y-axis calibration

I am new to 3D printing. I have RepRap Prusa i3 kit, with Marlin and Repetier software. I went through a somewhat laborious process of aligning the bed so that it is perfectly square with each axis. This was triple checked with carpenter's square.

I have an issue where only one of the six surfaces is not parallel to the corresponding plane. The surface is normal to the y-axis closest to rear of the printer. It seems to be leaning to the rear as the print gets higher, perhaps by about 0.5 degrees. The front surface is square.

Another issue is that one of the corners on the x-y plane (looking down) is slightly elongated where the print head moves from inside perimeter to outside perimeter on each layer.

I suspect that both issues are symptomatic of the same problem--perhaps y-axis speed, acceleration, or torque are the culprits? Solution seems to be in electronics or software at this point.

I have attached a picture that depicts these concerns. Help is greatly appreciated. I am using the printer to build precision parts for college physics research project.


Larry

well my printer is bolted to a board that has leveling feet and all rods on all axes leveled both z rods same height and bed as close as possible to level all belts need to be tight and all steps/mm set right may require frame to be readjusted. if you have access to machinist level all the better or a dial indicator

I found the yz-plane culprit. Y-axis stepper motor set screw came loose and fell out. It was only until the one screw holding the pulley on and the error getting really bad was I able to figure it out. The other was caused by the Z start point set to begin at same spot on the model with each layer.

I have gained a real education in the past three weeks on all the software settings.

I have already decided that my next 3d printer will be built with Openbuilds extrusion rails. There is just too much twisting and bowing taking place in the bolt stock and acrylic that is difficult to account for. I had xy plane squareness set dead on by the time I wrote my original post. This was checked multiple times both on the printer and on the prints. Three days ago I noticed it was out of adjustment. When I went to readjust, all the bolt stock nuts were still tight. So there seems to be some "settling" taking place.

Your printer isn't all bad- it's demonstrating what to avoid in the next machine.

If you click the link in my sig below you'll see one way to build a 3D printer the right way...

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Actually I think for the cost and accessibility of the technology to a general audience it is a very good product. However, I am an engineer, and a physics/chem student, so I know it can be done better.

Larry