My first impression and problems so far
So yesterday I got my mk3s and assembled it. I encountered some problems I wouldn't expect and I will post the two most important.
The first was one of the trapezoid nut, which was very hard to move. Check the video below.
https://mega.nz/#!BBVlSCgQ!WCB6VCso9bI5s9QvOAmC40vMxDikrvsNtFs4s9TRfqQ
Could I request for a new one? Is there any reason not to use a brass one and prefer a plastic? Also why not adding a replacement since many users have the same problem? Finally managed to "fix" it by rotating it for an hour to get it looser.
The other problem is low adhesion which causes model to pop out of the bed. I haven't managed to get a print complete although I searched a lot, read every resource provided by Prusa and having experience with 3d printing. I chose the double-sided textured pei powder-coated spring steel sheet.
You can see the z calibration process here. https://mega.nz/#!tAMVGSrK!ZoniNKP2aJ1JMhcXA8Fa97l7E0zpl7EW_VgkgceN7Tw
You can see the first layer print here. https://mega.nz/#!1BNVGCQK!kT1bY5EcdigvRm6ZjGslu8AijHWnmf-6ZJbmYvu98Go
Finally here is the failed print. It has a very smooth surface with no obvious errors. I tried many times (about 20) to print one of the sd files before making the video. https://mega.nz/#!wcVxAagR!JoKaa_WhGc2Y4A9B4D5x5WN_7AOxtylj5ej0-hHeNuY
Do I have to use glue on this sheet for PLA with default settings (60 degrees Celsious for the bed)? Do you spot anything wrong in my process?
And one last question about the kit? Why not use igus bearings instead of the classic linear?
Thanks in advance.
RE: My first impression and problems so far
Good Morning Kostas,
You may be unaware, this is a community support forum, using web space provided by Prusa,
Most of the folk on here are forum users and volunteer moderators like myself.
We have no power to help you obtain Spare parts... Would you please request these using the 'Chat' service which appears about 3 seconds after the page loads at the following address >>> https://shop.prusa3d.com/en/#_ga=2.238005573.438829455.1580205491-547399854.1580001281
the Plastic Nuts are made from POM which is a self lubricating material, it is used in preference to brass because it is :-
1, Self Lubricating,
2, Audibly, Quieter than Brass (Brass can cause a metallic clicking noises on retractions)
3, Electrically less prone to cause ' electronic noise interference' than a brass part moving on a steel part. this noise can lead to interference within the controller...
Looking at your first layer calibration print, I note that you are not usinf 7x7 mesh bed levelling, you can turn this on using the LCD Menu's
I would suggest that Live Z is a little too low, (Observe the last patch, the surface is not smooth there are small ripples in the surface) this means that your Live Z value is too large a negative number... If I recall correctly the value was -1.762mm you might find that a value closer to -1.700mm may be better...
Personally I find the Prusa Live Z / first layer calibration tool a bit difficult to use, so I use Jeff Jordan's "Life Adjust Z My Way" at the following URL. https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/
there are three files in a zip file at the bottom of the first post, that give easier adjustment for PLA, PETG, ABS with a 0.4mm nozzle.
From experience, many of us prepare the build plates by taking the build plate to the kitchen sink and scrubbing the build plate vigourously with Dish soap and hot water, using a clean, kitchen sponge
then rinsing well with fresh hot water, then drying withplain paper towels. making sure to handle the build plate by the edges to prevent getting fingerprints on the build surface
I also tend to run my heatbed at 70C for PLA...
Please try these options and see if your adhesion improves.
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
RE: My first impression and problems so far
The trapezoidal nuts are shipped on the threaded shaft, so support knows they turned freely when you received them.
They are easy to cross-thread during assembly - which I did to one of mine.
If you assembled your MK3S in one day - expect more problems. Good luck.
RE: My first impression and problems so far
In all fairness, I've found burrs where the ends of the z screws are chamfered/rounded. I could easily see how one might scrape a strand off the inside of the nut and cause it to bind. I'd start by taking the nut off and inspecting it/cleaning the threads inside it before replacing it entirely.
RE: My first impression and problems so far
Thanks for the help! I managed to print a lot of stuff perfectly by just finding the exact z height an setting the bed temperature to 65 degrees Celsious. I wouldn't imagine the even 50 microns would be so critical. Adhesion is still low, prints get of the bed very easily but not during the print.
RE: My first impression and problems so far
[...] I also tend to run my heatbed at 70C for PLA...
I tried prints with 70C bed temps as part of my struggles with the textured sheet, only to wind up with elephant's foot when printing PLA. Are you compensating for that with other settings?