Answered Strange rescaling during print?

I'm working on the disks on Thor's costume for my cousin. The model is great, good topology, high-poly with a file size of about 2mb. Great. But I've got a problem.

I cut the model in half so the orientation pics up more detail. The model dimensions are basically 100mm x 100mm. So, in half it becomes 100mm x 50mm.

The bed levels out correctly (finally!!!) and prints at 200 microns at the default of 210C, and comes out perfect! Except it almost seems compressed. My camera is dead but in the picture I uploaded, this is basically what is happening.

I recreated the model from scratch in Blender just in case the file was corrupted or something, then re-cut it in Blender (like I do 99% of the time).

The print itself isn't warped. It isn't even "elephant footing." The bottoms are completely flat. Yet, it comes out an Oval instead of Circular.

I have printed this and the "new" variation of the model 6 times and I'm getting the same exact problem.

 

I cut them in half, and made them sit flat, like in the pictures. If there was something wrong with the X or Y axis, there should be gapes where not enough plastic was extruded.

In 1 picture you can see the "gap" required to make a full circle. But none of the detail is missing.
In another picture it shows them standing with a 3vcr2032 battery laying flat for scale.

If there was a problem with the Z axis, there would be really nasty bits that didn't print correctly. But it's coming out super smooth, grabs all of the "scroll work."

 

Your test model seems to have come out perfect.

Now, one detail I forgot to mention was I printed the Thor chest Disk models at 10% infill. Could the model be sinking down, and still have perfectly even lines on the outer shell?

I'm about to print a disk half at 25% infill.

 

The extra density did nothing but waste more filament. When I print it as a full piece it prints just fine. "Basically" a circle. But I have to run it at 100 microns to get the detail semi-properly. As expected, there are too many stair-steps for my liking. Which is why I oriented the model differently. Which is what I do for all of my prints.

For a test, I made a simple cylinder, cut it in half, stood it up at 90 degrees so it had a flat base to print on, just like the chest Disks. And I'm having the same problem. I don't have a millimeter measuring tool, but I can only assume it lost between 5-10mm in height, while keeping 100% of the detail.

The dimensions of the model were:
60mm(X) [wide]
3mm(Y) [thick]
30mm(Z) [tall]

All of the layers are consistent. No X or Y shifting. And there is presumably no shifting in the Z axis as the lines are all properly "glassy" smooth. (I tightened both the X and Y belt as much as possible, no change).

I printed the cylinder again, but scaled the Z from 30mm to 35 mm, which would make the overall shape 60mm(X) and 70mm(Z). An oval.

Yet when it printed, it almost makes a perfect cylinder shape (when both halves are joined). So what the heck is going on? I'm afraid to print anything "major" like a 6 part highly detailed helmet or something.

 

I just stumbled upon someone else having the same problem. And they fixed it by doing something with the Firmware. The link that someone else provided on what to do gives a 404 error.
Page on forum:http://community.robo3d.com/index.php?threads/why-are-my-prints-losing-height-on-the-z-axis.5072/
"Fix" link, 404'd :http://help.robo3dprinter.com/Wiki/RoBo_3D_Firmware
OMG... Have all of my prints always been doing this and I just didn't realize it?? How do I fix the Firmware??

I'm using a ROBO3d R1 Refurbished Unit. I have no idea if it's a Refurbished R1+ or Original. I got it sometime last year I believe.

 

It's a threaded rod with a coupler believe. I attached some pictures (and a picture of the model number, 0340). There about 21 threads per inch.

I'm always having to manually adjust the Z-Axis. One side always goes up a tad bit faster. If I print something really tall, the right side is always about .25".

By manually, I mean I physically grab the couplers and twist them up or down. Do you mean manually in the sense that I tell the Z-axis to go (10mm for instance) up or down in the controls?

Sometimes it locks and won't allow me to down any further. Which leads me to grabbing the couplers and twisting them until the level buttons are being pressed evenly. Then I have to hit "home" while pressing down on the areas where the Z buttons are so it maintains contact. Because if I don't they get off balance again.

Which seems to be 1 of the problems the other forum member had. His prints were too short, fixed the firmware, his prints came out correctly.

So far as I can tell, the wires are not snagging on anything.

 

I must be missing something. I opened up the machine and I don't see anything resembling a card.
How do I change the stepper driver card?

 

While I'm looking for a mouse size screwdriver, I printed a cube. When it was done, it was:
(X) 12/16"
(Y) 12/16"
(Z) 10.5~/16"

Just like the disks, "squashed."

And by the way, thank you very much for taking the time out to try to help me figure out what's going on.

 

How might I go about doing that? That's what I was asking about earlier.

 

Presumably I have the 8mm rods. There are 21~ threads per inch.