Sunday, May 16, 2010

mendel 109 printing

After several diferent firmware attempts I retried joaz's mega fork and got success.
Ive been working on tuning since i got the first shotglass print. The reprap firmware shotglass printed fully though it was a very poor quality print. after a lot of skeinforge massaging and quite a bit of assistance from tonok on irc i was able to get a reasonably high quality shot glass printed. The second skeinforge print was a wades extruder which came out realy well (after numerous aborted attempts).

I found that my x and z steps per mm settings were off and made adjustments ( i hope in the right direction) but havent had a chance to get a full print since.

note for my changes i got 106mm out of 109 for full lenght and 25mm instead of 28mm for height.

for z (which was most pronounced) i went from 400 steps to 448. dont remember what i did for x off the top of my head but i went the same direction.

Friday, May 7, 2010

working on first print

everything is assembled and functioning to a point,but having issues with extrusion and posibly positional accuracy.

first off. ive been trying to use the nema 23 bowden extrusion but all i get are striped filaments, it appears that the motor heats up too much and softens the plastic. so I tried to use wades extruder but only had a makerbot stepper to drive it which was too weak to push noodle through at any reasonable rate. After talking to some people on irc i picked up some lin motors at a reasonable price and promptly pushed my barrel right out of the ptfe insulator :( .

I may construct one of nopheads pipe covered barrels next though i may just put in my dual block extruder barrel and try it first using a cable and wades.


I have another issue i saw in the little bit of printing i got before failure. My X/Y stepper motion is wrong. for some reason step direction is not being passed to my drivers before the step pulses. so when traveling in one direction the steppers do some of their steps forward and the rest in reverse so my print looks completely wonky. it really becomes noticeable on short segments.
Im using the Ardrino MEGA board, pololu stepper drivers and I believe joaz's mega port.
Ive tried david buzz's and mycoyn's but neither of them appeared functional when i tried them.
A couple of people suggested to just use the standard fork and do my own modifications but i have been hoping to not have to redo work that has already been done.
Has anyone else ever seen this behavior and have any suggestions?