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I thought it was configuration.h, but someone told me the file is called repetier.pde oh well.

On this website: https://github.com/seemecnc/RepetierMAX ... guration.h

this is line 174: #define EXT0_TEMPSENSOR_TYPE 97

Is that line the thermistor setting in our firmware? Any other places to make thermistor settings?

If we have our thermistor setting at 97 and makerfarm wants thermistor setting 3 for their j-head maybe that has something to do w/ my issue.

Please advise any and all.

You need to open the repetier.pde with arduino, one of the many tabs that open will be called configuration.h. So they are both right, kind of.

Yes that is the line that you need to set to the 3 recommended by the manufacturer.

Did you retune your PID coefficients with this head and filament?

Through Arduino I opened the repetier.pde file went to the configuration.h tab and changed the "97" in line #define EXT0_TEMPSENSOR_TYPE 97 to a "3". Hit File / Upload and got the upload complete message at the bottom of the screen.

I closed Arduino and opened Repetier. When I opened the EEPROM settings in Repetier I still had all my recently tweaked Repetier settings. When my machine was first built I tweaked my Arduino settings using the Repetier EEPROM window so I would have thought the Arduino upload I did tonight would have reverted all my EEPROM settings back to original old Arduino settings.

What did I do wrong when I uploaded my Arduino configuration.h?

Your EEProm settings will override many parts of the loaded firmware; it's by design and there for convenience. You can quickly change settings that you would otherwise have to change in firmware. If you want to stop that from happening you can disable the EEProm in the firmware.

Flateric wrote:Slipping extruder hob or perhaps stepper thermal resets?

inventabuild wrote:I don't feel the filament slippling when I grab it with wetted fingers. It seems to feed consistently, so I'm guessing the extruder hob is not slipping.

When I test for slipping, I sometimes put a little shard of painters tape on the filament a few inches before it goes into the extruder. Then I can see if it's really moving consistently.

A partial clog could make the filament slip occasionally - which would probably look like your "many-layers" image.

I opened my new j-head hot end and everything checks out ok including the Teflon in-liner which I took out and inspected.

The temp of the hot end checks out OK with my new Klein multimeter / temp probe (I might change the "3" back to "97" on that line of code in the firmware which I mentioned earlier to see if that affects the temperature, but that's for another day)

Before all this craziness with my layers I could heat my bed to 60 C and print fine w/ PLA. I found out that turning off the heated bed helps the first layer of PLA lay down much better now, but it still has issues. I don't know what changed to cause a heated bed to all of a sudden give me terrible first layers with PLA.

So I attached pics of my latest builds. The layer alignment is terrible:

[img]http://imageshack.us/scaled/thumb/17/g8gl.jpg[/img]

... and one side of the vase has dribbling from the hot end on every layer:

[img]http://imageshack.us/scaled/thumb/197/52d1.jpg[/img]

These prints are using the same settings, retractions, etc in both Cura and KISSlicer that I used before with awesome prints.

I am really at a loss as to why my prints went from stellar to this bad all of a sudden. The bed is leveled and I performed the 4 point calibration multiple times.

Any ideas what's going on here? Any ideas how to fix this?

626Pilot,

Do you keep framing squares clamped to your towers permanently? Can you take a pic?

Weird. That last print doesn't look like slipping filament to me.

So what all changed between when it worked last vs now? Just the j-head? No changes to arms, effector or firmware? No chewed belts or slipping pulley? And you're checking for gaps between the towers and top/bottom plate?

Definitely starved for plastic. If that's the grey or white stuff, I don't like it and probably won't use it again.

You might try increasing the extruder width setting a bit....

Well JohnStack you hit on something.

The ugly layers were a result of bad white PLA and I'm surprised because I got it from Ultimachine.com

Here is another pic of the RMAX extruding the bad batch of white PLA at 190C (it looks kind of like extrusions of cottage cheese):

[img]http://imageshack.us/scaled/thumb/29/0uls.jpg[/img]


Here is a pic of the RMAX extruding the bad batch of white PLA at 165C (looks better than at 190C):

[img]http://imageshack.us/scaled/thumb/834/l24t.jpg[/img]

As I mentioned previously I verified hot end temp w/ a Klein Multimeter thermocouple thermometer so I suspected JohnStack might be right about white PLA being problematic when all of a sudden it started printing best at such a low temp. A few weeks ago my white PLA printed beautifully at 190C, but it looks like the batch started turning bad or I got to a bad point in the roll.

So I switched to black PLA. Here is a pic of black PLA being extruded at 190C as it is working the rest of the white PLA out of the hot end. Notice how nice the layers looks especially compared to the white PLA:

[img]http://imageshack.us/scaled/thumb/838/sv55.jpg[/img]

Here is a portion of another black vase I just printed at 190C (compare this to my first picture in white PLA on page 1 of this topic; it's like the difference between night and day):

[img]http://imageshack.us/scaled/thumb/834/a8sg.jpg[/img]

So, it is clear the white PLA is the culprit in my major layer problems. Ezra owner of Trinity Labs also mentioned in his Google Group that white PLA can be problematic. With so many people having problems with this color IMHO there s/ be a sticky warning people about white PLA. I spent many hours over the course of many days tweaking my RMAX thinking that's where the problem was. If there is a white PLA formulation that is trouble free (at least as much so as the other colors) then that s/ be mentioned as well.

As can be seen by my last pic I am not out of the woods yet. I still have a few sporadic layers with chatter in them.

So I'm still looking for help to finish off this last problem so I can start printing nice stuff again. Please let me know if anyone has any suggestions.

So now it looks like I have a bad thermistor in my brand new j-head which could account for the sporadic z-chatter. The saga continues...

