Reduce cusping & faceting during mill contouring of a cylindrical surfaces

[GaryT]

I work in a small Tool & Die shop equipped with a Hurco Ultimax 3 & a new Haas Super Mill 2.  We are still using MC X2.

The problem I had was on the last job on the Haas, milling a round part. First thought anyone has... cylindrical ---cut on lathe? Sadly, I  could not. It was a cylindrical groove ( 3.610" I.D./3.922" O.D. x .562" dp.) that made the seal edge of the final molded part. I used a Toolpath-Surface finish with a 3/32" ball end and took cuts with a.001" step over  and I used "total tolerance" of 0.00005". 

This resulted with around the bottom angled surface it was faceted like a diamond (at 90 degree points). The at 0 & 180 degree positions on the circle the cutter was making moves of .015/.022 in "x" & .0001/.0015 in "y".  At 90 & 270 degrees  .0001/.0015 in "x" & .015/.022 in "y".

This leaves large cusps & faceting at 4 positions at the bottom angled surface of the seal groove. I have changed all the settings to eliminate/reduce the faceting, but the only way to get the x,y moves smaller is to use a smaller diameter cutter. 

What Toolpath/ Settings should I use? Am I using the wrong Toolpath? 

Any advice about a possible work around (other than a MC upgrade) would would be grateful. 

 

[Matthew Hajicek - Singularity]

First thing I'd do is check the machine for backlash, especially if it's old and/or abused.

[GaryT]

I will have someone check for possible backlash.

We purchased the Haas new this last year. I have run numerous programs on this machine. This is the only program / Cad that this machine has this problem with.

 It maybe from the hardness of the steel (46/50 R/C), cutter size, feed, & the depth of cut, causing the cutter(s) to flex when it does a .015"/.022" move. 

I have tried different settings to reduce the .015/.022 move,but I have been unsuccessful in reducing it.

 

[GaryT]

3 minutes ago, GaryT said:

I will have someone check for possible backlash.

We purchased the Haas new this last year. I have run numerous programs on this machine. This is the only program / Cad that this machine has this problem with.

 It maybe from the hardness of the steel (46/50 R/C), cutter size, feed, & the depth of cut, causing the cutter(s) to flex when it does a .015"/.022" move. 

I have tried different settings to reduce the .015/.022 move,but I have been unsuccessful in reducing it.

 

If at first you don't succeed.... so much for Skydiving!

[Matthew Hajicek - Singularity]

If you post your code or the Mcam file people can check your work.

[jeff]

Can you show us a screenshot of your filter settings?

[#Rekd™]

Surface Finish - Scallop usually leaves a real nice finish.

[GaryT]

I could not get a screenshot of the "Filter setting" (not present in MCX2). I have attached a zip file of the MCX  & posted NC files.

I am trying the Surface Finish-Scallop. I did not use it before before because it took a long time to do processing. If the settings are to tight , my computer will lock-up MC & crash .

So far it has been 45 minutes. Hopefully, it will not error.

Thanks,

CAVITY_BLOCK.zip

[Machineguy]

Since this is on a Haas, write everything down about the toolpath, settings, material, and put it in a log book

Do this for all surface toolpaths. Write down what worked and what didn't.

This will be for that machine.

 

Machineguy 

[jslaero99]

I can't look at the file but it definitely has to do with 'filter settings'. When generating arcs, you'll get rid of the facets + your program size will reduce dramatically. HTH!

 

           JS

[?Mark]

.00005 for a total tolerance?

 

That's waaay too tight. You should loosen it up and filter to try to create arcs especially for a machine such as haas. As little point to point moves as possible. Backplot will give you a great idea on the smoothness of the toolpath (turn "display endpoints" on)

[GaryT]

I have success! It was a combination of errors on my behalf. I changed to a "Constant Scallop" and I reset the "total tolerance", set starting point to the center of the outside diameter of the groove , turned on the filter ratio, set it to 1:3, & used 1.8 min r. & 1.97 max r. 

It returned a radius cut instead of linear moves. Smoothing out my passes.

I would like to Thank everyone for your help.