X End Motor Bracket Failed / Recommended Print Settings for Replace Parts
My X End motor bracket cracked while I was trying to fix my X axis belt tension so I downloaded the current design files and I am going to print the R3 part in ABS. I just plastic glued the crack and used pliers to hold it together. I got the tension numbers below 273 X and 268 Y. I have a few questions. I am using PrusaSlicer 2.1.0 and I built an brand new profile for Zyltech ABS and the prints are coming out nice.
In the instructions for printing parts it says to use 20% infill with Grid @ .20 Layer height. What I noticed is that it neglects to tell you what settings are being used to print the parts like the vertical and horizontal shells and doesn't recommend any settings to reduce print time?
What I want to know is what settings are ya'll using on the farm to print the current parts?
Can I reduce the infill with ABS? ( I planned on reducing infill and increasing shells instead where it is needed since the original part failed.)
What Slicer Quality settings are you using?
How long does this part take to print at the farm?
Thanks in Advance!
RE: X End Motor Bracket Failed / Recommended Print Settings for Replace Parts
Original parts are printed in PETG. ABS has a tendency to shrink more as it cools, this means any holes etc will be smaller which will probably mess up fitting in the smooth rods etc as I seem to recall the tolerances with the PETG ones are rather tight to start with.
RE: X End Motor Bracket Failed / Recommended Print Settings for Replace Parts
I already knew they were printed in PETG. I figured there could be tolerance differences but I am more concerned with strength. I can make adjustments for the shrinkage. I would just like to know specifics about the stock parts and print settings.
RE: X End Motor Bracket Failed / Recommended Print Settings for Replace Parts
The belt tension numbers only show friction on the axis - you will never get the belt tight enough to see 240 ... In other words, the LCD belt tension numbers are meaningless.
My LCD numbers are 295 and 296; belt tension is 8 pounds (more than enough). I have also had my belts as tight as 25 pounds (belt maximum, and damaging to motor bearings). LCD still showed 290's after a self test to update them.
RE: X End Motor Bracket Failed / Recommended Print Settings for Replace Parts
that part is adequately strong, the failure is caused by incorrect installation process, the angled screw is not intended to be a Jack, and the elongated screw holes are finite in length, most of the tensioning is done when the belt is located in the X carriage, the rest is done by turning the motor around the pivot screw, by hand, and the angled screw is supposed to be snugged up against the mounting screw, to stop it backing off!
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: X End Motor Bracket Failed / Recommended Print Settings for Replace Parts
that part is adequately strong, the failure is caused by incorrect installation process, the angled screw is not intended to be a Jack, and the elongated screw holes are finite in length, most of the tensioning is done when the belt is located in the X carriage, the rest is done by turning the motor around the pivot screw, by hand, and the angled screw is supposed to be snugged up against the mounting screw, to stop it backing off!
Joan
This wasn't an installation failure. This is just poor design. I looked for a re-designed X motor mount on Thingiverse before I decided to print the R3 version. I read the current build guide and loosened the screws and reset the mount as tight as I could by hand before applying the angled screw to hold it in place. You can't tighten the top left motor screw down once you have applied force using the angled screw. So that one screw has to be loose enough for it to work. When it popped the crack was on the inside of the part. Looking at the crack it seemed more like an issue with the PETG failing where there was the least layer adhesion. I tightened it more to open it up and applied glue, held it together with a vice grip and left it to cure for 24hrs. Once that glue set I was able to tension it without it coming loose.
I did my research before I asked these specific questions. I am sure that ABS wouldn't have broken as the PETG did because the layer lines are printed at a higher temp and I could use different infill rather than Grid per Stefan's infill print time vs strength tests.
In other printer mods like the CR-10 the tension is applied on the opposite side where the idler is. I expect someone to have designed a new method to fix this problem but I had not found one that worked like this: https://www.thingiverse.com/thing:2078121 for the MK3.
Now with all of that, it still doesn't negate my original questions about the part print settings that haven't been published.
I find this as irritating as when people post prints on Thingiverse that don't have Thing Details.
RE: X End Motor Bracket Failed / Recommended Print Settings for Replace Parts
I swapped out the parts I printed in ABS and I had no dimensional anomalies or shrinkage in the ABS. It came out really nice since I had already calibrated everything from scratch. I have an X/Y of 276 now after testing.