What makes you think you have a bad thermistor, IME they either work or they don't.
They're not exactly complicated things, so they are unlikely to break if they work at all.

Trying to troubleshoot my last sporadic layer probelm I ran my PID and it gave me ridiculous numbers. So I ran the PID numerous times and each time the numbers changed significantly and they were all over the board and I had not tweaked anything in the software or on the RMAX. Sometimes when I ran the PID I would get what seemed like millisecond spikes in temp from 200 C to 240 C then back to 200 C in an instant which caused the PID to error out with the message "PID Autotune failed! Temperature to high". Such short spikes in temp and subsequent cooling are physically impossible with the RMAX electronics I'm using at room temperature.

So we will see when I get the new thermistor if that solves the problem or the problem persists.

That's more likely a poor connection somewhere, but it could be a bad thermistor.
Can you see the spikes on the temperature graph in Repetier?
PID autotune can be a complete crapshoot, especially if you're heater is on the more powerful side. If you are using a heater cartridge with the JHead, you might want to try reducing PID MAX in the EEPROM settings, start by halving it.

I think you should consider the idea that your PLA is picking up water vapor as it sits out...this causes the splooge (for lack of a better word) that you're seeing. Just a guess.

barnett wrote:Weird. That last print doesn't look like slipping filament to me.

So what all changed between when it worked last vs now? Just the j-head? No changes to arms, effector or firmware? No chewed belts or slipping pulley? And you're checking for gaps between the towers and top/bottom plate?

What do you mean by gaps between the towers and top/bottom plate?

Polygonhell wrote:That's more likely a poor connection somewhere, but it could be a bad thermistor.
Can you see the spikes on the temperature graph in Repetier?
PID autotune can be a complete crapshoot, especially if you're heater is on the more powerful side. If you are using a heater cartridge with the JHead, you might want to try reducing PID MAX in the EEPROM settings, start by halving it.

Well I bought a replacement thermistor and a new hot end from MakerFarm so I would have a back up:

http://www.makerfarm.com/index.php/j-he ... ament.html

So I hooked up the new hot end and I'm still getting bad layers, but now they are sporadic instead of all the time:

[img]http://imageshack.us/scaled/thumb/4/u9fr.jpg[/img]

and I'm still getting blobs, but now primarily in the vicinity of where a new layer starts:

[img]http://imageshack.us/scaled/thumb/32/ho4k.jpg[/img]

I'm using prime, suck, wipe = 10, 10, 5 w/ speed = 55. Before my machine became crippled I used these settings to make beautiful prints so I don't think my issues have anything to do w/ KISSlicer's settings.

I did notice w/ my 2nd new j-head that the PLA extrudes a little crooked out of the nozzle regardless of temperature:

http://www.youtube.com/watch?v=s0nHHjDK ... e=youtu.be

My RMAX has been down for weeks now, not able to print anything decent. Any ideas / things to try?

... I get even worse results with Cura. Look at how starved for filament this layer is:

[img]http://imageshack.us/scaled/thumb/10/su7c.jpg[/img]

What do you mean by gaps between the towers and top/bottom plate?

When you're attaching the t-slot extrusions, you're supposed to make sure they are straight and spaced correctly by checking for gaps between the inside edge of the aluminum (closest to the center of the printer) and the top and bottom melamine plates. You could get geometry errors if the towers are skewed. Sounds like you resolved the geometry trouble in firmware, so this may no longer be relevant.

I just read the thread "Cause of The Lean" and I'm wondering if incorrect motor current, a fan on the RAMBO board or both might help w/ the sporadically bad layers my RMAX is printing. Here's my motor current settings:

// Motor Current setting (Only functional when motor driver current ref pins are connected to a digital trimpot on supported boards)
#define MOTOR_CURRENT {175,175,175,135,135} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)
//#define MOTOR_CURRENT {35713,35713,35713,35713,35713} // Values 0-65535 (3D Master 35713 = ~1A)

Also, I'm using the stock Nema 17 w/ my EZStruder, but I'm wondering if it has the torque to drive a bowden or if I need a gear reduction motor?

I think you are running too high of current on your steppers personally. I think they default to a overly high current actually. Also try reducing your max extruder speed from the default of I believe it's 60? to something more reasonable and attainable like 24-30 with a muchg lower accel. Try this, you may be surprised. I have walked others through this, and they have been surprised at the results. Essentially anytime you extruder sounds different on it's retract (grindy, scratchy not smooth) it's not doing it's job correctly.

Set prime/suck/wipe to 5mm. Less if you can manage. If you are using a J-head or Budaschnozzle you don't need more. In fact, making it retract longer increases heat soak further up in the head. THIS IS THE WORST THING YOU CAN DO WHEN PRINTING PLA!!! I find my J-head and Budaschnozzle like retracts between 3 and 5mm. Any more than that, and they will eventually jam!

Also, the J-head you got doesn't have any heat dissipation milling in the PEEK section. That's no bueno. Look at http://hot-ends.com and you will see the difference - heat sink fins are milled into it. I found the Budaschnozzle better than the J-head for PLA (aluminum heat sinks are obviously way better at dissipating heat than something that was selected specifically because it's NOT very conductive of heat.) I also have an E3D hot end on order, and the consensus seems to be that it's the best for printing PLA, hands down. It's all metal and has LOADS of heat sink fins, so it ought to be the best by far at heat dissipation.

Also, do you have a fan for part cooling? That will make a huge difference. I've been working on a ducted fan just for that purpose. Just watch. Point a small fan at one half of your build and watch that half come out better than the one with no fan blowing on it.

I actually use an adjustable height room fan set to low, about five feet from the printer. Works great.

g.