Could the Ultimaker 2 print a cuboid with dimensions of 193mm x 172mm x 26mm?!

[tomprice 0]

Hi,

I'm looking to purchase an Ultimaker 2 but need to be sure that it can print cuboids of the above dimensions! The cuboid does not need to be solid and not of great quality - can be of very low density (ie 5%). But the cuboid would also need to be completely enclosed - no holes. I've been playing around with a Da Vinci 1.0a (!) and it has really struggled to print these cuboids (only prints in ABS) - suffers really bad with warping and the software does not allow infill,wall thickness or bed temps to be customized much...brims and rafts have very little effect too.

Would anyone be able to give their opinion on how the Ultimaker 2 would handle printing these cuboids please? And what would be the best settings to use in Cura?

Thanks in advance!

Tom

[gr5 1,451]

Yes.  It couldn't do one 220X220 because of the clips but since one of your dimensions (172mm) is nice and small for the platform this is an easy print.  Well, easy for me.  The biggest issue would be warping off the bed - this is a solved issue but new people still struggle with it.

Basically you would need to print some brim on the bottom layer that you can cut off with a razor after the print is done.  You would need to use the heated bed at 60C and some glue (comes with the printer).  You might be unsuccessful at first but post on the forums here and I'll help you get that cuboid to stick so well you will be amazed.  Brim is a feature of Cura.

I recommend you download Cura (it's free at UM website) and slice your cuboid and look where it places the brim (layer view) and where the clips are that hold the glass down on the print bed (they are shown visually in Cura) and you can rotate around and see it from different angles - you will have lots of margin.  You can also rotate the cuboid on the bed.

ABS is MUCH harder to print this large as it shrinks twice as much as PLA and I recommend PLA. You would probably have to enclose the top and front yourself to keep it sticking to the glass at those dimensions.

If you want it water tight you will want to use a larger nozzle - I recommend a 0.8mm nozzle which can also print 4X faster (4X the area).  You can get 3rd party nozzles if you as this forum how.

[neotko 1,413]

I had a davinci aio and a duo and well ultimaker it's just a completely different world. But even on davinci you couldndo that, just use hair spray so the abs don't move on that glass (it's really bad the glass of davinci) the downside it's because that glass it's really bad it can break (check solidodle davinci forum). For abs to avoid warping on the davinci what I usually did was to put blue tape covered with hair spray apllied with a sponge. It hard really hard to take off the print but works. On um2 abs I just can't give you any clue but move to pla, it seems better and it's less dangerous for your lungs.

[tomprice 0]

Thanks for the suggestions!

I purchased the Ultimaker 2 today and have been testing today. Printed the Robot sample which I was very impressed with! However having issues printing the cuboid. The first layer sticks without any issues - but the next 3-4 layers are troublesome. The infill layers do no seem to be sticking to each other that well and the walls/shells are being pulled in/collapsing. I was printing at 0.4mm layer height with 0/8mm shell thickness. Is this pushing the Ultimaker too far? I'm just testing with 0.25mm layers with 0.5mm shells. Printing speed is at 100mm/s with travel speed at 150mm/s. I'll post results of my next print!

[tomprice 0]

 

[IRobertI 468]

I was printing at 0.4mm layer height with 0/8mm shell thickness. Is this pushing the Ultimaker too far? I'm just testing with 0.25mm layers with 0.5mm shells. Printing speed is at 100mm/s with travel speed at 150mm/s.

 

0.4mm layer height is way too much. And not so much because the UM2 can't do it, it's more that it's physically a bad thing to do. With such thick layers and such a small nozzle the layers wont get smooshed together properly. I wouldn't go over 0.3mm and I print 99% of my stuff at about 0.1mm.

However, with that speed you're pushing too much volume. 0.4'0.4*100=16mm3/s which is way more than you will be able to print. Ultimaker tests the printers to 8mm3/s.

0.8mm wall thickness is fine. 0.5mm is not. You always want to make this a multiple of your nozzle size which is 0.4mm. Cura can do some tricks to print walls that are not multiples of 0.4mm but you get better results if you don't.

0.25mm layers should be ok at a reasonable speed (maybe 50mm/s) but I would recommend going below that. With such high volume you might also want to bump up the temperature from the default 210C.

Travel speed of 150mm/s is fine, you can even bump it to 200-250.

[IRobertI 468]

Oh and another thing. You might think that 50mm/s sounds slow but remember that the print head on the UM2 is very light and because of this it can accelerate much faster than a printer with a heavier print head. So 100mm/s on a printer with a heavy print head might not be even close to that due to lower acceleration.

[gr5 1,451]

If you want to print 16 cubic mm/sec you will need a larger nozzle. google "olsson block" for more details.

There is another issue with .5mm shell/wall - it will do that on one pass I believe which means it is basically making one pass with a .4mm nozzle but over extruding by 25%. This is difficult to do (requires extra pressure) and so you will be have to print slower than normal volume if you do this. Because of all the extra friction of stuffing all that PLA in that tight space between the nozzle shoulder and the print.

So any shell not a multiple of 0.4mm is for experts only - when you've done 100s of prints and really understand what's going on. For example if you need to make a water tight cup, or print very small letters in a different color these are cases where you might mess with shell width. Or thin walls in an architectural print.

[gr5 1,451]

Here are my recommended top speeds for .2mm layers (twice as fast for .1mm layers):

20mm/sec at 200C

30mm/sec at 210C

40mm/sec at 225C

50mm/sec at 240C

The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA.

[gr5 1,451]

Oh - another thing - your part is very large and it will likely shrink and warp up off the bed. You need to the brim feature as a minimum to keep that from happening. If it still warps up with brim let us know or google this issue as it is easy to fix once you know the tricks.

[tomprice 0]

Thanks for all of the suggestions guys...you've been a great help!

I've managed to get a decent print off in a reasonable time frame...so I'm happy

Layer height: 2.5mm

Shell Thickness: 1.2mm

Print Temperature: 240C

Print Speed: 50mm/s

Brim: 10 lines

I also printed it vertically which allowed me to print it hollow...so saved on quite a bit of filament!

Thanks again.

[gr5 1,451]

Maybe you mean .25mm layers? 2.5mm is - well - crazy thick.