Reinforce Your 3D Prints with Steel

Reinforce Your 3D Prints with Steel

Today, I am going to show you how you can
reinforce your 3D prints with steel and how much stronger they will become. To start, we of course need some steel. And in order to keep things simple, we are
going to use steel wire. This is stranded wire with a total diameter
of 1mm. The basic idea is to cut out paths inside
your 3d model. Your slicer is then going to add additional
perimeters around it and therefore creates a foundation, in which you can press the steel
wire with the help of a soldering iron during the print. Additionally the path guides the steel wire,
so it’s really easy to align it. I am going to explain this with more detail
later in this video, but before that I want to answer the most important question: Does
this even work? For that I have modeled 3 different test parts. While on the first one the forces will pull
in the same direction as the wire is oriented inside the part, the second one will test
a bending situation and the last one combines pulling and bending. I printed the test parts with clear PETG and
both, the reinforced and non reinforced parts, have used the exact same G-Code. I also quickly put together this test rig. It’s basically just threaded rod which,
if I turn it, will pull on the test sample. A crane scale then shows the force applied
to the part. And just to be clear, in this video I am going
to use kilogram as a unit of force. I just think it’s more appropriate to do
so in this case, but if you don’t feel comfortable with that, just multiply all the values with
9.81 to get the forces in the unit Newton. Alright, here comes the fun part. The reinforced bend and pull test parts both have an increase in strength of more than
50%, the combined test part of more than 100% compared to the plastic only parts. Interestingly, the combined test part was
the part with the least amount of wire loops inside. It might be an interesting topic for a future
video to see, how the amount of wire inside a part influences the strength of it. Even though I would take the exact numbers of all these measurements with a grain of
salt, I think it’s safe to say that embedded steel wire does have a positive effect on
the strength of 3d printed parts. However keep in mind that this technique only
improves strength in the x and y direction and, depending on your parts geometry, might
work better or worse. But this shouldn’t stop you from at least
trying to reinforce your parts, as it is really easy to do so. Let’s say we want to reinforce this part
right here. Currently it is completely solid. I would like to add 1 layer of wire, so I
create an offset plane and position it right into the middle of the part. Next I create a sketch and project the outlines. I create an offset to those outlines and set
the distance to a multiple of the extrusion width of my 3d printer. This isn’t necessary, but will ensure that
we are getting some nice perimeters around our steel wire. Next I add another sketch and create a rectangle
with its center right on the path we created before. The edge length is set to roughly the diameter
of our wire. Lastly I sweep this profile along one of the paths we created in the sketch before. After doing the same thing for the other two
paths the part is ready for slicing. I am going to show you how to process that
part in Simplify3D, but any other good slicer should work similar. First you want to check number of the layer,
which is going to be printed right on top of the steel wire. In this case, it’s layer number 13. Now we only have to add some G-Code, which
tells the printer to stop at that layer. Simplify3D lets you do this quite easily with
the help of a GCode script. Theoretically, you could also do this manually. I have added both codes inside the description
of this video. They basically just pause the printer, move
the printhead out of the way and wait for you to resume the print. At your 3d Printer, start the printjob and
make sure you have a soldering iron within reach. I would suggest using a thick tip and a temperature
around 300 degrees Celsius. Also you should use a cheap or already worn
out tip, as it is going to oxidize very quickly because we don’t add any additional solder. Wait till the printer stops, move the printbed into a comfortable working position and then
start pressing the wire into the plastic. The start and endpoint of the wire are going
to create a weakpoint, so make sure to not place it right into the critical areas. Other than that, there isn’t a lot to consider:
Just follow the path and press onto the wire. Make sure to completely embed the wire into
the plastic so that it is flush with the surface. Try to keep the amount of cuts as low as possible,
so that in the best case, you have one continuous wire. When you have finished embedding the wire,
extrude some plastic manually to compensate for oozing, clean the nozzle and auto home
your printer. Lastly just hit resume print in the printers
menu. And that’s basically it for this video. If you have a great idea on which parts to
use this technique, let me know in the comments. Thanks for watching and have a great day.

