Undersized tubing fixed by scaling to 99%

I’ve been rebuilding my mpcnc this week to a slightly smaller size and going over it all to give it some maintenance. I’ve always had play in my x,y,z axis but figured it was a pitfall of the PLA conduit nature of the machine. I just reprinted some parts at 99% scale to test and it’s eliminated all the play, all bearings engaged!

I bought screwfix 25mm conduit in the UK, not great but served me okay I guess.

Unfortunately after this dicoverery i’m now reprinted all the parts involving bearings…

Hope this helps someone, also print one bearing part and check against your tubings!

From personal experience: Also double-check your mm/step (or step/mm) settings in your firmware/EEPROM to make sure your printer is printing dimensionally accurate parts from the get-go. There are plenty of calibration prints on Thingaverse that are 100mmx100mmx100mm prints you can use to verify that your printer actually knows how to move exactly 100mm. I found out I was printing at 99.3mm or so. Enough to cause problems. You may find you’re printing at somewhere greater than 100mm…

Yeah, it should be hard maths to get the ratios, but I was off due to some error (belt stretch?)

Yes, most of the time when we see this it’s because your printer is printing 1% too big…

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