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1995 Micromill spindle control

Posted: Wed 07 Apr , 2010 15:39 pm
by Bongo
Hi;
I have a 1995 micromill with a smartstep/3 controler. The machine is from a school in the USA. I reviewed the dos software manual and had a question about spindle speed control. The spindle motor control is a KBIC-240DS (not a sprint400 controller shown in some drawings.)

My question - Is the spindle speed controlled by the software or by the speed control knob on the front of the machine.

The dos manual I have shows some milling code examples. In these examples you create code specifying the spindle speed.

The KBIC-240DS can be controlled by an input voltage but I cannot find any information on the wiring that shows the control voltage going to the controller. I have not had the chance to connect the Micromill to a computer to test the code examples.

Regards

Re: 1995 Micromill spindle control

Posted: Wed 07 Apr , 2010 17:24 pm
by Steve
Hi,

I am not sure on this one. The KB drive has inputs P1 P2 and P3 these are for an external potentiometer. I would follow the wires and check where they go. If there is an analog control there will only be wires on the P1 and P2 terminals. If there are 3 wires there will be a pot that controls the speed.

The Denstep control card had an analog output built in on it but the smart step did not.

Re: 1995 Micromill spindle control

Posted: Wed 07 Apr , 2010 22:33 pm
by Bongo
Steve;

Thank you for your reply,

The controller has 3 wires for a pot. I could not find any information on voltage outputs on the smartstep/3 card and it is very difficult to trace the wiring since it is in wiring trays. The wiring diagram in the Micromill Dos manual was a little hard to trace but I did not see any analog outputs going to the controller. The Micromill Dos manual had the information about speed control in the code so I had hoped that it would. Once I get the computer set up I will find out.

Regards

Re: 1995 Micromill spindle control

Posted: Thu 08 Apr , 2010 9:15 am
by Steve
Hi,

The Terminals P1 and P3 have 10V DC on them. The pot wires to this, I think it is 5K ohm. P2 is the analog in.

Be carfull around the spindle drive as it is uniscolated and all the terminals are floating at mains potential.