Thanks Gcode. The problem was lack of experience. The groove just appeared to be offset in Backplot but was actually OK as Verify showed. The rough/finish problem was right/left compensation problem. I'm surprised to find how different to use Lathe is from Mill. Yes, I'm still using V8.1.1 . Are you strongly recommending I should upgrade? Thanks, Hugh. [ 11-18-2002, 10:53 PM: Message edited by: Hugh.Venables ]

I'm trying to form a groove but the system wants to use the wrong side of the grooving tool, offsetting the toolpath on the job by the width of the tool. I also tried to use the same tool to profile the front. It roughed OK but then used the wrong side to finish. I can't see how to control this. Thanks, Hugh Venables.

Hi Jay, I'm still using V8.1.1. I have thought that I should think about upgrading but am probably worried about the time it might take me to get used to the new version. The best support available to me by far is this forum. 'Nuff said. Cheerio, Hugh.

Thanks Chris. Really appreciate your time. Hugh.

There was a thread on this a month or two ago. I was quite surprised by the number of highly competent Mastercam users who manually calculate their own speeds and feeds. I would think the folk at CNC Software must be a little disappointed but then again, I haven't managed to do anything very useful with what's available in Mastercam myself. Maybe there needs to be a tutorial set up somewhere to help set it up properly. Hugh Venables.

Thanks guys for your help. Could I just clarify a few things: Greg, that's the pull down menu at the bottom left of the allocation page and I have to select LATHE8M.CFG (metric), right? And in the pulldown menu at the top centre of the Start/Exit page also? Peter E., this one has an Yasnak LX3 control. Did you send Mastercam to it? What post processor did you use? There are 20 or so files in the .tl8 library. They mostly begin with L but there isn't one with MM in it. There is a Ltools.tl8 and a Ltoolsm.tl8 . The file name is in lower case in the library, when I select it in the pull down menu it goes to upper case. I have selected Ltoolsm.tl8 Peter E. & Chris M., Do you guys mean never ever use TNR comp, or just use it in the computer and not in the control? I presume the lead in/out is for the TNR comp to be applied. Jim, Sounds really good, how soon can you organise this? Jadkins, thanks for the rap on the machine. We need some encouragement. Can you expand a little on the lead in/out values direction, please? Ours has a Yasnak LX3 too. What post processor do you use? Is there one in the V8 mastercam library that will work? Thanks a lot for your time on this everyone, I really appreciate it. Hugh.

Hi there you wonderful lot. I need to start using Lathe V8.1.1 as I am even more fed up than usual with the conversational on our Hitachi-Seiki HITEC-TURN 20SII. I'm remembering all too clearly why it spends most of it's time gathering dust. When you manage to get a program going in it it's a really good machine but the conversational........AARRGGHH!!! Anyway, I had a look at MC Lathe and it's set up for inches (horror). I had a look at screen, configure but couldn't figure out what to do. Every time I changed something, closed and opened it had defaulted back to the original settings. I need to configure the dimensions and tools to metric. There doesn't appear to be a metric material library as there is Mill. Can someone please tell me how to do it. Please assume I know NOTHING! Having configured it any words of wisdom on how to become incredibly competent instantly would also be most welcome. I have the V8.1 tutorial book but it is a little tedious. Thanks everyone, have a good wekend, see you Monday. Hugh Venables.

There has been some discussion of this on this forum before but no firm conclusion. Try a search of previous topics and have a read. I'm interested too but would haven't got around to trying it. I don't think it would do any harm to specify your issues. You might get a better answer to a more specific query. Hugh Venables. [ 10-31-2002, 07:42 PM: Message edited by: Hugh.Venables ]

Thank you Andrew for a very informative post. I feel obliged to admit that the reason I didn't consider radial chip thinning is because I never have. My excuse is that all our work here is prototyping and one offs but I'm not sure it's a very good excuse. Your adjustment formula is very interesting and certainly reduced the margin by which I "won". If the two cutters hadn't been such extremes, I wouldn't have "won" at all. The benefit of using a larger cutter for a smaller WOC is clearly demonstrated and the closest thing to an answer to John's original question. Hugh Venables.

Sorry about the duplicated posts guys. having a little server trouble I think. Or maybe a little bit of computer illiteracy......... Hugh Venables. [ 10-29-2002, 12:08 AM: Message edited by: Hugh.Venables ]

John, take your 1" 3 flute and your 2" 3 flute and work out the speed and feed. For the same cutting speed and feed per tooth, you should find that the table feed for the 1" will be twice what it is for the 2". This simply because the 2" cutter rotates through twice the distance at the circumference between tips than the 1". Twice the table feed for the same depth and width of cut will translate into twice the material removal. It is the distance between tips around the circumference that you need to consider. A 1" 3 flute will work out the same as a 2" 6 flute. Hugh Venables.

John, take your 1" 3 flute and your 2" 3 flute and work out the speed and feed. For the same cutting speed and feed per tooth, you should find that the table feed for the 1" will be twice what it is for the 2". This simply because the 2" cutter rotates through twice the distance at the circumference between tips than the 1". Twice the table feed for the same depth and width of cut will translate into twice the material removal. It is the distance between tips around the circumference that you need to consider. A 1" 3 flute will work out the same as a 2" 6 flute. Hugh Venables.

