Support too compact to remove.

Hi all.

I'm trying to print a belt pulley but I'm having problem when slecting to use support.
I need the support as the upper edge would otherwise fell off during printing.

The issue is the support material is so compactly added that it becomes impossible to remove it afterwards.



I'm sure I'ts something with the settings but I've just started using Slic3r and 3D printing and if someone could point me
to some documentation or examples it would be great.

Cheers!

Have you calibrated the extrusion parameter? Over-extrusion will cause support material to attach itself too strongly to the part. Having said that, I found Slic3r's support to be unsatisfactory (though it may have improved in later versions), and thus used Cura for designs that required support. You could also consider printing the part in two sections that do not need support and gluing together afterwards. I print with ABS which can be chemically bonded with acetone, forming a joint that is as strong or stronger than a part printed in one section.

Dave

Thanks for the reply.
I suppose you mean the extrusion value in the firmware? I haven't.

Before I printed another object with support that a friend sent me the gcode from cura and the support could be removed perfectly.
So I imagine the extrusion is ok, just some parameter in Slic3r that is not correct.

And it seems there are indeed issues with support generation in Slic3r.

Source: [github.com]

The extruder must be calibrated for the printer in firmware, but there is also the "extrusion factor" variable to set in Slic3r (under "Filament Settings"). I find different filament needs a tweak to that parameter, and in my case even though my extruder is calibrated on the machine, I have to set an extrusion factor of around 0.8 to get a correct thin wall thickness.

It does however sound as if Slic3r's support generation is still unsatisfactory, so I suggest using a different application (such as Cura) for slicing designs that need support. Or you could use Simplify3D which generates really excellent support structures that you can hand-edit before printing to achieve the optimum result, but that is not freeware.

Dave

Ah ok, I'll check that out. Still lots to read and learn.
I did tried Cura in the mean time but for reason I can't get it to generate support for this model.

Asked a friend that been using it for longer and he also couldn't get the support to be generated at all for this model in Cura.

In Cura, set the "Support type" to "Everywhere". (Under Basic settings). Setting it to "Touching buildplate" will not generate any support on the part you show because the support needs to sit on the bottom flange, it cannot be supported from structures that start on the bed. The "Expert config" menu allows you to set the fill and XYZ distance of the support material from the model to get the right compromise between effective support and ease of removal (which I suggest leaving the defaults of 20, 0.7 and 0.15 initially), but I cannot find anywhere that allows you to set the trigger overhang angle, so I guess that's fixed - probably to around 45 degrees. Certainly it will be triggered by the 90 overhang on your part so Cura should definitely be generating support if your support setting is correct.

The alternative is to add support by hand in your design. For the part you show, I would try a thin (single perimeter) hollow cylinder (tube) between the outer circumferences of the flanges - make it half an extrusion width smaller than the flange outer radius. Hopefully the top flange will then bridge to that circumference OK, if not add additional smaller cylinders and/or thin radii. You can then cut through the single wall structure(s) and remove it/them, then touch up the edges with a small file.

If you want to send me the STL, your temperature and speed settings, your start and end codes and the XY position of your bed center, I could slice the part in Simplify3D and send you the G code

Dave

I did tried all those settings but Cura simply doesn't generate any support structure.





I'm sending the STL in attachment.
I'm runing PLA at 215 and 50(0.1 layers)-60(0.2 layers)mm/s of speed. Not sure how to get the bed center but it's 210x210mm.

Much appreciated for all the help you've been providing so far.

Edited 2 time(s). Last edit at 03/24/2015 09:36AM by Nandox7.

Quote
Nandox7
I'm sending the STL in attachment.
I'm runing PLA at 215 and 50(0.1 layers)-60(0.2 layers)mm/s of speed. Not sure how to get the bed center but it's 210x210mm.

Much appreciated for all the help you've been providing so far.

I will slice your STL tonight - but I am not sure of your settings, so if you can reply before I slice there is a better chance of success.

1) What is your first layer height?
2) What are the other layer heights?
3) Do you have a heated bed, and if so what temperature do you want set?
4) What are your existing start and end codes?
5) If you send the command "G1 X0 Y0" does the nozzle move to the corner of the bed or to the center of the bed?

The last is important to know, because some printers use the corner as 0,0 and others use the center as 0,0 If the wrong system is used it will try to print the part off the bed. If you do not know (4) or (5), upload a small G-code file that you know prints OK on your printer and I can find out from that.

Dave

Edited 1 time(s). Last edit at 03/24/2015 09:52AM by dmould.

Sorry I'm still learning all this 3D printer related stuff. Reading a lot and still lots to read.

1. 0.1mm
2. 0.1mm
3. No
4. Start & End GCode.

Start GCode:
---
G21 ;metric values
G90 ;absolute positioning
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z15.0 F1200 ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E5 ;extrude 5mm of feed stock
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
---

End GCode:
---
M104 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G90
;G91 ;relative positioning
G1 E-5 F300 ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z200 F{travel_speed} ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90
---

5. To the corner of the bed

1&2 : I'm still using the settings included in the profiles the printer makes provides, these probably should be tweaked.

Find G code file attached for you to try. I forgot to ask what your filament diameter is - I have assumed 1.75mm. I have made non-printing moves 100mm/s and 35% infill. I assumed your tool (nozzle) designation is T1 - edit the G-code file if that is incorrect and change all "T1" to whatever you need.

Look through the first lines of the G-code with a text editor - it lists all the settings. If any are incorrect, let me know and I will re-slice with changed settings.

215 deg C is rather hot for PLA but cold for ABS - are you sure that is what you need? You can always edit the G-code file and change if you need to.

If you are new to FFF printing, you may find you get better results with a bigger layer height - I use 0.2mm or 0.25mm for most prints. The first layer is usually tricky to get right at 0.1mm, so you could also try a bigger 1st layer with the rest at 0.1mm if you are having trouble getting the first layer to print correctly.

I've attached a second G-code file with 1st layer height 0.25mm, other heights 0.1mm and 190 deg C temperature in case you want to try it.

Dave

Edited 1 time(s). Last edit at 03/24/2015 06:02PM by dmould.

Thanks again Dave, much appreciated.
I'll try those gcodes tonight.

I usually print with 0.2mm I went for 0.1mm for this specific part as it is a idler pulley and I wanted it to be as smooth and perfect as possible.
Yes my filament is 1.75mm and in regards to the temperature, it's an interesting question.

The profiles shared by the printer maker use 215 deg C per default, but in the filament spool it actually says 220 deg C.
I read a bit about it and saw some references regarding the fact that it can be due to the hothead thermistor, not all work the same and depending it's placement
the readings may vary.
So I'm curious and I'll try the one for 190 deg C as well and see how it works.

I'll post some pics later.