lathe canned cycles and job setup

[dan m]

when I use lathe canned cycle it seems to ignore the stock boundries in the job setup. is this common or am i doing somthing wrong?

[randy]

what do you mean ignore stock boundries does it look like it crashes

[dan m]

the tool rapids right into the face of the part and only wants to take 1 roughing pass where it should take 3 or 4

[randy]

try adding more stock to lead in and make sure extend counture to stock is checked

[CR]

can you load your file in the FTP site or e-mail to me

I do a lot of lathe canned cycle for different controls.

[chris m]

I have had problems with Mastercam not 'seeing' the stock in front of the part. I will often put a facing operation in [even that doesn't work right, you need to actually tell MC to leave .500 stock on or whatever] so that Mastercam will then 'know' where the stock is. This is actually a real pain in the a$$ but I never reported it, just work around.

 

Try checking / unchecking 'Extend Contour to Stock' and see if that has any effect, sometimes yes and sometimes no.

 

C

[dan m]

I put the part I'm working on is on the ftp site. It's in the Lathe folder and I called the part "canned". I have a couple questions on this part. I'm not sure if it makes a difference but it was created in solids. The 1st question; Is there a way to shorten how far the O.D. tool is traveling like you can in regular lathe rough? 2nd question; If I turn "compensation type" to off the tool don't rapid in to the face but if I set it to computer it hits the face. Any Ideas?

[chris m]

Dan

 

When I brought your file in I backplotted it and it looked OK, BUT, when I regenned the toolpaths it went crazy and now the rough turning tool makes all kinds of crazy moves. We have Solids but I don't like turning from Solid or 3D wireframe geometry. I would created a 2D profile of your geometry [above center only] aznd toolpath that instead of doing it the way you are now. This will eliminate some variables from the equation and show us what's really going on.

 

C

[randy]

i agree with chris sems like an easy enough part do it in 2d should be no problem

[dan m]

Level 10 is a 2D wireframe for the part. I redid the toolpath and in backplot it looks like its only taking 1 rough face cut and I want it to take 2 or 3 plus the tools still seem to be hitting the face.

[CR]

quote:

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when I use lathe canned cycle it seems to ignore the stock boundries in the job setup. is this common or am i doing somthing wrong?

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I took your file and mod.

loaded back to the FTP site ander canned2

 

I changed your tool paths as well the ref. points and the Lead In/Out values

 

Moved your solid to a diferent level

re-do your drilling cycle with out using your points and the center line

 

I did it in a hurry hope it help

Normaly I would have my Z0 at the front face of the part

I belive I got the weire moves becouse you have it on the back face and it load my defaul setting when I opened your file

[P_Scott]

dan m,

 

With most Canned cycles in Lathe, the Add Line parameter in Lead In/Out will help define an entry point away from the stock. Any particular reason you are using a Canned Rough instead of a regular longhand Face cycle, at least for the first operation? The longhand Face cycle provides much more control over entry and exit moves and won't produce that many more lines of code from the Canned Rough cycle. Also, almost every turning program I've seen in Mcam uses the front face as Z-O. Not that you can't program it the way you are, just that there are default reference points and things for you to be aware of in the Job Setup which may actually be the cause behind some of the unexpected moves.

 

You don't need 2-D profiles to machine a solid part in Lathe. Mcam will automatically generate a "slice" of the solid part to form a 2-D edge boundary you can select for turning toolpaths. When you select Toolpaths, choose Solids from the selection menu instead of Chain. The outline will appear as blue entities. I prefer Solids because then I don't waste any time generating extra geometry after converting the part. Just start machining it. HTH

[chris m]

The location of Z0 in this case is irrelevant. I use Z0 on both ends of my parts depending on how the part is made, workholding, material form, etc and Mastercam does not like a lot of stock in front of the part; period. There are tons of workarounds [like 'don't use canned cycles'] but the software really doesn't work right in this case.

 

Peter, there are SO many things that you can't turn without 'extra' geometry; for a simple piece like this there's no reason not to just get a 2D profile and be done with it

 

C

[dan m]

Peter

The reason I am starting to use canned cycles is we are starting to have problems getting material in a timely matter. they claim it's all going over sea's but i know nothing about that. So what we are doing is using stock which is laying around left over from other jobs. In some cases we might be facing off a extra inch or roughing a extra couple inchs from the o.d. In the past I always programmed longhand with no problem but it's starting to get to be a pain in the arse to rewrite programs for the extra stock. and the operators wont take the initiative to try to add a canned cycle at the machine. They would rather keep walking the offset in which is a waste of time. The reason we use the back face as "Z0" is we run alot of parts that are the same dia. this way the operator can run more than one job with the same setup and not worry about retouching there z offset.

 

Chris

2D geometry is not a problem. I actually create the solids myself and the cmm room uses them. I just thought there might be a simple way of toolpathing the solid in canned cycles. I know in long hand it woorks well.

 

Thanks for all the help