the 1/3 of the stock near the headstock uncut. From the tailstock in mark every cm, number the marks, measure and record the diameter over the marks. Now take your test indicator and mount it at the same level as the cutting bit, zero it at the 0 mark at the tailstock, and proceed to record what it shows as it runs down the same path the bit took. This will allow you to see and record the flex in the shaft being turned. Unless you are very lucky or have spent time adjusting the tailstock, it will show a taper in addition to the flex. That is OK. The next step is to turn the work end for end and back between centers. Now repeat the measurements with the indicator and record those. If the gap is affecting the carriage it should show up in different indicator readings.
 
Hey guys, just wanted to say thank you for all your input.
The good news (Theres a few bits.) It was the saddle that was bowed. From factory we could slip some decent feeler gauges in there on the back edge. We had to basically take a lot of stuff off it, but noted when the cross slide was moved in, the feeler gauges would no longer slip in.

For what ever reason the cross slide in that area it caused a rock forward and toward the workpiece. The tech spent a bit of time there and managed to work it all out and true it up. He said it's very unusual for this particular machine to have any error like that from factory.

After some messing around we managed to turn a 0.001mm deviation over 150mm. It's basically back to perfect. It's running dead and true now. I am very grateful for the tech coming over and sorting it all out. He had some great advice and tips on truing this thing up. It just goes to show often you can get caught up on what you think the problem is and not see other issues.

I'm still learning and acquiring better knowledge. The hints and tips provided were all very good and I actually watched the tech mic those surfaces as you all inputted. Very cool to watch it first hand.

He also said I did a great job of truing in the bed block because it's perfectly square now.
I'm back to turning parts for these dies in perfectly and getting vacuum fits on the dies and pins. Love it.

Once again thank you everyone.
If I notice any more issues with it I'll let you know, but man, I got so caught up with the error I didn't check the saddle with feeler gauges ... assumptions right :D
Thanks team. Happy camper :D Great lathe, surface finish I'm getting is just brilliant and easily hitting dimensions.

Jr we are only turning small punches and dies for heat treatment but they are a tight flip fit.
Material is 0-1 and 4140. Diameters we turn are from 20mm to 5.7mm. Working like a charm now! Thanks.
 
I wouldn’t be expecting to have to check out the fit of the saddle on a brand new lathe.

Having said that I once came across a 0.010” end to end taper on the table of a brand new “ out of the box “ milling machine. If I hadn’t have seen it with my own eyes !

Good luck with it, Tyrone
 
Qt MCritchiey: Tyrone, you would be shocked at the careless manufacturing techniques employed by some firms. I feel we lose a bit of quality each year as we demand cheap machines.
I agree to that

*But the OP's lathe being .004 error on the part in the last inch is more than I would like.
(.1mm in the last 30MM)

Removing burrs is an applied science. An old-timer sat me down at my first real grinding job and spent some time explaining how when you grind a part a greater burr is created here and a lesser burr there, If you flat hone on the flat, then the burr will/ may still be here and there. if you set the part down on the burr and take a grind the surface will be high here, and there. He went on to tell how you imagine burr and hone and wipe the burr from side to side so as to leave the imagined burr where it will not affect the next grind.

You see guys on youtube, even grinder manufacturers rep videos who flat hone a part bottom and set it on the mag, Grinding in tenths or better they will never/rarely make a part to size and square.
They don't have a clue as to what they are doing.
One big name grinder I would never buy because the manufacturer's video has dumb grinding method errors.
 
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Seems like the tech knew what he was doing.
Great outcome. I hope a full report went back to the manufacturer, so they could check through their process.
That's what creates quality.
Bob
 
Not that I could help anyway, but google drive is worthless, I have other things to do tan wait for a video to load. Not just you, always the case with google drive, pics, anything
 
I see what Matt is saying and what Tyrone is. I have also seen the lousy fit of those gaps. They screw them down to the lousy surface and pin it. Then grind it assembled. I bet the bottom of that lathe bed is lousy too. So when it was ground it had a burr or low spot. It's apart. Stone off the obvious burrs, assemble it leaving out the pins, Measure and align it like Matt says. get it as good as you can and if it needs stoning, stone it. I have also seen where a tool room foreman screwed one up trying to fit one. Some of these supposed machinists are crude as hell, I was called to fix his F up. I had to scrape the bottom and then shim it to get it to align properly. There are no easy answers here gentlemen.
What Richard has explained is dead accurate. A removed gap section will NEVER reassemble the same. I caught a machinist attempting to remove the gap section on my Victor lathe and went ballistic on him. Consider it a permanent gap bed lathe if it's ever loosened. Occasionally i have inspected the bed for twist. Correcting if will effect way surface transition between the bed and gap section. Necessary to smack the section with a large, dead blow to move it a tenth or two.
 
One big name grinder I would never buy because the manufacturer's video has dumb grinding method errors.
oh, do tell! I think it would be great if you can give us a hint at least, then let's see if we can spot them!

Not even grinders by most seasoned grinder hands standards, the Grizz and the Tormach.
Looks like the Tormach is out of production after a short manufacturing stint. (I am not surprised) I did send them an Email..they ignored it. (could have improved the machine and the videos.)
If company videos are poor, then how could they expect to make a machine/Grinder.
Re: After careful consideration, Tormach has decided to discontinue the manufacture and sale of our PSG 612 Surface Grinder (PN 32789). The standard warranty terms will be honored for all units shipped to date.

*Good, the tec found the lathe problem and fixed it..
 
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