Z-axis not smooth, feels notched at a point.

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ptchan5
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Z-axis not smooth, feels notched at a point.

Post by ptchan5 » Mon Mar 28, 2016 4:48 pm

Hey everyone.

So I've been doing a bunch of cutting on my SO3 and I think there is something wrong with my Z-axis. It's simply not smooth and after some use it doesn't move all the way up in the (+) direction; that is, it doesn't hit the stops. If I lift hard on the motor mount/z-axis plate while the machine is on, I can "pop" it back into place and jog it up and down through the entire range a couple of times. But then after a while it just does the same thing. It will never hit my z-axis limit switch either.

With the power off, I move it by hand up and down and feel like there is a notch or flat spot in the V-groove wheels because it does not move up and down smoothly in a continuous manner. Does that make sense? It's like it has two smooth ranges and has a point at which it gets enough resistance to tell the machine that it's hit a limit. But it's no where near that limit.

Anybody else experience this? Is it the V-rails? The wheels too tight with the eccentric screws? Not sure where to start.

Thanks,
Peter

WillAdams
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Re: Z-axis not smooth, feels notched at a point.

Post by WillAdams » Mon Mar 28, 2016 4:59 pm

Too tight eccentrics seems possible. I'd also make certain the belt tension is taut enough.

Another thing to look into is whether or no the washers are the same thickness --- there've been some discussions of this causing problems.

Post a video or check in w/ support@carbide3d.com

William
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ptchan5
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Re: Z-axis not smooth, feels notched at a point.

Post by ptchan5 » Mon Mar 28, 2016 5:22 pm

Thanks William,

yeah checked and re-tightened the belt, but that's not helping. There is a definite "thunk" at a certain point in the travel. Even after first assembly, the up and down movement was super tight. Is yours that tight? or does it easily move up and down by hand, like butter?

Peter

WillAdams
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Re: Z-axis not smooth, feels notched at a point.

Post by WillAdams » Mon Mar 28, 2016 6:14 pm

Mine moves up and down smoothly, and if memory serves, the assembly instructions indicate it should be so.
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Kyleitzen
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Re: Z-axis not smooth, feels notched at a point.

Post by Kyleitzen » Tue Mar 29, 2016 3:24 am

I had a similar issue with mine do to my initial assembly tightening The Eccentric nuts 180 degrees. DO NOT do this.
I believe they need to be tightened just until the V wheel will not slip. I believe it caused a temporary flat spot in the plastic which returns to round after proper adjustment. Mine would hit what felt like "a nick or flat spot" equivalent to the circumference of the V wheel.
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wunderaa
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Re: Z-axis not smooth, feels notched at a point.

Post by wunderaa » Tue Mar 29, 2016 3:27 am

FWIW, I ran into the same issue a while back. I had over-tightened my v-wheels in an attempt to get rid of some z-plate flex. I left it like that over night and flat-spotted the wheels. I loosened them back up and it appeared the wheels sprang back a little, but even today I have a little thud. Not saying this is your issue, just rang a bell for me. Had you recently tightened the wheels up?

ptchan5
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Re: Z-axis not smooth, feels notched at a point.

Post by ptchan5 » Tue Mar 29, 2016 4:26 am

OMG. That is definitely my problem. I tightened the cr*p out of the nuts to get them 180 degrees as per the instructions. I guarantee they have a flat spot in them. But you say they will bounce back? If not, do I have to buy new V-wheels? if so, how expensive is that?

Thanks,
Peter

HDVideo
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Re: Z-axis not smooth, feels notched at a point.

Post by HDVideo » Tue Mar 29, 2016 11:50 am

You might also want to check your Z-Rails to make sure they are parallel to each other and perpendicular to the X-Axis. From your description it sounds like the rails could be closer together at the top than at the bottom. Just a thought.

stuarttaylor00
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Re: Z-axis not smooth, feels notched at a point.

Post by stuarttaylor00 » Thu Mar 31, 2016 6:39 pm

Look down the top of your Carriage and see if there are any bolts hitting each other. I had this same notch, and that's what it was. I just filed a couple of millimetres off one of them so they passed without hitting.

I also waay overtightened my V wheels the first time, and ran it like that for a long time. But it didn't cause any long-term damage
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