I am having some issues on my UMO+

[Vitt1812 1]

Hi, I have Ultimaker Original Plus. In last week I have printed almost 40 hours approximately 5 to 6 hours prints.

I noticed some problems in last few prints that were made.

1. infill is not overlapping with Walls in some areas, it got worse in the last print that I had to stop. (pictures attached)

2. parts are way off in weight then what cura shows.

3. printer also makes different noise thhan what it sounded when I started the forst print.

4. In the last print I also noticed that home for X and Y was not correct. (something went off may be missing steps by motor?)

5. strength of the print is also not good. (I guess if other problems are resolved this will resolve automatically)

 

Do I need to recalibrate my printer? if yes what all things should I recalibrate?

Should I dis-assemble and reassemble the printer again? (I personalyy will not like this option but if needed I will do it)

Can there be answer to my problems in timing belts and pulleys?

[gr5 2,267]

I think you have 2 unrelated issues:

 

1) X axis slipped - you need to tighten the hell out of the set screws on all 6 pulleys on the X axis in particular the 2 on the short belt (the motor and the other one).  These are harder to get to but you can push the head around and use the long green hex driver that comes with the printer.  It's critical that you use a tool that fits nicely or you will wreck those set screws.  Most people don't believe me that it is slipping so if you don't believe me then use a sharpie to mark the shaft and pulley on motor and the other pulley on the short belt.  The screws should be so tight that you are afraid you will break something.  The shaft of the hex driver should be twisting a bit.

 

2) underextrusion.    This is cause for "lighter weight" and "weak part" and more.  Much harder to isolate.  Step one is to figure out if it is caused by feeder or hot end or settings.  Are you printing faster or thicker layers than when it was working fine?  If so that could be your culprit.  The UMO should top out at around 7 cubit mm per sec at normal temps or 10 cubic mm / sec at bad-quality-high-printing-temps of 230C (okay to do if you are trying to print super fast).  To calculate volume multiply print speed by "line width" by "layer height".

 

Test the feeder first - it should hold about 5kg or about 10 pounds - put the filament about half way down the bowden and hold the big gear with one hand and pull like hell on the filament.  It should not slip easily.  It should take about all your strength (or more) at that awkward angle).  Lift a 10 pound or 5kg weight for comparison.  You want the feeder on the UMO tightened such that the spring on the feeder is around 13mm.  Quite tight.  It should dig into and mark the filament somewhat.

 

If you have been printing hot for a while or if you have been printing 500 to 1000 hours or more, then you may be at the end of life of the teflon part.  Those are "consumables".  Like filament.

 

 

[Vitt1812 1]

Hi gr5,

 

Thanks for reply. 

I checked all screws on pulleys and motors and YES all screws for motrs and set screws on pulleys were a bit lose.

 

I also checked on feeder as you mentioned I tried pulling hard on the filament and it was pretty okay but I made made it tighter, by tightening the spring on the feeder a bit. my filament always had some teethmarks from knurled bolt. 

 

About settings in Cura:

I am using corse quality print settings and modified few settings under it. 

When I started printing for current project after few pieces I changed filament and then after few more pieces it started giving me issues.

 

I am currently using setings that I have exported from Cura and attached it here.

Basically layer height is 0.4mm, line width is 0.4mm and speed of printing infill is 60mm/sec printing temperature is 200deg C.

according to formula you mentioned volume is 9.6cubic mm and may be the temperature of 200deg is not enough.

 

Should I change tmperature and how do I calculate what it should be?

I am printing quite big pieces so changing print speed will result in more printing time.

 

I think my teflon part should be okay as I havent print a lot yet.

 

Thanks for your help, I really appreciae it.

 

Cura settings for printing.curaprofile

[gr5 2,267]

.4mm layer height!  Wow.  You should be using a larger nozzle.  I'm pretty sure you can use UM2 nozzles on the UMO.  It's easy to get leaks and I forget how to avoid those.  When you assemble the nozzle into the aluminum block I think you want the nozzle to hit something inside before it hits the aluminum face so it won't leak (threads themselves always leak).

 

Yes, 10mm^3/sec is fast as hell.  230C will work better but you should really get a bigger nozzle.

 

.6mm nozzle will print about twice as fast as 0.4 and 0.8 will print about 4X as fast as 0.4mm nozzle.

 

Oh - I remember one problem with um2 nozzles is you have to reset the leveling switch and I had to actually lengthen the slots for the Z switch to move it high enough (um2 nozzles are much shorter).

 

 

 

[gr5 2,267]

This is real data but I forget from what, exactly.  I think it was the original UM2 feeder which was a bit wimpy.  I recommend most people don't go over these speeds but the UMO can go probably about double these print speeds.

 

Anyway it gives you an idea of how temperature affects viscosity.

 

Note that your teflon part in your UMO will die faster (maybe 500 hours instead of 2000 hours?) at 230C or 240C.  Don't go over 240C for PLA.  PLA is wonderful in so many ways - one of them is the range of temperatures that you can print at.  ABS in contrast only prints well in a tiny range - around 5C.  I could argue it has a negative range (there is no good temperature for ABS - too hot and it caramelizes and clogs in your nozzle - too cold and you get bad layer adhesion).

 

How beautiful your part looks will go down with these higher temperatures.  Especially bridging and overhangs and, well everything.  But functionally the part should be good.

 

You should definitely be printing at 210C minimum when you are printing this fast.