Lathe V8.1.1 won't work?

[Hugh.Venables]

I had a really frustrating day today trying to do my second MC lathe job. The first (a toroid/donut which worked well) was before Christmas, so I admit my learning curve is a bit shallow. The first operation consists of a 34.5 m.m. spherical radius on the end of a dia. 70 m.m. round bar. I couldn't get anything remotely resembling a sensible tool path. Sometimes the tool headed straight for the radius centre and other times it would just do a small gouge where the radius blends with the cylinder. There was always a tool collision warning. I started from scratch and redrew it, same problem. When I use fit to screen I find there is what appears to be an extra stock definition to the Z+ of the job in the shape of a big cylinder with a small bore which is on many (every?) level(s) and which I can't delete. Tonight I tried the job at home on V8 Demo and it worked fine.

 

Could I have overlooked a default at work? Or have I got a problem with the PC or V8.1.1? Any ideas?

 

Thanks, Hugh.

[jeff]

Sounds like you have the settings different.

Stay with it Hugh,I had the same problems(and still do) when our company bought Lathe9.0 and I had to teach myself.

[Hugh.Venables]

Thanks for your encouragement Jeff, at the moment I really need it. Any suggestions as to what settings could cause a problem like this? I have to do the job but there is a limit to how many days I can go on achieving zero!

 

Hugh.

[Keith Graydon]

Hi Hugh,

A couple of things about the Lathe module.

 

Allways look at the "[ PLUNGE PARAMETERS ]" button on the Finish parameters tab. that Controls/inhibits certain tool motions.

 

tools must be defined/set-up properly. Click on the tool and look in the [ setup tool ] and [ job setup ] buttons.

 

Chaining can give a different result than you might expect from MILL. I often use Window/inside-intersect and let the start and end entities overhang the edges of my selection window (intersect).

 

Stay with LATHE its a little differentbut you will get the results your looking for.

 

HTH

 

-Keith

[Brendan P]

Hi Hugh,

As keith stated,plunge params. are very important to getting the right result.

Also,make sure your "tool" is compensated to the proper side according to your chain direction.

And Lead in Lead out values/directions play a critical role.

Sometimes you can get away with setting them to auto calculate.(but not always the best way).

It would be nice if mcam would tell you exactly

where your "tool collision" is happening to narrow down the problem.

It was frustrating for me to "GET IT" too.

Just use it everyday.

See if your boss will allow you to take sim home

to practice.

And stay up all night like I did!

[chris m]

Hugh

 

If the issues you are having are with roughing check out what your overlap settings are, I always turn overlap "on" but leave the amount at 0 (this does make for a different toolpath than having it "off") make sure you don't have equal steps selected in rough parameters and try adding a small horizontal line at X0 that extends to the face of your stock.

 

Can you post the file on the ftp? We have played a lot with problems like you're having; maybe we can help you.

 

C

 

[ 03-20-2003, 12:52 PM: Message edited by: chris m ]

[Hugh.Venables]

Thanks for all your replies guys. I have just got in and am about to have another go. What strikes me as strange is that I didn't have any problems like this (well, I don't remember having....) with the last job and it worked straight off on V8 demo at home.

 

Keith, I am using Quick Rough and following ,more or less, the V8 lathe tutorial book. I will look at the tool set up. Could it be better set up in Demo? The chain is just one quadrant. I'm surprised at how different Lathe is.

 

Bucket, the big problem is that there are so many different aspects to my job that I can't use it every day. My Dad used to have a saying "a Jack of all trades is a master of none". Sadly, it's true. (No offense to Jack....). I did practice last night with Demo and it worked perfectly....straight off.

 

Chris, I will have a fiddle with overlap as well and try adding the line. I'll have a crack at posting it to the FTP too. For some reason I have a bit of trouble doing that. Must be that old computer illiteracy rearing it's ugly head again!

 

Thanks all, much appreciated. Cheerio, Hugh.

 

[ 03-20-2003, 06:33 PM: Message edited by: Hugh.Venables ]

[Hugh.Venables]

OK, I managed to get it onto the FTP site. Thanks Jay. It's called Sphere R69.MC8 and it's in the Lath folder. If anyone would like to backplot the three operations and tell me what I'm doing wrong and particularly why the first two are different I'd be very happy to hear from you. Right now it's Friday afternoon and I'll be going home in a couple of hours. I am going away for the weekend where there is no PC (or TV either) so I can reply tonight at home but after that it'll be Monday.

 

Thanks, Hugh.

[Andy]

Hugh,

It looks like you have 3 Ops in the sprere69 file.

 

Op 1: Facing-- Reverse the chain direction or rechain in the opposite direction. In the ops menu left click geometry, then right click chain1, then reverse chain, ok, ok, then regen.

