Back to building and need advice

[rcrabb]

I like the idea of the PC power suplies. I do have a pile of these also. But that still doesn't get me away from the big current limiting resistors. I will be ordering the Xylotex board. But please keep me posted on your power supply project.

[project5k]

can do... i have already modified 1 of the power supplies, and linking the 12v's i can get 24v @ 7a or linking the 5v's i can get 10.1v @ 20a... so so far its working well... i tried my driver board and one of my motors laying on the desk here and at 12v i got something like 375rpm before it went into cogging, and then i tried at 24v and got something like 600rpm.. now this is with just the motor and a 3lb disk i spun up on the lathe, just for inertial purposes... so i'm hoping that at 36v i can get maby 750 usable rpm, but we'll have to see what the torque is like at that fast...

[candle]

its all about how fast the current curve goes up in motor windings
faster it is, faster motor will go before loosing torque
i've seen drivers using 160V DC at reduced current (for a given motor) to a half
initial torque was lower, but torque/speed curve was linear - 30% drop on max rpm - thats somethin'!

[Den-Den]

I am using the Xylotex 269 oz motors and their board and am very happy with it so far. Not sure how fast it will go, now running 50 ipm rapids with 1/2 - 10 acme screws. It would problably go faster but I have not pushed it.

[project5k]

well thats 500rpm, how long is that travel on that screw?

[Den-Den]

The travel is 18" x 18" x 6", I would want more speed if it were larger.

[project5k]

i understand.. im in the process of building mine right now, and if things continue to go like it looks that they will my 3'x3' should be able to do something like 75 IPM

[rcrabb]

Today I have recieved my Xylotex board. WOW. Durring my initial tests I am able to get about 900 RPMs before the motors stall. This test was done with the motors uncoupled. With my Stepperworld board I was only able to get 200 RPMs. I figure I should safely get 100ipm cutting with 180ipm rapids. I'm sure alot has to do with the increase in voltage but the investment was worth it.