Milling helical holes with cutter compensation (NX6)

[Denim]

Dear Sirs,

The shop I work for mill a lot of holes and bores with a helical downward motion. These are deep and tight tolerance holes, so we like to do a roughing cut and a finish cut both in a helical motion.

We use NX6.

My current method is to make a planar_mill operation with engage method set to helical and mill the hole with the engage move.
This works fine for roughing, but for finishing I need to use cutter compensation with "output contact/tracking data" activated. (The post processed program has to reflect the dimensions of the hole, not cutter centerline position)

NX will not start cutter compensation before the engage move is complete, so compensation is not applied before the cutter reaches the bottom of the hole when a helical engage motion is used to mill the hole.

My code for a 50mm dia hole has to look similar to this:

....
G0 X0. Y0.
Z2.
G01 G41 X25. Y0. D1
G03 I-25. J0. Z0.
G03 I-25. J0. Z-2.
G03 I-25. J0. Z-4.
G03 I-25. J0. Z-6.
etc...


I have not found a way to do this in NX yet, so as of now I have to program every finish cut by hand.. :/

Is there a way to do this in NX?

It seems like NX CAM's capabilities when it comes to milling holes with helical motion is somewhat limited..?

Best regards
Erlend

 

[joycejo]

It can be done but it is not as simple as you would think.
The main issue is using the tracking point so "(The post processed program has to reflect the dimensions of the hole, not cutter centerline position)"

You can activate the Cutter Comp from the Start of Path events and control where it is output. You will also need to define a start point.

The only thing I could think of would be to "Lie" about the size of the hole so the output reflects the actual size of the hole you need.


I don't know if the "Hole making" operations would be any better.

Best of luck




John Joyce
Tata Technologies
1675 Larimer St.
Denver, CO

http://www.myigetit.com

NX5,6 Solid Works, Solid Edge

 

[akerth]

Erlend,

We have developed a few add-ons for a variety of Hole operations that would solve your issues.

Please contact me and we can provide you with a solution that meets your needs,

Talk to you soon,

Ashley Kerth-
akerth@6dms.net
503.803.3294

6dms, Inc.
506 SW 6th Ave., Suite 600
Portland, Oregon 97204

http://www.6dms.net

 

[Denim]

Thanks for replying to my question, joycejo.

I managed to activate cutter compensation before the engage move by adding it to Start of Path events like you suggested. I got the G-code program to reflect the hole dimension by adding negative stock equal to cutter radius to the operation, but since this also messes up the verification and In Process Workpiece(IPW) it doesn't work very well for my application.

Hole_mill operations doesn't seem to be able to do this either.

Hopefully Siemens will add this functionality to NX in the very near future. A planar hole milling operation that works without the feature based machining module would be nice!

akerth, thanks for the info. However, I don't think my boss would be too thrilled with the idea of having to buy add-ons for functionality that ought to be standard in a top dollar CAM package in the first place..