Part Dimensions not jiving <Solved>

Hey all,

My issue is that in prontorface it will tell me that the part is 3mmx3mmx3mm. When the print is finished my actual dimensions are always smaller. I have checked the steppign with a caliper on oth x and y. While not totally accurate to the .0x measurement, thay are very close. The variation is also + or -, not consistanly one or the other. Any ideas?

Neil

I had to replace my y axis pulley due to continuing slipping issues. I replaced it with one of the larger diameter designs. I fired it up to get some numers as to far far off it would e now. VOILA!! problem disappeared. Looked at the x-axis pulley and it is wrong as well. That is what I get for running my numbers off of what the instructions said to install as opposed to what I actually did. Live and learn I suppose.

Edited 1 time(s). Last edit at 03/21/2012 05:14PM by foshon.

Perhaps the issue is with plastic stretching/contracting with temperature. Try to monitor the temperature while printing and see if the mis-sizing is correlated. As the plastic cools after printing it will contract, so try printing with a lower bed temperature and see if you can cut down on variation, then scale up your object to compensate for the shrinkage once you can get the dimensions consistant

If you have calibrated your x and y steps/mm correctly (to within 0.5mm) The only thing that would cause things to be too big or small is the amount of plastic being extruded.

3x3x3mm sounds like a small part, try something bigger like the 40x40x5mm cube (uses less plastic than the 40x40x40 cube)

Note that it's the outside dimensions that you want to calibrate first, the inside of circular holes is a difficult thing to master.

Last night I reclibrated x and y the same way I have seen extruder calibration explained. I measured the part and divided the directed step length by the actual. My parts came out the correct size but they shifted to the far corner of the bed and it was supposed to be in the middle. I understand why it did it, but how does one fix this?

foshon Wrote:
-------------------------------------------------------
> My parts came out the
> correct size but they shifted to the far corner of
> the bed and it was supposed to be in the middle. I
> understand why it did it, but how does one fix
> this?

It's not terribly intuitive. Go into the Multiply section of your slicer and select a 1x1 grid centered at 100x and 100y, assuming a standard 200x200 print bed.