Results 11 to 20 of 21
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08-03-2016, 04:54 PM #11
- Join Date
- Jan 2014
- Location
- Oakland, CA
- Posts
- 935
I wouldn't ride a motorcycle whose frame was FDM printed in plastic. Hit one of those "bumps in the road" too hard and you're vulture meat. But maybe I'm just over-particular about my personal safety; you can do what you want...
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08-03-2016, 05:19 PM #12
- Join Date
- May 2016
- Location
- SE Wisconsin
- Posts
- 206
Frame, no. Subframe, absolutely.
That's why the original intent was to brace it with tubing, so the weight is fully supported by the tubing and the rest is just for looks and holding light weight components in place.
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08-04-2016, 09:33 AM #13
you probably could get away with the petg - but just for cmmon sense I'd still use the aluminium reinforcement.
not worth taking risks with your life :-)
playing with the colorfabb xt/petg this afternoonLast edited by curious aardvark; 08-04-2016 at 09:39 AM.
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08-04-2016, 10:14 AM #14
- Join Date
- May 2016
- Location
- SE Wisconsin
- Posts
- 206
Motorcyclists are stupid though.
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08-04-2016, 10:37 AM #15
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08-05-2016, 06:18 PM #16
- Join Date
- Aug 2015
- Posts
- 256
I print mostly ABS which is plenty strong as long as I pay attention to two things:
Layer adhesion = printing at as high of temp as I can get away with and slightly over extruding.
Design = if I really need strength I'll divide a part in two pieces and print each at a different orientation and then glue the part together, the strength gain is sort of like what you get with plywood which is glued together at alternating grain patterns.
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08-05-2016, 11:27 PM #17
- Join Date
- Aug 2014
- Location
- Montreal, Quebec
- Posts
- 576
Well.... why not use 3D print as a sacrificial model. I would love to put carbon fiber tissue on it and resin vacuum it. You won't be able to argue with the results.
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08-07-2016, 12:08 PM #18
- Join Date
- Dec 2014
- Location
- North Carolina
- Posts
- 23
A couple of observations:
First, if you have a design payload of 250lbs, I think you need to design for 500-750 lbs minimum. That "bump" in the road could easily cause a 2G force making you weigh 500lbs for a moment.
FDM printing is inherently weak in certain directions as it is dependent on the tensile and shear strength of the interlayer bond, which is significantly less than that of most of the materials we use.
Tensile strength along the build's Z axis is almost non existent except for very large areas.
Compression directly along the build's Z axis will perform at or near the material specifications where directly supported, however, the beam strength (i.e. bending resistance between supports) is also reduced due the the weak interlayer bond.
IMO, FDM (at least with our hobby machines) is not suitable or safe for any kind of structural requirements in the ranges you need. It would be fine for enhancing the aesthetic appeal of an otherwise strong and well built aluminum structure that is properly designed to support all the loads.
Graham
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08-07-2016, 01:23 PM #19
- Join Date
- May 2016
- Location
- SE Wisconsin
- Posts
- 206
Yeah, that's pretty much what I assumed.
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08-08-2016, 06:09 AM #20
It's the terminator/wolverine principle. Flesh is weak, indestructible interior alloy skeleton - much better :-)
My 3D Norn Emissary print
09-13-2024, 02:28 AM in 3D Printing Gallery