RAMPS Troubleshooting

Hello All! I'm very new to this community/reprap in general.

I've cobbled together my first Prusa Mendel, with parts sourced from various locations (mostly mixshop, with some upgrades such as bearings, couplers, belts, etc from other places).

I've hooked everything up to RAMPS, but the only motor that seems to work perfectly is the y-axis. the x-axis mostly works, but occasionally makes a grinding noise as it moves.. or it'll move fine, then a few moments later you'll hear the motor pulsing even though it looked like it completed movement.. the extruder was working flawlessly, but now also makes a grinding noise for no reason..

I've replaced the Pololu controllers on the z axis which was previously acting really weird, and now that seems 'ok'.. (although i can't seem to get the clamps to actually stay stable on both sides).. I'm thinking the x-axis Pololu controller might be bad as well..

Anyway, I recognize these repraps are labors of love and patience.. but i'm quickly getting to the point where I just want to see it print something :-P.

I will admit I had a lot of trouble making the connectors for the motors to attach to the ramps -- these wires/plugs are really tiny.

so my question is --

Should I just throw out the RAMPS and go with something else more reliable for controlling the motors? , or is there some place i could send this to, to have them work through troubleshooting this? . I'm located in the Philadelphia area, and willing to drive someplace reasonable with the printer too..

Thanks..
John H

As far as I can tell, the RAMPS system is about as good/reliable as it gets for controlling Prusa repraps. Anything else will likely be more difficult. But as you've found, the connectors are a bit of a pain. And I'd be happier if the Pololu boards could source a bit more current before going into thermal shutdown.

That said, most of your problems are either going to be electrical connections, or physical problems with the ease of movement of the motorised parts. Like getting the alignment right for the two parallel X-rods. Or ensuring that the Z-motor couplers don't slip and throw the X-axis out of level. (I fixed that problem by using the metal barrel-shaped couplers that MakerGear also supplied, but folks have found ways to make the plastic clamps work, or even replaced them with aquarium tubing!).

And some folks get weird behaviour caused by crosstalk if they don't twist all their motor wires or their end-stop wires (I did that automatically without needing to be told, but most people have never worked with high-frequency data transmission before).

Anyway, don't give up! Stick with RAMPS and just keep fixing stuff til it works.

I've written a lot on my blog about how I built and aligned my MakerGear Mendel Prusa. Other folks have been kind enough to say the info has been helpful to them in their builds. Maybe it can help you too, rather than me trying to type it out again on a forum. You could start at:-

[brazenartifice.wordpress.com]

best of luck!

Andrew Roberts
brazenartifice@gmail.com
(I'm in Australia, so I can't help in person...)