MetalworkingFun Forum

Bench tested the motor, driver, micro controller (Nano) and the power supply. No smoke was released. Seems to work well under no load conditions.

Ed

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I connected all of the pieces for the power feed to test them and had a hell of a time trying to figure out how to change a positive number to a negative number. The motor driver turns the motor in one direction with a positive number (0 - 255) and the reverse direction using a negative number (-0 to -255). Of course the ADC in the Nano only gives you a positive number from 0 - 1023. In the end it was very simple but I wasted most of the day trying to do it the wrong way.

Now I have a hardware problem where if I turn the speed down quickly something is causing the power supply to shut down. Using my clamp meter I was seeing, at most, less than three amps. The driver is capable of driving 13A continuously, 30A for about 10 seconds. My power supply is rated at 13A. I'll hook up the oscilloscope to it tomorrow and see if I can see anything strange going on. I really could use a current probe for my scope but man are they pricey!  

Ed

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(05-11-2023, 08:02 PM)EdK Wrote: [ -> ]I really could use a current probe for my scope but man are they pricey!  

Ed

Standing by for the test results.

Back EMF?

(05-11-2023, 09:34 PM)Vinny Wrote: [ -> ]Back EMF?

That's what I'm thinking. I guess I'll find out tomorrow. I'm hoping I'll need a current probe so I can justify it.

Ed

(05-11-2023, 09:48 PM)EdK Wrote: [ -> ]

(05-11-2023, 09:34 PM)Vinny Wrote: [ -> ]Back EMF?

That's what I'm thinking. I guess I'll find out tomorrow. I'm hoping I'll need a current probe so I can justify it.  

Ed

(05-11-2023, 09:48 PM)EdK Wrote: [ -> ]I'm hoping I'll need a current probe so I can justify it.

What a Gomer, I already have one.  

Ed

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I got the problem fixed that was causing the power supply to shut down when turning the speed down at a fast rate. I read the datasheet for the power supply and it said that if it's an inductive load it's best to put a diode in series with the load. I did that and it fixed the problem. It was clearly a problem with back EMF. It took me longer to find the 60V, 35A Schottky diode I knew I had somewhere than it did to incorporate the fix and test it.
Now it's on to figuring out the mechanical side of this project.  

Ed

I thought I'd start a thread showing the x power feed project.

Ed

The left end of the leadscrew has a key in it so that should make it fairly easy to fit the power feed without modifying the leadscrew.  

Ed

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