astrodenny

Illuminarti - Thanks for the file, I could not find it for some reason or may have glanced over it. I'll see what I can do with it for replacement panels and take into account they will not be laser cut wood. I suppose too rigid of a z axis would not be as forgiveable during any type of misalignment. If the final design was to allow for slight movement, I can live with that. calinb- I too had to do some sanding for the Z axis bearings to fit properly. They seem to fit perfect now. The Z nut placement is what scares me the most (shifting during a print) and perhaps I'll have to work on this with replacement panels so it's stable. At this moment, I don't see it shift visually, but when I hear the z axis move to a certain point in height, something creeks which makes me nervous. I just don't want to take it apart until I have the panels printed and ready. In the near future, I'll be printing with ABS and converting the platform so aluminum would be my first choice although I'll have to source it precut. Thank you both!

I seem to be dealing with several issues: 1) The z lead screw definitely does not sit tight within the lead screw nut. There lead screw drive nut is not very tight fitting around the lead screw, it's slightly off in tolerance. With a push of the finger, I can make the lead screw shift within the nut. 2) As I mentioned to Illuminarti in another post, which I have not had time to examine yet, is that the lead screw drive nut does not sit straight between the two laser cut panels which hold it in place. I can push the the nut out of place with enough finger force. 3) With regard to #2, when the bed raises up / down along the lead screw - right about at which the bed passes the x - motor, there is a slight "cracking noise" as if the lead screw drive nut shifts against the wood. For #1, assuming the tolerances are off for the lead screw drive nut, I have a feeling it needs to be replaced. If so, I'd really like ultimaker to help me on this one. For #3, I think this has to do with something I messed up once. I forgot to tighten my z end stop while doing a bed level through Cura. The platform ended up hitting against the hot end, causing the bed to slightly bend. I remember hearing a slight crack of wood, but could not find what was happening. My guess is that one of the two small panels which house the nut may have cracked, leading to the lead screw drive nut be able to slightly shift if you apply enough force with your finger tip. I would love to be able to print replacements for these two panels before I take the bed apart; or perhaps a new design to hold the nut in place. Would either of you happen to know if Ultimaker has the STL drawings for these parts available? I've searched both ultimaker wiki/forums and thingiverse but couldn't find them. The other alternative is to design them myself which I'm trying to avoid (having to take apart the bed, measure the parts, reassemble the bed, print them, unassemble, then reassemble again. For future reference, does Ultimaker offer any of their part files for download anywhere?

How tight should the Z Axis be when resting within the drive nut? If you were to touch the z axis with your finger how loose should it be when residing in the drive nut? Or if use the ulticontroller to raise the platform all the way down, then back up, should you see any wobbling or loosness?

Thanks Illuminarti, sorry for the delayed reply! I'll toy with speeds and temps to get the corners sharper.

Pic of gear from the side -

Thanks Olivier - I'll try doing that. I just adjusted my short belts before the print, so this could be be it. Just to confirm, if my short belts are too tight, would it cause backlash? What if they are too loose? I remember seeing a post on this but can't find it.

Hello, I started printing an assembly for this snap together robohand from thingiverse: http://www.thingiverse.com/thing:92937 Printing with Black PLA Retraction on Temp: 220 Layer Height .1mm 20% Fill Print speed 50 mm/s Travel spee 100 mm/s For centered holes, there is a ring effect that occurs around the hole itself. Also, in the case of the first image, it seems as if the hole protrudes along the surface. I'm having trouble figuring out if this a mechanical issue or settings issue. Are my x-y melts too tight causing backlash?

I'm having better success with .1mm than .2mm. That being said, early on after my build I winged it and printed a material feeder gear in .05mm (Brass/Gold). Here is the result, which I was extremely happy with. I'll try .06 next time.

Let me rephrase - I understand the claw and its concept, but I was curious to know if there should be any play in the rods. When you tighten the C clamps down for belt tension, it tightens up the rod as well. Should the rods be completely tight or should there be any loosness or play? I noticed that in the directions you have to find a happy medium between the belts being too tight or too loose. But any additional tightening also seems to effect the rods being too loose or too tight. I guess I'm trying to find the happy medium so that the rods don't shift in the slider blocks.

When tightening each slider block how tight should the inserts (marked C) be against the axis? Should there be some play so the axis is slightly loose or should it be as tight as possible? I just wanted to confirm. Thanks!

Thanks Illuminarti, I'll give this a try and let everyone know.

gr5 - One other question - one of these prints were done using the quickprint settings in Cura. So, if the quickprint settings are preconfigured, shouldn't the z seam be less noticeable or non existent?

Thanks gr5 - I'll give this a shot and report back!

I did grease the screw - twice since using the ultimaker. Just to confirm, that sound of the platform raising along the z should be a smooth sound with out any stutter of any kind? It happens very quick but it is noticeable.

Hi Owen - thanks ... I've noticed this seam also on some (very rare) square prints. Does it also have an effect on cornering? For example a cube's corners seem a bit bent and not sharp?

