1 Topic by lost4good

  • lost4good
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Topic: Z Axis Wobble Isolation

While I am waiting for my flexible coupling to arrive to change to a M5 Z axis drive rod.  I was looking at how I wanted to try to eliminate the banding caused by wobble and noticed a number of previous solutions.

There is Lawsy's anti-backlash nut hugger, 2N2R5's Slop Nuts (love the name by the way), and a few others floating around in the forums and on Thingiverse.

In 2N2R5's slop nut post Lawsy linked to a YouTube video which seemed like a better route to take.

Here is my take on it and I was looking for feedback.

First, and M5 nut goes in the bottom of the device and two 3mm holes would need drilled/tapped into the aluminium build platform (SD3), and then a second M5 nut would be tightened on top to remove backlash and be glued to prevent spinning.

Thoughts?

Post's attachments

Spring Mount Z Axis.stl 172.93 kb, 19 downloads since 2013-06-25 

Z Wobble Plastic Spring Adapter Bottom.jpg
Z Wobble Plastic Spring Adapter Bottom.jpg 19.61 kb, file has never been downloaded. 

Z Wobble Plastic Spring Adapter Top.jpg
Z Wobble Plastic Spring Adapter Top.jpg 24.36 kb, file has never been downloaded. 

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2 Reply by 2n2r5

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Re: Z Axis Wobble Isolation

You don't need to glue the nut into place. Just make sure the space for the nut is the standard 3.9MM or whatever deep. This is a little different then how mine works because I don't try to soften the movement of X-Y. I will be interested to see how this works out. You should take advantage of the 4 M3 mounting holes that are already in the top of the bed. You can use one of my slop nuts to get the hole spacing.

Looks cool.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

2n2r5's Website

3 Reply by lost4good

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Re: Z Axis Wobble Isolation

I originally thought about using them but moving the mounting points outward should allow the spring action to be more effective.
I will print it tomorrow night and hope the couplers arrive before the weekend.

4 Reply by lawsy

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Re: Z Axis Wobble Isolation

My trapezoidal screw has just arrived but I'm still waiting for the flexible adaptor. I might give this a run in the meantime as I really like the concept.

Have you fitted it yet and if so can you post a photo?

lawsy's Website

5 Reply by MolecularConcept

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Re: Z Axis Wobble Isolation

Is this mostly a problem for the sd2? Where do these slop nuts go?

6 Reply by lost4good

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Re: Z Axis Wobble Isolation

I printed a test piece last night and noted the spring function is a bit too stiff. I may have to reduce the thickness or make the springs longer by increasing the travel around the center hub.

Also Autodesk Inventor messed up the scale of the model on export. Not sure why as this is the first thing I modeled in it, normally I use sketchup, but I like some of Inventors features enough to keep trying it.

I'm waiting on my 5mm-5mm Flex coupling to arrive from China to fit this to my machine. At the same time I am switching the machine to full linear bearings (Thanks Lawsy), real bearings on all Y Axis points, GT2 belts and pulleys upgrade, and eliminating the small Y Axis drive belt by switching the rear bar to 5mm and direct driving it from outside of the enclosure. Should be fun!

I will post pics when complete.

7 Reply by Zarni

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Re: Z Axis Wobble Isolation

Nice job,
I too saw the post too and thought that it was answering the question in a nice and simple way but I was just taking odudex's object and modifying it so it would accept the four screws on the standard bed. PC issues meant I haven't got very far yet.

I hope to have direct replacement for the stock 5/16 nut holder soon, fingers crossed with a blacklash solution as well.

As a suggestion if you make the nut hole deeper so you can get two nuts in with a spring between it should aid in the backlash. As long as one of the nuts is locked in place the other nut can't comes out.

Once all that is done then the linear bearings will be on order.

8 Reply by 2n2r5

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Re: Z Axis Wobble Isolation

Zarni wrote:

Nice job,
I too saw the post too and thought that it was answering the question in a nice and simple way but I was just taking odudex's object and modifying it so it would accept the four screws on the standard bed. PC issues meant I haven't got very far yet.

I hope to have direct replacement for the stock 5/16 nut holder soon, fingers crossed with a blacklash solution as well.

As a suggestion if you make the nut hole deeper so you can get two nuts in with a spring between it should aid in the backlash. As long as one of the nuts is locked in place the other nut can't comes out.

Once all that is done then the linear bearings will be on order.

There are existing solutions already that don't require bed modifications. Just a few screws and a couple nuts.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

2n2r5's Website