My ABS prints break easily

General discussion - share tips, talk about machine specific issues, and showcase your latest prints
RoboDLC
 
Posts: 33
Joined: Sun Apr 23, 2017 1:30 am

Re: My ABS prints break easily

Mon Jul 17, 2017 7:45 am

jfkansas wrote:Honeycomb kinda sucks due to all the short moves. Use rectilinear at 45 and -45 angles.

Does the extruder click on that infill like it is skipping steps?


Nope, no skipping.
I have several nice prints now after the following changes:
MAJOR walls around the printer to keep out cool breezes.
Dropped speed to 30mm/s
Upped first level to 30% speed

Several pieces later, some fairly complex and "largeish", no failed prints.
I have discovered that honeycomb takes a bit longer, but it uses less filament and is enormously strong for as little infill as it does. I think the key was the print cooling too fast. I may be able to increase the print speed with these discoveries. The majority of the difference appears to be environmental. My first successful prints were early morning, as the day went on and got hotter, the AC was on more and blowing towards my printer. The walls are blocking that now.

I'll say more as I discover more. (Yeah, honeycomb is a LOT for small fast movements. It is probably not a good long-term process as it is certain to cause more wear and tear on the mechanics.)

DLC

billyd
 
Posts: 168
Joined: Mon Jan 19, 2015 12:13 pm

Re: My ABS prints break easily

Mon Jul 17, 2017 8:32 pm

RoboDLC wrote:I print my ABS model. It prints beautifully (as in it looks great). When I flex spots that need to flex a little bit, the ABS just snaps off. I am using only finger pressure, not pliers mind you. I can just snap off a 5mm thick piece, with not a lot of effort.
This shouldn't be, so I am clearly doing something wrong.
I am printing eSun ABS at 235 C, bed at 100 C, .3mm layers and 50% infill. In fact, I can, with effort, break a 3cm construct along a layer line.
This suggests that the layers really are not fusing/bonding.
My printer is not in an enclosure, it is in my basement where it is always cool.

What should I do? to correct this. Please keep in mind that I cannot afford a huge enclosure...

Many thanks,
DLC


This is definitely temperature related. Keep increasing print temperature until you get stronger parts.

Couple of things to remember.

1. ABS can be print safely at much higher temps than you are printing. On some brands I use 265 c to get good layer adhesion.

2. All thermistors are not created equal. Meaning that your extruder thermistor might be reading higher than the actual number, resulting in even cooler temps than you think you are printing with.

RoboDLC
 
Posts: 33
Joined: Sun Apr 23, 2017 1:30 am

Re: My ABS prints break easily

Mon Jul 17, 2017 9:17 pm

billyd wrote:
RoboDLC wrote:I print my ABS model. It prints beautifully (as in it looks great). When I flex spots that need to flex a little bit, the ABS just snaps off. I am using only finger pressure, not pliers mind you. I can just snap off a 5mm thick piece, with not a lot of effort.
This shouldn't be, so I am clearly doing something wrong.
I am printing eSun ABS at 235 C, bed at 100 C, .3mm layers and 50% infill. In fact, I can, with effort, break a 3cm construct along a layer line.
This suggests that the layers really are not fusing/bonding.
My printer is not in an enclosure, it is in my basement where it is always cool.

What should I do? to correct this. Please keep in mind that I cannot afford a huge enclosure...

Many thanks,
DLC


This is definitely temperature related. Keep increasing print temperature until you get stronger parts.

Couple of things to remember.

1. ABS can be print safely at much higher temps than you are printing. On some brands I use 265 c to get good layer adhesion.

2. All thermistors are not created equal. Meaning that your extruder thermistor might be reading higher than the actual number, resulting in even cooler temps than you think you are printing with.


These are good points. I will soon have an IR heat reader to see about those temperatures.
Unfortunately, I have a cheesy J-head knockoff from the kit manufacturer and cannot print those temperatures. I plan on getting an E3D and making a new end effector and hot end clamp to use it - THEN I can play with the big dog filaments. But not quite yet.

After many successes and one "close enough" success I got part of a part and a big ball of spaghetti. I have reduced my layer to 0.2mm and reoriented the part. Have you ever noticed that some parts will suck to print no matter how you lay them out on the bed? Three of mine are like that. This is a printer designed by a friend of mine and I am attempting to print the parts. It is a Cartesian printer where the Z axis is the bed. Lots of bars and things to slide on the bars, which are tricky to align and even trickier to print. I am liking my delta Kossel more all of the time... Anyway, it will be a coup to get all of these parts to print, and I am on the last two. Hopefully I have enough filament!

