1 Topic by ccorwin

  • ccorwin
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Topic: 3rd z axis rail?

Has anybody ever made a third rail at the door side of the table? I think this might help with z axis wobble. I might print some parts out to see if it will work. I think in the front left or right corner with an arm atatchment to the underside of the table.

Technology Teacher -Minisink Valley Middle School
3X Solidoodle 2 pro, 2X Solidoodle 3 with 6" beds, 5X Solidoodle 4
Many commercial & home-built CNC routers & laser engravers

2 Reply by vince7c95

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Re: 3rd z axis rail?

This guy attempted it:
http://www.soliforum.com/topic/994/craz … e-banding/

3 Reply by caswal

  • caswal
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Re: 3rd z axis rail?

Woo, I'm a guy.

Currently the third rail is removed, as I am replacing that with a proper rod and linear bearing.

Lead Programmer & Co-Owner of Camshaft Software - Creators of Automation - The Car Company Tycoon Game

caswal's Website

4 Reply by tealvince

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Re: 3rd z axis rail?

ccorwin wrote:

Has anybody ever made a third rail at the door side of the table? I think this might help with z axis wobble. I might print some parts out to see if it will work. I think in the front left or right corner with an arm atatchment to the underside of the table.

While your case may of course be different, I believe most of the banding people experience is not due to actual lateral movement in the bed, but instead due to z-axis moving in a non-linear manner when the z-rod presses sideways against the nut, which causes layers with unequal heights.  Many people (myself included) have now effectively eliminated banding using Rincewind's modified firmware that lets you calibrate z-axis movement to compensate for the non-linearity.

5 Reply by ccorwin

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Re: 3rd z axis rail?

Cool, I'll have to look into the firmware tip. I have some
1/4" rod and will model/ print the parts in a few days to expirement. I just notice the shaking the x and y axis deliver can effect the cantilevered table.

Technology Teacher -Minisink Valley Middle School
3X Solidoodle 2 pro, 2X Solidoodle 3 with 6" beds, 5X Solidoodle 4
Many commercial & home-built CNC routers & laser engravers

6 Reply by solijohn

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Re: 3rd z axis rail?

tealvince wrote:
ccorwin wrote:

Has anybody ever made a third rail at the door side of the table? I think this might help with z axis wobble. I might print some parts out to see if it will work. I think in the front left or right corner with an arm atatchment to the underside of the table.

While your case may of course be different, I believe most of the banding people experience is not due to actual lateral movement in the bed, but instead due to z-axis moving in a non-linear manner when the z-rod presses sideways against the nut, which causes layers with unequal heights.  Many people (myself included) have now effectively eliminated banding using Rincewind's modified firmware that lets you calibrate z-axis movement to compensate for the non-linearity.

Got before and afters?

Former Solidoodle employee, no longer associated with the company.

7 Reply by tealvince

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Re: 3rd z axis rail?

solidoodlesupport wrote:

Got before and afters?

Here's a photo attached. 

There are lots of photos from other folks with more extreme examples on the z-wobble-compensation thread, but I had an unusual case of a nonlinearity that no not only had a sinusoidal component, but also had a discontinuity that caused regular groove in the output of .1mm prints.  I got great results measuring the bed position with a laser pointer setup and using it to define a custom compensation curve:

http://www.soliforum.com/topic/1165/fir … pensation/

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8 Reply by pcpoirier

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Re: 3rd z axis rail?

Has anybody tried to straighten the screw?
Just put it on a sheet of glass,  find the high spots and tap down then down on something soft like wood using a plastic hammer.

9 Reply by solijohn

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Re: 3rd z axis rail?

pcpoirier wrote:

Has anybody tried to straighten the screw?
Just put it on a sheet of glass,  find the high spots and tap down then down on something soft like wood using a plastic hammer.

In many cases part you'd want alter is the threads of the screw.

Former Solidoodle employee, no longer associated with the company.