Need a little help

[big_d]

All right... I've been reading for days now and I think my brains about satuarated for the time being, but I still need a little direction. I recently purchased a used older PR. It came with everything minus the electronics and a spindel/router (no big deal, I'm going to start out with one of my routers). After considering many avenues including going 4G, Ascension 1000, Bob Campbell's upgrade, etc, I have decided to put my own components together for now since this is my first shot at cnc.

Here's where I need help. I have the 4 stock steppers which I intend on using. They are the PK299-01AA's with 6 wires. I can go half coil as suggested by Mike Richards on one of his posts, wiring is definatley not a problem for me. I have already decided to go with 4 Gecko G202's for the drives, and a 50V PS-6N50R12 power supply from Antek Inc to power them. I am in limbo on the breakout board though. I've looked at Campbell's, PMDX's and cnc4PC's but I'm not sure which is the best route to go. I do want the ability to be able to kill power to the router on errors which it seems most have. I also want to be able to run Mach3 which I'm assuming all will do? I guess another route could be a Gecko G-Rex, but I don't think I really need to go there yet. Anyone that has any suggestions or uses any of these, I would greatly appreciatte any info.

This seems like my biggest hurdle right now, but in my mind I know squaring the bot is going to be a bigger one.


Thanks,
David

[Brady Watson]

The PMDX-131 or G-Rex are both suitable for breakouts & supported by Mach3. Personally if this is your 1st CNC, your learning curve is going to be much steeper with this setup than if you just bought the 4G upgrade & learned SBP code instead of G-Code.

-B

[conceptmachine]

David,
Learning g code is not any harder than learning SBP code in my opinion especilly if you are not familiar with either of them.I upgraded with the ascension and mach and i love it,i've not had one single problem since!If you need any help with mach just send me an e-mail.
shawn

[big_d]

Thanks for the replies guys. Brady, as far as the pmdx, is there any readon the 122 board wouldn't work for me. I know the 131 has the opti-isolation and another relay I think, but some of the competitors boards have this as well at a supstatialy lower price. I just want to make the right decision so I don't have to do this again anytime soon. I've ruled out the 4G for this reason. Plus it would be a larger investment for a machine that I'm really not sure of and I don't want to have to learn software/coding twice.

[richards]

David,
I use the PMDX-122 for $81. (As Brady suggested, the PMDX-131 would also work, but it costs $183 and requires you to mount the Gecko directly to the breakout board. Personally, I prefer to mount the Geckos to a thick piece of aluminum heatsink.)

Also, I would opt for a higher voltage power supply. The 50V unit will work, but it is only about 8X the PK299-01AA's rated voltage. A 70V power supply will give you higher speeds.

If you feed power to your controller through a door mounted disconnect to isolate all power from outside the box from connections inside the box, and then run the power inside the box through a latching contactor, you could easily wire a Normally Closed E-Stop switch to the latching contact on the contactor so that you could kill all power to the controller quickly in the event of an emergency. I've got a schematic for that circuit floating around here somewhere, but I can't seem to find it at the moment. Send me an email (email address is listed on my profile), and I'll send you the schematic.

I have the PMDX-122, the Gecko G100 and the Gecko G101/G102 boards. In my opinion, the G100 would be overkill when used with the PK299-01AA motors because you wouldn't be able to use speeds higher than the PMDX is capable of delivering; however, if you like technology for the sake of technology you wouldn't be satisfied with anything less than the G100.

EDITED: David, it looks like you posted while I was composing.

[big_d]

Thanks Mike... you got email.


David