How to fix this

I ran into a problem with my printing.

I am printing a custom model using skeinforge for slicing. In two of the layers it calls for a solid layer. Even though the solid layers are normally laid down in a 45 degree pattern, for whatever reason they are printed left to right parallel to the x axis. Once it finishes these two layers the subsequent layers are shifted a few mm on the y axis. After about 6 layers the y axis is back to the correct alignment for the rest of the print. So what I end up with is half of the model shifted over on the y axis.

This model and the large gear for the screwless gear cube on thingiverse are the only prints that do this. On all other prints all sides have perfect sides.
Somehow the tiny steps in the y axis during these solid layers is throwing it off.

Printing the same model prior came out perfect. Then I added a hole in the model which created the need for solid layers, so I am pretty certain the horizontal solid layers are the problem and the fact that you can visually see the difference just after those layers.

Has anyone had this experience? I can't think of anything other than the y belt itself, but considering all other prints are fine I am not sure what to try next. Thanks for any help.

Edited 1 time(s). Last edit at 05/17/2012 04:36PM by kwdelre.

Although I have no experience with this this could help you troubleshoot but it will be a lot of work.
With a gcode viewer you can look at what should be happening. [www.webgl.com]
Then you know it it is a printer problem or a model problem.

There is a check box marked "infill in direction of bridge" that cause the solid layers wherever skeinforge thinks it has an overhang. If you turn it off they will go away but it may cause a weakness as the reason skeinforge does it s for strength in certain places.

The lost steps are a mystery but may just be a sign that you need to lubricate things.

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Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Definitely not a model problem. I've been through the gcode layers and all is good. Model is correct in the RepSnapper view also.

What type of lubrication should I use? What all would I lubricate? Sorry, the printer is pretty new and I haven't had to lubricate anything yet. Thanks!

kwdelre Wrote:
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> What type of lubrication should I use? What all
> would I lubricate? Sorry, the printer is pretty
> new and I haven't had to lubricate anything yet.
> Thanks!

Its hard to say without knowing what printer you have, but if it uses bushings you want some kind of grease on the rods (I use Vaseline as it is pet / kid / clothing friendly). If it is a Linear bearing machine you should put a few drops of oil in the bearings. Putting oil or grease on the Z lead screws is also something that is needed every so often (grease can attract dirt and dust so be careful).

But seeing as you are new I would suggest abandoning Skeinforge now and going to slic3r as it is way faster and I prefer the code it makes.

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FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Sorry,

I am using a printer built from Botmills kit. I use skeinforge mainly because Botmill provided settings for it.

So do you just put some vasaline directly on the belt? The petro side of it won't hurt the belt?

Thanks!

kwdelre Wrote:
-------------------------------------------------------
> Sorry,
>
> I am using a printer built from Botmills kit. I
> use skeinforge mainly because Botmill provided
> settings for it.
>
> So do you just put some vasaline directly on the
> belt? The petro side of it won't hurt the belt?
>
> Thanks!

Sorry not the belts, the smooth rods. But since you are using a Botmill kit that means you have a true Mendel with lots of little bearings everywhere and they do not need lubrication except on the Z lead screws.

Check if the axis moves easily when the power is off and if they feel sticky or tight or wobbly you will need to adjust the bearings to get really smooth movement. If all of this is fine I would try lowering the travel speed and then the print speed.

Also I would still try slic3r. It requires little to no tuning to get things going.

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FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Thanks, I'll be thinking with slic3r tonight....