3d printing engine brackets?

[siggyfreud]

Hey all,

Noob question for you all. Would the strength of prints provided by a standard 3d printer using PLA or ABS be capable of printing brackets strong enough to use on a car engine? I'm rebuilding a 66 GMC, and am trying to showcase "new" technology as part of the build. I'd love to be able to create customer brackets for the alternator, power steering, etc using a 3d printer, but want to ensure the materials and builds are strong enough for daily driver use, withstanding both environmental factors (heat/cold), as well as tension caused by the devices they're holding.

Is it realistic, and just a matter of things like fill pattern, design, infill density . . . or am I being unrealistic.

Thanks all!

[jeffmorris]

I don't think that plastic parts are as strong as steel parts.

[siggyfreud]

I'm not suggesting or thinking they would be. I guess my question is, are they strong enough? I've seen a lot of automotive components getting replaced by composites. Intake manifolds, oil/transmission pans, differential covers, pulleys, etc. So I guess my question isn't, "can they be as strong as current metal brackets," but rather, "can I print something strong enough?"

Cheers,

[Mjolinor]

I think heat will be your big problem. PLA is certainly out if you intend to fasten it to the block or the cooling system. I see no reason for not using it for a lot of the smaller stuff very easily like brackets for the water bottle or battery retainer etc. Engine mountings should be strong enough as long as you use nylon or similar, maybe ABS but for sure I would be keeping a close eye on them. I wouldn't trust them where the engine is actually held in and hanging but the sort of mounts where it is between chassis leg and engine where it "sits" and can't actually fall out.

ABS may be OK, new technology, new uses. Suck it and see.

[curious aardvark]

yes and no.

bear in mind that apart from peek - all fdm filaments will go soft at anything much over 100c.

Strength wise - carbon fibre reinforced nylon is damn near indestructible. Unless you use the mymat stuff - it's also a total bastard to print with.

Polycarbonate is probably your best bet. higher glass point than abs, pla and pet. fairly cheap and easy to print as long as you can get it to stick to a surface (buildtak recommended). It's got more flexibility than abs as well as being pretty stiff.

The two issues you'll have are pretty much just size and operating temperature.

If you want to invest a little dosh in the enterprise then the mark forge will produce parts with continuous carbon, kevlar and fibre glass reinforcement on a nylon base. Proper tough :-)

[LambdaFF]

I'd love to be able to create customer brackets for the alternator, power steering, etc using a 3d printer, but want to ensure the materials and builds are strong enough for daily driver use, withstanding both environmental factors (heat/cold), as well as tension caused by the devices they're holding.

You will notice that 3D printed items are more or less limited to aircon, upholstery, ... items with little to no mechanical stress and or are just comfort items. In term or safety their failure is not significant. For me that is not a coincidence but a realistic decision.

My experience in helicopters makes me wary of vibrations : I would stay way from items that are subject to important vibration cycles such as engine, alternator, starter generator... In FDM printing, the layer bonding will be a weak point even if you design your components to avoid stress along those lines. Also, the mechanical properties of plastics vary significantly between -10°C and +30°C in stiffness and elasticity thus requiring important safety margins.

If you have a go at it, I would strongly suggest that you make endurance tests of your components in real life condition before selling safety related items : that would give you an idea of the life duration you can expect and sell. You can survive a failed aircon duct, a damaged engine linked to a failed bracket is something else entirely.

[curious aardvark]

what he said. :-)

With the right material a lowish temp environment - no reason at all not to use fdm parts. But do some serious destruction testing first - and against a standard part.

[djprinter]

You could 3d print the part, test fit it, and then have it reproduced in steel by a foundry.