Harrowing tales of the Z-platform

Summary:

My z-stage is exerting lateral pressure on the rear captive nuts..

Harrowing tales of the Z-platform

MaskedRetriever 04 Jun 2009 00:38

I think my z-stage slots end too far apart— there's lateral pressure on the captive nuts which makes the rod resist turning, causing missed vertical steps. I've actually dremelled it inward a bit, and it's working a *little* better, but I'm not exactly eager to mow way in to my nice acrylic z-platform if this is something anyone else has a less invasive fix for.

Any help on this one?

Re: Harrowing tales of the Z-platform

Conrad2468 04 Jun 2009 17:17

how would your z stage move up and down? cause there are no threaded holes just the guide thingys.

Re: Harrowing tales of the Z-platform

MaskedRetriever 04 Jun 2009 18:21

So you've got the nuts on the z-rods. My z-platform presses sideways against them fairly hard, increasing friction between the nuts and the rods, which then bumps up the torque needed to turn them.

Heavily lubricating the rods has reduced the friction enough that it no longer sticks, but when the belt is off the two front rods turn *effortlessly* while the two back ones are hard to twist. All this has me leaving it for now, but it's a mechanical issue I ultimately want to fix…

Re: Harrowing tales of the Z-platform

Conrad2468 04 Jun 2009 21:59

I have the opposite problem…my z stage just moves around freely!

Re: Harrowing tales of the Z-platform

MaskedRetriever 05 Jun 2009 01:20

So— it sits on the bottom unless you push it up?

Your order of things should be:

Wood square with five holes in it, one barely large enough for the rod to slide through, bolted to the Z-platform, trapping a nut at each corner.

The square, if securely fastened to the platform, keeps the nut from moving from below to above the platform. The platform's sides are notched to hold the nut securely. Is this what your setup is like?

Re: Harrowing tales of the Z-platform

Conrad2468 05 Jun 2009 02:31

if i hold the tray completely (or even remotely) level it slides freely up and down! i have 4 nuts on the rod…..2 on top to secure the bearing and 2 on bottom to secure the bottom bearing.

Re: Harrowing tales of the Z-platform

MaskedRetriever 05 Jun 2009 03:26

There's your problem! You need FIVE nuts per rod.

One in the middle, to be trapped up against the platform. This holds the platform in place and allows the pulley system to drive it up and down.

Re: Harrowing tales of the Z-platform

clothbot 05 Jun 2009 03:29

Yeah, you missed the fifth nut. I did that the first time too.

The picture of the 'Z-Stage Sandwich' doesn't show the middle nut hiding behind the wooden holding bracket in the middle. The only clue that you have that you forgot one is when you try to 'Check your z-stage!'

Re: Harrowing tales of the Z-platform

Conrad2468 05 Jun 2009 04:20

CRAP!

Re: Harrowing tales of the Z-platform

Conrad2468 05 Jun 2009 20:02

ok, so it goes….dice thingy, nut, and the acrylic? secure it…right?

Re: Harrowing tales of the Z-platform

MaskedRetriever 06 Jun 2009 00:08

Yep— now your z-stage should be stuck firmly to the dice thingy, which traps the nut and holds the z-stage still relative to the position of the nuts. Once you've got that, your z-stage should move along with the top pulleys.

Re: Harrowing tales of the Z-platform

Conrad2468 06 Jun 2009 14:18

cool thanks!