[john86126]

I currently have mechtronics controller with 57BYGH405A stepper motors and im trying cnc a harbor freight mini lathe problem is once it gets any type of resistance it stalls I was wondering if anybody can recommend any better motors or do I have to upgrade my board and my steppers im currently looking at these NEMA 23 Stepping Motor | 24.0 kg-cm | 4 Wire | 57BYGH310


I currently have these NEMA 23 Stepping Motor | 21.0 kg-cm | 6 Wire | 57BYGH405A

and this is the current board im using http://www.easy-cnc.com/web/download...3Axis(NEW).pdf

[john86126]

260 OzIn 4-Wire Stepper Motor -

how about this motor would that be enough?

[lucas]

I currently have mechtronics controller with 57BYGH405A stepper motors and im trying cnc a harbor freight mini lathe problem is once it gets any type of resistance it stalls I was wondering if anybody can recommend any better motors or do I have to upgrade my board and my steppers

This motor is rated for 277 oz.in, a phase current of 3A and has an inductance of 2.4 mH.
It needs a 48V supply to operate properly at speed.
Your drive has 24V and 2.5A max ratings, it is higly underrated for this motor.
How did you connect the motor: half or full winding?

The other (310) motor you are looking at is a lot worse than your current one with an inductance of 16.2mH, torque will fall down rapidly when it's turning.

I don't know what torque is needed for that lathe, what do others use?

Try to find that or just try another drive with a supply of 40-48V and 3.5-4 current per phase.

[john86126]

It setup to run in series

[lucas]

Serie or full winding increases the inductance and reduces torque at speed further.
What current setting are you using? 1.5A should be the correct one for this motor.
Do the stall's also occur at really low speed?
If this is ok then a better drive and a half winding connection will almost certainly solve the problem.

[john86126]

yes im using 1.5 amps or 3 volts... the motor will spin no problem however i can stop it fairly easy with my finger is it possible it can be my motor turning specs in mach 3?

[lucas]

Can you also stop it at real low speed, motor running at +-100RPM? Please try this first

Mach can't be the problem, there could be a mechanical problem, guides too tight, alignment issues..
Are you using direct drive on the screws or gearing, are it the original screws..?

Did a search for you and found several posts where they recommend a +-200 oz/in motor for a mini lathe conversion so it should work with your motors.

[john86126]

yes I can stop it at that speed I currently have the motor disconnected from the lathe just sitting on the table so I can take the lathe out of the equation. yes im using the stock screw with a direct drive... can you recommends a better driver? I was looking at the gecko however they dont seem to support 6 wire steppers

[lucas]

The motor should have enough torque at low speed even with the drive you have now.
There must be something else wrong, wich power supply are you using, volts and amps?

Gecko does support 6 wire motors:
Support

[john86126]

im using an 18.5v 6.5 amp power supply

[john86126]

well I was browsing Youtube and I found a mill that uses the same board as me and goes way faster with torque So i dont know what my problem is

heres the steppers
http://www.kelinginc.net/KL23H276-28-4B.pdf

heres the video

[ame=http://www.youtube.com/watch?v=a37Gqjg6GgA]Harbor Freight Mini Mill CNC Conversion - Video and Pictures - YouTube[/ame]

[lucas]

I assume you have the problem on all axis and motor's?

The power supply could be the reason: measure the supply voltage when the motor is running and check if the output doesn't drop too much.

If this is ok restart from the beginning, check wiring, current setting, .. all the steps from the manual, etc..

Don't take anything for granted, it could be something simple like your DVM wich is bad and causes wrong readings and thus wrong current settings.

If nothing helps: contact the seller of the drive, they might have some quick checks to verify if the drive is ok.

[john86126]

I currently only have the one motor side completed so I havent been able to test the other axis's well I check everything and everything seemed good so Im kinda stumped I was going to email the company but I think they went out of business so I may just buy those 4 wire steppers and see if running them in full coils instead of the half I have now works

[lucas]

... so I may just buy those 4 wire steppers and see if running them in full coils instead of the half I have now works

It setup to run in series

?? Which connection scheme are you using now, should be series (= full coil) with the current motor and info you provided.

That other motor will be worse.

[john86126]

?? Which connection scheme are you using now, should be series with the current motor and info you provided.

That other motor will be worse.

im sorry I ment parrallel im new hahaha

you think this motor will be worse?

http://www.kelinginc.net/KL23H276-28-4B.pdf


that motor is the same motor used in that video

[lucas]

Parallel?? none of the 3 motor's you linked to can be wired parallel, only 8 wire motors can.

I understand being new creates confusion but that support document from Gecko explains it very well.

Your current motors should have torque enough IF wired in series = full coil at low speed with the driver you have. If not there's a problem somewhere else: driver or power supply, that Keling motor is slightly better than your's but won't work untill the problem is found.

[john86126]

what I ment is that the motors I have now are wired in series the new motors that I posted in the last post those are only 4 wire so I figured that was parallel? the only reason I say the other keiling motors is because I saw them working with the same board

Parallel?? none of the 3 motor's you linked to can be wired parallel, only 8 wire motors can.

I understand being new creates confusion but that support document from Gecko explains it very well.

Your current motors should have torque enough IF wired in series = full coil at low speed with the driver you have. If not there's a problem somewhere else: driver or power supply, that Keling motor is slightly better than your's but won't work untill the problem is found.

[H500]

The board has a POT for adjusting the motor current. Perhaps you have it set too low.

[john86126]

I have it set for 3.0v and according to mechtronics 1.5 amps I have verfied this 3 times already

[H500]

The motor needs 3 amps. With 1.5, you will only get half the rated torque.