The bed itself does not move at all. The Z axis rod does have some play within the Z nut. The z nut itself does shift a little (when pushing on it). So, when I auto home and the build platform raises, what could that brief stutter be? Shouldn't the sound of the z motor be a smooth whirl? I had posted a seperate topic regarding the Z seam - I get a nasty line showing up on anything circular: http://umforum.ultimaker.com/index.php?/topic/2304-cant-get-rid-of-this-line-gap-in-circular-prints/ Not sure if this is interrelated?

I'm stumped on why I'm getting these gaps or lines in my prints, mostly when the print involving circular drawing. Here are two pics The first print is a recreation of "Fat Man"; the first atomic bomb As the extruder head rotates around the print, the filament seems to "jump" in the same section. Here's another print of a funnel. It was a failed print, but you'll notice the same gap/line located in roughly the same cooridinates. In both cases the line appears and seems to occur in all circular prints. After printing the atomic bomb, I noticed my X-Y motors were a bit loose. I tightened these up, then printed with retraction on. Here is the reprint of the atom bomb The line is still there. There are also some inconsistent layers, but I beleive this is due to a much needed axis alignment. It's the line/gap that is driving me nuts. In a previous post, I'm also having issues with my Z axis - but not sure if this is related. http://umforum.ultimaker.com/index.php?/topic/2294-z-axis-drive-nut-assembly-loose/ Any help is greatly appreciated.

I was toying with my Z axis using the ulticontroller. I set my build platform all the way to the bottom. I then pressed auto home to watch the Z raise. As it raises, you know that standard whirring/humming sound it makes from the motor? It used to be a consistent pitch. Very briefly, the sound seems to stutter for a brief second as the bed raises. It's not consistent. I've checked the motor, seems tight. Coupling is tight as well. When the stutter occurs, I noticed the coupling pauses for a fraction of a second as it's rotating. I think as the bed raises, the drive nut shifts or something is preventing it from raising smoothly.

gr5 - they don't seem to be in x and y, however I probably should explore this further. I too had to file down a few parts to get things to fit - espescially the print bed. My drive nut does not stay in one place. With enough force I can nudge it in a different direction or make it slightly off center with my finger. At least, this is one of the issues that has me concerned. At one point while leveling the print bed, I accidentally started the bed leveling wizard in Cura without tightening my z end stop. The bed hit the extruder nozzle and I thought I heard a slight crack of wood in the print bed. I have feeling this is from the two brackets which hold the z nut in place.

Just an update, after using up the tape included by Ultimaker, I used a fresh roll of 3m 2090 and the prints are sticking less - much easier to remove, although still some minor force involved. Perhaps I had an unusual roll or just bad luck with the previous tape. By the way - I tried out the Duck "Clean Release" tape I mentioned however it gave me the opposite effect - it wouldn't stick at all! Thanks everyone!

I've been experiencing "steps" in certain layers of my prints. The print can have a nice quality, then all of a sudden you'll notice layers that either skip or seem to jump. As I narrow the problem down, one thing I noticed that has to be an issue is the drive nut assembly for the Z axis The two slotted plates which hold the drive nut in place in between the panels - my drive nut is loose and there seems to be some play (http://wiki.ultimaker.com/Ultimaker_rev.4_assembly:_Z-stage) I can actually wiggle the drive nut a bit. At one point I may have accidentally cracked the wood which may be causing the nut not to stay in place tight. Before I take it apart, I'm wondering if anyone has an stl file for these pieces (see Step 1) so that I can print a replacement ... or perhaps an alternate modification part which will hold the drive nut in place. I only have one printer at the moment (this will change soon :mrgreen:) The other question I have is regarding the Z axis itself - is the axis normally a bit loose? If I slightly wiggle the axis rod, I'll notice it will move a bit within the drive nut. Is this normal?

I'll check this out weiin, thanks!

gr5 - I believe it as most seem to be having the opposite problem. I'm still using the 3M 2090 tape that was included with Ultimaker. The parts are so gripped on, that I've ended up tearing through the tape and scratching up the acrylic print bed during removal. I suppose the bed ends up like this over time? I'll test with another roll of painters tape. I went out and purchased more 3M 2090 and a roll of "Clean Release" Painters Tape by Duck. I'll try your advice and alternate layer temps while squishing the first layer. Thanks!

I don't know about that ... and not complaining - the ultimaker prints great. However, parts that are smaller than 2 inches still stick to my bed even with new tape. Not only that, I have to tear up the tape trying to remove the print as well as reapply new tape. So the problem still occurs with fresh tape. Both with or without alcohol. For 4 inch or more parts, it seems to stick, but I still need a bit more than usual force to get it off the bed (usually at the sacrifice of the newly taped bed). In some cases, the tape still stuck to the bottom and requires extra time to clean up.

My prints stick to the bed and it takes both force and an act of nature to remove the print off the build plate. Is this because my Z-axis alignment is too close to the print bed? When I level my bed, I use a piece of paper to help measure the amount of gap between the print and hot end. Usually it's enough to grab the paper with adequate friction but I can still slide it back and forth.