HMC part prog. help

[M. Anderson]

Hi all,

 

I am having problems and need some help, PLEASE?

 

I have put up a file on the FTP site in the "MC8_Files" folder called " mark_temp2.mc8".

 

What I am trying to do is run this part on another shops machine that has a 4th axis. I have went thru what I can find on how to program this in MC and just cant seem to get it right.

 

If someone would look at this file and explain to me what is set incorrectly (or how to do it correctly), I would be greatful!

 

What I am trying is to make the toolpath wrap around the part radialy in a arc. In other words let the part rotate in the Y axis ( the 4th axis ), and the spindle move in the Z and X axis only.

 

I almost had it - then lost it - and NOW! I can not even get back to where I was.

 

When I almost got it right, I was still way off, because when I posted it, I was getting about - +2.3 meg's worth of - 4 to 5 degree indexes not a smooth radial arc cut.

 

I am using "MPMASTER.pst" set for a horizontial. The same post they use at that shop. The machine is a Mazak ??450 HMC, "True 4th axis", cutter is BN 5/32 carbide, material is 1018 steel.

 

The shop where I am going to run this has MC9.0 or MC9.1, not real sure - so you can use newer software if needed (I am just at V8.1, but can use their computer if needed) - but they don't, or never have, used the 4th axis as anything more than a indexer for tombstone work. So no help there!

 

If some of you who use or program HMC's have time to look at this - tell me what in the world have I managed to screw up so bad. I am just to the point of giving up!!!

 

Thanks,

 

Mark Anderson

 

Going to read some more!

[Mark Mossberg]

Mark,

 

MC always wants to keep the tool axis normal to the surface in 4th axis surfacing. This is why you see the wierd rotations around the angular blades. These angled surfaces also skew the whole tool path. It would be nice to have a way to force the tool to stay on center. Seems like I figured this out once before. I'll look around tomorrow at work. Also, since the conical surface goes under the lower edges of the blades, it will gouge them.

 

Since you can't finish them with a ball mill anyway, you might want to try setting the blades as check surfaces and rapid over them. Then you can index and use a flat mill to finish some of the square edges.

 

After looking at the whole thing though, don't you think it would be easier to do with sheet metal ?

 

Regards

 

Mark

[jplecan]

I've been experimenting with learning rotary feeds since getting Mastercam 9 a month ago (and installed 9.1 yesterday). I've also noticed all the in-between angular positions between start angle and end angle (these could be manually deleted). Another cutting method to try would be Flow 5ax if you can break the surfaces up into sections in between the ribs, you can use a bull nose cutter in Flow 5ax, this will rotary feed too. In v9.0 the bull nose cutter would skip back and forth in x to either side of the end flat while rotary feeding, but in 9.1 the cutter seems to stay at x zero. Hope this helps you get going in the right direction.

 

Jim

[jplecan]

Mark,

I posted a file called "mark_temp3.mc9" in the

mc9 files folder of the FTP which rotary feeds the conical section over 180 degrees using Flow 5ax so if you trimmed the conical surface into sections between the ribs maybe you could use this method. I don't know what effect the bull nose tool has on the taper though. HTH

Jim

[M. Anderson]

Mark,

 

This is just a prototype, the real ones wil be made from a stamping and rolled, or a forming die.

 

Jim,

 

Thanks for your help - I have managed to get this running finaly. Gave up on what I originaly was trying and did it a different way so I could use a 3/8 flat endmill. Turn on all layers and you can get a better picture of what this ends up as. Then this part gets cast into nylon and is for support of the thin coating of nylon.

 

Thanks for everyone's help, Mark