Re: [CAD_CAM_EDM_DRO] Circuit or Kit

On Wed, 4 Sep 2002 13:41:35 -0600, you wrote:

>Don't get hung up on the rule of thumb about using 10 - 25 x the voltage to
>drive steppers. It is true that you can get faster rapid moves with higher
>voltage if you are using current limiting drives, but you can also drive the
>motors at lower voltages and get fine performance. My first CNC set-up was
>with a Camtronics 5 amp chopper drive kit running at 24 vdc. It gave me 90
>ipm on that machine. Yes I could likely have gotten 120 ipm if I used 60 vdc
>and drives that could handle the voltage, but so what. 90 ipm was more than
>enough.

True enough - I'm running 28V 4A on MAE stepper motors that are rated
for 75V 5A max 1.7mH - 230 Oz/inch (they don't give a voltage rating
like most manufacturers - just mH, A & Max voltage). They are
frightening at 50V!!

I'm quite happy at the 30ipm rapids I get, and rarely cut at more than
12ipm - can't get the spindle speed fast enough for my little Taig!

As set now - it will shear a 1/8th mill - no problem! (Don't ask -
GCode brain fade ;)

I've had loads of questions since publishing my web pages, mostly on
this very subject, people read the motor label - it says "5V 1A" so
they feed it 5V and wonder why it doesn't work very well (Or even at
all) !!

I always point them to Mariss's motor white paper - It would be a damn
site better if the motor manufacturers did as MAE have done and rate
them for max voltage! What do you guys think?

Steve Blackmore
--
Pilot Consultancy Limited ***** Computer Consultants
Telephone 01744 752256 Mobile 07831 768478
Email: steve@... WWW: http://www.pilotltd.net