Convert a manual grinder to auto feed?

Flyinfool said:
Does the load mater in generating motor heat like a "normal" motor, or do steppers make the same heat regardless of load?
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The load makes no difference on a stepper, they draw the same current loaded or unloaded. What you normally want to do is set the idle current reduction to ON, SW4=Off
 
Glad to see your having fun with the stepper motors.

I do have a few more to trade with if anyone would like send me a PM.
 
OK I did have SW4 set to off. I dropped the steps per rev to 1000 and I upped the amps from 2.1 to 2.7 the motor was not getting hot so I will up it another notch. I can still hear it skip a few steps when it reverses direction. This helped a lot but made a new problem appear.
The motor shaft is now spinning in the pulley bore.
The motor shaft is .250 Dia and has a light straight knurled finish and has a light press fit to the pulley, and I ground 2 flats for the set screws.
I am thinking I may have to add a key way. The cogging of the motor must make some really high torque spikes.

I never cut an internal hey slot before. This should be interesting......
I will also get the spring bumper put back on, they should help a lot with the reversing.
 
For the pulley slip problem I would figure out how to build something like this. https://www.mcmaster.com/6435k12

Holds much better than a set screw. A key is not the best system for a bi-directional system. But on a shaft that small, you could assemble the pulley on the shaft then drill a 1/8 hole, half in the pulley and half in the shaft, and install a roll pin.

One problem you may have is that the acceleration of the motion profile is too aggressive. You normally need to ramp up and down over some period of time. If you are doing an instant direction change it is going to be an ongoing problem.

1565661294452.png
 
Yes the accel and decel curves are what is really needed, The controller that I have does not offer that option. I think that to use acel and decel curves I would have to have a controller where I can set the travel distance so that it has time to accel or decel. Right now I just have limit switches at each end of travel to tell it to reverse.

When I get to the motorizing the Z axis for the step over I am leaning toward an Adriano or raspberry pi board, then it will be easy to put in accel and decel curves. That will be a major learning curve for me since I am really bad at writing software. It is to bad that the Tiny Controls Surface grinder controller is no longer available, It looked to be perfect for what I want to do.

I can see that I still have a LOT to learn. But I am having fun doing it, so I will continue.
 
I did look at this controller on the SainSmart website, they have all of the info and downloadable manuals.
www.sainsmart.com

Single-Axis CNC Servo Stepper Motor Motion Programmable Controller

Only $39.99. Buy SainSmart 1 Axis CNC Servo Stepper Motor Motion Programmable Controller with fast shipping and 1-year warranty and technical support from SainSmart.
www.sainsmart.com www.sainsmart.com
It is also $10 less than Amazon.......

That is the controller that I was looking at for the Z axis. I could be all wet but it looks like I would have to rewrite the program for each job. As in a change of step over distance or table speed or length of travel.

In reading through the manual I did not find anything that looks to me like a accel or decel setting.
 
Well I started on the Arduino.
I bought a starter kit and I was able to make the LED blink. :D OK I have a LOT of learning to do........
Yes this leaves me a very long way from having something that will make my SG run.

I am starting to compile a list of features and variables for the machine that will be needed / desired. There will be a lot more variables for use inside of the program once I get that far.

At this time I have no intention of trying to automate the Y axis now or in the future, Just the X and Z.

So far my list is.
Length of travel in X and Z
Speed in X and Z
Acell and Dcell in both X and Z
4 grind patterns (Zig-Zag slow steady Z feed, Step at one end, Step at both ends, and None) (None has Z motor turned off for manual input.)
Hold X position for dressing wheel
Jog buttons.
Limit switches for X and Z
E-Stop button

Anything else I should consider????
 
Welcome to the world of machine programming. :) It took me 2 days to get the hang of turning an output LED on and off with a computer when I first started many years ago. A few weeks later I had a whole machine running, so you'll get there. :encourage:

I would add a ''teach'' function. Jog right, press enter to log position, jog left, enter, etc. Do this for both axes. Saves entering actual position values into the computer. This would work well for a grinder since you always overrun the part a bit, and the actual reversing position is not critical.
 
Good idea, added to list.

My starting problem is that I know nothing about programing anything in any language. So i don't even have a clue as to how to structure a program let alone the syntax of of all there cryptic function names.
Even the starter kits and manuals are loaded with TLAs right from the begining that I do not know what they mean.
 
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