problem with geckos

[cowanrg]

well, i finally got my geckos for my round-column cnc conversion. its my first, but i spend about a year or so reading up on stuff.

all WAS going well. i am doing three independant power supplies, one for each axis. right now, i am pulling +5v from my computer power supply. the power supplies are pretty basic. they are 24-0-24 5A transformers, fed into a bridge rectifier, and spit out into 2x 12,000uf caps. so, i get around 35v out.

the +5v line is just tapped from the power supply leads in the computer. there is red, black black and yellow. im tapping from the yellow and black to get +5v.

SO, pin 1 gets black (negative) from supply, pin 2 gets positive (red) from supply, 3 gets first coil, 4 gets opposite end of the coil, 5 gets second coil, 6 gets opposite end of coil, 8 gets dir signal, 9 gets step signal, and 10 gets +5v.

the step and dir signals have been fed through various ways. i have a breakout board, but its not the best, i kinda had to rig it up to work. it WAS working fine though. BUT, i just got it out of the circuit because it was easier to wire up 1 axis for testing. so i was taking the dir and step wires from the gecko and wiring them straight into the parallel cable. then i tried directly into computer, then i tried into another computer, then i tried the breakout board again.

here is what is/isnt happening. the light on the geckos (201) comes on. i measure (with my meter) +35vdc across pins 1 and 2. i measure +5v across pins 1 and 10. i have the pins setup correctly in mach2 (ive checked it, and then wired it for Y axis, and checked that), but no go. the motor doesnt sputter, or do anything. it just sits there. it acts as though its off. also, im not sure how relevant this is, but when metering the coils on the motors, i get nothing. they dont seem to be getting any power when im jogging them in mach2.

i tried throwing a meter on pins 2 and pins 3 then to ground, but i cant seem to make out whats going on. i get +5v from pin 2 (step pin) to ground, and when i jog, it just sags down to 4.99 or so. pin 3 (dir pin) to ground gives me +5, then i change direction, and it goes to 1.6 or something, then goes back when i reverse.

i thought it might have been a bad parallel port, but i tried my other computer, and same thing happened. i have 3 geckos, ive tested 2, but i hesitate testing the third of somehow my configuration is eating geckos. but lights turn on when they get power, and all seems to be ok. is there some other way i can test them to make sure they work? its like they arent getting a signal.

thanks guys.

[ger21]

I'm not sure exactly what's wrong, but when power is supplied to the Geckos, the motors should lock up. If they don't, the Geckos are wired wrong.

Also, if you wire the motors wrong, it will kill the Geckos instantly, so be careful there.

[cowanrg]

ok, a good update...

i emailed pminmo, since he's been helping me out some and he had something for me to try. he had me basically make a switch that would the step terminal on the gecko to the ground of the +5v. this bypassed the computer and sent a step command directly to the drive.

all three drives are moving. so, it is my wiring. im not 100% sure how its wrong, but it obviously is wrong somehow...

[cowanrg]

i tried hooking it up to the computer one more time. i fed the +5v from the computer into the breakout board, which grounds that supply with the ground of the parallel. i checked wiring, but no motion. motors are locked though, they just dont seem to get a signal from the computer.

i ordered a breakout board from cnc4pc yesterday. ill wait until that arrives. i dont entirely trust the breakout board im using right now. i had to rewire a LOT of stuff on it and the pinouts were all incorrect, etc... i guess as long as the drives and motors work im happy. i can always replace the parallel port.

[gabe pantess]

hey how's it going? i just got my first g201 and i am trying to get it going. i read the manuals, wired it up, and tried to give it step and direction pulses from a basic stamp, but the stamp won't get mysignals right. when i FIRST put power to it, it locked it up. now it kind of intermittenly locks it, sometimes by itself, sometimes if you just turn it a little on powerup, so i don't know if it's fried or not, especially until i get a breakout board.

gp_fab

[cowanrg]

well, i had some help, but got the problem resolved.

it turned out to be a bad motherboard, and bad parallel port. so thats why some of the commands were getting through. some of the pins were ok, while others were toast.

i replaced the mobo and it worked fine. one of my geckos was bad though. i have a guy taking a look at it. if he cant figure it out, ill have to send it back. it turns the motor, but has NO power at all. you can stop it with your hands very easily.

gabe pantess,

wait until you get the breakout board and try it then. you have too many variables when using a basic stamp... or just hook up the wires directly.

[motomitch1]

QUOTE:the +5v line is just tapped from the power supply leads in the computer. there is red, black black and yellow. I'm tapping from the yellow and black to get +5v. QUOTE

Isn't the black and red 5v and the black and yellow 12v?

[pminmo]

with the 45 degree tabbed corners up it s/b 5V (yellow), gnd, gnd, +12V(red), I think..............

[motomitch1]

I just check mine I'm getting 5v out of the red wire from PC power supply and 12v from yeller
I didn't check it with the black wire i was using the case for negative.

[motomitch1]

nice little power supply
http://web2.murraystate.edu/andy.bat...OWERSUPPLY.HTM

[NC Cams]

more links relating to PC based power supplies:

http://www.antennex.com/preview/archive3/powers.htm

http://www.procooling.com/index.php?...s&disp=52&pg=1

NOTE: if you put a 100k 1 watt resistor across the storage/filter capacitors, you'll bleed them down and reduce the el-zappo potential.