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incorrect extruder bearing?

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I cant get enough tension on my filament (1.75 mm) but i can't tighten my extruder upgrade anymore. does any one know where to get a new, better bearing that works with the mk8?

Was this extruder working fine then stopped? Or just upgraded and you can't get it working?
You need check if spring is not too weak, Chinese kits often have poor quality materials, my printer's MK7 hobbed gear made of stainless steel got bent teeths by filament, plastic damaged steel. My colleague printer with factory fitted MK8 had weak spring, it took nearly month to find this out. Also check if stepstick for extruder is adjusted properly, motor should be really warm during printing, I have set nearly 2A current.

I used a local library printer to make my upgrade, and used the strongest spring I could find

Ok i assume you are using the mk8 extruder upgrade and since you installed it the motor skippes stepps?
(correct me if I understood you wrong)

That has nothing to do with the fillament tension. If you realy want to get more tennsion on it simply put one or two washers between the casing and the spring. But I dont think that this is your problem.

I had the same problem with my ctc prusa after switching to the mk8 extruder kit.Its because the extruder gear of the mk8 kit has a much bigger radius than the ctc one. So that means the steps per mm aren't correct anymore and the printer trys to extrude a lot of fillament much to fast. Thats why the motor starts skipping steps.
You have to calculate the steps per mm new (there are many sites with calculators for that) and update that in the firmware. if your Board can't be updated (like mine, the eprom is blocked) you can buy a new Board, or put the correct settings in the printersettings in your slicer where you put the starting gcode in.
A diffrent approache is to simply set the flow much lower that schould be your first try to verify if that is realy the problem. I needed to print with a flow around 40 percent.

Other reasons why the fillament isent fed correctly could also be a clogged nozzel (clean or change the nozzle), to low tempereatur settings (print at higher settings), or to low voltage at the steppermotor (can be corrected with the smal potentiometer on the steppermotor driver directly on the board, whatch a youtube tutorial for that)

hope i could help you

I can change the steps/mm in slic3r but I've tried to find the best option by messing around with that in Pronterface, no luck. I also know my nozzel isn't clogged because it flows out, it jst won't do it correctly. My brother's printer works fine with the same parts. any other suggestions?

As I said a simple washer on the screw that holds the spring bringes more tension between the fillamentdriver and the baring.
You could also try to play a little bit with the potentiometer on the stepperdriver. Perhaps it gets not enough current, but be carefull to much current could overheet the stepper motor and demage it.

sometimes the nozzle temperature sensore is better or wors build in. so the temp it reads can differ from the actual temp of the nozzle. try cranking up the temp to 230°C just to be sure it isen't an issue with the temp sensor.

but I still think you have to high flow like it was with my mk8 kit just try a testprint on 40 percent flow to be sure.

sorry but that are all the issues I can think of that can cause your problem.
I realy wish you best luck an good prints. good night.

I know my nozzle temp. sensor is off, but I can try that when I get a chance. I'll let you know how it goes