John, it's not just the number of cutting edges you have to consider. It's the relationship between the number of tips and the diameter of the cutter. To put it more simply, look at the circumferential distance between tips. A 1" cutter with 3 tips will have a better removal rate than a 2" with 5 tips, for the same depth and width of cut. Of course, as the tips get closer together there gets to be less chip space between them. Generally, solid tools can have tips closer together and still have more chip space. Like Chris, I was a little confused with your first post. Isn't a shell mill an end mill with a removable shank? Hugh Venables.

John, it's not just the number of cutting edges you have to consider. It's the relationship between the number of tips and the diameter of the cutter. To put it more simply, look at the circumferential distance between tips. A 1" cutter with 3 tips will have a better removal rate than a 2" with 5 tips, for the same depth and width of cut. Of course, as the tips get closer together there gets to be less chip space between them. Generally, solid tools can have tips closer together and still have more chip space. Like Chris, I was a little confused with your first post. Isn't a shell mill an end mill with a removable shank? Hugh Venables.

Thanks James. I'm still not sure whether a translator does the same things as MC's file convertors. You are quite right, importing DXF's loses some line work (entities). This is a bit of a nuisance, as a lot of our students still use Autocad. Can anything be done to get around it? Hugh Venables.

What's the difference between a translator and the file converters that already come with Mastercam? I've used some of these, DXF from Autocad seems to have some problems, ASCII was handy, SAT and IGES were OK if I remember right. I just clicked on STEP and I get a box across the bottom of the screen, "enter stepin access code" which I presume means more money if I want to use it. Certainly very handy to be able to read in all these file types from different CAD systems. Hugh Venables.

We have a VQC 20/40 A. Your 20/40 B has X travel of 1000 m.m. (39.37" for those unfortunate enough to be using inches) compared to our 635 m.m. We have the standard 4000 RPM spindle, options were 6000 and 10000. There are four manuals, an Operating manual for the machine, an Operating manual for the control, a Programming manual for the control and a Maintenance manual for the machine. The manual we use most is the Operating manual for the control as it has a list of several hundred alarm codes. There would originally have also been an enormous manual of wiring diagrams and another of mechanical parts list. We had two days training from a local Mazak expert to get us started. When you get used to it, the Mazatrol is so quick to program and edit that I don't always post from Mastercam. Take note of Pip's warning about the magazine tool grippers. When placing tools in them, rotate the tool holder left and right to make sure it has gone all the way in and engaged the key. Never bend the air blast hose around to the back of the spindle to get it out of the way. These tool grippers cost AUS$800 (US$400 or so) ! Good luck to you, it's a great machine. Hugh Venables.

This sounds a bit sad. I was hoping to have a go at using it to slow feed on corners in pockets. Manual editing does get tedious on deep pockets with a lots of passes. And there's always the possibility of making a mistake.......... I must admit I put up with the squawking on roughing, put in an extra finish pass, just edit the finish passes and hope it takes out the chatter. What MC version are we talking about? Hugh Venables.

Thanks Peter, I'll give it a try. Hugh.

Crikey Jack, just as I'd written you off as Multax re-incarnated you come up with some good stuff. Many conventional machines had separate spindle and feed motors with no chance of synchronous feed hence IPM on the feed gearboxes. I think we should flog the point a bit harder that G94 is a left over of these steam powered machines and there is no longer any need for it. It's just there for some people's old fashioned comfort zone. Older CNCs didn't have encoders. The control "knows" within reason what the spindle and axes are doing and is able to synchronize the feed. It comes a bit unstuck on tapping, particularly on reversal where it has no idea about over-run. For this we need floating tapping holders. Machines with encoders always know exactly where the spindle and axes are allowing rigid tapping. I'd be wary of restarting a tap in a tapped hole, I suspect only machines with encoders will do this successfully. Gary, are you absolutely sure your control won't accept G95? Surprising. Hugh Venables. (maybe this ones not a lost cause after all)

Ah! Chris. That's what all the old cooters used to say over here in the 1960s. Don't fret. It'll happen. Steelthom62 I agree 100% with you. IPR is a stand alone dimension. IPM is meaningless without RPM. Also as you said the machine will maintain tooth load with IPR if the operator overides the RPM at the machine and IPM won't. I can't see any reason for using IPM. Only problem is you're right and everyone else (almost) is wrong/different which can lead to confusion. Hugh Venables. (supporter of lost causes)

To get IPM first you must have IPR and multiply by RPM. Why bother to do that if you can work with IPR? Once you get used to it I would think IPR would be more useful to read at the machin.. IPM only means something in conjunction with RPM. IPR relates to chip load only via no of teeth. IPM relates to chip load via no of teeth and RPM. But for all that when I enquired about working in G95 instead of G94 I was told "forget it, no-one does it". So neither do I, much as I'd like to. But back to Kevin's poll. Why use inches when you can use m.m.? Hugh Venables.

Thanks Jim. The really slow feeds are the main problem, but some that aren't all that slow are slower than they ought to be. Also slowing down when the cutter is on the outside is hard to understand. I presume it doesn't work. I'll just have to continue to edit them in manually. Took a couple of hours on the last job. Hugh. [ 08-26-2002, 02:53 AM: Message edited by: Hugh.Venables ]

Thanks Jim. It seems to me that the system is calculating the compensations incorrectly (grossly overcompensating). Sure, setting a minimum will stop ridiculously small feeds but the compensations still seem to be incorrect. No one has tried to reassure me that it does work yet, so I presume either no one has tried to use it or it really doesn't work. Smit, I agree, it would seem more appropriate to have it optionable within operations. Thanks, Hugh.

At times mine slowed down around the outside and around the inside it slowed to 1/1000 of the linear where it should have been about half. Hugh.