To all: I am listening and applying all suggestions that I can. You are helping me get some successful ABS prints going! Thank you all.
And, because I HATE it when people post questions, and then say "thanks I got it working now" and never tell us what they did, I will be sure to report all that I did and what eventually worked the best!

regards,
DLC

wirlybird
 
Posts: 568
Joined: Sun Jul 17, 2016 12:32 pm

Re: My ABS prints break easily

Tue Jul 18, 2017 5:58 am

Sounds good. JF knows his ABS! My basics on ABS are that it doesn't like to be squished as much as PLA on the first layer. I have good luck at 230 but I print it pretty slow. 2400mm/min basically but get very nice parts. Also use only enough bed temp to keep things honest. On most parts I get to 95 after a few layers. Generally works well.
Thanks for the reports back on progress. It surely will help others.

upsm
 
Posts: 144
Joined: Sun Mar 12, 2017 4:37 am

Re: My ABS prints break easily

Tue Jul 18, 2017 6:51 am

RoboDLC wrote:I will soon have an IR heat reader to see about those temperatures.

if you are not getting something very expensive and you are not very proficient with it IR contactless thermometer is going to give very inprecise results. you have to deal with both emmissivity (not easy with alu heat block, brass nozzle, abs oil and other dirt on the nozzle and heatblock) and size of the measuring spot (they tend to be rather large on the ir thermometers) .... ir camera helps but these cheap ones (like seek thermal or the flir adapter for ios phone) while showing great the distribution of heat, they are even less precise then properly placed ntc (dunno about those $20k flir cameras never used those, if you have access to those they probbly work better :D :D )

RoboDLC wrote:Unfortunately, I have a cheesy J-head knockoff from the kit manufacturer and cannot print those temperatures.

check position of the ntc, check if your ntc is properly typed in the firmware. often ppl change ntc in the extruder with some ebay ones with same 25C resistance and while the temp "looks close enough" it can be 50+C error there :( ...

good thing to do, if you have time, will, energy, money (not much needed :D ) is to get a thermocouple and thermocouple reader .. you can get cheap PRC made DMM with thermocouple for under 10$ in PRC shops, even cheaper online (then you just have to wait too long for them to arrive)... get the TC that is just a "dot" on the tip, small ball, not the one with large metal 3-5mm probe.. so "the cheapest one" :) .. you attach that to outside of the nozzle and then wrap it with kapton tape, or better, if you have, silicone tape.. it will hold the TC in place and will insulate it from surrounding ... then heat your nozzle and monitor temperature from TC and temp your firmware is reading from NTC .. this way you can easily get idea what is the "real" nozzle temp for every readout in your firmware :D .. when you do few heating/cooling sessions you can remove the tape and TC and use hotend as you did before.. TC, even cheap PRC one, is pretty accurate (inside the 2C in combo with cheap PRC reader) so it's easiest way to get the data you need.

RoboDLC wrote: I plan on getting an E3D and making a new end effector and hot end clamp to use it - THEN I can play with the big dog filaments. But not quite yet.


you might want to check flex3drive, they have effector + extruder (remote torque, so direct extruder but motor is remote so it does not way on your head making delta work waaaaaaaaaaaaay more precise) that is super light and very performant!

as for your issues with abs, I think you got the answers ...
- curling / warping - enclosure, abs tends to warp, likes to warp.. enclosure helps... also, reducing speed helps, 30mm/sec is imo safe speed for ABS (50% outside perimeter, 30% first layer, 80% solid layers) without heated chamber, everything over that creates risk of warpage
- delamination, week parts - up the temp, your interlayer adhesion is too low, up the temp to get layers to properly bond
- calibration - looking at your pictures you need to calibrate your extrusion (attm you are underextruding)
- clean your nozzle - I don't see that you have clogs in your nozzle but when you print for a while "too cold" it's common that pieces of plastic stay in the nozzle and after being "cooked" for a while they harden and create partial (or full) blockages. to be on the safe side, since you obviously printed that abs too cold for a while, I'd get that nozzle cleaned (I don't like heat, I clean nozzles with acetone, since I only print ABS, acetone is ideal, it cleans the nozzle completely without having to use any other tools ... in case of "hard clog" I use guitar wire to declog and then just soak the nozzle 24h in acetone, rinse with water, then rinse with alcohol and return back to the hotend)
Used cars search engine
  • TT UP Plus 2 / Smoothieware
  • M150 / Smoothieware
  • Custom (mendel) / Smoothieware
  • Custom (darwin) / Smoothieware
  • Custom (darwin) / Marlin
  • Custom (darwin) / Replicape

RoboDLC
 
Posts: 33
Joined: Sun Apr 23, 2017 1:30 am

Re: My ABS prints break easily

Tue Jul 18, 2017 9:07 am

Things are getting better.
As you can see from the "Bottom" photo, very nice and clean, mostly.
Settings .2mm and slowed to 40mm/s, 30% underspeed on first layer, 60% on walls and infill.
235C hotend and 100C bed.

