CAD CAM EDM DRO - Yahoo Group Archive

Re: Transformers and gecko drives

Posted by caudlet
on 2004-03-28 14:23:34 UTC
--- In CAD_CAM_EDM_DRO@yahoogroups.com, "callcbm2000" <callcbm@d...>
wrote:
> I have a machine controller transfomer hooked up to three Gecko 320
> drivers. My question is would it be wise to hook three transfomers
to
> each drive or is this unnecessary. The transformer is hooked to 110
> volts and puts out 24 volts ac. The amperage I'm not sure as there
is
> no rating on the tranformers. The output wire is about 12ga
wire.The
> cost of these are not a issue as I have at least 15 Transformers
the
> same

Is the single trasnformer getting too hot? Can you keep your hand on
it for 3 seconds? If its constantly overloaded it will heat up over
time. One of the ways to try and determine the output of a
transformer is to measure the wire. Transformer designers don't
oversize the wire since even one size larger will often force you to
use a bigger bobbin and core thereby driving the cost up. #12 should
take you up to 15 to 20 Amps of current. Another way (really rough)
is to weigh it and figure about 20 watts per lb. If you know the
secondary voltage and estimated wattage then you have the projected
current number

> The motors are dc and rated top voltage is at 34 this is based on
per
> thousand RPM and amperage is at 20 amps.the size or rated torque
for
> x-y is peak torque 1.77 N-M rated .353 N-M, z motor is 1.06 peak
> rated at.212. this info is from Minetia rm dc servos Ugrmem-02 I'm
> not sure of the OZ -in. But when I run two axis at the same time
the
> motors or movement slows down, running one motors it spin faster.

one N-M is equal to 141.6 oz-in


> I'm using Master 5 software and maxed the speed I want to up grade
to
> mach 1-2 But need bigger computer or Clock speed I'm presently
> running a amd-k6 3d processor. The machine has ball screw drive The
> pitch I'm not sure but one revolution moves .0200 and if I'm right
> thats 5 turns per inch? I'm seting the machine to do 21/2 d carving
> and would like good speed.

.020 pitch is 5TPI
What are you encoder specs. That will determine the pulse rate you
will need. What IPM is your target?


> If I can perfect this My next two projects are to rebuild a Nc Elto
> knee mill that is set up with steppers all 3 axis with ball screws
> and a Sheldon 17" x 36" Lathe with Steppers on both axis factory
> install same as the mill. The chopper drive unitfor them are much
to
> big and out dated But first get the Router to work.

Each project is a learning experience. Once you finish the router
and use it for a while you will come up with things you would do to
improve the design and you can take that knowledge into your other
retrofits.

I would get a DC voltmeter onto the raw DC and monitor it under
load. That will tell you if the power supply is heafty enough. It
would take a measurable drop in the DC to slow the servo's down since
they will try to maintain the same speed by changing the pulse width.
Make sure the motor wires are big enough to handle the average
current the motors see. If the DC voltage with one vs two or three
motors is within 10% you need to look elsewhere.

Let us know what you find.

> Thanks for any help
> Randy

Discussion Thread

callcbm2000 2004-03-28 10:58:12 UTC Transformers and gecko drives caudlet 2004-03-28 14:23:34 UTC Re: Transformers and gecko drives callcbm2000 2004-03-28 14:40:22 UTC Re: Transformers and gecko drives caudlet 2004-03-28 17:28:01 UTC Re: Transformers and gecko drives ballendo 2004-03-28 19:30:07 UTC Re: Transformers and gecko drives