Anti Z wobble Z nut

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piercet
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Re: Anti Z wobble Z nut

Post by piercet » Wed Jun 08, 2016 10:09 pm

They shouldn't be too hard to move but will conform to where the parts want to be at, to test, loosen the ieadscrew nut and see if you can slide the lower carriage easily. Depending on how aligned your assembly is, they may not want to move that much.

catzcradle
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Re: Anti Z wobble Z nut

Post by catzcradle » Fri Jun 10, 2016 1:48 pm

So I installed the new assemblies last night. The process was less difficult than I expected, and the print quality is significantly improved. One odd thing, is on the tube I used to test an after print, the rear-facing most 1/8 of the cylinder had zero showing of the banding The rest of the part is still visible in white, but far less as you can see in comparison to the double bearing holder prints.
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piercet
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Re: Anti Z wobble Z nut

Post by piercet » Fri Jun 10, 2016 2:18 pm

Nice job!

The anti wobble works on two different axis. The lower sliding portion handles banding on the Y axis, the upper section with the 4 pins deals with banding in the X axis direction. It is possible to have one of the axis on one or both anti wobble be "sticky" and not move enough, which will still show as wobble. It's also possible that the Z axis igus bearings have enough play in them that they are allowing the axis to shift in that direction even with the Z wobble. that issue will tend to show up as intermittent layer wobble rather than a regular wobble matching the leadscrew. The sticky axis issue is usually the culprit with any remaining wobble.

There is one other possibility, and that is rod sway on the X or Y axis. What happens there is either X or Y axis moves slightly on the rods themselves, alternating side to side as it moves front to back caused by the belt pulling slightly to one side or the other. Usually that is very very minor, and it is fixable with hardened rods or other modifications along those lines. You can tell it's that when the issue seems to be present worse in the middle of the part and get better as it gets near the edges on a larger part.

catzcradle
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Re: Anti Z wobble Z nut

Post by catzcradle » Fri Jun 10, 2016 2:34 pm

I'm guessing it's sticky. When fully assembled, the steel pins through the little igus bearings were slightly sticky no matter what I did with the bearings. I got it mostly gone by wiggling the pins in the iges bearings pretty hard until they slid through nice. That would be in the Y direction. I also hit the pins with a little silicone spray which helped. The X axis slides super smooth.

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piercet
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Re: Anti Z wobble Z nut

Post by piercet » Fri Jun 10, 2016 3:01 pm

You may have to use a tool to clean up the little socket the bearing flange sits in. theree is a bridge operation at the top there when the piece prints and it can have some excess droop in it at that point. The metal rods should slide in and out just as smooth as the pins do. Either way it looks like you already have quite a bit of improvement heh.

catzcradle
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Re: Anti Z wobble Z nut

Post by catzcradle » Fri Jun 10, 2016 3:26 pm

Yeah, when I do this for the other taz, I'll have to keep that in mind. The one thing I ran into is the new holder just kisses my left side fan holder/fan. So I'm printing a thinner flanged version to have a little gap. I did use a dental pick to try to clean out the grooves in the lower part. Thankfully for the other machine I only need to buy some more nylon spacers and the igus bearings.

holydeltawings
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Re: Anti Z wobble Z nut

Post by holydeltawings » Fri Sep 23, 2016 10:57 pm

I installed this upgrade recently and it worked for a couple prints. Then all of a sudden it stopped working and started making the wobble even worse. Any ideas. Would heat from a hot box cause parts to expand and bind? Would the weight of the x axis reduce the ability to glider easier? I have the openbuilds x axis installed on this machine as well.

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piercet
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Re: Anti Z wobble Z nut

Post by piercet » Fri Sep 23, 2016 11:45 pm

If you printed it in abs they shouldn't deform, the steel pins might expand though. Check that it isn't locked over to one side or the other of either slide. You may want to pull the metal pins and lift the axis then check that the pins slide properly still. Its also possible that the bearing rotated in the groove in one of them and is now binding . you also may want to loosen the nylon pin bolts and re tighten them to allow them to re center.

holydeltawings
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Re: Anti Z wobble Z nut

Post by holydeltawings » Sun Sep 25, 2016 2:27 pm

I took the bars out and threw some white lithium grease on them and put them back in and that did the trick. seems to be printing fine now. I also purchased one of these:

http://www.armysurpluswarehouse.com/har ... -reel.html

Going to take and rig it up to the x axis to act as a counter weight to bring some pressure off the motors or maybe the carriage.

Daniel
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Re: Anti Z wobble Z nut

Post by Daniel » Mon Jan 02, 2017 10:11 pm

This upgrade seems nice, does anyone know where to find « 8x Igus 2MTRI MYI-03-03 Flanged Bearing, 3/16" IDx 3/16" L » in Canada. I found it only in US and it's 2$ for 5, and 20/30$ shipping :\

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