It made all my banding issues go completely away with one straightforward mod.... done.

this !!

Seriously?  You used a M3 for your Z Screw?

Absolutely.  My original goal was to push the envelope, with the premise that going to as fine a thread as possible would be best at eliminating banding, an effect demonstrated previously on other platforms.   I ordered a stainless steel M3 rod, half expecting to be too flexible, but I found it to be a lot stiffer than I thought and more than adequate for the job.  In fact, since the bed on the Solidoodle is kept in alignment with the two solid Z rails, the problem with an M8 or the standard 5/16-18 rod is that they are *too* stiff, which magnifies any alignment or straightness issues, exacerbating banding.

There are a bunch of other threads where folks are using M5 or M3 z-rods with great success.  I like the M3 because the thread finer (.5mm vs .8mm).  It made all my banding issues go completely away with one straightforward mod.... done.

http://www.soliforum.com/topic/2154/fix … aded-zrod/

TheBaron wrote:

Yeah, I found a lot of Z axis mod stuff, but I couldn't find something that specifically said how to deal with the aluminum bed. Everything seemed to involve the old school wooden bed.

If you have the equipment, one thing you could try would be to use a 5/16 brass bolt as an adapter.  Just drill and tap a hole down the middle to accept the new rod.  This is what I would have done for my M3 if it weren't late at night (with stores closed) when I did my mod.

M3 ?!?!  Seriously?  You used a M3 for your Z Screw?

Yeah, I found a lot of Z axis mod stuff, but I couldn't find something that specifically said how to deal with the aluminum bed. Everything seemed to involve the old school wooden bed.

If you have the equipment, one thing you could try would be to use a 5/16 brass bolt as an adapter.  Just drill and tap a hole down the middle to accept the new rod.  This is what I would have done for my M3 if it weren't late at night (with stores closed) when I did my mod.

Hey guys, I have been having some pretty significant Z banding lately and am looking at replacing my Z screw with either a much finer pitch (M3 or similar) or a proper ball screw if I can snag one from my boss for cheap enough. However, all the guides and tutorials for replacing the Z screw are built around the older Z carriage with the wooden platform. Mine is the metal one and the threaded nut seems to be a part of the assembly itself. I was wondering if anybody had any experience in changing the screw out on one of these aluminum jobbies.

Thanks!

Aside from the PEM nut, the aluminium bed has the same procedures for removing it as the wooden bed. I think someone already posted a link to the PEM nut removal guide. The mounting holes around the Hole for the threaded rod are different so you will need to choose a replacement nut hugger accordingly. Adrian posted an M5 nut hugger for the aluminium bed. There is also the slopnut that has options for m5, m3, and the original 5/16". 

On a side note, this probably didnt need its own thread. This topic has been discussed to exhaustion. I this what we do need is a sticky in the hacks and mods that lists all previous z-axis mods.

The original 5/16" screw that comes with the SD is about 8mm in diameter, so I wouldn't go down to an M5.  I would look for something a bit more substantial, like a M8

In the meantime, I am trying the well nut trick. Printed this retainer plate: http://www.thingiverse.com/thing:100053 and picked up some 4-40x1/2" socketed cap screws. Went together without too much trouble. Going to print a new test print and, if the difference is really noticeable (it has been from my smaller improvements) I will post pictures. Maybe I won't have to take this whole thing apart.

I may change to an M3 rod in the future.

Thanks!