Help With Roughing a Tapered Auger

[NodecoMachine]

Hello,

  I'm trying to figure out how to rough out the helix of and Auger using HSM toolpaths.  We keep getting more and more Augers that we need to make and our current strategy is extremely time consuming. First thing is, we do these on a Haas VF0 with 4th axis (HA5C which is a small full 4th) and simply do a X, Z, and A move do feed down along the Auger "flights" but take full width and shallow depth.  
  My goal is to do more of a peel milling operation starting furthest away from the 4th axis and rough towards the 4th axis to maintain as much rigidity as possible while roughing.  What would be the right toolpath to choose for this?

Other details:

  The part is approx. 14" long with 3" major diameter and 1.5" minor diameter on large side and tapers to 1.25" major diameter and .38" minor diameter.  The pitch is 1-1/4" and we turn a "blank" of finished OD dimensions before bringing it to the mill.

  When roughing with our current strategy we need to offset the tool off center in Y so that while the part is rotating the material is not coming up into the center of the bottom of the endmill.  Staying on center in Y made terrible noises.

  We have MCX6 at the shop but I also have access to MCX9 at my other job both have multiaxis toolpaths.

[taperlength]

What size end mills are you using?

I assume the large end of the blank is held at the 4th axis and the small end with a center?

[NodecoMachine]

7 minutes ago, taperlength said:

What size end mills are you using?

I assume the large end of the blank is held at the 4th axis and the small end with a center?

3/8" (Linky)

Your assumption is correct, large side in 4th axis and supported with center.

I think I've stumbled across my solution.  In THIS video he uses multiaxis flowline.  If I did a small lead/drag angle and choose the "flow" to be across and not along the helix?  I really want to avoid using the 4th axis' rotation to do the roughing.  Meaning I want the 4th to be more of an indexer than a full 4th so that I'm not relying on the small weakish 4th axis to rough the material.

 

[mkd]

I'm thinking a high feed cutter (sandvik 390?) similar in size to what you are currently using would be the fastest approach. Probably would be able to do great right at Y0.

wouldn't a full forth peel mill action rely on the rotary spinning back and fourth too much? I'd love to see it work, though.

[NodecoMachine]

7 minutes ago, taperlength said:

What size end mills are you using?

I assume the large end of the blank is held at the 4th axis and the small end with a center?

3/8" (Linky)

Your assumption is correct, large side in 4th axis and small side supported with center.

I think I've stumbled across my solution.  In THIS video he uses multiaxis flowline.  If I did a small lead/drag angle and choose the "flow" to be across and not along the helix?  I really want to avoid using the 4th axis' rotation to do the roughing.  Meaning I want the 4th to be more of an indexer than a full 4th so that I'm not relying on the small weakish 4th axis to rough the material.

 

[NodecoMachine]

19 minutes ago, taperlength said:

 

[NodecoMachine]

3 minutes ago, mkd said:

I'm thinking a high feed cutter (sandvik 390?) similar in size to what you are currently using would be the fastest approach. Probably would be able to do great right at Y0.

wouldn't a full forth peel mill action rely on the rotary spinning back and fourth too much? I'd love to see it work, though.

  I like the high feed mill idea.  I'll have to look into it further on our next batch.  I keep hearing good things but sometimes its hard to get my pop (boss) to fork over the dough for new tools.  I finally got him to switch over to carbide variable flute endmills a couple years ago, before that he was still using HSS corncob roughers lol.

[mkd]

1 minute ago, NodecoMachine said:

  I like the high feed mill idea.  I'll have to look into it further on our next batch.  I keep hearing good things but sometimes its hard to get my pop (boss) to fork over the dough for new tools.  I finally got him to switch over to carbide variable flute endmills a couple years ago, before that he was still using HSS corncob roughers lol.

HSS corncobbs do well in certain applications.

I like what the youtube guy did at the 27min mark. (dang that guy needs to edit out all the long winded talking haha) . Cutting the helix with the side of the endmill would work great with the cutters you have.

[David Colin]

SUBSTITUTION.mcam (example file)

This can be a little tricky but 2D dynamic toolpath with substitution enabled can make really clean toolpaths. It can be helpful for 4 axis roughing.

 

SUBSTITUTION.mcam