[Metalmidget]

I bought a Tormach last May 2009 and have not yet used it because I am a
"newbee" at this. I have put it together and made two visit to Waunakee
for great workshops. I have turned it on and it works, but I cannot use coolant because I work in cast acyrlic, so I need a compressor to cool the bits.

I am making detailed molds of photo images and the molds are 8x8 inches square and the acylic is 1" thick. The images are .125in. deep at the most, so they are very shallow and the bits are round endmills, 1/32, 1/16, and 1/8" to mill out the images. I will be making some large things. I do have to use a 1-1/2" facemill to initially mill the parts for the first operation. The result is a very light relief.

I have been told to use a vortex with an air compressor. Some of my files
are running up to 3 hours because the resolution of the photograhs (turned to mesh) are 80dpi. They were larger, but the files were taking so long to
run with detail that they were not cost effective.

Any suggestions on the correct air compressor that I could use for
the Tormach and connect to the (120 coolant outlet). Matt Doeppers
from Tormach said the Forum would be a good place to get
suggestions.

I would greatly appreciate any information. I want to get started on
my mill before I am old and gray.

Thanx in advance

[Jeff E.]

Why do you think you can't use coolant? I use coolant when cutting acrylic and it works great. The vortex cooler uses huge volumes of air - I fear more than you will get from a 120v compressor. Try some coolant - you have nothing to loose...


Jeff E.

[zephyr9900]

Metalmidget, I second what Jeff says. I've machined cast acrylic extensively using Boelube 70105 water-soluable coolant with great results.

Randy

[Don Clement]

I would recommend using flood coolant if possible before going to a vortex type cooler. Vortex coolers have a voracious appetite for large volumes of air. My Vortec 610 cold air gun http://itwvortec.thomasnet.com/item/...n/610?&seo=110 has a requirement for 15 SCFM @100psi and keeps a 5hp dual stage compressor with 80 gallon tank running almost continuously.

Don

[Art Pentz]

A note on the coolant output on the Tormach:

The coolant/mister relay is on the Tormach main controller board and current (amps) is limited by the relay contacts and the printed circuit board traces.

The controller board appears to be fused at 7 amps for all the relay contacts.

To use the coolant output for compressors, large pumps or high speed spindles, I recommend adding a power relay to take the load off the controller relay.

As a rule, I don't like power control relays sharing a circuit board w/ logic and driver circiuts - especially since the motors in pumps and spindles tend to be highly inductive loads.

Quite a few of us use the coolant output to power high speed spindles (routers, die grinders etc.) - this is very handy, but the output (amps) is limited as furnished.

In addition, the Tormach 115 volt power cord is relatively small gauge wire - you should upgrade to a #14 gauge minimum for larger loads.

Adding a relay will also allow you to switch 220 volt pumps, spindles etc. when properly wired - use a 115 volt coil relay switched by the coolant relay on the Tormach controller.

My .02;

Art Pentz

[MichaelHenry]

FWIW, I've been using Hangsterfer S-500 coolant for a couple of years now on acrylic, among other materials, and have found no effect on the acrylic parts - no crazing and no micro-fractures around stress points.

Mike

[ImanCarrot]

I use 50% ethanol/ 50% water in a mister (low presure- barely visible) and I get an optical finish on cast acrylic.

Oh sharp tools! you need sharp tools!

[grhd76]

I know this post is asking about coolant, but what spindle speed will you be using?

After looking at the spindle speeds the Tormach 1100 works at (max 5000 rpm), can you even cut acrylic? All the bits I've seen that are used for cutting acrylic recommend speeds upwards of 18000 RPM. Can you cut acrylic at lower speeds and still get a decent finish?

I'm interested to hear your results once you start cutting.

[Don Clement]

I know this post is asking about coolant, but what spindle speed will you be using?

After looking at the spindle speeds the Tormach 1100 works at (max 5000 rpm), can you even cut acrylic? All the bits I've seen that are used for cutting acrylic recommend speeds upwards of 18000 RPM. Can you cut acrylic at lower speeds and still get a decent finish?

Isn't spindle speed also a function of cutter diameter?

Don

[grhd76]

Isn't spindle speed also a function of cutter diameter?

Don

Surface cutting speed is a function of cutter diameter. I tend to think of spindle speed in terms of RPM.

If I remember correctly the cutters I was looking at were about 1/4", so not too big. If you use a larger bit say, 1/2" the surface cutting speed will be higher when ran at the same RPM. But if even the 1/4" need ~18000 rpm, you'd have to use a pretty large cutter to match the surface cut speed of that bit and be able to run it at 5000 RPM of what the Tormach can do.

I dunno...maybe you don't need that fast of speed? I'm getting ready to buy a Tormach and am curious about whether it can handle acrylic. (I'd be stoaked if it did).

[Don Clement]

If you need that kind of speed then you might consider the new speeder.

Don

[MichaelHenry]

I ran a job a while back using 1/8" 4-flute carbide end mills in acrylic. Checking back in the CAM file, speed was 4000 rpm and feed was 16 ipm.

That seemed to work fine and the parts worked (and are still working) well. I used Hangsterfer S500 collant at about 6% concentration, which gave a pretty darn good surface finished.

Mike