Home built printer with Y axis problems

Hi all!

I've built a quite big printer, 100*90*90cms in dimentions. Everything's working fine, except for the Y axis. I'm using NEMA17 motors, wired in mirror (or parallel) with T5, Z36 pulleys and T5 belt in 1:1 ratio, as shown in picture. The problem is that I can't calibrate the Y axis...to be totally honest it absolutely won't move the way it should. I'm using a Sainsmart Mega2560 with RAMPS 1.4. The motors just act like they don't know what to do. I mean they either got a clicking sound or either shake like hell, but they don't move the y axis the way they should... Steps/unit in the prusa calculator showed me 35.56 steps/mm, but even like that it's not working correctly. could somebody help me what to do?

Hey,

First of all the printer you are building looks awesome!

As for the juttering on the Y-axis it sounds like you need to calibrate the Pot's on your stepper driver.

It is simple to do:

On your stepper driver there should be a small circle with a cross on it.

This cross is for a screwdriver to alter the amount of current going to the Motor.

Rotating the pot anti-clockwise decreases current, and clockwise increases it.

What I would do is turn it anti-clockwise for maybe 1/2 a turn and give your printer a Y move command from your control software.

If nothing moves, slowly increase the current by turning the pot in a clockwise direction.

Try this out and see what happens.

If it doesn't work, let me know!

Alex

(Oh! And another thing which could cause this is a loose connection for one of the motor wires. Double check they are all secure and there are no cuts etc to each of the 4 wires! Check this before you alter the Pot's on the stepper driver as you could do some serious damage if a wire is unconnected!)

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NFireLabs - The World First Modular 3D Printer - At An Affordable Price!

Hey, I've been trying to adjust the POT on the driver before, yes, it does make some difference, but it makes just what I wrote in the other post. The motors either make a strange noise, either want to tear this whole printer apart. If I can, I will make a short video so you can see what I mean...

Have you checked the wiring like I mentioned at the end of my first post?

Yes, I've checked the wiring, everything is OK. Here's the link to a short video, which was made after another setting in Marlin, namely the steps/mm. but this is the best I can bring out of this axis and it's making me mad

[www.dropbox.com]

Quote
[email protected]
Yes, I've checked the wiring, everything is OK. Here's the link to a short video, which was made after another setting in Marlin, namely the steps/mm. but this is the best I can bring out of this axis and it's making me mad

[www.dropbox.com]

Are you using 2 motors on the Y axis if so how are the motors wired (Series or Parallel) ?

Yes, I'm using two motors, which are wired correctly, i tested it before i mounted them on the printer. They work in mirror, i mean one is moving forward, the other is moving backwards...

@[email protected]

I noticed that your Y? axis is racking. After you figure your problem, consider adding an anti-racking cable system.
It's possible to use an anti-racking system to drive your axis, but that would entail a redesign of your pulley locations.

Yes, it's shaking a little bit, but since both pulleys should move at the same time, if i could get the motors to move right it should't be a big problem. Anyway is 17.77777778 correct for steps/mm in my case?

Edited 1 time(s). Last edit at 11/19/2014 02:22PM by umbyka@yahoo.com.

That is a beautiful piece of machinery you have made . If you remove the y belts do the motors spin freely? Maybe there is just too much inertia for those little nema 17 motors to overcome.

I think you are asking a lot of the nema 17 motors

Thank you yes, the motors are spinning without the belts on, so do when i load a test file on the board, that one that moves every axis 5mm-s. But when i load marlin, the y arriage won't move, just the way you can see in the video. Maybe user A2 is right and because it is rackling it cannot move parallel both sides...

Hey guys, I'm back again. I solved the shaking problem, but I'm still having problems with the Y axis. I made a short video of what the problem is...I've been playing around with setting the right values for default max feedrate, but I can't get it to move normally as it should.. Has anybody got any idea?..

[www.dropbox.com]

Can it be that the Nema17 motors just aren't strong enough?

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http://www.marinusdebeer.nl/

Thanks for the reply, but no, the motors are more than enough After playing more with default acceleration settings and default max feedrate settings, the axis moves as it should almost...mainly I've got firmware setting problems now. By the way if you put the whole X&Y axis on LM20UUB bearings and stainless steel rods, it should move like charm, so it does. Now I only hope to get the right settings...