If you were to recommend a good name brand lead screw, which would you recommend? link, etc.. Just an example to get me started on the right foot. As I've said before, I'm a noob when it comes to hardware, although I use artistic 3d software professionally. Hence my artistic anal-retentiveness for perfect precision 
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The stepper shaft itself looks to be about 5mm, so a drill in the neighborhood of 5mm or #9-#8 would be good. I would give them the motor and tell them what its for and let the machine shop decide. As to depth, boring it extra deep probably wont hurt anything, so have them bore it 3/4 inch (19mm).
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I will be taking the z-rod off and attaching the new brass rod with zimmer62's method mentioned above.
I have asked Solidoodle for the exact measurements for the hole that is to be milled into the Z-rod but they have yet to get back to me (I'll bug em again after this)
In the mean time, does anyone happen to have a spare rod lying around that they could measure the depth and diameter of the milled hole for me? Bonus points for the diameter and depth of the stepper motor nubbin!!
Thanks in advance! I'll be sure to take pics of the process as it unfolds. Probably sometime in the new year.
]]>Although I gotta say, when printing the calibration .5mm hollow square it moves realllly really slow.. It took an hour to do it at .1mm
here are my prints .1mm (repetier/slicer) , .2mm (pronterface/skeinforge) and .3mm (pronterface/skeinforge) http://goo.gl/8FIsa
]]>If there is more banding or misaligned layers when printing faster, it would be from the nozzle moving a little too far due to some wiggle, or bending somewhere in the system. I've noticed that one of the Y axis pulley mounts at the front of my printer bends back and forth a little on faster moves which might be giving me some inconsistency. Someone posted some beefier replacements on Thingiverse which I think I'll try out - http://www.thingiverse.com/thing:36446.
If you are using Slic3r, the best thing to do is turn your outer perimeter speed to something slow like 20-30mm/s and let the inner perimeters and infill run faster.
]]>the probleme is even worst...
i have a S2 1st batch with a abs coupler.. i use the original skinforge of the pack.... no wooble or very little in .3mm print, but moderate wobble in .1mm print..
Solidoodle send me a new motor without the coupler.... not i have always wooble (in .3 or .1mm)..
less with skinforge... but a lot with Slic3r...
i made some test and it seems that the wooble are linked with the speed of the printing head...
speed increase.... worst wobble
]]>From there we could post our wobble with a read out from calipers of the spacing of the banding. Maybe I will make a little staircase that can sit in front of the .5mm hollow box at set step increments of 5mm to illustrate visually the scale of the object.
Then we can determine based on that image of the print if this is a consistent issue across solidoodle2 z-axis or a gcode issue.
The first question I should ask.. could anyone supply us with a .gcode file setup for solidoodle2 of the box (http://www.thingiverse.com/thing:5573) that they are certain that it is printing without a wobble?
.3 .2 and .1 would be great.
Thanks guys, ill get on making that little stair case tonight.
idea for stair case that I mentioned - https://www.dropbox.com/s/7i799v1wpt0hc … _image.jpg
]]>(actually I feel that it *could* be the answer for some, the trouble with the coupler is that it's so easy to get the rod and stepper axle non-aligned/non concentric, so if you were really really careful you probably could get decent prints using this...)
The best fix is probably always going to be a precision drilled screw that is either exactly the same size, (and you'll heat the screw to expand it before press fitting onto the stepper) or driller slightly oversize, (and you'll glue it to the stepper).
The glued method would seem to allow more play in the fit and more opportunity for the z screw to set at an angle and give you problems.
Even then I'm still not convinced that the standard diameter z screw is going to hold up that well, if we seriously believe that the amount of people reporting wobble issues all have bent screws then why do we think that a similar diameter lead screw is less likely to bend, either in transit or in use?
but we still come back to the questions:
is everyone experiencing wobble? -is this a generic issue.
how are we identifying this wobble? -what do prints look like, heavy banding, but at what spacing?
is one persons wobble verified against another persons printer?
(so imagine that one gcode file has heavy banding on your printer, but no banding on mine. then we know that all settings flow etc are the same (and assuming that we both measure our filament width to be the same and nozzle temp is measured (with hardware not just what's reported) then we could say that a printer was *likely* to be at fault.
it would seem that is one person had issues on all prints then there are two likely candidates.
Z screw or slicing software settings.
There is a thread where one user is seeing near perfect prints from skeinforge and heavy banding from slic3r, in this case do we blame the machine or blame slic3r?
]]>If you have any before after print photo's too that would be amazing too!
Does anyone have any experience with the couplers? I think I'll stay with the hollowed out z-rod myself, but good to know. Maybe it would be easier to fine tune if it ever did start to lean to one side or the other.
]]>using a metal tube larger than the screw, slide that down over the top.
Then using a nut thread that down against the tube until the leadscrew pops off from the motor.
Attach the new leadscrew using some sort of super glue.
"Get a shaft which is slightly larger than the Z-screw. Then you'll need a nut which you can screw down against the shaft. What is going happen is that the shaft will eventually force the Z-screw off of the motor. "
"You said you're using a new brass screw. We use a special metal glue. It's a super-glue. You can use any super glue. We use threadlocker red. Apply 2 drops to the opening in the screw. Apply one drop to the top of he motor and hold the motor so you can push down onto a firm object holding the screw against the motor. When you've set it. Put it aside for about 4 or 5 hours to dry. Then reinstall the z-screw onto the printer."
The only thing here the I question is the "brass" part I didn't think the new screw they sent me was brass, I'll try and find time this week to take a look and maybe even do this procedure.
]]>like that?
the only thin that would concern me is:
Solidoodle switched to a drilled/press fitted z screw as the coupled z screw gave loads more wobble.
will a metal fitted Z screw coupler actually fix the problem or will it introduce more problems?
so far as changing to a proper lead screw goes,
I'm not convinced that this is the be-all-end all solution.
I don't think that a direct replacement (e.g. m6 for m6 replacement) would be enough.
after all the threaded rod started life straight. -thin rods are likely to bend!
If I were replacing the z-screw and going for a proper lead screw and nut I'd got for a larger diameter if only because that would be less likely to warp. (although if would also mean firmware changes as the step - moved distance will have changed).
basically, I think a similar gauge lead screw will sort out backlash problems, but I would think that the screw would be just as susceptible to bending during shipping as the threaded rod was as it was shipped to Solidoodle.
]]>The bottom of the Z rod is drilled out so it slips over the motor shaft.
as long as she can't slip I'm fine with it. Can't beat the SD price
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