More Upgrades – X axis Linear Rails

Finally got a few hours over Christmas to knock up the X axis linear rails upgrade for the printer.

Printer seems to run nicely and i’ve printed a few small things….I’ll work on quantifying any improvements next as, right now it only ‘seems’ better, and print quality improvements are really marginal. The biggest difference was on the Y axis bed, and I suspect there are now easy further improvements to be had………

Photos Below

Side view showing the new Carriage (designed by someone else)

The new idler mount – this was needed as existing thingverse ones don’t have space for the rail at the top

Top down view of the new rail carriage

side view of the new idler and it’s tension adjustment screws

First signs of life and possible ‘bugs’

Everything’s gone superbly up to now…The printer’s levelled all lovely like.

The bed moves back and forth as it should.

So, lets try a first brand new print , as I already have one printed months ago, which I broke due to not enough infill…It’ll be a good ‘benchmark’

Wanhao D9 Idler mount from Thingverse

Err, doesn’t look great does it….The first layer went down lovely, then at some point during these first 6 or so layers, a shift happened, there’s some blobbing, and, well, it ain’t too pretty.

First thoughts are many expletives, followed by a ‘ah well, that was a fun experiment’ resignation.

The rails aren’t perfectly frictionless in their moving, but they aren’t bad either..I’ve seen worse on automated production lines….Could I be experiencing STICTION????

If so, that’s gonna be some mechanical engineering stuff i’m going to have to figure out…Whilst ‘fun’ trying to calculate stuff with excel, wikipedia and various internet forums (are the MGN12 ideal for this job? – who knows?)…..I don’t fancy being bored, typing crap out on a computer (yes, i’m blogging, typing stuff out on a computer, hopefully not crap), I want to get stuck into tinkering, printing…..

I try another print and just stand and watch……

I luckily and quickly notice an odd ‘cyclic’ type of motion happening with the pattern laying down, almost a tiny figure of 8 type of motion happening on the print head with respect to the bed…..

I have a look underneath to see what’s causing it, maybe the bearings are wobbling, or i’ve not tightend the rails properly?

In summary –

Tighten the belt holder holding nuts when you re-assemble the thing! these ones shown below…..

Yes, tightening these two solved my odd pattern issues and layer shifting

first signs of life…

Look at that sliky smooth motion!…Give it a shove and it keeps on going…a bit at least.

Certainly , there’s less friction than the old wheels!