[h_2_o]

If someone can help me out with this it would be appreciated. I have the g320's hooked up correctly, however i am having a problem getting the motor to do anything at all. I get the flutter/humming thing going on but nothing else. I have the settings set at this
Tun DAMP and GAIN to the 10 'clock position (8 'oclock = fully CCW, 4 'oclock = fully CW). Turn LIMIT fully CW.

and still nothing but the fluttering/humming sound.

anyone have any idea what might be going on with this?

thanks

[mlaws1172]

Is the servo locking up so that you can't turn it with your fingers?
mike

[h_2_o]

correct, it seems to be fluttering between 2 encoder points creating the humming sound. at least that is what i think it is doing. anyway yes it is locking up.

[Al_The_Man]

Is the encoder phasing correct for correct direction? One way to check is to swap the A & /A if differential encoder or the A & B if single ended.
Al.

[h_2_o]

al i have a, a-, b, b-, z, z-, +5, and grd. I was guessing that the a, b connections should be used. are you saying that i should try the a-, and b- connections and if those do not work swap a,b connections to the drive to see if it works then?

thanks

[Al_The_Man]

If you have differential encoder, which you appear to have, a direction change can be done with a swap of A & /A, I am not familiar with Gecko they may have an alternative method, but this should work with all applications, where the direction phasing is wrong.
Al.

[ViperTX]

Al...you may hit the nail on the head....I don't believe that Gecko accepts Differential Inputs.....you have to have a Gecko adapter to convert the differential to single ended.

[Al_The_Man]

In most case the if a system only uses single ended, then with a differential encoder output, the A, B & Z can usually be used WRT to common and the Complements left un-connected.
In this case then the A & B would be swapped to reverse the phasing/direction.
Al.

[mlaws1172]

I would look at the computer and make sure you it is putting out a signal telling the motor to move. sounds like the gecko is working.

Seeing how you have differential encoders , i would add some recievers and use them.
mike

[Al_The_Man]

Seeing how you have differential encoders , i would add some recievers and use them.
mike

According to the specs, don't gecko g320 take differential encoder?
Al.

[mlaws1172]

no they are set up for single ened. one thing to watch for with the encoder you are useing is what they draw for amps. Gecko is good for 50 ma.

but if the servo is locking up then it is seeing the encoder. for it to move it has to see a dir. and sterp signal
mike

[mlaws1172]

what brand of encoder are you using?
mike

[mlaws1172]

didnt mean that they won't work with diff. encoders. they will doing it the way you are. but you arent taking advantage of the diff. feature. the diff. signal will carry farther and ttake make noise.
mike

[h_2_o]

ok, now i have a different problem. I went through and redid my wiring and found a ground wire that had a break in it so i think that was causing some headaches. anyway i redid the wiring and now what i get is a motor that spins, but only spins. I can not get it to stop except when i get a fault on the gecko drive. to try and test i am using mach3 and have set the pots to the default or the above mentioned positions. I am using an optioisolated breakout board from cnc4pc. for the outputs i am using pins 2 and 3 for the x axis only. right now i just want to get one drive going correctly. I am fairly sure the problem i am having now is somewhere between the parallel port and the encoder. however i have no clue where to really start looking. if anyone can give me any suggestions or a good place to start it would be appreciated.

thanks much for all the help

[Bubba]

As stated earlier, the Gecko is good for 50 ma supply for the encoders. On one of my first setups, I used a servo with diff. encoder and it "worked" for a while. Then all of a sudden, I happen to notice the current requirement of the encoder ----120ma! You may have to have a seperate supply for that encoder and there is a resistor that has to be put on the gecko if you do that.

Read the manual as I don't remember off the top of my head the size or location right now.

[mlaws1172]

h20
you need to divide and conquer. first set up the geckos without the computer. Gecko instuctions tell you how. then hook up the step and direction signals from the computer.
if the motors are running away they, try swaping the a and b wires. if you don't know the amps of the encoders hook them up to an external 5Volt power supply.

you will need to put a 470 ohm resistor across terminals 6 (enc-) and 7(enc+). you will also need to run a wire back to 0volt from the 5volt supply ,hooked to terminal 6 (enc-).
mike

[Al_The_Man]

Why do you need a resistor across the encoder supply?
Al.

[h_2_o]

h20
you need to divide and conquer. first set up the geckos without the computer. Gecko instuctions tell you how. then hook up the step and direction signals from the computer.
if the motors are running away they, try swaping the a and b wires. if you don't know the amps of the encoders hook them up to an external 5Volt power supply.

you will need to put a 470 ohm resistor across terminals 6 (enc-) and 7(enc+). you will also need to run a wire back to 0volt from the 5volt supply ,hooked to terminal 6 (enc-).
mike

i'll take this in parts. I did hook them up exactly like the g320 manual says. the reason i said i rewired them was because of the broken ground originally. I figured better safe than sorry so i rewired everything. I have not tried the step/dir from the pc as of yet, but will soon.

as for using an external psu for the encoders, i am doing that and do have a 470ohm resistor across 6 and 7.

as for this statement

you will also need to run a wire back to 0volt from the 5volt supply ,hooked to terminal 6 (enc-).

this is the first i've read anywhere you need to run any more connections to terminal 6 if you are doing this. so i need to run a grd from the psu i am using for the encoder back to enc -? again i'm asking because i've not read anywhere else that says this.

thanks, and i will try swapping a/b right now and post back.

[h_2_o]

hehe did a bit of playing and still no good, however if i read your post correctly and i should ground or 0v the encoder pole of the drive, which i did do i get the motor humming again but not moving. if i swap a/b out i get the motor spinning but will not stop like before. I have to run now but later i am going to connect a- and b- and see if that helps, maybe they are all out of phase or something.

thanks again for the help guys and hopefully soon i'll get this working correctly

[ViperTX]

Al the resistor is across terminals 6 and 7 when an external supply is used to power the encoder....I have no idea what it's for.....except as a minimum load.