Not happy - Y-Carriage and Bed holes do not line up / Lead screw wobble
Received my kit last Friday, and in my excitement I began assembly. Came to the point where I mount the bed, and found that the screw holes between the Y-Carriage and the Bed did not line up perfectly. I could screw in most screws ok, but always one wouldn't want to screw in.
My first thought was maybe I didn't assemble something right - checked the dot location (no problem its on the top of the Y carriage on the back left), checked my Y carriage linear rods (looking good), checked the linear bearings (nothing binding and moves fine). Checked my measurements, and rechecked again.
Finally checked the measurements on the holes on the bed and the holes on the Y-Carriage - its off by about 1mm where the Y-carriage is slightly shorter than the Bed. The bed has holes with about 21cm distance between then, and the Y-carriage shows about 20.9cm between each hole.
At this point, I just wanted to finish the build and print something - already spent about 8 hours with the build at that point. Eventually I got the bed on, after some repeated attempts at screwing it together. XYZ calibration was perpendicular and good so i'm thinking 'No problem!' - I did it right!
Small prints came out fine , but as I started to try larger objects, the outer edges were coming off the bed after the first few layers.
I took a flat piece of glass, and could see that there is about .5mm gap around the outer edge, or possibly more. In the menu, I corrected some of it using the manual bed levelling option, but I really think I got a badly manufactured Y-Carriage or Bed or BOTH!
I also found after my build was finished that my front right leadscrew is slightly bent as well (wobbles and hits the top z-bracket). This is causing some banding on the sides of printed objects that is really annoying.
Not very impressed with these issues after spending so much money on this printer. I'm hoping someone at Prusa can help me out.
Thank you.
Re: Not happy - Y-Carriage and Bed holes do not line up / Lead screw wobble
Just to note - I have pretty much taken apart everything. I even printed a new top Z bracket to see if perhaps it was a defect in it causing the lead screw wobble. I've bought grease to see if that would help too.
I have disassembled the bed so many times now I have lost count. I have done so many XYZ calibrations I can do it blindfolded.
Sorry for my frustration, but when I purchased the Prusa, I was hoping that I wouldn't encounter the types of issues one encounters with a cheap A8 or Prusa clone. You spend 7 weeks excited to get the real deal, and then these issues come up and you can't help but feel a little let down. 🙁
Re: Not happy - Y-Carriage and Bed holes do not line up / Lead screw wobble
Morley,
Most important thing is you need to contact Prusa via eMail or chat (bottom right corner of the Prusa Shop page). Prusa isn't really monitoring these forums.
There have been a few cases with badly warped beds and as far as i recall, they all got replaced by Prusa under warranty. I'd say get a metal ruler or straight edge and take a picture showing how warped it is and send this on to Prusa support. Maybe include pictures or better yet a video of the leadscrew as well. A little bit of wobble is usually ok, but if you see actual banding, this could be out of tolerance as well. I'd try to see if i can fidget about with readjusting mounts, etc. but if it is bent, it's bent.
Re: Not happy - Y-Carriage and Bed holes do not line up / Lead screw wobble
Sometimes the X axis Screws on the ends of the smooth bars, are tightened too much and this causes displacement of the top of the Z leadscrews when the extruder is towards the bottom of it's travel.
regards joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Not happy - Y-Carriage and Bed holes do not line up / Lead screw wobble
I'll take the photos and send them in tonight. I sent in details of my problems last night, but haven't heard anything back yet.
I think it also good to document the issues here as well, as others might be encountering the same problems as I am.