Well the mystery deepens. Here is a photo of two objects printed from the exact same Gcode file (same SD card too). Both were printed using the SAME spool of black Foxsmart PLA. The one on the left was printed on my new Reprap Wilson. The one on the right was printed on my repstrap. Both printers are running repetier firmware (the wilson has had both 0.91 and 0.92 running on it with identical results, it is now running 0.92, the repstrap is still running 0.91). Both printers have ALUhotends, but the one on the Wilson is their current shipping product, the one on the repstrap is a few months older. The differences between them are mostly cosmetic improvements, the core guts are the same. Notice how yucky the print on the left looks compared to the one on the right. Both measure identically, (same diameter of the outside and inside circles, same height) so the X,Y, and Z calibration on the two printers are both within 1% of perfect (as proved by those calibration cubes). The measured amount of extrusion INTO the hot end for 10mm of commanded extrusion is right. IE: Ive calibrated Esteps so with the SAME PLA a command from Repetier Host to extrude 10mm of filament pulls 10mm INTO the Extruder. Both printers use direct drive extruders, and have MK7 extruder drive gears. The Wilson has a 1.8 degree/step motor, the repstrap has a 0.9 degree / step motor. Esteps setting in the firmware for the repstrap is 195, on the Wilson I had to use 133 to get it to calibrate. One more difference, the repstrap uses DRV8825 steppers, the Wilson uses A4988 ones. The jumpers are set correctly for both to give 16X microsteps. Now for the crux of the matter. The object on the left weights in at 3 grams, the one on the right is 6 grams! So the cause of the difference is obvious, there is LESS PLASTIC in the defective one! WTF is going on here? Anybody been there and fixed that?
Posted on: Sun, 04 Jan 2015 17:08:53 +0000