cairn

I remember the bad old days of Bennet skateboard truck base plates: they broke so often I gave up on them, and would be wary of using plastic (even injection-molded glass-reinforced nylon like the Bennets) for any truck component. My application is a little less demanding, but I've had to abandon using printed parts for testing.. just not strong enough for safety :(

The parts would end up being injection-molded, which can yield very strong parts. I've been milling test parts from solid Delrin, but this is expensive. Would be great to achieve similar strength with printed parts, but I'm coming to the conclusion it ain't possible..

I agree. Also, I am goinbg to swap to a wider nozzle for the same reasons..

So far I've printed my parts twice, once with 100% infill and once with enough solid top/bottom layers to completely fill the part (in z-axis). I'm using S3D, which predicts about 10% heavier parts with all solid top/bottom layers, so there must be less air in these parts. I tested them both with my rigorously scientific "put in vise and whack with hammer until it breaks" test: 100% infill lasted 2 whacks, all solid layers lasted 5 whacks. Both brittle fractures.. Esthetics are secondary at this stage of prototyping, so yeah I'm thinking heavy overextrusion to guarantee as much filling as possible. I'll take an ugly but strong part any day.. Final production parts would be injection-molded in some super-strong glass-filled resin, so my proto-parts look quite different.

Yep, your points seem to represent the consensus here. I am going to do some testing of various materials and settings, if I can get my hands on some lab equipment. I'll certainly post up the results. One big unknown is how very cold temperatures will affect things. I would expect some increase in brittleness for most materials.. "If I were in your place, and my life would depend on it..." Ha, I have broken three parts so far in testing. Was quite 'exciting' to say the least...(and thinking back, always happened on very cold days) Ah well, they call this learning by messing up

Any 3dsolex reseller. Check their web for a list of nearby sellers. I think even 3djake sells it Thanks, time for a little upgrade and some experiments..

You probably need their I2K thing as well -- @neotko knows better... What is/where can I find this 'thing'?

Been looking at the Polymaker website and the material looks promising. Also some tests on Youtube, but mostly brilliantly non-scientific. interesting figures for strength from the Polymaker website: Seems like PolyPlus is better.. Also, they recommend annealing.. ever tried? I've got a 3D Solex nozzle on a UM2- you think that setup will handle the 270C required?

I hear you. Not much I can do about the orientation, and it's tensile strength which is critical, so to avoid delaminating I'm going for 100% solid layers (not 100% infill which still leaves a lot of air in the part, at least with S3D) I'm not convinced by ABS- problematic printing for not enough added strength?

@peggyb For the win, but thanks everyone for the good ideas. I am printing a structural part so I have adapted it to maximise strength. So: First print the red and green parts, then print the blue part and drop the red and green parts in cold as the print progresses. The red part is printed on glass, so it has a perfect surface, and it already incorporates the holes. It just needs to be positioned carefully with some registration details, and the height will be critical to ensure a good bond with the blue part. The green part falls away when the print is done, and can be reused. All good

I'm printing a few components for an experimental snowboard binding and it would be nice if I didn't die during testing, so how to achieve the strongest possible print? I am experimenting with combinations of infill and solid layers/borders. S3D is telling me that 100% infill actually produces parts about 10% lighter than parts printed with enough solid bottom and/or top layers to fill the print, but maybe the infill patterns are stronger than the X by Y solid layers.. Anyone have any experience properly testing parts to destruction, or any other rigorous proof which is the best way to print the toughest parts? So far I am trying: Print slow (45mm/sec with a .4mm 3d Solex) Print thin (well, .15mm layer height) Print fat (extrusion multiplier 1.2 for added squashing) Print hot (230 for PLA to get better layer bonding) ..anything else I could try? C:)

Sorry if that sounded a bit snippy.. Google is great, but I'm hoping this community is greater (or at least more focused..)

Thanks, I googled before posting here.. Anyone had experience with PLA mold release agents?

I've been getting some horrendous underside surfaces, the support just never seems to be enough to get a smooth result, and then sticks too much and damages the surface when you remove it. I have been experimenting with purpose-made support objects, but I've hit a snag. What I'm trying to do is first print a support object, remove it from the bed, start the print proper, and then at the right moment drop the support part into position so the overhanging parts are supported. You would then remove the support part leaving a smooth surface.. I used a light oil on the upper surface of the support part in the hope that it would assist removal, but to my surprise it seems to have increased the bond strength if anything. Does anyone know what to use as a release agent or barrier film to stop the two parts fusing together? In theory you could then remove and reuse the support parts repeatedly, giving better results and saving material. This works where you have a completely flat overhanging surface, so that the support object can be dropped in level with the ongoing print without risk of colliding with the print head.