Small 3D Pocket? help needed.

[kprice1658]

This is my first piece to mill out, so I'm struggling with it. Width is approx .300in at the center, .250 at one end down to .125 at the skinny end.

I have tried starting with 1/4" Surface Rough pocket, then Surface Contour with an 1/8 - followed by Surface Finish leftover. I tried several different types of operations. Best outcome was using a 1/16" ball end mill - but still quite a bit of material left. I was only using 3 operations.

How many toolpath operations would you normally see for something like this?

I'm still learning the terminology - but is this a Pocket operation?

Thanks,
Kevin

[crazythunder]

On what system you are using to program this part. I would think if you are having to use that small of a cutter you want to leave no more than .002 to .005 anywhere for it to cut. I would probably use 2 of these tools with finish operations. The 1st finish operation would leave .0025 to finish and have a greater step over once you have done the operations you have listed above. By using a tool the same as you are finishing with as a semi-finish operation gives you more predicable results for the finish tool as well as what you can expect for the finish operation which will improve the quality of the mold which is always the bottom line on molds.

[AMCTony]

I would do this is 3 opps. first I would use a 1/8 ball mill to rough pocket cut the recess. Then I would use the same cutter to parallel finish the pocket but leave 0.0015 on the surface for a finish pass. Then I would use a 1/16 ball endmill 2 flute carbide to finish this. Use parallel finishing with very high cut tolerance and a small step over. Look on www.haascnc.com and they have tips on 3D machining. I would machine parallel to the narrow width and start on the left (wider end of the pocket).

[kprice1658]

Thanks guys. AMCTony - that points me in the right direction. I wasn't sure which type of tooling passes to use, Pocketing, Contouring ,etc.. Did not try parallel. I will try your suggestions tonight when I get home.
Thanks again,
Kevin

[kprice1658]

Ok - I gave that a try and have very choppy edges. Using the 3 paths with a runtime of 30 minutes. I added another finish parallel pass - just playing around and the time went to over 3 hours. It didn't look bad - but still had some edges on the sides and scallops on the bottom....

Suggestions?

Kevin

[HuFlungDung]

Kevin,
You did not mention what CAM software you are using. This would help someone get the exact terminology for you.

For a certain depth on your mold, where the walls rise to near vertical, you may be able to use Z level or waterline machining. This will create a toolpath in the form of level loops that follow along inside the contour. I suppose a general cutoff point would be wherever the slope of the wall becomes 45°, then from there down, switch to the planar type finish. However, it can take some care and attention to get the second toolpath to feather smoothly into the first one, due to tolerances used in creating the two different path styles.

[kprice1658]

hfd,

Using mcamx2. I haven't tried the Z level finishing yet - about the only one I haven't. I'll look a that tomorrow.

Heres a pic using surf.finish.contour - runtime of 2hrs.18mins. Still needs work.
Kevin