[borrisl]

I'm a late bloomer. Taking forever to convert my two shoptasks into "super" machines. I have VFD's with 2hp 3ph motors. Just got them hooked up tonight and turned on. Wow! Incredibly quiet. Almost silent. Of course I've removed everything out of the case. So, I have one motor with pulley, one belt, going to spindle. No gears, no additonal "stuff". I push the button, bang 150 rpm, push again, bang, 1800 rpm. And any speed inbetween with the push of a button. Amazing. If any of you are considering a motor upgrade, this is a great option. Quiet and 2hp.

[acerocket]

I have had my Shoptask Eldorado for about 2 years now. I am considering making the switch to CNC and am quite interested in the VFD motors. Can I ask what kind of VFD drives and motors you are using? Are the motors 220V 3 phase? I have been looking for a few days and there are so many options I have no idea where to begin. I Thought it would help to ask someone who has made the switch.

[PoppaBear10]

Well I use 2hp KB Electronic DC drives, and Lesson 2hp variable speed DC motors, also very quite.

Automation Direct has some good prices on Motors and VFD's or other type drives as well. They have both AC and DC motors and drives.

One thing you want to look for if you are using "Machx" to control your machine (or other controllers probably as well). You want to make sure you can control the Drive via a +0-10v or +/- 10v input signal (if you use a +/- 10v imput signal they you will have to have a digital to analog converter board and then run that through a reversing relay so you can get a +0-10 on your m3, and a -0-10 on your m4).

Your other choices would be to get a drive controlled via PWM (do-able in Mach but lots of noise problems with PWM).

Lastly you could run a Servo/motor for your spindle drive again configurable in the "motor tuning", in mach.

scott

[acerocket]

Thanks for the reply PoppaBear10. I am just begining to start gethering all the components and will no doubt be reading and re-reading a lot of these threads and asking questions.

[Ron111]

Borrisl, poppabear10, acerocket and the rest of the Guys lend me your ears,

fella's need a little wisdom, or maybe a good bit of gut feel. The situation is this. I bought the cnc shopmaster a little over a year ago to prototype a militaryweapon accessory. Now, I doing limited production runs. I have upgraded the Mill motor to a 2hp motor(3450 rpm) and am able to cut 6061 .060 to .070 deep (full width cuts) at 18 ipm (4 flute cobolt mill 1750rmp), but I can see evidence of the machine flexing as I cut 1/2" wide full with slots about 2" deep.

Let me put my web site and you can tell what I'm doing.

http://www.safestshot.com. I realize that I may be working the machine a little harder than what it is intended or maybe not. Any way to make the mill a little more ridgid, or better feed rate speed feed suggestions (with the higher speed motor) higher spindle rate are possible, but not sure what the pully and drive bearnings will tollerate.

The answer maybe to be content with cutting less and slower, but now it's time for me to be silent where the wize voices can be heard.

Speak to me old great ones (a little humor never hurts)

Thanks for your input!

Ron

[Ken_Shea]

Ron,
Here are a couple of common things you might consider.
1) Switch to carbide 3 flute Aluminum Cutting
http://www.lscarbide.com/products.asp?cat=32
I think you will be pleasantly surprised with the difference, even over cobalt.

Get two if you are able, one standard length for normal machining and a long reach for the deep slots you mention, you may need to reduce the DOC and/or feed when going that deep.

2) RPM As fast as your equipment will go, you are slow even for the Cobalt, close for HSS.

3) Try your current settings, if there is still a problem reduce the DOC which you can offset most of by increasing feed.

Some sort of chip evacuation should be used as well.

Always chuck up the cutter as short as possible.

Before the above you might just try increasing the RPM.

[PoppaBear10]

Yep, what Ken said