There are limits to what you can do with an FDM printer to make your parts stronger. It really comes down to adding more plastic, like increasing wall thickness or boosting up the infill percentage. Other than that, redesigning the part to put more material where the part is most likely to fail is about the only other thing you can do. Unless, of course, you have access to a fiber laser cutter that can make internal metal supports for your prints.
As [Paul] explains it, this project stemmed from an unfortunate episode where a printed monitor stand failed, sending the LCD panel to its doom. He had taken care to reinforce that part by filling it with fiberglass resin, but to no avail. Unwilling to risk a repeat with a new tablet holder, he decided to test several alternative methods for reinforcing parts. Using a 100 W fiber laser cutter, he cut different internal supports from 0.2 mm steel shim stock. In one case he simply sandwiched the support between two half-thickness brackets, while in another he embedded the steel right into the print. He also made two parts that were filled with epoxy resin, one with a steel support embedded and one without.
The test setup was very simple, just a crane scale to measure the force exerted by pulling down on the part with his foot; crude, but effective. Every reinforced part performed better than a plain printed part with no reinforcement, but the clear winner was the epoxy-filled part with a solid-metal insert. Honestly, we were surprised at how much benefit such a thin piece of metal offered, even when it was directly embedded into the print during a pause.
Not everyone has access to a fiber laser cutter, of course, so this method might not be for everyone. In that case, you might want to check out other ways to beef up your prints, including just splitting them in two.
Cool. I’m gonna runout and buy a carbon fibre curing oven to see if I can use it to make my plasticine parts stronger.
Carbon fiber curing oven is a much cheaper option than a fiber laser, so GOOD PLAN!
If i had such a laser, I would not even think about 3D printing such a part in the first place, but would just cut it out, and maybe weld few points. Way faster, and more robust.
I mean, this is a post about how you can use a 3D printer to decorate the strong parts that you can obviously make if you have a fiber laser. But sure, I guess that is a crafty suggestion for a limited audience.
I do covet the ability to make parts like this though, and I’d seriously consider a fiber laser if were 3 figures and sort of carry-on sized. I’m not sure that is doable, but maybe an ECM machine? You never hear about that for some reason.
Rack robotics is working on the PowerCore diy Wire EDM project that may interest you.
That thin piece of metal would bend if you used it by itself. The plastic keeps it straight so it doesn’t buckle. It will be far stronger than either alone. Google up beam failure and you will see how structural components fail.
What he has made is a truss, inside and stabilized by the plastic part. Very cool. The critics don’t know what they are looking at. Great demonstration of real engineering!
While the fiber laser is nice to have, and allowed him to make a part with the least material making for an informative demonstration,a set of punches and some tin snips could be used to similar effect. Strips of metal and a battery pack spot welder could also do the trick in some cases.
Great for a 3D print USS ENTERPRISE where the reinforcement can be decks
Why isn’t he using carbon fiber tow with long strands wrapped around those mounting points in contnius towing? That would make it really strong.
Chopped glass fiber is not strong as the fibers are short.
Carbon Fibre is actually very weak material, it’s strong only because it’s held in place with epoxy. Look at Oceangate Titan – if it was made with steel nothing would happen. They decided to make a pressure vessel with carbon and it crushed like a can of Coca Cola.
It didnt crush like a can of CocaCola.
The issue wasnt that carbon fiber is weak.
Carbon fiber is quite strong under the right conditions.
The issue is in the way that it fails. They under engineered and used defective material and the shell shattered under the pressure.
I thought the verdict was that flaws were inevitable on such a large object and would have developed during pressure cycling in any case, and thus any modern submersible worth its salt has a titanium hull.
But yeah also they milled it, severing the continuous strand in a thousand places and ruining it even further. Several engineers quit and washed their hands of it when they saw how the hull was handled. Not great to say the least
The Titan failure was a host of failures way beyond material choice. There is no reason you can’t use CF for a sub – its even been done successfully. But to do it successfully you actually need to make the CF part correctly, it needs to be properly designed, constructed and then tested before you go and use it. Then when the monitoring systems put in because you skipped most of the last 3 steps suggest it might have cracked on previous dives…. Of course you go and dive again!
A good question, the only thing I can think of is they don’t really know composite work well enough to know what options exist. As you are right it aught to be perfectly good method and will definitely be tougher than just chopped fibres.
I would how much strength you would get from using steel foil, especially sth thin enough to cut with a cheap home desktop laser cutter.
I do not know of any cheap home desktop laser cutter that can cut steel foil of any kind. Do you have a link to this? I’d like to see it.
i guess this shows the poverty of my workshop and perhaps the poverty of my imagination but i just don’t use 3d printed parts where they aren’t appropriate. i’m not a structural engineer but i did sit through a highschool physics class on static analysis :) and i just figure out the path that carries force and don’t use plastic for that. sometimes i actually get pretty elaborate (but not necessarily accurate) in my analysis of the forces involved…i’ve definitely been known to estimate the amount of PSI internal to a piece of steel to get a ballpark figure over whether a 1/4″ bolt steel rod will do it or do i need 1/2″.
dowel rods, steel rods, bolts, sheet metal, sheet wood, these are my tools. i don’t need a laser cutter because i don’t make curly shapes just to prove i can.
for example to mount a heavy duty cargo trailer to my bicycle, i 3d printed two precisely-shaped parts that grip the back of the rear triangle (seat stay and chain stay) snugly as a sandwich, and provide a flat surface on the outsides. i lined them with cut up inner tubes so i could put that snug fit under an even pressure. and then on the two outer flat sides, i put 1/16″ steel plate, just cut to a simple polygon with holes drilled for bolts. and then 3 bolts, one with an eyelet on it, and i’m set. the bolts and steel plate alone will prevent the trailer from escaping if the plastic turns to dust, so the plastic is just there to give it a rigid defined shape. it doesn’t meaningfully carry any of the weight, though it is under a lot of dynamic compression force when it’s moving.
you know, just basic mechanical engineering skills. putting laser cut metal reinforcement in a decorative part works too but the fact that it started out with a catastrophic failure i guess sours me on it even more than the affluence does. i guess that’s just my sour grapes though…i started with engineering concepts and then got a 3d printer, i didn’t get a 3d printer and then found myself forced to learn mechanical engineering.
I have noticed a pattern on this site, and with the “maker” type in general, that many people will go to astonishing extremes and put forth enormous amounts of effort to avoid having to touch an angle grinder and welder and measure things manually. Lots of projects will multiply the work involved quite a bit, seemingly just to be able to say that a robot did it.
Lets not forget (in this case) the seemingly original failure to properly understand strength of materials and under what conditions said materials should (and should not) be used. This feels like a bandaid fix for something that should have been done better from the start.
.. or maybe it’s just for the clicks.
CNC Kitchen would have a blast with this!
The failed parts looked pretty scary, bit too razor bladeish. Holding a monitor, maybe. Making better 3d printed hand tools…
I started 3D printing over 10 years ago and was printing hollow parts that I’d put steel bolts in then fill with epoxy. A little bit cheaper than the above method and none of the parts failed either.
Consider the strength of a fiberglass ax or hammer handle. Owens Corning Fiberglass Direct Roving (a long continuous strand of glass) wrapped continuously around the pivot points then filled with slow cure epoxy, vacuum bagged to remove bubbles would be my preference to strengthening the part. Or to eliminate the vacuum bagging, you could wrap and epoxy as you build up the filling. Pack it with a small dowel. Much less expensive than the laser cut part. Carbon fiber roving is also available at a premium.