[smokediver576]

Evening Tormach'ers,

I am getting ready to set up some fixtures to machine my Kydex holster parts and need to machine & drill some 1/4" ABS plastic.

Drill sizes are 3/16" and 1/4" and two flute HSS endmill is 3/16"

What kind of feeds and speeds would folks recommend?

As for G Wizard...... as a total newbie, would folks recommend I get a seat of G Wizard software for helping me with feeds and speeds for other projects or do I do better searching the Ol interweb? I know Bob is a great supporter of this site and is a super great guy from what I hear. It seems like his software would at least give me good starting points....

Happy Labor Day weekend to my fellow USA family. I'm actually thinking of taking the whole three day weekend off for the first time in years (other than some house work and playing on the Tormach)!

Thanks,
Awall

[bevinp]

Give GWizard a miss. It has a number of faults/bugs that Bob believes are just "lack of feature". Here is the link to a discussion about it:
http://www.cnczone.com/forums/tormac...c-tormach.html

I have since found HSM Adviser to be far more reliable and more capable.

Good luck.

[SCzEngrgGroup]

I second bevinp's assessment of GWizard. I gave up on it years ago, and have been using HSMAdvisor with zero problems.

I've never machined ABS, bit I'd expect it to be pretty similar to Delrin, which I treat pretty much like aluminum.

Regards,
Ray L.

[Steve Seebold]

The secret to machining ABS plastic or Deleon is to have REALLY SHARP CUTTERS. Until recently, carbide cutters weren't sharp enough so I always used HSS.

[pickled]

ABS likes the O-flute cutters. If not available use a new 3 flute 1/4" HSS EM. I have ran this combo for a decent surface finish at 6500 RPM and 35 IPM on the 770 with an air blast. DOC was 0.125" and WOC was 0.1". You can push the feed WAY faster for roughing the shape out. Using an air blast or fog buster helps keep the stringers and cling-ons down. I definitely prefer machining ABS much more than UHMW. A standard 118 degree HSS 3/16" twist drill will work fine for your holes, but the material does like to try and climb up the drill on you.

Other than the Adobe Air annoyances of being asked to update G-Wiz I find it pretty easy to use. I really like the G-Wiz Editor though! I really do hope that Bob gets 4th axis support integrated into that product someday soon though!

[CadRhino]

+1 I have g wizard and agree with pickled - bring on the 4th axis please Bob
Ultimately, it is a starting point and one will learn what their machine and cutter combos work best and with what speed.

ABS likes the O-flute cutters. If not available use a new 3 flute 1/4" HSS EM. I have ran this combo for a decent surface finish at 6500 RPM and 35 IPM on the 770 with an air blast. DOC was 0.125" and WOC was 0.1". You can push the feed WAY faster for roughing the shape out. Using an air blast or fog buster helps keep the stringers and cling-ons down. I definitely prefer machining ABS much more than UHMW. A standard 118 degree HSS 3/16" twist drill will work fine for your holes, but the material does like to try and climb up the drill on you.

Other than the Adobe Air annoyances of being asked to update G-Wiz I find it pretty easy to use. I really like the G-Wiz Editor though! I really do hope that Bob gets 4th axis support integrated into that product someday soon though!

[wtopace]

I own both GWizard and HSM Advisor. Since getting HSM Advisor, I have been pushing my feed rates way up there (eg: 42 IPM roughing with a 3/8 TiAlN 4fl mill in 12L14, 65 IPM in aluminum) as recommended by HSM Advisor... with no ill effects whatsoever. G-Wizard still seems to always recommend the slow and steady approach, usually about 2-3 times the total spindle time for the same metal removed.

I would recommend HSM Advisor overall, but G-Wizard has some neat reference tables in it that I still use pretty frequently, probably not worth the money for the references alone though.

You should probably buy them both and support zero-divide and Bob - both seem to be great people with passions for machining. At least you can compare the outputs if you question something. Both packages combined are the cost of just a few end mills and both software packages will pay for themselves quickly.

Happy machining!

[Moggot]

I've found ABS to be an unpleasant material to work with. It just gets really stinky. It's easy enough to machine, and cheap, but ugh, that smell!

My experience with Gwizard and its recommendations for Delrin are that it is extremely conservative. I routinely increase the calculated feeds by about %50 at the machine with good results, and I suspect I could go quite a bit higher. I'm not sure if that's because the material model gwizard uses is incorrect, or if it is just purposefully conservative.

[Steve Seebold]

The burrs created when machining ABS or delrin are easily reduced if not totally eliminated.

When I machine either material, I use an end mill from Quinco. It is a right hand cut, left hand spiral end mill that actually pushes the material and the burrs DOWN while you're machining.

You can look the cutter up in Quinco's online catalog.

Try it, you'll like it.

[mountaindew]

The burrs created when machining ABS or delrin are easily reduced if not totally eliminated.

When I machine either material, I use an end mill from Quinco. It is a right hand cut, left hand spiral end mill that actually pushes the material and the burrs DOWN while you're machining.

You can look the cutter up in Quinco's online catalog.

Try it, you'll like it.

Whiteside calls this tool design a compression cut. I use solid carbide spiral up, down and compression cut router bits for plastics and get good results.
As you mentioned in another thread you get what you pay for and they don't give these away. The cutters will also do non ferrous metals with decent results.
I find a quality cutter is required for good results, with feeds and speeds a secondary concern. "unless the tool is 1/8 or smaller"

[MichaelHenry]

The burrs created when machining ABS or delrin are easily reduced if not totally eliminated.

When I machine either material, I use an end mill from Quinco. It is a right hand cut, left hand spiral end mill that actually pushes the material and the burrs DOWN while you're machining.

On through cuts, does the cutter produce burrs on the bottom edge?

[Steve Seebold]

On through cuts, does the cutter produce burrs on the bottom edge?

Probably.

[MichaelHenry]

Probably.

Too bad, burrs on the top of HDPE/UHMW parts I used to make were a minor PITA to deal with so a cutter solution would have been nice. Those were all milled all the way through, though.