Noob Prusa i3 problems Help Needed

Hi everyone, I hope I can find some help here

This is a 6 week old Prusa i3, I'm not sure if it was ever working. The previous owner wasn't successful but he admits to not being technically minded at all and he didn't finish the assembly as far as i can tell (the hotend was still in the bag)

Now, my experience with it -

Pronterface connects fine to the printer, but when I tell it to set the temperature of bed or hotend it sets the target and then just leaves the hotend and hotbed at whatever temperature they are. No change in either.


The hotend graph on Pronterface shows a constant 24 Celsius with minor deviations to 25 and back again.


I've tried Marlin, it gave me constant endstop hit errors, zero movement and no response on heat, although the bed did rise in temperature when requested, and pronterface indicated accordingly.

I'm now on Sprinter (not modified), and I get no heat on hotend, none on bed, and no movement.

In Arduino IDE, i am able to send blinks and stepper tests to the printer, the LEDs on the printers board light up and flash in red. No movement on printer though.

I would also appreciate some help in where what should REALLY be connected in terms of wiring.

I have a fan that came with and no idea where it should go, with what I believe to be the "lever" referred to in forums, but i dont know where this fits in.

Did I damage the printer electrically? Is the wrong thing plugged into the wrong port? I dont know

I'm looking for any information that can help me diagnose or at least get moving in some direction.

 

Thanks I'll look over what you've attached I really appreciate it.

In the meantime I picked up that one of the two fuses on the ramps consistently reaches solar temperatures shortly after power on....

my conclusion is that there's a huge short somewhere on the board. The LEDS on it will respond to signals from the arduino but no signal ever makes it out of that board to the steppers. The ramps controller is blown. Or at least enough of it is fried to warrant a replacement.

This is probably because I at some point had the polarity from the power supply mixed up, idiotic as that may seem.

At least the arduino is still working and I have spoken to a much more knowledgeable friend also who says he doubts that anything beyond the ramps got damaged on the printer.

So i've got a new ramps on the way which HE will wire up for me.

Then we'll upload your marlin and she what I can get to work.

Thanks again. I'll post updates.

 

One other thing I think indicated a blown controller = The commands I type return no echo.

 

Also in answer to your question my component setup is identical to yours.

 

I have another question.... Probably not directly related...
But what in the world is this thing? Looks like a... Switch? Lever? It came with the kit and I can't find any reference to it online.

Thanks for being patient while I learn....

 

Google seems to also have no similar item in any if it's results... Image search or otherwise.

 

Here we go, new RAMPS in hand, wired up right, bed heats up but no stepper movement. Also no feedback on bed temperature in Repertier host - reports a steady 22c.
Going to load dddman's firmware attachment now and see what happens.

 

Yes indeed! This is not the land of plug and play. This is the land of plug and pray.
The firmware enema worked in that it gave me back control of the steppers. Thank you thank you thank you dddman. I'm now going to figure out the calibration, hopefully no more craziness, but I will post again.

 

It's tomorrow now, just before dawn. I'm still unable to get this printer to move on Z. Thre's a buzzing motor sound, the rods turn, and the extruder does not move at all.
Horizontal X and depth Y are moving but terribly off (x seems to start in the middle of the bed and end somewhere where the printer isn't. Y does something similar.
Also the Z threaded rods are not straight. I've tried setting the speed for Z to a lower value but no improvement.
Any ideas?

 

Anyway.... Apart from the rods I think this is indeed still a calibration issue. It's not so easy for me... Despite the numerous articles on calibration all over the Web I still don't know where to start given the type of details you would need to use Prusa's calculator tool.
Any assistance would be greatly appreciated

 

It appears that after all the tinkering we have progress. I gumbled (stumble upon while googling) the lower setting solution shortly after I posted last and it didn't help this z problem.
It did point me in a certain direction though.

These rods were not easy to turn at all by hand either and they strained against the surrounding parts, so I loosened up these parts a bit. Then I used a lubricating oil to get some glide on the up and down movement. Then I tightened those bits again.

I saw movements up and down so that seemed to have worked. The movement was limited but that was due to not having calibrated yet.

Also there is a plastic sheath that holds the rotation from the motor on the z rods. One of these had come loose from the motor. I replaced to tubing on both rods with pvc tubing I had here that fit like a glove if handled right. I'm going to also cable tie them again but the movement is now looking good.

Then I used the Prusa calculator with values that seemed correct to me and came up with the calibration settings.

I now had movement in the right area on all axes.... Mostly. Next up is levelling down the hotbed and setting precise limits for z.
At the moment the nozzle is touching the paper and according to repetier I'm still at 2cm away from where I really am. So a little tweak somewhere in the firmware or homing and an endstop adjustment sounds likely.

My setup also survived another electric short that tripped the house power. In fact it was shortly after the spark and smoke that the z axis seemed to come alive. Don't ask me what really happened there

Today I also had a guy from a local 3d print business (whose YouTube channel I've been mining for info and where I got the replacement RAMPS for the previous one I blew) over for a couple of hours to teach me more on the components and give my machine an inspection. Knowledge is power, right?

I should be printing something very soon, just need to catch up on some sleep.

Will update here.

Thanks for reading this very wordy post

 

Two days ago I printed a reasonably successful whistle from thingiverse so I think I'm nearly there.

Thanks for your assistance and support dddman

 

Let's see if I can upload from this phone....

 

Now one more little caveat.

The heatbed thermistor never reports an adequate temperature for printing.

Meantime my filament us boiling in the extruder.

I have the standard thing at the bottom where the two wires come down under the bed and meet in a silicon blob taped with kapton to the hole on the pcb (red plastic heater).

I had a look at what Josef Prusa suggest as a solution for wiring the thermistor. His approach is almost cowboy style and I enjoyed reading his narrative.

My question however is the following: is my understanding of the following correct?
The two wires need to not meet up. That will just pass the bias current cleanly along and you will have a maxed put temperature being reported straight away.
There has to be a substance between them through which current (heat) will travel and diminished by the surrounding materials. Once the surrounding material is hot enough so that no loss is of heat is evident, the current passes through with no loss and input =< output and we have required temperature.

AM I missing the boat or am I close?

 

Thanks I'll try it this way.

I'm minus the silicon blob though.

From what you're saying and from what I read on Josef Prusa's blog that shouldn't make too much of a difference.

If heat can travel along the pcb to from the one wire to the other then we have the probe we need, in theory.

Will update.

 

I see. I tried this now but it appears these thermistor wires of mine are too far gone to do anything with. It still reads 0, or if touched together it reads the bed max temp

I'm just impatient.

But you know what they say: what you do in your haste you regret in your leisure.

I ordered 2 new thermistors complete with cable to ramps. Will go and pick them up tomorrow and see what I can do.

Will update