SoliForum - 3D Printing Community — Printer is offsetting layers and scrunching Y axis movement

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T20:32:42Z

I have been using a fan since the issue first surfaced (120mm running off another PSU). I will certainly check to see if the belts are to tight (including the one on the y motor), and re-level the bed. My instructor is getting some white lithium grease so I'll try that too. Thanks for all the help guys!

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T20:02:57Z

Mithrandir, you said you followed the steps, just make sure that included the fan we talked about. As you can see from last two posts this is really important. Go to thingiverse and search for fan housings. There are a number of designs, including my own. Any of them should work great, and most use a 40mm fan. Also, smitty50500 had a cracked belt. Check this too. Sounds like your belt is just too tight.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T18:51:16Z

GH105 wrote:

You might want to try putting a fan on your electronics board that drives the stepper motors. I did this and the problem went away.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T17:43:04Z

You might want to try putting a fan on your electronics board that drives the stepper motors. I did this and the problem went away.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T14:57:21Z

I would go through all the calibrations again. Even the trimpot voltage. It's important, IMO, not to miss any of the steps. All are really important.

As for bent jack shaft, this is caused from having the stepper to jackshaft belt too tight, which, you sort of need to have tight, otherwise you can get a bit of elongation in your printed holes. Smitty50500 had a recent post, which I can't seem to find at the moment, where he took my reworked front idler brackets and added bearings, as well as a pillowblock bearing to the jackshaft. It's really good stuff, so search it out. When I upgrade my bushings to bearings, I will use Smitty's pillowblock and reworked idler brackets. Again, just search it out on this forum. As for the pillowblock, it will allow you to keep your primary y axis drive belt tight, without deflecting (bending) the shaft. Keep in mind, you can make the belt so tight you can't even move the y-axis. Good luck!

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T14:12:44Z

Briggs, I am following all of these steps, but I did notice a physical problem today. The back smooth rod (to which the y axis is driven) seems to be popping at a regular interval, in two areas on the y axis. I am gooding to grease all of the rods when I get more grease, but I now wonder if this back rod is bent. Any suggestions?

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T13:07:36Z

Mithrandir, looks to me like there are all sorts of issues. Be sure to level bed, set z-tab to squish first layer, calibrate extruder flow, put a fan on the controller board to keep it cool, grease all rods and pulley shafts, adjust belt tension, ensure no binding of filament, etc. Have you been to soliwiki and gone through all the calibration steps, as well as the other things just mentioned? I did all this and my printer works great. Solidoodle has a couple videos that are good too, and also the instructions for adjusting your trimpot voltages.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-22T10:42:53Z

This is what I got yesterday:

I was trying to print a cube, but with each layer the y direction wasn't hitting its mark.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-20T13:56:08Z

It sounds mechanical Lawsy. My carriage is dialed in really good now and it moves effortlessly, even if you push from just one side. I found that when replacing my cracked idler bracket that my idler pulleys had almost no grease on them. Without grease here I would imagine the aluminum galling fairly quickly on the steel shaft (cap screw). I use a Teflon oil for the bushings on the jack shaft to make sure the lube gets way in there (will upgrade to y axis bearings one of these days). I use ultra lube white lithium for shafts, lead screw, and front idler pulleys. And, the belt from my stepper to the jackshaft is really tight (if not i would get a lot of backlash here on my particular printer). So, even with tight belts it moves easy.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-20T11:49:00Z

Perhaps. That is an option I didn't even think of.

The carriage has been very stiff moving by hand. To the point where trying to slide it forward with the steppers off moves the printer on the table instead of the carriage sliding.

Bit better tonight, got a 2 hour+ print to work without errors.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-20T11:45:33Z

lawsy wrote:

I'm still having intermittent troubles with the y axis skipping. The only thing I haven't done from Briggs' list in replacing the idler blocks.
If I can't fix it I'll redesign the x-carriage entire assembly.

Is it possible that the Y motor is giving up?

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-20T10:09:05Z

I'm still having intermittent troubles with the y axis skipping. The only thing I haven't done from Briggs' list in replacing the idler blocks.

If I can't fix it I'll redesign the x-carriage entire assembly.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-20T02:27:25Z

The soliwiki link posted by op7ical is essential for all us newbies. I would also suggest making shifting x/y axis problems a sticky. It really can be a multi pronged problem.

For me the cure was lube, belt tension, more accurate and rigid y axis idler blocks, 40mm fan for x stepper, 40mm fan for electronics, and finally, adjustment of trimpot voltage.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-20T00:28:20Z

I had a skipped step yesterday. I had powered down my printer for a day. Started it up and started a 12 hour print. About an hour into it, the printer shifted on the Y axis. I cleared the wasted print and immediately started the new print. It printed the entire thing successfully with no skipping. I am wondering if the shift is caused by the electronics changing after they eat, then can continue without issue if you start again right away.

Re: Printer is offsetting layers and scrunching Y axis movement

2013-05-19T05:55:26Z

So I jinxed myself and had a layer shift just after posting.

Next step was to adjust the stepper motor driver trimpots. Each was about 0.02V out.

I also turned my non extrusion travel speed down to 130 from 150.