Hot end not working and Z axis motors wont run

Ok so here are my specs, I have a reprap clear frame printer. I am running a ramps 1.4 and i'm using Sprinter software. So Last summer I built the printer and attempted to get it running but after much trial and error I became frustrated and set the whole project aside for a few months. Returning I still have the same two problems. Firstly the Hot end wont heat. When I send the command to heat the tip it just flat out does nothing, No lights come on the board, no voltage at the output pins. The bed on the other hand seems to work flawlessly, Lights come on and it quickly rises to temperature and then maintains. On a whim I purchased a new Ramps board but that does not seem to cure the problem.

The second problem is with the Z axis motors. When I give them input they buzz and turn back and forth but don't really go anywhere. They seem to turn freely by hand with the printer unplugged. If I plug the Y axis motor into the Z port it also buzzes and moves back and forth. But if i plug one of the Z axis motors into the Y port then it turns just fine, raising its side of the printer. Now, Its worth pointing out that when I built this printer I had to swap out all the pins on all of the motors because they were all incorrect. All the other axis move just fine now except for the two Z ports. So there are my problems, Can someone please offer some advice?

Having dual Z motors requires more current than a normal axis as you have two motors and they are not only positioning systems but have to cope with the effects of gravity. That being said first make sure that you have all of the jumper pins plugged in underneath the stepper drivers. Then try to boost the current using the pot on the stepper driver. If that still doesn't fix the problem your feed rate in your firmware is probably too high. For my Prusa i have my max feed rate set to only 2mm/s. Many of the firmware's have extremely high default values that are too difficult for the steppers to keep up with.

If none of those fixes work try a different stepper driver in the socket. Use one from another Axis that is known to work for testing purposes. If the motors work than you will need a new driver. A4988 are the most common with drv8825s being a good choice if you need more amperage.

For the hotend you probably have a dead MOSFET or channel on the Arduino (assuming you used the same one for both RAMPS boards).

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Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller

Ok my stock speed on the Z axis was set at 2, I increased it to 3 and now it seems to move much better but no matter what command I send it only wants to go down. I have also discovered that there is more resistance on the motor then I originally thought, As I can stall them out by simply pinching the threaded rod with my fingers. But a huge thanks, I'm really glad to see this thing starting to move.

They probably need to be lubricated with some oil or grease. You may be able to get a little more torque with the drv8825 drivers.

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Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller

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gmckee
They probably need to be lubricated with some oil or grease. You may be able to get a little more torque with the drv8825 drivers.

Ok I got some Hoppies #9 gun oil and using a Qtip I worked some of the oil into the threaded rod and the smooth bearing shaft and as soon as the oil worked its way inside it started to move much easier. But I am still having problems with the Z axis only moving in the Z- direction even if i command it to move Z+

Does it refuse to move after you home the axis? When you home the axis does it move in the correct direction?

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Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller

When I home the Z axis it goes down until it contacts my switch, making the red light on the switch come on. it then pauses for a moment and moves down a little further, Bending my switch. If I then attempt to move it up it just wants to keep going down and if I command it to go down it wont move at all if the switch is pressed. Also I recieved a new motherboard "Arduino mega2560" and it has not fixed any of my problems.

Edited 1 time(s). Last edit at 01/11/2016 07:16PM by nibbler125.

Many firmware do a fast and then slower homing of the axis. They go quickly to the limit switch, back up, and then hit the switch again. It may be that the motor goes to go in reverse (the pause) and then goes to find the limit again. Perhaps your acceleration is too high in the reverse direction? Just out of curiosity why are you using Sprinter? You may want to try to see if Marlin will fix any of your issues. Look up "Thomas Sanladerer Firmware Basics" who will walk you through configuring Marlin. Make sure to download a stable build of Marlin. These problems are starting to sound firmware based.

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Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller

Ok I made a breakthrough on this project. I found out that the hot end temp sensor is bad and since the Ramps/Arduino was not detecting the sensor it was not allowing the hot end to heat up. I plugged the bed sensor into the hotend port and instantly I felt the hotend heat up in my hand. Of course I turned it off since I know it would run away and eventually melt down. But this is a very good step in the right way.

Did you try turning up the voltage on the stepper driver?

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Tunames
Did you try turning up the voltage on the stepper driver?

Yes I have, Anyways I have fiddled around marlin and got nowhere so I have returned to sprinter. The Hot end problem has been traced down to a bad temp sensor but the Z axis is still being a huge problem. Currently I have my Y axis motor "when plugged in normally the Y runs great" plugged into the Z and whenever I give inputs the motor moves very loudly and erratically. Also I can easily will the motor to move in either direction by pushing in one direction or the other.