Re: [CAD_CAM_EDM_DRO] Re: Rong Fu RF 45 vs RF 31 CNC - Help!

Hi Cap,

Where is this group, and is there a URL? I'd be interested in
seeing/hearing what you've done. My RF-31 is still waiting for
conversion. I have some Sanyo Denki R730-012W 80V, 4.8A, 300W, 2500 rpm
servos for the X and Y axis. I'd like to use Gecko 310s.

Can you give me the stock #s for the ball screws and nuts?

Thanks in advance for any information you can provide.

Alan KM6VV


capteod wrote:

>
> As the project leader of a SIG of the Valley Metal Group, which
> converted three (3) RF-31's to CNC with Servo Motors, I can tell you
> that any of the machines made on this model are convertable. We had
> ENCO, GRIZZLY and an Actual Rong Fu. They were all compatable.
>
> We chose to build with Servos and GECKO drives. We are getting
> feedrates of 60 inches per minute and rapid feeds of over 120 inches
> per minute.
>
> Our plan was to maintain the overall footprint of the machine and we
> made a maximum effort to compact this conversion. The Z AXIS servos
> system is concealed inside the head, and driving the spindle
> directly. I found that using the Rack and pinion supplied as
> standard with the RF-31 you could not get accuracies of +/-0.010"
> due to the rough mACHINING OF THE RACK AND PINION.
>
> The servos we used are ELECTROCRAFT and they draw about 6 amps
> each. We used commercial ballscrews and nuts from ROCKWELL and the
> ball screws specifications are accuracy of +/-0.004" per foot. When
> I measured these ball screws the numbers were less than 0.002"/foot.
>
> We made our own ZERO BACKLASH ball nuts using two ball screw nuts,
> two adapters and a spring. The ballscrew nuts cost $27.00 each and
> if you purchase a zerobacklash ball screw it will cost $127.00.
>
> I have extra parts from this conversion group and i will be selling
> them since one of the members of the group dropped out of the plan
> and we had made parts for the fourth unit.
>
> Everyone thinking of this conversion should look at MACH2 for
> software as it is better than anything available. This software is
> true to the ANSI standards, and is equal to the FANUC/GENERAL
> NUMERIC controls which cost over $15,000.
>
>
>