A Tea between friends :-) How was Your Day

[Titus]

Hyped:

So I placed three of those on one plate.
Now with the new leveling(by eye and feel rather than paper), "new" coupler(aka, less shit), and the new glue(tesa stick lover now) it seems I can finally reliably print more than one part, one at a time The dream!

However I think my leveling isn't perfect yet as you can see from the difference in surface looks(they are all totally flat though). Any ideas to fix this?

When printing something like this however, I noticed the balls came loose from the bed, causing the print to fail:
http://www.thingiverse.com/thing:915039
I wonder whether that is the size, not enough cooling causing the edges to curl up, or the travel speed, or I don't know?
Any ideas?

[LePaul]

Where on the bed was each piece? The middle obviously looks amazing, the top (far left in thumbnail) needs help. Other one not too bad

[Titus]

Yeah, I figured that, but I have no clue
Also, since all 3 points are coupled it's hard to just turn one 1 up right?

[nilrog]

It could be that the glass is not 100% flat in combination with only 3 leveling points.

[Amedee]

or the X/Y rods bananas...

(Although the glass plate is not always perfectly flat, the probability to bend the rods is higher than bending the glass... )

[Izzy]

Where they in that order on the bed, or was the middle and bottom ones swapped. I would think that there was a slight difference in the bed level.
The only problem I had with the glue stick was the build up, and scrapinging it off, I now use a good quality hair spray ( you can see from the picture I use polish not hair spray on my head ) from my wife, which I find gives a better hold on the plate for PLA's.
If you want to tweet the bed level I print 3x 1 layer thick washers, I place 1 close to each bed levelling screw in Cura, run the print, then measure them to find the differences, remember that the screws are M3 with a pitch of 0.5mm so if you need to alter one screw by 0.05mm it's 36degrees or 1/10th of a turn. IF you aim for 0.1 mm or 0.2mm depending on what you normally use for your 1st layer you will be on the ball, it's well worth spending the time to get it right for better prints.

[LePaul]

There's a glass store near me...might be interesting to get a different piece and compare. Anyone know the glass specs off hand?

[Izzy]

Also check the levelling screws heads, make sure they are below the level of the aluminium plate, mine were proud before I gently increased the countersink.

[Meduza]

It could be that the glass is not 100% flat in combination with only 3 leveling points.

"Only" 3 points is still the best solution possible, since three points define a plane without trying to bend the bed, anything more and you will have to rely on trying to bend the bed to shape.

[nilrog]

If you want to tweet the bed level I print 3x 1 layer thick washers, I place 1 close to each bed levelling screw in Cura, run the print, then measure them to find the differences

And to verify that your bed is flat you should print one in each corner.

"Only" 3 points is still the best solution possible, since three points define a plane without trying to bend the bed, anything more and you will have to rely on trying to bend the bed to shape.

If you have a perfectly flat plane, then yes, 3 points is the best/simplest. I never disputed that. The case was if the bed was not 100% flat.

[Meduza]

And if your bed is not 100% flat in any direction a 4 point bed will probably not solve it since it can be bent in quite many ways that cannot be fixed with a 4 screw setup either, to be sure that we can fix any bent surface we need a infinite amount of screws at a infinite number of places, and that seems like a very tedious bed leveling process to me, and i rather pay some more for a flat bed from the start

[nilrog]

and i rather pay some more for a flat bed from the start

True, but judging from the other forum, even though we pay a premium for UM printers...the parts are not premium. If they were then we would not see all the reports about bad bearings, bent rods etc. They are still good, if not really good (otherwise I would not have bought one ). But they could be even better.

That said, I don't think his problem is with the glass. But if it had been you could get better results with at least one more adjustment point. It would be more tedious to adjust, that's true. But there is always a price to pay for every choice you make.

[Neotko]

Inthink the bearings/nut problem that it's poping more and more on the um forum it's just a bad batch. That can happen to anyone. IMO the quality it's ok, but they should run some quality test for some parts, like linear bearings or z nut. Also they always offer a replacement so it's quite ok. But also, the cheapest misumi bed linear bearings are amazing superior to the um ones. Like, amazing.

[jonnybischof]

...even though we pay a premium for UM printers...the parts are not premium.
...

You don't really pay a premium price for UM printers. If you've ever bought premium stuff from Misumi, you know that these parts combined, and adding electronics and case, will cost you about as much - or even more than - an UM2. But then you have bought a bunch of parts, not an assembled and tested machine.
If you add all the work, logistics, and support that UM has to put into their UM2 price, then it becomes clear that the mechanical hardware parts they use are very cheap stuff.
I think that their biggest problem (materials wise) is the manufacturing cost of their electronics. If these weren't that expensive, the whole machine could be made cheaper, OR use better hardware parts.

I am actually building a printer made from Misumi parts. It's retail price would be in the 10'000 Euro range, because the raw materials alone cost 2000+ EUR.

It is stunning how some people will sell you a working 3D printer for 300$. These are either Chinese workmanship (which, sadly, seems to be available for pretty much... well... for free) or the people selling them don't make any money with their sales. And that means the company would not survive for very long.

[LePaul]

I've watched a few guys (mostly from the BB-8 Builders Club) dive into the cheapest printers they could find, mostly Chinese. What a nightmare. You try to warn these guys but since one or two had OK luck, they, being a novice, think they will be fine too.