Re: [CAD_CAM_EDM_DRO] Re: Arcsin 3 axis

OK I have a design for a roller bearing CNC router sized with a work space
volume 48X48X6 in. I am still working out the axis static weights which
will have
some effect on the ability to accelerate the Axis, but some mass is good in
dampening. Using rolled ball screws for the driving mechanism would
direct drive
300 oz/in steppers push such a thing if it is hooked up direct drive, or
would I need
to run a 2:1 or 3:1 reduction.

It was my understanding that bipolar drives perform better and a reasonable
performance should be possible with 3-3.5 amps @ 48 vdc.

Second , if I have 2 48 vdc supplies rated @ 6amps could I run them in
parallel
to the controller to get about 12 amps input.

I do have a 75 volt supply, and the Geckos are tempting. How much better
performance could I get adding in the extra $120 for the geckos? Would it
be a direct ratio to the voltage increase.


caudlet wrote:

>Dave: After studying the site I came away with the following thoughts:
>
>The chopper and microstepping approach make this a contender for the
>middle part of the market. The Three amp rating puts it square between
>the Xylotex and three Gecko 201's. It would be a good choice for a
>design where you had 3A stepper motors (maybe up to 3.5A). The 48VDC
>rating is reasonable (better than the 35 on the Xylotex and not as good
>as the 80 on the Gecko's). Depending on the stepper motor that voltage
>should give pretty good performance.
>
>The only thing I see about the unit is that the cost is relatively high
>compared to the Xylotex (2.5A @ 35V 3 Axis = $145.00) and three Gecko's
>(7A 80VDC X 3 units = $342) at twice the specs but only 28% more in
>cost.
>
>If you are into soldering, the Hobbycnc 4AUPC Kits are very reasonably
>priced. They are Unipolar divers (3A 44V) but are chopper and
>microstepping and have gotten some good comments from the list members.
>
>If you can give us an idea of the type and size machine you are going
>to build we can talk about the motors then we can talk about the best
>drive boards for the application.
>
>