Reprappro Huxley, Y motor, heatbed + extruder issues

Hello, Rui here from Auckland, New Zealand.

I've recently put together a reprappro huxley which I bought the parts from the reprappro website. It came with the pre-soldered and supposedly pre-programmed Sanguinololu electronics board.

I've wired it up correctly - i believe, installed the pronterface software (the pre-packed version, instead of the phython installations version from the github site); the power seems to be going through as the fan is going and the software recieves the machine.. but I am currently experiencing these problems (i have no prior experience with electronics so all of this is first time)

1. the Y motor is going in the same direction whenever I turn click either of the direction buttons on the pronterface interface.
2. the extruder motor is whistling and clicking with no movement. I've read somewhere that it may be because the motor is not receiving enough voltage and it may have something to do with turning the potentiometer on the electronics board, but I'm not sure how to do it correctly.
3. the heatbed first worked and was heating up the platform; giving the appropriate readings in the software. but when I tried turning the hotend resistor power around and then putting it back, the heatbed stopped working and so did the heatbed thermistor.
4. no response to the hotend thermistor nor is it heating up.

apart from that, the z and x motors seems to be working correctly.

Can anyone write me up a detailed checklist/ know what the problems might be? I'm a bit stumped and will appreciate your help!


Grace and peace,
Rui

Some fairly detailed answers and pointers

1 this points to the direction line to your stepper driver not toggling, either a dead stepper driver, or dead Microcontroller Pin. Or a bad joint between the two. Swap the X and Y Stepper cables (while it is off) Then try moving X back and forward in pronterface (this should move y back and forwards) If it moves fine try moving Y back and forth (x will move) if X is now broken then the issue is with your main board. If the Y steppers still only moves forward there there is something wrong with your Y stepper or its wiring. (I doubt this, but its good to check)

Turn it off and swap the cables back.

If it is the PCB, while everything is off swap the two Pololu driver between X and Y
In this picture (link) from the left hand side its drivers 1 and 2. (it is labeled on the board as x-axis and y-axis)

And try again, If Y starts to work but X stops, you have a dead Pololu driver (I suspect this)

If Y continues to be dead you either have a dead micro controller or a bad solder joint (if you get to this point, ill write more on how to test it, you will need a multimeter)


2 Firstly while off check you can manually turn the large gear on the extruder by hand turn it 2-3 revolutions in both directions it should turn smoothly (without any filament in it) . If it does Is probably is the variable resister. The Extruder is the 4th pololu driver on the board from the picture above. The current can be turned up by turning this variable resister clockwise. This should be done while off! or with a plastic screwdriver, do not use a metal screwdriver while on, you will short something and kill the pololu driver. If you only have a metal screwdriver, you going to have to turn off, turn the variable resister up a fraction, turn on, try, and repeat till it moves. If the variable resister get over about get over about 2/3 a revolution stop. there is probably something else wrong.


3 you did what? Im going to ignore this till you have all axis going (one step at a time) but check the thirmister like in step 4 it should show room temp.

4 the hot end wont heat up if the thermistor isn't working, its a safety feature, Does the software show the temperature as room temp or something silly? if its something silly, look into the thermistor wiring.

Hope this helps, and no Im not in Auckland. So I cant help directly.

Edited 2 time(s). Last edit at 04/24/2012 07:24AM by Dust.

Thanks for your reply and time man!


1, I suspect that it may be a dead PCB pin. I've given the swapping motor cables a go and the Y motor moves successfully in both directions while the X moves only in one direction in the Y slot (telling me that the Y motor is OK). I swapped the Stepper drivers around and still the same problem occurs; the Y motor only moving in one direction (after the motor connections are swapped back), so I'm thinking that its either the dead PCB pin or the software? (I have a multimeter)

2. I have turned the large gear several revolutions and it moves (relatively smoothly, still a bit of force resisting but not much more than the moving X axis - given since installation I have been shaving the gear teeth to make sure that it did so, because the printed part was not precise at that scale..) I also tuned the driver by turning the potentiometer clockwise as you suggested while the whole thing is off. Still no movement. What i do hear is the an increased clicking in the motor and whistling as I feed it more voltage. what do you reckon could be wrong?

3. Here is where I reckon I might have messed things up. INITIALLY when I first wired everything in. everything was working except the HOTEND thermistor and heater, and the EXTRUDER MOTOR. After reading in the wiring part of the reprappro huxley instructions; it mentioned that the Hot End pins that connects to the Hot end heater resistor (which I've soldered a Y as per instructed) had no POLARITY. So with that in mind I reversed the connector and plugged it back in (the part circled in the image. When I tried connecting the power, I had no response, but i heard a faint clicking in the power pack. Here's where I reckon I might've short circuited something? I then flipped the EH connector back to how it was originally and power came back on again, but this time the HEATBED stopped responding (I saw that the positive 19V had been accidently pulled out of its screw socket - so i rescrewed it back in but still no response with heatbed.

Sorry man its a bit messy!

4. Should I be checking the soldered wires and what is the best way to do so? Thanks for letting me know about the fail safe feature with the thermistor. in the instructions it said to fully wrap the thermistor in plumber's PTFE tape then put it into the aluminium heat block. would it not work it the termistor and its connecting wires are touching the heatblock, thus so should I be checking it the thermistor is properly wrapped? would electrical tape work the same to wrap the thermistor?

Prior to the messy step 3 when the heatbed is working, the pronterface showed the temperature of HOTEND (t) as 0 and HEATBED ( as 9. now the that the heatbed stopped working (after point 3) I'm getting constant readings of T: 123 and B:104 when both are plainly cold.


Appreciate your help bro! Been putting heaps of time and working on this for the last couple of weeks and its guttering to have it not work. I'm dying to use it to print some architecture models for uni studio!


Grace and peace.

" the Y motor is going in the same direction whenever I turn click either of the direction buttons on the pronterface interface. "

Either button or not at all for one? If it's not at all for one it could be endstop related.

[forums.reprap.org]

After reading the above... I would say with 99% confidence you have blown the micro (the large black chip) You say it was working and the firmware is unlikely to be changed.

The thermistors are also directly connected to the micro.

I would say get a new micro at this stage, get one pre programmed eg [www.emakershop.com]

(this may not be the only thing, but one thing at a time... FETs could also be gone, thus no heating on build platform)

In regards to the thermistor, put you multimeter on to resistance, un plug your thermistor from the main board and measure the resistance from the plug threw the wires and the thermistor to the other side of the plug. It should read about 100K (this changes with different temperatures. If it reads something near 100K, hit the thermistor with a blast of hot air from a hair driver the resistance will should change.
If it read zero there is a short somewhere. You can't use electrical tape, it will melt. (the legs will get near to melting temp, thus the need for PTFE tape (high temp) you can also use kapton tape

Since you say X is working, I would swap the X and E cables, then tell X to move and see if your extruder moves.
If it does swap it back and swap the driver chips between x and e and retry e. Remember to always turn off everything when plugging or unplugging anything.

Actually ill go one step further than that, since you know X works, take out that stepper driver and try all the other stepper drivers one by one in the X position, to test all the stepper driver modules still work.
You can leave the drivers your not useing out of the PCB while testing.

Alright man I'll give the above a go, will let you know how it goes.

And with regards to possibly being endstop fault, the y motor moves in the same direction when I click both pronterface y axis buttons.


Thanks for your help!