RE: [CAD_CAM_EDM_DRO] CNC Newbie

I would recheck that diameter. .631 sounded large so I went out to my
shop and I checked a few of the ballscrews I have laying around they all
meaasure ~.615.
I had converted my mill drill to run off of steppers and I replaced the
acme leadscrews with ballscrews on the XY axis. On he Z axis I made
eccentric bushings to roll the the pinion in closer to the quill rack
for less backlash.
Servos are faster, so much smooother and don't suffeer from stepper
motor resonance and they are closed loop. Today a servo system barely
cost more than a stepper system. I would go with 600 oz in PMDC servo
motors using a 2/1 ratio timing belt drive with ballscrews. I can email
you some pictures of some slick stepper/servo motor mounts I made for my
mill drill if interested.
Dan

-----Original Message-----
From: jlwas2002 [mailto:jlwas@...]
Sent: Wednesday, June 25, 2003 8:27 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] CNC Newbie


Hi, guys I am thinking of joining your world.
I have an RF-45 ,mill drill that I am currently adding some Thomason
ballscrews to. They are .631 " with the anti-backlash nuts. The
machine is manual with a possible CNC future. I have some books on
the suject on the way, but this board is more hobby based, so here
goes.

I will be designing a simple brake system for manual mode. I would
eventually like a dual purpose machine if possible. I currently have
those cheap linear scale DRO's on the machine now.

Now for the Q's.

Which is the best setup to go for? I have a set of stepper motors ,
Eastern Air devices model type LA34CKK. I think they are 620 Oz/in at
around 10 Amp! These steppers were free! I know about steppers
missing steps and they have good stall torque characteristics. I was
thinking of using feed back using say US Digital' E6D encoders on the
ballscrew ends. Or do I spring for a servo system? I have no idea
what is the best affordable servo system to go for. I know certain
servo type systems are out of this world.

I am guessing that a belt drive system is propably best for a dual
purpose machine? Any suggestions?

Jason



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