 

Op 2: Facing--Looked ok for facing.

 

Op 3: OD Turning--Change the tool comp to "Right", also disable stock definition.

 

Dont give up, I did many hours learning this stuff.

Good luck, let us know....

[Hugh.Venables]

Thanks for your time Andy. I did as you suggested.

 

Op. 1 Having reversed the chaining direction, I now just get an approach to Z0.200, D-6.600, and a retract at Z0.200 to D55.883. That's all.

 

Op 2 As you said it looks OK. The trick to this is that Op 1 & 2 were created one after the other with the chaining for Op 2 coming from "last" after chaining for Op 2. I'm fairly sure that otherwise the two Ops were created identically. Why the difference?

 

Op 3 Changed the tool comp to right, now the tool approaches to Z-24.4, plunges in to D67.400 and turns to Z-34.400. That's all. I couldn't find where to disable stock definition. Then I found Disable Stock Recognition in the Stock Recognition pull down and it works well. Can you explain the stock recognition caper to me so I can logically remember it next time? When and why do you have to disable it? I'll be interested to see if it's disabled in Demo when I get home.

 

I guess I'm getting there but it's not too smooth and I've got a bit to go yet. Thanks for your reply, I'm going home now, will try some more on Monday.

 

Thanks again for you input, Cheerio, Hugh.

[dan m]

Hugh,

 

As far as I can tell with op#1 by reversing the chain the tool wants to plunge in on the face, which you would have to enable, plunge parameters. You don’t get this option in quick toolpaths. The difference between op#1 & op#2 is under stock recognition op#1 you have “Use stock for outer boundary” And op#2 you have disable stock recognition.

As far as I can tell the stock recognition has to do with job setup. When you use this you have to make sure you pick your chains right and your comp is set right.

Op#3 looked good just had to change your comp from right to left. Hopes this helps.

[Brendan P]

Hugh,as maybe stated earlier.

The "quick" operations do not give you as much

"flexibility" when trying to make your tool do

exactly as you want.

A lot of playing around with the parameters,and

backplotting the path,and watching the results

may help you understand how each change will

effect the results.

Thanx to Aussie for the support!

[Hugh.Venables]

Thanks for more help, guys. I'll try some more on Monday. Have a good weekend. Cheerio, Hugh.

[chris m]

Hugh

 

I downloaded the file from the ftp and I'll fool with it a little tonight; talk to you next week

 

C

[Hugh.Venables]

OK, I have selected Disable Stock Recognition and got the two ops to behave the same. I think I prefer OP#3. Now I'll have a crack at finishing the front and then try to groove out the bit behind the ball.

 

I'm a bit disappointed at how many tricks I seem to have to learn to make it work. It really doesn't seem to be very intuitive. Is V9 any better?

 

Thanks again for helping. Cheerio, Hugh.

[Andy]

Hugh,

I think that MC just gives many choices to suit different applications and preferences. Thats what makes MC so powerful. But with that comes the need to learn all the tricks, which I certainly do not know, but am also learning gradually. Play around with the stock def. Try making the stock twice as large and then try the different stock def. choices. I have not had time to mess with that yet but I will eventually try it, and then try to remember the results.

good luck,

Andy

[chris m]

Hugh

 

I played with your file a (very) little and got some decent results. My computer is having major issues right now and I can only run Mastercam for about 3 minutes before the machine locks up hard and I have to reset so I can't really do much. Our IT guy is supposed to swap out this machine in the next day or so; I'll be more able to help then (probably too late to be any help to you).

 

A couple of things (I'm in V9, by the way, but that shouldn't really affect the stuff we're looking at):

 

- I extended a small line from the front of your piece to the stock and one from the "top" quadrant up to the stock boundary

 

- I used rough instead of quick rough (I've never been to excited about the "quick" toolpaths) and turned the stock off instead of facing (tool must be defined as "OD" not "Face"

 

With these settings the toolpaths looked OK, though you'll probably have a little xxxx where the machine doesn't go below center; you should be able to add a line extending .0312" below the centerline to deal with this, my MC just doesn't run long enough.

 

Let us know how you are coming along

 

C

[Hugh.Venables]

Thanks Andy, Thanks Chris, your input is much appreciated. My biggest problem is that my job requires me to do too many different things at the moment. This afternoon and tomorrow afternoon I have a welding student lab to run that takes all afternoon. I was going to spend most of this morning preparing some more weld pieces but got dragged off to get a thermo lab going and so it goes on. I'll be lucky if I get back to this job until Thursday. Makes it hard to become familiar with any system. It's taken me over three hours of interruptions to finish this message.

 

Cheerio, Hugh.

[chris m]

I'm very familiar with that situation.

 

I've got my new box now so I'll fool with it a little more today, maybe

 

C