printing with ABS on UM2

[lieven-standaert 0]

Hi,

I’ve been playing with an UM2 and ABS over the weekend.

A quick search here turned up little info on the subject.

As I have always been printing with ABS and PLA (I always used Makerbots befor),

I though my notes might be useful:

-please note this is based on one weekend of use. My conclusions might be specific for th few objects I printed

-default settings are 260° print temp and 50% fans. I turned off the fans and reduced the temp to 230°. I printed on the glass plate using the glue. No raft, just a brim

-the idea behind turning off the fans is that you want to minimize thermal shock/stress in the print. ABS shrinks a lot more as it cools than PLA, which tends to warp prints. That is why the Makerbot rep2X has an enclosed printing chamber. It keeps the ABS at 50°…

In general you want the ABS to cool down slowly.

In order not to get saggy prints without thee fan I increased minimum layer time in Cura to 25s.

I would advise putting an enclosure around your UM2 if you are interested in ABS-prints (the one I’m using isn’t mine, so I’m holding off on the modifications for now)

-I have never been able to get reliable prints with ABS at the highest resolution. A print that comes out nicely in the Makerbot Rep 2 at 0.1mm with PLA would fail with ABS /0.1mm on the Rep 2x.

The UM2 seems to confirm this; I get very good prints at 0.15mm, but a print at 0.06mm failed

The 260° in the default settings might enable higher resolutions, I haven’t tried that.

Best, Lieven

 

[gr5 2,173]

-I have never been able to get reliable prints with ABS at the highest resolution. A print that comes out nicely in the Makerbot Rep 2 at 0.1mm with PLA would fail with ABS /0.1mm on the Rep 2x.

The UM2 seems to confirm this; I get very good prints at 0.15mm, but a print at 0.06mm failed

 

You start out with a hypothesis about ABS versus PLA and then conclude something about layer heights? This is confusing.

What have you found ABS has trouble with more specifically? Bridging? Overhangs? Lifting Corners? Ugly surfaces? Clogging? Underextrusion? Uneven extrusion?

I haven't done much with ABS but 245C and zero fan has worked well for me so far. Bed at 110C. Hairspray on the glass. Use brim.

But to cover the front of a UM2 all you need is some plastic wrap. No permanent modification necessary and it only takes a few minutes. And to cover the top all you need is a box of the right size.

 

[Artiz 27]

Not sure about that 110C Bed temp... seems that if you have your bed temp up to high all the time you get a lot of warping and curling if you are printing anything with a bit of detail... especially at the beginning of a print... "Horses for courses" as they say. A 260C nozzle (higher) temp does seem to be the most reliable in my experience too.

Same goes for fans too... if you are printing a detailed part having the fans at 100% are important for fixing & drying/cooling your initial supporting/foundation layers to the build plate (especially important if your print is going upwards)... you can always turn them off later.

Having said all of that I am a bit of a print fiddler/tuner which is usually a dangerous game to play... nothing worse than losing a print that you just didn't watch or didn't bother fiddling with though.

[Artiz 27]

... there's a few build plate fixatives out there and as we all know that initial fix is 'key'

I use a Matt Clear Sealer (solvent) spray (Valspar @ B&Q in UK) which I also use to completely seal/bond my prints when cool. I'm making detailed working parts for spearguns so this sealer is essential for my end products.

This fixative works at lower temps for ABS so I reduce my initial build plate temp to 50C and spray it on a split second before the print starts... works every time.

I also start at 80% speed which gives a nice thick/fixed brim to hold everything down as well as a material flow of 120% for your initial foundational layers. Fans @ 100% reducing to zero depending on initial levels of detail.

After 30 mins I bring my speed up to 100%... my buildplate temp up to 90C and reduce my material flow to 110%... checking back every hour or less.

Nozzle temp @ 260C throughout... seems to work for me!

