Gap between infill and perimeter

Hello,

when I try to print the infill and perimeter are always disjoint at the same places. Please, does anyone know how get rid of the gaps? Has anyone experience something similar and what did you do about it?

I read several posts here, it most probably looks like there is a backlash somewhere. The problem is, I don't see any backlash, I cannot move the carry by hand (it does not "wiggle"), the carry (X axis) moves very smoothly and when I try to tension the belt even more, the gaps grow bigger. I even tried to increase the current for the X stepper, it's so hot I cannot touch it but the gaps are still there.

Also, when I try to manually move the extruder along X axis say in "+" direction (a few clicks of 0.1 mm) and then I try to move it in opposite direction, then carry will ignore the first few clicks (also 0.1 mm), and then it moves normally.

I have Mendel, Gen3 electronics with Gen3+ extruder upgrade, Splinter fw and I use Pronterface with Slic3r.

PS: The X stepper always moves on (i.e. does not ignore) the clicks but the carry doesn't move.

Edited 1 time(s). Last edit at 04/22/2012 07:11PM by Ecir Hana.

Quote

Also, when I try to manually move the extruder along X axis say in "+" direction (a few clicks of 0.1 mm) and then I try to move it in opposite direction, then carry will ignore the first few clicks (also 0.1 mm), and then it moves normally.

That is backlash. Maybe the pulley is loose on the motor shaft? Or perhaps the belt is binding against the idler washers?

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nophead Wrote:
-------------------------------------------------------
> Also, when I try to manually move the extruder
> along X axis say in "+" direction (a few clicks of
> 0.1 mm) and then I try to move it in opposite
> direction, then carry will ignore the first few
> clicks (also 0.1 mm), and then it moves normally.
>
>
> That is backlash.

So I have to figure out where it happens because I cannot see it anywhere.

> Maybe the pulley is loose on the motor shaft?

It once got loose but I fixed it and it's very rigid now.

> Or perhaps the belt is binding against the idler washers?

I tried that too (albeit with loose belt - just with bare hands, "as if" the belt was properly in-place), the carry moved smoothly.

I thought it might be in the fw, but now I figured out that the stepper reacts properly.

The belt's tension members can break so that while the belt looks superficially okay and works when moving things by hand, it stretches at the broken spot(s) when printing and causes inaccuracies in the print.

and is there a other selusion?, i have the seem problims and the printer seems ok

it's backlash, no other solution. Fix it in the firmware, or with Skeinforge that has a backlash compensation.