Shrinkage

Mostly Printed CNC - MPCNC Troubleshooting
1

So far i printed a few parts (i print on an Ultimaker Original+) including a corner block in PLA.
But i get an inner diameter of about 24.5mm for the IE version. The stange part is that the outer dimensions of the part are exactly the length cura shows me. (48.4mm x 53mm x 53 mm).
Because i dont got my ballbearings yet i just printed out 3 dummy with and OD of 22 and put them in the middel joiner and this part fits the tube just fine.

So i am undeterminded if i should just sand out them corner blocks to fit my tube.

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2

I found when I use a larger extruder nozzle hole diameters are less accurate. I had to stop using my .5mm nozzles because the holes were all to tight, but fit great with a .4mm…who knows why.

You should be able to sand the corners a bit and get them to fit. I just stuff them in there without the screws then fit the screws.

3

Stange… i allready got a .4mm nozzel. But the bearings should arrive by tomorrow and if the roller and joiners fit the tube well I’ll just will go and sand the corner blocks to fit the tube.

4

All my tubes fit through all of the bearings very well.
I printer the 25mm version, and the holes in the corners and top of Z, were about 24.5mm.

But with the help of an adjustable hand reamer 23.0 to 26.0mm, I now have a very good finish plus they are all 25.0mm.

By the way I used ABS as that is what my printer uses at the moment.

Cheers
Greg.

5

So here is a little update on my prints:

At first an adjustable hand reamer sounded like a great idea but the fact i don’t own one and they are like min 25€ I gave up on this idea.
My simple solution than was that i scaled the corner blocks,feets and the cornerblock lock up by 2.5%. Now those parts fit nicely.
The joiners and rollers however fit perfekt printed at the original size.