ABS Cracks and Gaps

ABS Plastic

yes it does - that's why you use pla or pet-g instead :-)

It is difficult, but if you reduce your sharp corners as well as increase the amount of heat into your filiament it can be fixed.

I find that sharp or sharper corners are normally where the cracks propagate from. There is a good reason for this called stress raisers if you want to research it. If you dial up your heat or dial down your speed and reduce sharp corners it will help a lot.

Thanks - Dylbbert
The original thread was asking the question:
“Has anyone ever used DAP kwik seal plus to fill in the gaps and cracks after an assembly of 3D parts. After gluing the 3D printed parts, there were some gaps and cracks. I used the kwik seal to fill in the cracks and gaps, then I used fine sandpaper to flush the kwik seal with the plastic parts. For the purpose of this project, the kwik seal worked great! It has filled in the gaps and cracks, and I like it...
I like your response and I will explore the idea of dialing up the heat or down the speed to reduce sharp corners...But sometimes you need a sharp corner...oh well, it’s like a Möbius strip...oh well, in the end it gets figured out. Thank you

Thanks - Aardvark

I’ve never used pet-g. How do you like it? What have you used it for? Is it more expensive than pla or abs?

personally I find pet-g to be a right pita. Real fiddly stuff to get right and prints too slow for me.
But, if you get the settings right it can make some incredibly strong parts.

I generally stick to pla 99% of the time. Yet to find anything that isn't better printed with pla than abs.

Yeah, I hear ya. I do the same, mostly always printing using PLA and ABS. I've also printed with Proto-Pasta Stainless Steel. I liked it! Just too expensive...I've also tried ColorFab Bronze, again very expensive, and I still have figured out how to use it...I print using a Flashforge Creator Pro and a Xinkebot Orca 2 Cygnus. What do you have? Have you tried any exotic filaments? Do you go as far as using Acetone on your finished prints to remove the lines and create a smoother prototype? Just curious how you like doing that? If you do, is it alot of work working with Acetone?

I think it all depends on the part (design and usage), printer and ABS quality. I love ABS and have not used PLA in a long time. I have been recently making small part with exacting size needs and the ability to tap threads and slide on metal rods. All these parts are small and printed at 100% infill and I designed them so have fillets on the edge that need them. They do not nee to be larger .6 -.9mm radius on the edges that meet the build plate to prevent lifting and a nice skrt of 4 passes .004 from the part, which removes well.

PETG is easier to print in that it needs no heat in the enclosure, and will not come loose on the bed. Drawbacks are that is not as rigid as ABS will strings and buggers a little and is not as strong. It also does now tap well or slide well. Advantages are it is inexpensive, can withstand higher temps then PLA without deforming and is not broken down by UV rays so good for exterior parts. Also if you need flex in your design it works great for thinks like wire clips and other mounting clips that need to bend and camp back down.

Nylon, have had mixed results, but plan on revisiting nylon. Main issue I have had is it is too flexible for the parts I am currently making. I plan on trying the production models with nylon again, since I have not done so since initial prototype. Again, does not thread well, at lease the stuff my printer can print. There are industrial nylons that need higher heat and are harder just have not tried them as of yet.

Far is quick seal, it should work if your part is not mechanical requiring strength.

Cool! Thanks - Airscapes

I like your thinking. I agree that ABS has been pretty solid when printing small parts.

PETG sounds interesting, I'll have to try and experiment. I like that its inexpensive...

I have not tried Nylon, but I do like the idea that it is a flexible filament. I've been wanting to try a flexible for a while, just can't figure out what to print...

Yeah, it was for a Halloween Stormtrooper helmet I printed, nothing requiring mechanical strength. It worked out well, at least I don't have gaps and cracks anymore :)

Thanks for the filament tips!

Let me clarify, nylons is not flexible as in stretchy or soft like TPU, it is flexible as in it bend and does not snap. It is very tough but not stiff..

Okay. That’s interesting. I’ll have to experiment. Kinda like heavy spaghetti? (but nylon filament)

No, what I mean if you print a 50mm x 10 mm x 4mm part, and the try and snap it in the center, the ABS will resist bending and then when enough force is applied snap like a woodend stick. A part printed the same with nylon will start to bend with less force and keep bending without snapping. One part that is always mentioned as nylon is good for is hinges that need to bend back and forth a lot without breaking.

Gotcha. A bendable part with less force that keeps on bending without snapping. I understand... But isn’t a door hinge two parts anyway. Nothing there needs to bend, just one piece attached to wall, and other hinge attached to door, and then open and close...and sounds like the weight of the object attached to the “nylon” hinge would begin to bend in the opposite direction because of its weight and the material holding it in place and because it’s bendable...I’m tracking.

Not a 2 part hing.. more like the lid on a plastic box or other such item. It has many uses just does not work for thing you want really rigid, at least not for me. Good luck and experiment it is the only way you will know what works for your particular part.

Thanks - Airscsapes