3D Printing Accuracy Needed

Hi All,

I’ve printed the c-foot as a sample part to test how .75" EMT would fit. I have 2 printers and the foot from each printer fits on loosely, and while on the conduit, it’s possible to very slightly rock the foot on the conduit. I expected to have a slight friction fit to get the foot on, but not to the point of having to hammer it on. What kind of fit is preferred for the conduit? Are there variances in the conduit itself . . . should I try another source of conduit just to compare, or is it more likely my printers are the issue? I tried measuring the conduit and got 23.4mm, not 23.5mm, but that could just be my caliper being off.

I looked into dimensional calibration for the printers, but for each method found, I found counter points saying not to do that, as it would make things worse.

Anyhow, so I thought I would try here first, and see if there are any recommendations as how best to proceed.


Best to check your printers calibration with a 100mm test print in each axis, also do a 100mm extrusion test.

We have another thread right now with their prints being too small…Luckily we are confirmed to fit over thousands and thousands of prints. So your printer is likely just off a bit. Easy fix.

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Every opinion is on the Internet somewhere. You just have to find the ones you agree with and assume they are true :).

Did you caliper your prints? I measured the STL this morning for Dane and it is supposed to print at 23.8mm diameter.

eerily similar to my thread from today lol

Except exact opposite. We get a lot of odd coincidences like this around here.

Thanks Ryan, I’ll design a 100mm cube and see what I end up with.

I came up with 23.65 which doesn’t sound right based on your STL reference. I don’t have telescoping gauges, so maybe my measurement is off. That was based off of my best fitting print of the bunch with the least jiggle while on the conduit. The looser fitting prints of course got larger from there.

There are some more efficient test parts already on thingiverse. Printing a whole 100mm3 a few times would be a waste of time. It is just the longer the part the more accurate the calibration.

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If that’s the right measuremwnt then you should be alright. Did you try installing the screw to close the gap on the tube?

I did not try to tighten up the foot with a screw as I thought the foot was supposed to slide on being a little snug, not have room to rattle around a bit like mine do. Also wasn’t sure how much flex the PLA will take before it cracks over time.

I think he’s designed them to flex snug after you install the screw. If it was printed too big, then you’d definitely have problems with cracking trying to cinch it down, but my guess is your printer is fine.

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Thanks for pointing out this model. Printer wasn’t horribly off . . .




How do folks handle compensating for this? In this case, seems like scaling X and Y to 99% would get it close.

Slic3r PE has XY Size Compensation, but it’s in mm, would have to be adjusted for every part.

Is there a better way?

Those numbers don’t seem too bad to me, maybe just a slight over extrusion.

Maybe another picture, or see if your bolts are just a little off. Loosen the inner ones and put the Z in, then snug them back in. That might force them apart a bit.

Maybe you have me confused with a different issue? I’ve not shared any pics or gotten to the bolting stage yet. I’ve only printed feet and they are a tad loose. The measurements above were from a calibration print that should have been 100 x 100 x 50, so I’m a little on the long side with the following results:




I wasn’t sure the best way to compensate

1mm over 100mm is 99% accurate. So a 23.5mm hole would only be 23.7mm that is within design spec. If you want to try and get the numbers better you can change your steps per mm in the firmware. I don’t think this is the problem really, make sure your extrusion multiplier is set at one and not less in your slicer?

Confirmed extrusion multiplier is at 1.

One last question for now. Given that you sell sets of the 3D prints, how do your feet fit on the conduit? Is it a slight friction fit, or do they slide on somewhat loosely, and are tightened up with the screw?

All conduit is going to be a little different.

Mine stay on by themselves, snug, Picking up a random “C” foot (you are printing the ones that have a “C” embedded in them correct?) I get just under 23.5mm ID, 40.6mm tall

Look, if you are worried, make sure a screw will snug it up fine, build a roller and make sure it goes on with some tension. if that works you are fine. Check a Z mount just to be thorough. You are only checking one part, try checking a few of the others as well. Any clamping piece should stay on without hardware.

Thanks Ryan. I have what I need now. I was trying to get ahead of the game and get the printing out of the way, so good that I started early. I expect to order a parts bundle from you in a couple months. Appreciate your help.