Getting organized before printing parts

Not too bad but maybe you can do a little tweak to get it better, if you really wanted to try but it is probably fine, the Z is more commonly way further off. No one notices printing basic stuff, when it come to real parts it need to be checked.

Are you implying that Batman Buddhas aren’t “real”? Philistine…

Everyone knows the only real prints are Baby Yoda.

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So if my test cube measurements are pretty close. Why are my part prints so far off?

You still need to check your Z, the axis that is most likely to be off.

If that isn’t it you could be over extruding or printing too fast.

Thanks Ryan. Sorry to ask as I am new to 3D printing, but what would over extruding be? extruding too fast? to much material?

I have slowed the speed down quite a bit from what when I started my first parts. I’ll check my settings and post them - probably tomorrow.

The parts that I measured that were off are the Z_Lower_C_Burly and Z_motor_C_Burly. Both of these the holes are flat - XY axis. I’m wondering how the Z axis would affect that.

Thanks again for the help

The slicer knows how much filament to push out while it is moving. If you are pushing out more than you need, then you are “over extruding”, and your print lines will be too fat. When many lines get smooshed together (like the perimeters), then the extra material gets pushed out, making the part bigger.

I’ll reprint the test cube to see what I get for the Z dims.
Here are my settings. I’m a bit at a lost for what I would need to change if anything.
Kinda overwhelmed by the number of variables.

Any suggestions would be greatly welcomed.

All of those settings are what the machine is trying to accomplish. Over (or under) extrusion is often caused by the “E steps per mm” being off. This is based on the specific mechanical properties of your extruder (gearing, steps per revolution, diameter of filament driving teeth, etc.). You want to be sure that when you tell the machine “push through 10 mm of filament” it isn’t pushing more (over extrusion) or less (under extrusion) than 10mm. There are lots of tutorials available for dialing this value in for your particular machine.

I had good luck (quite some time ago) working through https://reprap.org/wiki/Triffid_Hunter's_Calibration_Guide which helps to fine tune a lot of aspects of the machine. I found this particularly helpful in getting familiar with a new machine.

https://3daddict.com/3d-printer-extruder-calibration-steps/ and https://all3dp.com/2/extruder-calibration-6-easy-steps-2/ are more targeted just at getting extrusion properly calibrated.

Once the mechanical aspects are dialed in for the specifics of your extruder, there’s an adjustment most slicers support for individual filament variations. In Slic3r it’s called “extrusion multiplier” and you tweak this to tune flow based on how far the drive teeth “dig in” to the filament as they work to push the plastic through, as that changes the effective diameter of the drive teeth.

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OK, I just finished the full 100mm cube and here are my measurements.
The dimensions in the circles are the Z axis dimensions at that corner.3
The red numbers are new based on the completed cube, black is from yesterday

We also did an extrusion test and measured right at 100 mm.

If the measurements are good, could it be printing speed as Ryan mentioned?
Based on the settings I posted yesterday are there any speed variables (or other settings) that look off I should try to adjust?

FYI, not sure it matters but I’m using a Lulzbot taz 6 with cura for lulzbot.

image

Those numbers are pretty good. I have no idea why your print holes are so small. I assume it will work in the end, Just go slow and do not over tighten anything since it will already be under pretty good tension.

Thanks Ryan. I had a friend test print one of the parts I was having issues with and his turned out fine. Im going to take a look at his settings later today and see if something stands out.

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FINALLY! got a good part. 23.1 mm for the diameter.
I ended up resetting all the defaults. I did follow recommended speeds and temperatures from the filament maker and used 2 wall lines. I would like to try 3 on the next print.

Cura for lulzbot has three different profiles, speed, standard, and high detail. Previously I had used high detail thinking it would have better dimensions but this time I tried standard.

Cura also defaults to printing inner wall lines first then outer lines. I changed that to outer wall lines first.

Not sure which did it, but its what I’m using from here on.

thanks for the help guys.

This can cause overhangs not to work as well, you might want to change that back.

Will do.
Thanks for the advice.

Where is this method explained. I’ve been reading this entire thread as well as your Tampa thread, I even Googled it but I’m not seeing what is being described. “What is the ‘Tape Measure method’?”

You cut a tape measure and stick the tape measure and the wires into some wire loom. Then attach the ends so the tape measure goes straight, turns 180, and attaches. The loop wil move, holding the wires in place.

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We need a hot linked “tape measure trick”, good link (Maybe new page in docs?)?

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So it’s a way of supporting the wires, the loom, giving it some rigidity, and spring at the same time?