Oddly shaped holes?
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@arhi I'll give that a shot. Thanks for the tip. Do you have a link? I'm on android, having a hard time finding it.
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@Surgikill Maybe you can tighten the bushings. Cut the bushings lengthwise and make the bushing holder's clamping force adjustable with a screw.
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How can this small play affect only small circles and not all the rest of the print?
In theory at each segment change it should slide a little...
The holes are more or less regular and look like an hexagon. (a little melted but not that much, so the hight temp should not be the culprit for the hexagon shape )
Belts must be tied properly but the problem imho lied elsewhere.
The slicer resolution is fine? (should be set at least as the nozzle size. Maybe is bigger?)
Really curious to see what it is
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@giostark Small circles cause rapid direction changes which throw the loose parts around more than larger features of the print. It probably affects the larger features, too, but is more visible on the small ones.
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@mrehorstdmd Yea, there are issues on the other parts, but not as bad. Any idea how I can fix the wiggle? I'm not sure if the aluminum rods would fix it.
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@Surgikill I think it's this one:
https://play.google.com/store/apps/details?id=com.gates.carbondrivecalculatoror this
https://play.google.com/store/apps/details?id=com.gates.pttoolkit
both can be used i think
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@Surgikill As I posted above, clamping the bushings down a little tighter on the rod would help. If they aren't made to be tightened, cutting a slit with a saw will allow them to be tightened by modifying the clamps that hold them to have screws that let you squeeze the bushings a little tighter on the rods.
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@mrehorstdmd They're held on with zip ties, so not sure how well that will work. it could be a printer issue besides the gantry. I have a print running right now so I can't mess with it. I've attached a picture, maybe that will help.
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Are those maybe the type of bushings that require a certain amount of compressive force on them to get them to fit properly on the rod?
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@Surgikill As you have discovered, zip ties are not a particularly good way to hold components of a precision mechanism together. I'd start with a redesign of the extruder carriage that allows those bearings to be securely fixed and also squeezes them down to fit the rods better.
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At minimum, I would add a rubber band and some nailing wire !
(sorry, couldn't resist)
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@mrehorstdmd Yea that's not happening. That is the redesign. I looked into bolting them on, and I lose a shitload of print volume, which is the whole point of this printer. I used the same design previously, and didn't have an issue. Also why I used 4 of them, instead of 2.
It's also hard to see, but there is a cutout for the linear bushings to line up in. Those zip ties are only holding it in that groove.
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@Surgikill Then you're back to looking for rails that match the diameter of the bushings. Good luck- you're going to need it.
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@mrehorstdmd They're 12mm rods. I don't think that's the issue. As soon as this part is done, I'll show it to you, but after loosening the belts up a bit I don't see the carriage wobbling anymore, but the artifacts are still pronounced, even on large circles (3" diameter)
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@Surgikill, picture ?
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@mrehorstdmd I might be able to use something like this. https://www.igus.com/product/1185
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@Surgikill, I was looking for a picture of a round thing of 3" like you mentioned. Surely the first picture doesn't show a round object ... is it ? Sorry for not being clearer.
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How fast do you print with that machine?
Maybe you should use the Igus rails that match the bushings.
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Carbon fiber rods arenĀ“t precision ground sliding surfaces,
I donĀ“t know who came up with that idea but itĀ“s terrible. This will not last for any significant amount of time.
You may temporarily get less ringing, but so will upgrading the steel rods to a bigger size.
I would personally never use igus bushings or bushings in general because by design, they require a bit of slop / play that causes backlash.
An added negative is that the carbon fiber dust that will accumulate over time is REALLY bad for your lungs. -
@mrehorstdmd I was considering just grabbing some cheap steel rods to see if that fixes it. I don't print that fast right now, but the goal was to have a light carriage so I could up the speed. I was looking at Igus aluminum rods. Not sure if I should get those or the steel rods.
@NitroFreak said in Oddly shaped holes?:
Carbon fiber rods arenĀ“t precision ground sliding surfaces,
I donĀ“t know who came up with that idea but itĀ“s terrible. This will not last for any significant amount of time.
You may temporarily get less ringing, but so will upgrading the steel rods to a bigger size.
I would personally never use igus bushings or bushings in general because by design, they require a bit of slop / play that causes backlash.
An added negative is that the carbon fiber dust that will accumulate over time is REALLY bad for your lungs.Not really sure how I'm going to get carbon fiber dust. The bushings are designed to wear. Not the rod.
