When I calibrating the machine, I heat the extruder with temperature 205 press the “down button”.
But the motor didn’t move, I have find out the reason of that is EXTRUDER BEARING was too tights.
The problem is the spring is the most loosely level, how can I fix it?
hi,
Verified that the pressure between the two gears of the extruder is not too high, the motor must be a minimum free
I got my kit from Maplin and had a similar problem.
For mine I went through all the tests fine but when it came to printing rather than smooth rotation the gear would stutter.
My first attempt to fix this was to try increasing the calibrated voltage to 0.55v, but this didn’t help.
I then tried relaxing the main bearing, but no luck.
What worked me was relaxing the three slotted bolts on the stepper motor.
So after about twenty hours work I have a 3D print.
Not sure about the bed calibration as the case was missing a bit on the right…
Do you mean the bolts that connect the stepper motor to the frame of the printer?
If you mean other bolts is it possible to make a picture of them?
I mean the three bolts in slots that mount the stepper motor to the extruder assembly.
Not sure if this forum likes attachments, as usually they have a initial period when you can’t post them and I only joined this morning.
Yes, the motor should not be to close to the large gear.
Also loosen the bolt on the hobbed bolt a bit.
[quote]Not sure if this forum likes attachments, as usually they have a initial period when you can’t post them and I only joined this morning.[/quote]I’m sorry but the forum does not support any form of upload, even after a grace period. What you see is what you get 
Loosen the extruder motor bolts solved my stuttering problem too.
Thanks a lot for this hint. Now it works like expected.
Great!
Please help!!
I still have problem with stuttering step motor. I have dismounted the step motor from any mechanical interaction, in order to avoid interactive forces to the motor.
Now, I manually actuate the extrusion command in the repeater host software. This will distribute currency to the extruder step motor.
However, it seems that current/voltage still engaging the motor, EVEN AFTER the extrusion operation is completed (hence, no current shall go to the step motor).
The behavior is some what different time to time - some time it run smooth, some time motor stuttering, sometime current seems to actuate the motor 5-10 seconds after the extrusion operation. Some time there are a mix of all those.
Please, can some one give me some useful hints …. or should I ask velleman to send me a new motor?
Greatful for answers
Cheers!
Did you already try to swap the extruder stepper driver with another axis?
maybe the stepper driver is bad.
…. stepper driver? Do you mean the stepper motor?
No, have not tried a motor swap yet. That is the last thing i put on the list.
Confirm that you refeer to the motor. The same motor which are moving the bed via the x-,y- z axis and feed/extrude the plastic filament). Really need to be sure before I cut up my beautiful creation… 
Cheers for your reply
Nope! It’s the small rectangular printed circuit board plugged in on the controller board.
There is one for each motor. Try to swap two of them.
Make sure the hobbit bolt is not to tight
Hobbit bolt? LOL ;
Lord of the Rings edition?
cheers,
Christian
Ok, “Driver”! With other words, the circuit that manage och distribute the motor current… kind of I guess.
Thanks - I will try the driver swap … BUT where is the hobbit bolt placed? (sorry I’m novice RP-builder, even though my engineering education )
You should set the engagement between the gears with a filament in the extruder and the pressure spring under tension. The bearings and shaft (bolt) move under load.
It’s a Hobbed bolt since it was in theory made by the Hobbing process; en.wikipedia.org/wiki/Hobbing
In reality these bolts were usually made by an amateur process known as ‘free Hobbing’ using a thread tap; reprap.org/wiki/Making_a_Hobbed_Bolt
My K8200 kit came supplied with a bolt that had been straight knurled; en.wikipedia.org/wiki/Knurling
The HOBBED (“Hobbit”) bolt is the large M8 Screw with the hobbed part in the moddle.
It sits in the extruder to feed (push trough) the filament. It is the one that is driven by the large extruder gear.
cheers,
Christian
I have to excuse myself of being absent… but of good reasons!
However, I have tried to swap motor driver circuit. IT SEEMS that THE CIRCUIT is the problem.
If any Velleman representant read this: do you want me to fill in some kind of form to claim a replacement?
Thanks for helping me in this. Appreciate it greatly.
/Tobbe
You can send an email to support[color=#BF0000]at[/color]vellema[color=#BF0000]dot[/color]be
Thanks for the support info - I sure have to use it later on.
However, I need further investigation. I swapped the driver circuit, the extruder motor did go smooth but I still have problem to pull the filament through the melting process.
I continue investigate and will get back to you dear fellows…
/T