Re: Ultimaker 2 Problem with thin walls
well the perimeter print order has been brought up many times over the past year and while yes i see you point on that its also much better for cooling doing it the way it does right now. your small holes at the end of the stick for instance would have alot of nozzle contact and get heat soaked. the current print order would give some time for it to cool and harden before the nozzle comes back for the next perimeter. this makes for cleaner surfaces. not in all cases of course but its just good practice really. if your nozzle isnt primed after a rapid movement then you need to tweak your retraction settings. you should not have an unprimed nozzle after a jump. usually everyone has just the opposite problem and complain about the oozing during a jump leaving surface bumps. you are the first person i ever heard say they had the opposite problem. every printer is different though. as for the thing that nick posted on, if you look closely at the picture you can see the filled one on the right, the walls are thicker due to too much plastic being put there. its a physical limitation of the printer from the nozzle diameter. slic3r may be able to put an extra extrusion in there which i understand and that may be fine for some prints but if you are printing parts where tolerances matter this just doesnt work. i am not sure if this is a feature in slic3r which is able to be turned off and on or not. that would be nice. i havent used slicer in quite a long time.
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Nicksdesign
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- Joined: Sat Oct 04, 2014 9:23 pm
Re: Ultimaker 2 Problem with thin walls
It's true that the walls on the right print are somewhat thicker than the left print with the void in the middle. However, it's not clear to me that that is because the fill pass over extruded because it couldn't be done or because my printer is not well calibrated. There is a lot of variation in the wall thickness on the left print even with the voids (0.9mm to 1.5mm). Any excessive fill which may be causing the excess width could be due to a lack of calibration of my printer.
For example, the width of the single perimeter extrusion is 0.46mm. I'm not an expert, by any measure, with the MB slicer. I consider it to be poorly documented. If the MB slicer is set for a 0.4mm, than I may just need to adjust the slicer settings to calibrate. This isn't a forum for the MB slicer, so I don't want to dwell on it here.
The setting I'm using with Slic3r to fill in these voids is user settable for threshold: fill areas below the threshold.
Nick
For example, the width of the single perimeter extrusion is 0.46mm. I'm not an expert, by any measure, with the MB slicer. I consider it to be poorly documented. If the MB slicer is set for a 0.4mm, than I may just need to adjust the slicer settings to calibrate. This isn't a forum for the MB slicer, so I don't want to dwell on it here.
The setting I'm using with Slic3r to fill in these voids is user settable for threshold: fill areas below the threshold.
Nick
Re: Ultimaker 2 Problem with thin walls
hey nick, its probably not your printer. what you are posting above and our whole conversation here is an extremely common topic of conversation everywhere. in the past year i have seen this come up more times than i can count. its just part of 3d printing. its nice to see though that slicers are trying to make their best effort at an attempt to help the situation. i know makerware for instance has or had a feature (so im told) called spur. this would take 2 walls and put a single one between...if it fits. some people seem to love it other hate it. s3d only does it in multiples of 2. a single center wall feature would be nice BUT since s3d has such a nice preview feature its very easy to slice and see what needs to happen then adjust the extrusion width to everything fits real nice. it usually doesnt have to me bumped too far. s3d will squish or overlap 2 lines to a certain point so your pic which has single walls could be bumped to 2 then the extrusion width down a hair and your preview would show 2 perimeters and a fat center line. the fat center is actually 2 passes. im also still not 100% sure what auto width does. does it just calculate the proper width for the nozzle or does it adjust the width for certain spots of the model as it slices. that was something i meant to ask clayton at makerfaire and just forgot. while i agree with you that it should just print and we should not have to worry about adjusting for things like that, printing just isnt there quite yet. i think some of the biggest advancements we have to see in home 3d printing is on the software side.
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Nicksdesign
- Posts: 4
- Joined: Sat Oct 04, 2014 9:23 pm
Re: Ultimaker 2 Problem with thin walls
The Makerbot slicer does have a function called a 'spur', both internal and external. This is a perimeter pass that is not a full closed loop. With full loop perimeters, there is always an even number of perimeter passes across a part layer. With the internal spur function enabled, instead of dropping a total of two (one each side), the slicer will print two on one side and one on the other. This is better than leaving a void nearly two passes wide, but still leaves a ~0.4mm wide void. The slicer does not print any fill, or top/bottom fill, in this void either, so the void is completely through the part.
To put some numbers on what I'd like the slicer to do: consider the open space is less than the normal width of extruded fiber, say 0.3mm when an full width fiber is 0.45mm (a typical width) with a 0.4mm nozzle. If the extruder nozzle is centered over the void, the existing solid (cooled) plastic should constrain the extruding plastic to the narrower void. As long as the amount of plastic extruded is only the amount needed to fill the smaller space, there should be no problem. If the amount of plastic extruded is too great, the liquid plastic will bulge upward forward and behind the extruder nozzle. Because the plastic on both sides of the void is cooled, I don't see how any over extrusion into the void could cause the previously extruded plastic to bulge sideways and produce a wider result. In order for the extruding plastic to bulge the sides, the cooled plastic would have to delaminate.
I think the reason my solid print of the test part has thicker walls is mostly because my printer is extruding more plastic than the slicer is calculating: for example, if my slicer is set for 0.4mm for the extruded fiber and the actual width is 0.45mm. In addition, there is quite a bit of variance in the wall thickness even in the example without the fill. This is probably due to backlash.
I really like a lot of the features of the Simplify3D slicer, but what I conclude from reading here is that it will leave even bigger voids (0.8mm+, or nearly two passes wide) than the MB slicer does. The ability to partition a print vertically with different print settings does allow for some ability to deal with this for some part designs, but not all parts can be orientated appropriately.
Nick
To put some numbers on what I'd like the slicer to do: consider the open space is less than the normal width of extruded fiber, say 0.3mm when an full width fiber is 0.45mm (a typical width) with a 0.4mm nozzle. If the extruder nozzle is centered over the void, the existing solid (cooled) plastic should constrain the extruding plastic to the narrower void. As long as the amount of plastic extruded is only the amount needed to fill the smaller space, there should be no problem. If the amount of plastic extruded is too great, the liquid plastic will bulge upward forward and behind the extruder nozzle. Because the plastic on both sides of the void is cooled, I don't see how any over extrusion into the void could cause the previously extruded plastic to bulge sideways and produce a wider result. In order for the extruding plastic to bulge the sides, the cooled plastic would have to delaminate.
I think the reason my solid print of the test part has thicker walls is mostly because my printer is extruding more plastic than the slicer is calculating: for example, if my slicer is set for 0.4mm for the extruded fiber and the actual width is 0.45mm. In addition, there is quite a bit of variance in the wall thickness even in the example without the fill. This is probably due to backlash.
I really like a lot of the features of the Simplify3D slicer, but what I conclude from reading here is that it will leave even bigger voids (0.8mm+, or nearly two passes wide) than the MB slicer does. The ability to partition a print vertically with different print settings does allow for some ability to deal with this for some part designs, but not all parts can be orientated appropriately.
Nick