These parts are complex and have to be printed with supports for a large portion of them. This print had what looks like my supports collapsed or messed with the first layers in contact with the supports ("top" image). Is this a temperature issue or a problem with how I do supports? I have attached my factory file, this one is a little changed in that I am using some advice and I dropped the print speed. I didn't lose a support from the bed, but I noticed that they looked like they collapsed on the outside, where on the "top" picture you can see that the base above the supports slopes off. Any ideas?

My success rate is improving, even as I use up meters of filament...

Many thanks as usual,
DLC
(I labeled my photos in reverse of how I meant to, for some reason...)
Attachments
threaded rod mount bottom(4).factory
(883.57 KiB) Downloaded 6 times
IMG_2950.JPG
top
IMG_2949.JPG
Bottom

upsm
 
Posts: 144
Joined: Sun Mar 12, 2017 4:37 am

Re: My ABS prints break easily

Tue Jul 18, 2017 1:34 pm

RoboDLC wrote:Things are getting better.
As you can see from the "Bottom" photo, very nice and clean, mostly.
Settings .2mm and slowed to 40mm/s, 30% underspeed on first layer, 60% on walls and infill.
235C hotend and 100C bed.


you might want to print a temperature tower btw I didn't see anyone sugested that, it's good to find best looking print that's strong enough (when you overdo temperature print becomes very strong but ugly) ... anyhow this looks like a decent ABS print. there are visible warping issues, enclosing the print should help but since I don't have any experience enclosing delta's can't help there... the skirt or ooze shield .. full height of the object .. it can help with warping (traps heat in) but nothing beats a good insulation around the printer :D
Used cars search engine
  • TT UP Plus 2 / Smoothieware
  • M150 / Smoothieware
  • Custom (mendel) / Smoothieware
  • Custom (darwin) / Smoothieware
  • Custom (darwin) / Marlin
  • Custom (darwin) / Replicape

RoboDLC
 
Posts: 33
Joined: Sun Apr 23, 2017 1:30 am

Re: My ABS prints break easily

Tue Jul 18, 2017 9:51 pm

Well, I am kind of getting there...
My latest discovery is that if too much of the model is on supports, those supports will let you down. I found this 5 hours into an 11.5 hour print.
I am going to remaster this part to get a larger portion in direct bed contact with minimal height supports. This will probably mean building in some kind of support that is much stronger and more reliable for "high lift" support.

Sigh, I do not have enough ABS filament to attempt this print again until I buy some more. This is a 40 meter part.

Thanks,
DLC
Attachments
IMG_2951.JPG

User avatar
dkightley
 
Posts: 1176
Joined: Tue Mar 10, 2015 3:09 pm

Re: My ABS prints break easily

Wed Jul 19, 2017 2:57 am

May I suggest you use the forum as a tool to learn....and not purely a platform to shout "Help".

A single search term of "support" yields many threads talking about supports....one of being this one where I advised how supports can be made stronger:
viewtopic.php?f=9&t=7769&hilit=support

Note that despite the title of that thread including "PLA", the mechanics of support are the same!
Doug Kightley
Volunteer at the National Tramway Museum http://www.tramway.co.uk
Railway modeller and webmaster at http://www.talkingtgauge.net

RoboDLC
 
Posts: 33
Joined: Sun Apr 23, 2017 1:30 am

Re: My ABS prints break easily

Wed Jul 19, 2017 9:49 am

dkightley wrote:May I suggest you use the forum as a tool to learn....and not purely a platform to shout "Help".

A single search term of "support" yields many threads talking about supports....one of being this one where I advised how supports can be made stronger:
viewtopic.php?f=9&t=7769&hilit=support

Note that despite the title of that thread including "PLA", the mechanics of support are the same!


Thanks for the pointer, there is a lot of noise out there and folks often do not say what finally fixed their problem.
However, I was not asking for help with my last post. I am trying to document my path towards enlightenment with the thought that it might help others.
Of course I could simply vanish without comment if that is the more accepted means to use the forum.

Thanks all,
DLC

PreviousNext
Return to General Discussion and Tips