Forward a post please !!

[picclock]

Hi

I've received a request for information from cncfrenchteam on HMEM. However my account from them is completely borked. Could someone point him to this post or forward it to him.

So in reply to cncfrenchteam :

>>>>>>>>>>>>>>>>>>>

Hi

I remember that the width of the high step pulse controlled the motor coil current - hence the torque. If a stream of pulses at 500hz is sent to the stepper input normally this would be a square wave, with high and low pulse times of 1 mS. Adjusting the high time whilst keeping the frequency constant would alter the ratio, say 0.5mS high and 1.5mS low. So although the frequency (motor speed) was constant the mark space ratio was altered. It was only after I had started to alter the board I realised what they had done. I think it used an SLA7051A driver chip sheet attached. Pretty certain it was set to half step - see data sheet. The setting of the motor current is quite important with all stepper motors. They really work best into fairly constant loads where the winding current can be optimised. Too much current with a light load causes the armature in the motor to over accelerate and possibly oscillate, too little may not overcome stiction and load resistance.

Hope the info works for you - its all still working well on my lathe using an old laptop power supply.

Good Luck !!

Best Regards

picclock

>>>>>>>>>>>>>>>>>>>

Many thanks

Best regards

picclock

[dsquire]

Hi

I've received a request for information from cncfrenchteam on HMEM. However my account from them is completely borked. Could someone point him to this post or forward it to him.

So in reply to cncfrenchteam :
.
.
.
Best regards

picclock

picclock

I have forwarded a copy and a link of your post here on MadModder to cncfrenchman. I have also sent him a PM explaining this to him. I hope it all works out OK. Let me know if there is anything else that I can do.

Cheers 

Don

[picclock]

@dsquire

Thankyou very much for your efforts on my behalf. Because he requested information on that site there was no way I could get in touch with him and I would not have him think I had not responded to his request, which would be rather rude.

Please accept my best regards and a virtual beer. 

many thanks

picclock

[dsquire]

@dsquire

Thankyou very much for your efforts on my behalf. Because he requested information on that site there was no way I could get in touch with him and I would not have him think I had not responded to his request, which would be rather rude.

Please accept my best regards and a virtual beer. 

many thanks

picclock

Hi picclock

Your welcome, just glad to be able to help out. 

What is the problem that you can't access HMEM? You could always invite cncfrenchteam to join up with MadModder. If you need any help I would be happy to act as a go between to help you. 

Cheers 

Don

[cncfrenchteam]

Hi picclock,

Thank you for your answer. It's really helpful and I hope we'll manage to make the motor work as we want to with the information that you gave us !

I'll give you some feedback when we do it.

Thanks again and thanks to dsquire for forwarding your post !