I really like your limit switch design. I have this problem with my Align power feed, I don't damage anything, but it rolls the microswitch box over when I manually crank. I understand you keeping this simple. I'm surprised that you don't feel cogging of the stepper motor when manually cranking this, so this is a good thing. I'm guessing your stepper amplifier has some protection diodes to protect the output transistors. I'll have to keep that in mind and check that with my future install.
The X axis.
- Thread starter deeferdog
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BaronJ
Grumpy Old Git.
Hi Guys,
The complexity of using a stepper motor to drive the table was one of the reasons that I went for the DC wiper motor and a variable voltage power supply. The bonus of using a tumbler is that you get a neutral position that completely disconnects the drive.
I actually made two of these with wiper motors from two different cars. One drives from the left and the other from the right. The first one of them placed the motor above the end of the mill table, which is why I got a second wiper motor and built a second one.
The complexity of using a stepper motor to drive the table was one of the reasons that I went for the DC wiper motor and a variable voltage power supply. The bonus of using a tumbler is that you get a neutral position that completely disconnects the drive.
I actually made two of these with wiper motors from two different cars. One drives from the left and the other from the right. The first one of them placed the motor above the end of the mill table, which is why I got a second wiper motor and built a second one.
Thanks for the interest shown in this post. Here are the three circuit drawings. There really only needs to be one combined drawing but I have broken them up in three because that's how I built this project, a Control box, a Stepper control box and a Limit control box., the last only being used when it is required to set the table stops. The circuit could certainly be refined but as I am not into production with these, as long as it works then I'm happy.
I have included a drawing of a latching relay circuit for those that may not be familiar with them.
The following notes will help understand the Limit Control box:
i) Relay 1 will latch when HOME limit switch makes.
ii) Relay 2 will de energise when PUSH is pressed. This will cause the stepper to rotate CCW and unmake the HOME limit.
iii) When REVERSE limit switch unmakes, Relay 1 will unlatch. This will energise the stepper to rotate CW until HOME limit makes, causing Relay 1 to latch. The stepper will stop and the green LED READY will illuminate. The circuit will now wait until the operator presses PUSH, whereupon the cycle will repeat.
I will try and upload the video by tomorrow.
Cheers, Peter
I have included a drawing of a latching relay circuit for those that may not be familiar with them.
The following notes will help understand the Limit Control box:
i) Relay 1 will latch when HOME limit switch makes.
ii) Relay 2 will de energise when PUSH is pressed. This will cause the stepper to rotate CCW and unmake the HOME limit.
iii) When REVERSE limit switch unmakes, Relay 1 will unlatch. This will energise the stepper to rotate CW until HOME limit makes, causing Relay 1 to latch. The stepper will stop and the green LED READY will illuminate. The circuit will now wait until the operator presses PUSH, whereupon the cycle will repeat.
I will try and upload the video by tomorrow.
Cheers, Peter
Here is a video link showing some clips I stuck together of a gear being cut on my mill with the stepper motor as the X axis power drive. Thanks for watching. Cheers, Peter.
