Extruder Issues

Hi, I hope someone on here can help.

For the last couple of weeks I have been having problems with my extruder, so much so that i've changed from v9 mendel-parts to a wades with a j-head nozzle, although it doesn't seem to have solved the problem.

When printing, the filament will not stick to the bed. (glass bed heated to 60 deg C, cleaned with acetone while cold, have tried on the aluminium plate + kapton combo). It has in the past. I noticed that the v9 was barely extruding anything, and not in a stream like usual, the extrusion would curl up to the nozzle. I assumed this to be a nozzle issue. I have since changed nozzle and extruder, and while now the extrusion streams from the nozzle, it almost seems to be cold as it is exiting the nozzle (using transparent blue PLA from reprap central, which I have made parts with before, so I don't think it can be the filament) as usually the filament is glassy, whereas now it has a whitish edge to it I assume this to be the cause of it not sticking. I have tried extruding at 185 C, and at 210 C, with no change. I have tried manually feeding filament at different speeds (100mm/min to 300mm/min) with pronterface, with no change.

The only thing in common now is the stepper motor, and the Gen 6 board. The firmware reports the temperature as being correct, so I don't see how it can not be melted!?

Any help with this would be greatly appreciated as this almost has me pulling my hair out

Have you got the nozzle the correct height above the bed for the first layer? The gap should be equal to the layer height.

Plastic curling up to the nozzle is not really a problem when you are extruding at the correct height as it sticks to the bed and does not have chance to curl up.

Some people can get PLA to stick to glass at 60C. I need the first layer to be much hotter, about 100C. [hydraraptor.blogspot.com]. Then again some people can get ABS to stick to glass but I cannot. YMMV!

---

[www.hydraraptor.blogspot.com]

My PLA sticks quite fine with 55C bed 200C nozzle if, as u mentioned, the height is correct. just wondered why it wont stick any more, cleaned nozzle and bed and fuzzled around for bout 1 hour, then i realized the height of about 1mm ^^

I print with a 0.35 nozzle, 0.25 layer thickness, and an initial height of 0.2mm, i have a small piece of steelsheet to check it.

I use car window cleaning foam, and it works fine.

some questions:
What kind of hotend do you use ? with heating resistor and block or NiCr wire ?
Do you have a chance to check the resistance with a multimeter or something ?
Did u check the filament feed ? if it feeds what it should ? (just had problems there, nozzle was partially blocked)

hope to help somehow

greetings

Pete

thanks for the quick reply guys. Although I have tried different print heights, I will double check this tomorrow, and I will try different bed temperatures.

Used to be that the first layer was being printed 10 degrees lower than the others and would warp part way into the print, but i've turned the temperature setting off in skeinforge, and i've tried doing a print from pronterface.

Hotend is a J-Head MK2 0.5mm Nozzle on a Wade's Extruder printed by A.Bower.

Old Hotend was a mendel-parts v9 0.5mm nozzle on their own extruder.

The J-Head nozzle uses a 5.8 ohm ? resistor, as opposed to the 6.5 ? ohm resistor on the MP nozzle. Checked before putting in to see real difference, J-Head was about 6.1 ohms. Using the same model thermistor as the v9 nozzle so I don't have to change the firmware.

Think the nozzle is clean, although never had problems before, once it was heated up, the extruder would run as normal. Also, as it is a new nozzle, and neither will stick filament to the bed, would assume that the nozzle isn't the problem, but I will check anyway.

Calculated steps/mm from new extruder, (as now on a Wades) to be 260.869. This about right? Stepper is a SY42STH47-1684B.

Hey, last night, I tightened the hot end to the extruder as i realised it was loose, and today I tried printing at different heights, and managed to print a small part, although the layers below were very 'wet' as it was printing.

Afterwards, it will not print again.

I've noticed that the hot end becomes loose once it is heated up due to it being so short and allowing the heat to travel to the extruder. Could this be part of the problem, as the nozzle moves with the force of the stepper motor, rather than building pressure in the nozzle?

Thanks for the things to try so far.

Hi Folks,

I am a newbie.
I bought an Axis 2.1 Plus from BotMill.
I have it assembled and I am having nothing but problems I don't understand. Your help would be appreciated.

I am using Skienforge for the gcode. RepSnapper for the printing.

1. I am not getting a Current Temp reading. Target set at 200C.
2. I am getting the filament coming out at the dump site after I let it heat up for a long time.
3. I have the nozzle set at between .05 and .1mm above the bed with tape on the bed.
4. The resistor reads 7.5 ohms.
5. It tries to print one layer shifts over tries to print another layer offset from first layer.
6. The filament comes out of the nozzle intermittently.
7. The print stop after trying to print one or two layers.
8. I have adjusted the tension on the x axis and check the gear for tightness
9. I have tightened the springs on the extruder.

Why am I not getting the Current Temp reading in RepSnapper and how do I solve the other problems?

I recommend going to the REPRAP IRC channel and asking for help there. It would be more interactive and there are plenty of knowledgeable people who can guide you.

in repsnapper, if you click on the communication logs tab (under the GCode entry box), you will see the temp feedback lines?...

mine are reading out fine, and used to show the current temp.

however, now my current temp is empty, but the lines are still ok in the communication logs. (note I had to separate the : from the 'o' or it would show as a )

....
15:08:48 Send >>Received: start
15:08:48 Send >>Sending:M104 S200 
....
15:08:51 Send >>Sending:M105 
15:08:51 Send >>Received: ok T:82 with parameter T:82**************************************
....

I wonder if there's a glitch in the sprinter firmware for the M105 response that's making it so repsnapper is missing the temp feedback?

-------------- edit

Only thing I can see in the firmware response is that:

Serial.print("ok T:");
Serial.print(tt);

tt used to be float, now it's an int... is it possible that's causing a problem?

-------------- edit

I tried modding the firmware to cast the (tt) as float for printing and repsnapper still won't display temp

guess I'll try regressing to my May 2011 build of the firmware and see if that helps...


Aggresive Wrote:
-------------------------------------------------------
> Hi, I hope someone on here can help.
>
> For the last couple of weeks I have been having
> problems with my extruder, so much so that i've
> changed from v9 mendel-parts to a wades with a
> j-head nozzle, although it doesn't seem to have
> solved the problem.
>
> When printing, the filament will not stick to the
> bed. (glass bed heated to 60 deg C, cleaned with
> acetone while cold, have tried on the aluminium
> plate + kapton combo). It has in the past. I
> noticed that the v9 was barely extruding anything,
> and not in a stream like usual, the extrusion
> would curl up to the nozzle. I assumed this to be
> a nozzle issue. I have since changed nozzle and
> extruder, and while now the extrusion streams from
> the nozzle, it almost seems to be cold as it is
> exiting the nozzle (using transparent blue PLA
> from reprap central, which I have made parts with
> before, so I don't think it can be the filament)
> as usually the filament is glassy, whereas now it
> has a whitish edge to it I assume this to be the
> cause of it not sticking. I have tried extruding
> at 185 C, and at 210 C, with no change. I have
> tried manually feeding filament at different
> speeds (100mm/min to 300mm/min) with pronterface,
> with no change.
>
> The only thing in common now is the stepper motor,
> and the Gen 6 board. The firmware reports the
> temperature as being correct, so I don't see how
> it can not be melted!?
>
> Any help with this would be greatly appreciated as
> this almost has me pulling my hair out

Edited 2 time(s). Last edit at 10/01/2011 06:46PM by cakeller98.

- removed -

Edited 1 time(s). Last edit at 10/01/2011 06:47PM by cakeller98.

I tried that and I can't figure out how to enter my question.
I there any instructions that I missed.