Masteram Lathe, roughing a casting profile

[Toolio Iglacius]

Hi,

Can someone help me out with a method to rough turn a casting profile with mastercam, the only way I can do it now is to rough out a whole cyclindrical shape containing the casting, which cuts lots of air. Im sure its simple but I just can't get it to work, thanks in advance.

[Trevor Bailey]

If you have the finished geometry already, copy the geometry and offset the "roughing distance". After that, in the job-setup, select chain for "stock boundary". That should take care of the problem.

[Toolio Iglacius]

Thnaks for the response Trevor, I tried that, it says tool collision with stock, then asks if I wish to continue. If I continue I just get the rectangular stock cutting air as usual.

[gcode]

Toolio,

Experiment with your lead in -lead out settings

That may fix the problem. If you can, post your

file on the FTP site and I'll take a look it.

[Guest CNC Apps Guy 1]

IF you're using Version 8.1 Lathe, AND IF you are chaining your stock boundary(remember in lathe you only have to draw 1/2 the part unless you're doing twin turret stuff but that's a whole other issue) your rought cuts should only cut the stock IF on your rough parameters page of your roughing cycle you tell it to use stock recognition. If it still fails, try as was suggested befire, adjusting your lead in/out.

[Fred from Université de Sherbrooke]

I would try: Toolpath-->next menu-->canned-->pattern. Think it's the best way for a casting...

[Trevor Bailey]

I would only use "pattern" if you had a very basic part profile. Then again, while I do not know what your geometry looks like, strategies will certainly differ. If you are getting the "stock" alarm, I would bet that you have problems with the lead in & out. However, it may be how you selected your chain for the casting boundary in relation to the "chuck boundary" that is giving you the conflick. Even in that case, lead in/out should take care of the problem.

[Toolio Iglacius]

Im sorry, I should have mentioned im using V7.2c Lathe.

Not sure what you mean by lead in /out, is that entry exit vectors?

Id like to put the file up on the ftp site but the proxy server here where I work won't allow it

Thankyou all for the excellent replies

[ 01-08-2002: Message edited by: Toolio Iglacius ]

[cadcam]

Toolio,

Eamil me the file i will put it on my FTP for you.

Hope this helps

[cadcam]

Ok All,

I have received this nice mans file and located it on the FTP under lath folder.

Please help this guy.

Have a good day.

[Toolio Iglacius]

Thanks Cadcam !

[rsbeadle]

Hello Toolio. I am not familiar with MC lathe but I ran a lathe for several years. I would recommend creating a finish pass in the direction you want to rough (up and in from center or down and out from O.D.), but make several ops leaving less and less stock each pass or using multi-passes if it is available (?). I use to do it with tool offsets at the machine starting at +.250 (depending on stock on casting) and working back to zero. Hope this helps.

[gcode]

Toolio,

I just got home from work.

Downloading your file wouldn't do any good

as you are running 7.2 and I'm running 8.1.

I'm not sure if 7.2 can do waht you want or not.

I frequently fixed stock collsion problems by

playing with the entry/exit vectors.

[gcode]

Toolio,

I downloaded your file and checked it out.

THe offset chain you are using as a casting

boundry needs to be a closed chain.

[Kenneth Potter]

""""""Toolio Iglacius """""

Nice Name

[P_Scott]

Toolio,

Great Name BTW! Unfortunately in V7.2c, Mastercam Lathe doesn't have Stock recognition like it does in V8. That means even when you have the correct cast stock defined, as a closed contour, the Rough cycle will still assume the stock is a cylinder. Also you are machining this part in the Positive Z. You may want to move it to the Negative Z, unless you intentionally do it that way due to the type of control you are using.

My recommendation, if you're doing this type of thing on a regular basis, is to update to the latest version of Mastercam Lathe. It's a hell of a lot easier because the toolpaths are Associative and when you can chain your casting stock, it will only rough out the material that's there. If you need to change something, change it in the parameters and Regen the toolpath. No more Redo's. If you contact your dealer now, they might even have a course to show you all the new things being done for V9, which will be released soon.

[P_Scott]

Toolio,

I forgot to mention that you could always use a Finish toolpath and have it take a few passes instead of Roughing it out. Just divide the stock by the number of passes you want to use and use that distance for the "Amount of each cut" value. I have added the toolpath to your part and will download it to the same folder on the FTP site. I will "zip" it so you might be able to download it through your system. If you can't, just try a Finish toolpath instead of the Roughing toolpath. Good luck.

[Toolio Iglacius]

Yes, I think I need to see the boss about an upgrade, surely a lathe upgrade shouldn't be to expensive.

For the moment I'll use several passes of finish cuts to satisfy my casting stock removal needs, like was suggested.

Thnaks to all of you for your help, its greatly appreciated, this forum really is a great resourse, I've been using mastercam now for a year or more but unfortunately only just found this.

[gstephens]

In v7, you have to chain the finish -inner boundary - geometry, then chain the "outside boundary" - your stock boundary - in the same rough toolpath. This will cause the passes to be calculated from the stock boundary instead of the "block" shape.

[ 01-11-2002: Message edited by: gstephens ]