Does your Makerfarm Z axis move up slightly?

Makerfarm I3, 8" Ramps 1.4, ABS 3mm, 0.50mm head.......

I've been fighting keeping my printer calibrated, it changes every single day, sometimes from one print to the next. There was one time when I noticed the nut that gets trapped up inside the right side carrier of the Z axis, was working it's way down the threaded rod. I was able to get it back into place, but while doing that I noticed that if I lift up on the right carrier, it will move about 1/2". I tried the left side and it's pretty solid. I'm wondering if this is the cause of all of my problems? I've checked all 5 screws and nuts and they are all tight.

What is allowing this to move?

Check 3 things:

1, that the nuts are all the way in their sockets on the Z axis carriers. Try not to lift them out once they are in.
2. Make sure your bed is not warping like mine did.
3. Make sure you have your machine on a perfectly flag and level surface. Do not move it once you calibrate.

Check your bed level calibration each day before printing.

Its on a desk that sits in the corner and never moves, the desk sits on carpet that has concrete underneath it. I know the printer isn't moving, it's got to be something loose somewhere.

How did your bed warp and how did you figure it out?

How is your Z axis limit actuator bolt held in place?

If it's just through the wood, you'll have trouble. Put at least one nut on it. Two are better (one on each side).

If your Z axis drive nut does not drop back into place easily, there's something in there holding it up. A piece of laser wood, a metal filing, a rough edge, something. Get rid of what ever it is and the nut should drop into place

If the nut is "walking" out of it's pocket, then something is hanging up the Z axis. You are binding somewhere. Best bet would be the plywood to the smooth rod on the side that's lifting. The motors are monster strong on these printers. You can have a lot of drag and they will pull the carriage around. On the Z you are relying on gravity in the down direction. It does not take much to get things to hang. I'm assuming you have cleaned and oiled the smooth rods recently ....

My bed was hitting the front end, but not at first. Each day it got worse until the y axis couldn't hit the end. So just do a visual inspection.
My workspace is very flat, and I noticed eventually that even moving it one inch messed it up, now it is sitting on a piece of aircraft aluminum plate.

I put locktite on my Z axis end stop screw, and it doesn't move in the wood.

You can shift the M8 thread rods a bit to change the relation of the front end to the rest of the printer. It's not going to fix a badly warped Y carriage board. A straight edge will tell you pretty fast if the board is warped or if the M8's have moved. There are things that might un-warp the board and stabilize it. Whether they are worth the hassle - who knows....

I have a set of custom U clamps printed up to screw my printer down to the top of the table (It's a scrap lumber printer specific table). If I get bothered enough I'll use them.

I also noticed some of the laser cuts coming from makerfarm are not perpendicular. My z axis nuts took a few times to settle in. I mentioned it to Colin, I think he is taking a look at it.

I usually have to recalibrate after every 8 hours of printing or so (more often if I print a lot of tall pieces, say over 60mm).

As my i3 6" Prusa came from Makerfarm, it had vinyl tubing coupling the Z axis stepper motors to the 8mm threaded rods. I found that tended to slip (especially as the vinyl tubing heated up in proximity to the heated bed) and put in a fresh piece of vinyl tubing and shrunk heatshrink tubing around it. Since then it has been pretty solid.

I could not use a metal coupler because the holes in the bottom of the Z axis travellers barely allow more than the rod.

I've also had problems with the nuts coming loose at the top.

As far as the Y bed warping, I've got a slight warpage toward the front of the bed. I'm hoping to compensate using spacers but this has caused some of my bed lifting problems. I think the Prusa i3 design that only has three bearings on the smooth rods is a bit weak - it's the front side where I have only one bearing that is below the plane where it should be.

The assembly instructions suggested fixing the Z endstop to the frame using nylon wire ties. I still have that but it really doesn't seem robust enough.

So far the only one of these issues that's more than just an annoyance (needing to recalibrate) is the Y bed being slightly warped.

Good suggestions here for me to follow up on! Thanks!

I've had zero trouble with the vinyl tube after my first disaster with it. One of the dogs (I'm still not sure which of the three) decided it was a chew toy. The local Lowes replaced it for some ridiculous cost (14 cents?). If it ever loosens up I know where to get more. Metal couplers on the Z rods are not a good idea. Check out "Z axis banding" for all the details. The Z rods need to be able to move a bit.

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I am seeing my bed level change when the printer is hot compared to when it's cooled off for a day or two. It's very consistent. If I simply level it hot, it seems to work ok. I hadn't realized that was what I was doing untill I let things cool down for a few days.

Edited 1 time(s). Last edit at 11/21/2013 10:03AM by uncle_bob.