[cloakfiend 995]

Unless you need the temperature aspect of ABS, I really don't understand any other reasons to print with it? Good Brands of PLA look just as good (maybe not flat top surfaces but thats about it). There is no other reason to use it. Strength is the same if not better with PLA for me. So if you don't need to put it in direct sunlight all day or under a hot lamp, or some other high temperature situation, i wouldn't even bother with ABS at all. Also all regular Colorfabb PLA smooths wonderfully at high res better in acetone than ABS as well, so its the nail in the coffin for ABS as far as I'm concerned.

I used to be the other way round and hated PLA at the start, but now regarding ABS, I wouldn't even touch the stuff.

Edited October 30, 2015 by Guest

[Artiz 27]

"but now regarding ABS, I wouldn't even touch the stuff."

Yup agreed... although every now and again something does come up which is not suitable for printing in ColorFabb XT-CF20, which is my preferred material of choice... nothing better.

I'm currently printing a (scanned gloved hand) speargun handle in ABS because it needs to be light, highly detailed and waterproof whilst also using 90% infill... mainly because I want to screw directly into it... but also because I've run out of carbon fibre of course.

PLA is not even an option for me...

Edited October 30, 2015 by Guest

[JohnFox 25]

I agree with cloakfiend PLA is FAR easier to print than ABS. For my applications, the only reason to print in ABS would be its stability to high pH liquids. When I switched from ABS to PLA, the print failure rate dropped from about 40% down to zero.

[cloakfiend 995]

 

@artiz you mentioned 'ABS because it needs to be light, highly detailed and waterproof whilst also using 90% infill... ' PLA is light, high quality, and waterproof if dense enough, so i still dont see why you have turned to ABS? Have you attempted in PLA and ABS. Id like to know the difference? does ABS survive better under salt water than PLA. Not that ill ever use it, but im curious, so the next time i flame someone for using it, ill know why they flame me back correcting me, lol.

[Artiz 27]

@artiz you mentioned 'ABS because it needs to be light, highly detailed and waterproof whilst also using 90% infill... ' PLA is light, high quality, and waterproof if dense enough, so i still dont see why you have turned to ABS? Have you attempted in PLA and ABS. Id like to know the difference? does ABS survive better under salt water than PLA. Not that ill ever use it, but im curious, so the next time i flame someone for using it, ill know why they flame me back correcting me, lol.

 

Everything is trial and error for me still but PLA gets strangely slimy in sea water so I don't bother with it... not convinced it is fully waterproof?

ABS is also far easier to sand down but even better is the XT-CF20 as long as you orientate correctly. Not so good for tall prints cos layers don't seem to adhere particularly well. The handle I mentioned was a tall print so ABS was the most suitable material... as I said though all is still trial and error for me.

I'll upload some photos when I get time...

Edited November 7, 2015 by Guest

[Artiz 27]

Everything except the handle is printed in XT-CF20 but I used ABS for the handle.

This is obviously a prototype but I still want to test it as a working example for either plastic extrusion or aluminium milling at a later date. Easier said than done of course regarding strength, durability etc but so far so good... bar a few technical issues. I've broken it down into component parts which makes printing easier of course but the handle had to be printed in one piece.

Still a long way to go yet tho...

 

Edited November 7, 2015 by Guest

[cloakfiend 995]

Nice prints. I guess abs has its uses after all! I found mine to be actually weaker than pla on my printer but i guess i only tried one brand.

[Artiz 27]

Nice prints. I guess abs has its uses after all! I found mine to be actually weaker than pla on my printer but i guess i only tried one brand.

 

Perhaps I should try other brands of PLA too... ColorFabb's PLA's seem to be top of the list. The XT-CF20 will be hard to beat tho... it's strength with the added fiber regarding working parts is particularly outstanding and why I bought my UM2 in the first place... a 3D printing material that could/may withstand the stresses inherent in spearguns at last was just too tempting to ignore... not actually sure whether XT-CF20 is regarded as PLA/ABS or just a new copolymor category of it's own?

Edited November 7, 2015 by Guest