My Newbie thourghts on printing PLA, PLA Flex and ABS

Well

What a step learning cure it would be without forum like this ..

PLA and PLA Flex. These are quite easy to print , large tolerances on extruder temperature range and easy to stick down to Blue tape although the cheaper blue tape seemed to work better than the more expensive ones made by 3M which seem to have a shiny finish to the surface.

Now ABS...

What hard stuff to print and stick to Glass etc..

After trying glue stick, hairspray kapton tape and ABS slurry on Glass , the only one I had any success with was Hair spray and that only just holds, takes very little effort to remove not like PLA which has to be prised off.

I found that the first layer was very critical, so Bed flat as you can get it. I managed within .2mm across the entire plate and 0.04 in the middle of the plate, ( need to look at why the aluminium plat is no longer flat..)

The hot end nozzle has to be no more than 0.15 mm off the plate. I also used the Advanced setting in Slic3r to do the first layer at 150%.

Brim .. I had to use a Brim every time no smaller than 6mm

Did all the test for getting the layers to stick together , my sweet spot looks around 245 deg C, and I managed to maintain a wall thinkness within 0.03mm and the only way was to use the filament multiplier.

The next issue .... is infill so many different comments on type % etc. ..

Has any one any comments on Humidity and ABS? I have noticed when printing ABS I get the odd "pop" noise from the nozzle like its steam escaping and then a defect appears in the print. Im in Pukekohe and the Humidity at the moment is about 95% .. and ABS likes moisture ..

Any thoughts....

I think there is some reference to humidity experiments on the forums, I recall reading about people cooking their ABS in an attempt to remove the moisture. I also recall reading thoughts that most of the moisture gets in at the point of manufacture, not sure on this though.

in regards to your plate not being flat, have you tried relaxing some of the tension in the frame to see if this reduces this?

Hi Zerker

I might get a few meter's of the ABS nd bake it in the Oven for a while to see if the issue goes away.

I just finished a 5 Hour ABS print.. the surface finish was good but the strength of the layer bonding's was not as good as I hoped.

Im now up to 245 deg If I use thicker layers will the bonding between layers be better as there is more filament to cool down.

There is no Fan running on any of my prints and the speed is down to 30mm/s or do I need to go even slower?

Quote
moth4017

The hot end nozzle has to be no more than 0.15 mm off the plate.

Any thoughts....

Your nozzle gap is too big at .15mm. You need 0.1 max and .05 would be optimum (the thickness of a typical Supermarket receipt. However, you need to get that bed pretty level.

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Waitaki 3D Printer

Hi

the layer bonding between each layer is still very poor.. compared to my PLA prints which I have to use a hammer to break, my ABS prints come apart in my hand.

I even got out my thermocouple to measure the Hot end temperature its within the range I expect..

Im wondering if I just have poor quality ABS its from the same supplier as the PLA, and that's perfect.

I think its time to give up on ABS. anyone in NZ want to try my ABS filament ill send it to FOC , just PM me your Address and ill send you a few meters

Sounds like your ABS woes are filament related and you might benefit from trying a different supplier. Running slow and hot with no fan cooling should make layers stick together OK. No mention of heat bed temperature - I assume you have this set to suit ABS. I usually run it at 110 deg C. Professional machines use heated chambers for ABS to prevent warping from causing delamination. You can improve things by putting a large cardboard box over the whole machine to limit drafts. I assume you don't have the power supply fan or electronics cooling fans creating breeze across the build plate. I have seen somewhere someone using a plastic oven roasting bag cut open and taped on loose around the bed and up over the extruder. This keeps heat in and drafts out to make ABS print better. When I print ABS I do it straight onto kapton tape and glass. I use a brim if there are sharp corners on the bottom layers. I'm using Diamond Age ABS and it works fine for me. Holds OK to kapton and self releases when temperature of bed is down to 40 deg C after finished. I have only had delamination issues when I left cooling fans on by mistake.

On 3M tape - I made the mistake of buying 3M #2080 tape first. It is shiny and made for masking delicate surfaces like freshly painted surfaces. I found that I could get PLA to stick to it adequately but the tape tended to lift from the glass around the edges if your model had a large footprint. I am now using 3M #2090 tape with the crepe type surface and this is much better all round. I would prefer to use the heatbed with PLA because like the ABS, they self release when the bed cools. With blue tape I need to replace the tape often as it gets damaged when chiseling parts off. I am using blue tape at the moment because I have made some modifications to increase the print area for a special job and my standard sized heatbed wouldn't work so well heating a 300 x 230 piece of glass.

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My Prusa Mendel i2 inspired Repstrap with welded steel frame: [youtu.be]
And my Smartrap derived Briefcase 3D printer: [youtu.be]

@ n.glasson

I had the bed at 110 , I managed to get the ABS to stick to the heated Glass with Hair Lacquer . But still could not get the ABS layers to stick to them self.

m going to get some more ABS from another supplier and try again