Stepper shaft spins but carriage not moving

Hello to all. I am new to arduino and to this forum and this will be my first post - I am hoping that someone may provide some advice or a solution.

I have combined 3 steppers from old cdrom drives into a mini 3D printer. All the electronics have been connected and I am able to activate each stepper motor. However, 2 of the 3 steppers move the shaft but the carriage is not moving - basically the carriage arm slips over the stepper shaft as it rotates. Any ideas how to get the carriage to move as the shaft spins?

Thanks.

taz1973:
basically the carriage arm slips over the stepper shaft as it rotates. Any ideas how to get the carriage to move as the shaft spins?

You need to post a photo of the machine and maybe a diagram also.

At the moment I have not the slightest idea what sort of system you have.

...R

I agree that a picture may be a good start…sorry for that. Please find the pictures. Basically what happens is that the shaft of the stepper spins but the blue carriage is not moving - it just skips over the grooves of the stepper shaft. Any suggestions?

If the "blue carriage" has threads that match the grooves in the shaft, you need to add a tensioner of some sort.

Many linear positioners use a captive nut like this, which can't skip.

jremington:
If the "blue carriage" has threads that match the grooves in the shaft, you need to add a tensioner of some sort.

Many linear positioners use a captive nut like this, which can't skip.

The blue carriage may have had a button or pin that mated the thread on the lead screw, but is now missing. There seems to be a spring as part of the blue carriage that was a tensioner at one time.

Paul

Image from Reply #2 so we don’t have to download it. See this Image Guide

ec01e275f8f82324eec05410271938b2aaed89c3.jpg

For the future please use a lower resolution image that will load more quickly. 640x480 is usually perfectly suitable

…R