Ellipsis instead of circle

I am working on a printer! What contest?!?!?!?!?!

I don’t think removing material from that spot will do anything. that will only move the bearings along the conduit tangent, not normal to it. I agree all the same scale pieces, preferably no scaling and just get the right size tube.

24.95mm would fit the IE version no problem. 0.05mm is not the issue, pretty sure +/- 0.25mm would work just fine.
Something else is fishy here. plenty of complaints about how tight the parts are, never once has anyone said too loose. 8mmbolts and 22mmOD bearings?

About the 24.95mm… you are right, 0.05mm is way to small to produce this problem.
If you calculate the scale in relation to the 25mm you get an 99.8% ((24.95 * 100) / 25), the value is mostly negligible.

can you give more info about the 3d printer you are working? what type of printer, is an delta? corexy? prusa?
About the context, some months ago i receive an email to submit the printer in some type of contest, but i never submitted anything because i was sure i will not win. At the time i only uploaded the project on thingiverse, so i was pretty sure it was some type of contest promoted by them. I see on the thingivers page of the cnc you have win an contest and assumed it was the same one.

my printer is a delta, a geeetech g2 pro.

Yes 22mm od bearings and 8mm bolts.
I think my printer needs a calibration… but for now reprinting in scale at 98% I think I should get everithing fine.

An stupid question, your are sure that your printer prints objects with the correct dimensions?

In fact, assuming that the IE version stl files are correct, and it’s surely so, I think my printer doesn’t print in correct dimensions, but scaling at 98% I find a perfect fit… and so I’ll try to reprint the missing pieces in this way. And then I’ll see.

I should do a calibration, but if I calibrate now, I will not know if print at 100% or at whatever scale factor.
Anyway, if reprinting with the actual settings will do the job, ok, if not, I’ll do a calibration and restart printing.

you can simply print an 20mm cube calibration to check… is an print made in less of 20min

I’ll do it as soon as possible and I will share the results! Thank you.

Well, I printed the 20mm cube for calibration… It measures 20mm on all the sides… See the pics…
I don’t know why I need to scale all by the 2%… But the new “better middle z” fits perfectly and now I have the axes in square… I didn’t finish mounting the CNC so I didn’t try a cut yet… Tomorrow I’ll see what happens …

Hi Gianluca,

When I measure a square block such as the one your have, close the vernier jaws along the entire surface, from corner to corner.

That way you see any undulations and a more actuate measure.

By the way I would suggest your second photo measures about 19.85mm but without seeing all the digits, not sure. Except to say that it is not 20.00mm

But at the end of the day your 3d printer is calibrated quite well.

Cheers
Greg.

Greg, You are absolutely right!
This confuses thighs a little more: if my printer makes undersized object it is strange that I have to scale down the pieces of the cnc…

About calibration of the printer, if it was yours, should you be satisfied with the current settings, or should you search a more accurate calibration?

It’s my first 3d printer, and it’s my first calibration… :slight_smile:

Gianluca,

My thoughts are that if you print in ABS and the result was what you showed in the images, all should be fine.

ABS requires higher temps to build so there is more shrinkage then PLA.

If your prints are with PLA, you may see if you could tweak it a little. But to be honest I think your prints are fine
and the more you worry about getting your prints 100% accurate the longer it will be getting your MPCNC up and running.

I’m printing with a Devinci 1.0A and I’m unable to calibrate, apart from the first layer and bed height. Which can be a pain
in the butt at times. But the print you showed is very similar to what I would get on mine, and my MPCNC is fine, with a bit
of hand machining!

Good luck with it all Gianluca.

Cheers
Greg.

I print in PLA. I’ll follow your suggestion and keep the actual settings.
Thank you very much Greg!

@Gianluca Magnani Since this is your first calibration, you might want to take a look at this guide: http://www.reprap.org/wiki/Triffid_Hunter’s_Calibration_Guide. It’s very detailed, with solutions for specific problems.

That said, I agree with Greg - 100% accuracy is not required. I had to do a little sanding on the roller and middle z pieces to get bearings to fit, and I made a wedge that I applied with a c-clamp to open the corner blocks to fit the tubes in. I am very happy with how my MPCNC works.

Karl

Thank you Karl!