--Have been making do with a Sherline cnc rotary table; it works but
it has a few issues. I'm thinking of stepping up to a closed-loop system
with a little more torque. Can someone suggest something that doesn't cost
ten times as much? Not even sure if one exists tho...

--
"Steamboat Ed" Haas : $150,000,000,000 in pork??
Hacking the Trailing Edge! : Where's my share???
www.nmpproducts.com
---Decks a-wash in a sea of words---

steamer wrote:

--Have been making do with a Sherline cnc rotary table; it works but
it has a few issues. I'm thinking of stepping up to a closed-loop system
with a little more torque. Can someone suggest something that doesn't cost
ten times as much? Not even sure if one exists tho...


Replace the stepper with a big larger DC servo and encoder and a Gecko
drive. Use the same RT and add a few hundred dollars in the new servo
and drive, drive with same software.

Pete C. wrote:
Replace the stepper with a big larger DC servo and encoder and a Gecko
drive. Use the same RT and add a few hundred dollars in the new servo
and drive, drive with same software.
--Neat idea; me liiiike! Forgot to post link to current work:
http://www.youtube.com/watch?v=CASnbTeknzE
--Kinda silly setup but it uses a lot less power than the MiniMill
and it's adequate for the job.

--
"Steamboat Ed" Haas : $150,000,000,000 in pork??
Hacking the Trailing Edge! : Where's my share???
www.nmpproducts.com
---Decks a-wash in a sea of words---

"Pete C." wrote:

Replace the stepper with a big larger DC servo and encoder and a Gecko
drive. Use the same RT and add a few hundred dollars in the new servo
and drive, drive with same software.

I built a few motion systems on my former companies dime. I know steppers are cheap but
if you blow past the limits, a servo recloses the loop when it has a chance. Steppers
just sit outside, kicked to the curb, never catching up again.

Wes

Wes wrote:

"Pete C." wrote:

Replace the stepper with a big larger DC servo and encoder and a Gecko
drive. Use the same RT and add a few hundred dollars in the new servo
and drive, drive with same software.

I built a few motion systems on my former companies dime. I know steppers are cheap but
if you blow past the limits, a servo recloses the loop when it has a chance. Steppers
just sit outside, kicked to the curb, never catching up again.

True, though servo system can be and are built using both steppers as
well as the usual DC and AC motors. I believe one company makes a
product that is a stepper with an integral encoder and drive.