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!

 

MGN12H rails small tweaks to perfect…

Ok, the rails are on and working a treat, kind of…

The right angled fittings I purchased to secure the 20×20 extrusion to the 40×40 have some little tabs on them, I can’t find any readily available way of securely making this connection with off the shelf parts so i’ll have to grind down one side’s tabs…

The slight amount of pressure this tab is putting on the extruision is enough to twist it and stop the MGN rails from running smoothly!

A secure 20×20 extrusion. But slightly twisted due to the small lump

View from below…if I add a little drop down to the right hand carriage, it’ll be easy to re-use the existing limit switch by mounting it on the side of the 2020

Close ups of the existing limit switch and the protrusions on the right angled mounting block.

Overall, minor things , but shows you should plan things a little in advance and test fit stuff before ‘going for it’

Fortunately this is nothing a quick angle grind and carriage print can’t fix….which means re-assembling the original printer to print a new bit, D’oh!

MGN12 rails update – Fitted and The printer moves!

Finally bit the bullet and stopped printing stuff long enough to shove the rails on the printer……..

And, the carriages fit perfectly!

The movement of the blocks is very nice and smooth  – though right now, no real notable difference from the V-wheels……

It’s alive! – kind of. MGN12 Rails update

Well, the MGN12H linear rail carriages fit into the new carriage adaptors I quickly knocked up in Tinkercad perfectly!

And, don’t they look lovely in Purple (great filament from 3D Filaprint)

Now, to dismantle the printer and see if the print bed tray fits…………

That’s the problem with printing stuff to upgrade a printer, iterating takes time and stuff gets dismantled waaay too much! I need a second printer :-p

MGN12H crappy linear rail bearing blocks

What’s more sensible than spending $9USD on a basic, possibly non working chinese no-name bearing block?

……..Spending hours and a few quid trying to do ’em up!

Parts I’ll need…

• 3/32 Drill Bit (or possibly 2.4mm if it needs some play) …………..[edit, turns out a 2.4mm is too small! Looks like 2.5 is the go]

• 3/32 Ball bearings (bound to loose a few)
• Something to drill with
• something to clamp down the carriage without damaging it

After a few minutes with the calipers and Tinkercad, I give you……….

Chinese ‘cheap’ clone linear rails MGN12 Beware and a teardown

The Cheapy ‘Hiwin’ clone rails and blocks arrived a while back and they haven’t really dissapointed. By that, I mean, I kinda got what I was expecting. Still, only a small premium paid and 3 workable carriages / rails……