local_offerevent_note September 22, 2019

account_box Matthew Anderson


100 thoughts on “Reinforce Your 3D Prints with Steel”

  • Some of you criticized that I haven’t included normal, non hollow plastic parts in the test. I also regret not doing that, so today I rerun the test with those. They were sliced with 3 perimeters and 70% triangular infill, so that they include as much plastic as the steel-reinforced parts (even a little more).

    Pull (Bar): 98.2kg

    Bend (Hook): 44.6kg

    Combined (Ellipse): 105.7kg

    Looking at these numbers, it seems like the additional perimeters that are caused in the hollow parts actually help to increase their strength.

  • I wonder if one could design a hotend which continously injected a thin steel wire in, so that every layer is reinforced by many thin steel wires?

  • You could try layering some steel/stahlvlies between two printing layers (or every 10 Layers) and fuse with a heat gun. This will result in much better distribution of the strain, and load sharing between the reinforcement and filler material.

  • There's a really interesting part of this because if you first made a study of the part and made an conscious study of the stress.. You can reinforce the part in a certain geometry an achieve much better results.. Congrats for work!

  • Fantastic idea! Soldering together both cable ends would make it much stronger! For that you need to cut cables at perfect length and need to make a curved holder (steel U-profile?) in which you can solder the cables together with the correct bend radius. Why not putting several layers of cable on top of each other?

  • It would be so cool if you could get an extruder head to heat a wire and pass it onto the print. you would need a lot more narrow wire to avoid kinking but there's probably a magic diameter and offset that would work. glass fiber, real carbon fiber stands would be cool too

  • i wonder if i laser cut a carbon fibre or glass fibre sheet and use it the same way here steel wire is used…..

  • I have successfully imbedded some aluminum sheet into a project. It actually had 12 different pieces of aluminum added at varying times during the whole build.

  • It might be stronger if you use a spiral pattern path around the holes, that way you can use 1 continuous wire and the tension can be distributed across the whole system more evenly. The inner concentric circle parhs dont lend much strength. Just my 2 cents. Great idea either way!

  • For those using Cura, there's a plugin on Thingiverse called "Change Filament at Z" that adds the gcode to pause, move the print head out of the way, and wait for you to resume the print. I've used it for multicolor, but keep meaning to try embedding objects (most likely magnets).

  • I'd like to see an AI 3D Mesh Bender with High Stiffness Aluminum Wire, that uses a pinch arm to heat the joint spot. Then 3D Print plastic over it.

  • I guess the best thing about this is that if the part does fail when holding something, there's also a last strand holding everything together.

  • Hi. Do you have som tips for reinforcing a 3D printed piller? The force will be applied diagonally from the topp.

  • What if, instead of a square channel, you did a circle but stopped the print about 5% above the center? That way the wire would pop into the channel with no space around it.

  • Even better.: Use Dyneema or Spectra where the ends are tied together. You won't get a weight issue and you'll get better strength than steel.

  • What if you annealed the part as well? I'm sure this would only improve the interface between the print and the plastic.

  • did the prints without wire had the hollow tubes for the wire in them as well? because if the prints without wire were printed without the hollow tubing, then that would make it weaker

  • Can you also plan to add a variant with the cable beeing crimped? You should also make the proper reservation in the 3D model for the crimping sleeve to be hold. IMHO, this would result in impressibe strength. To go further you should also think about better force management, like wire crossing.

  • I wonder, if you were to change the design of the test part with two eyelets that held at 165.2 kg. Rather then the running the wire parallel, cross it or crimp it together at the start of the loop. I speculate that the tension causes the plastic to break because as you pull, the wire would spread. I think it could make that test part stronger than the others. Also, if you were able to crimp the ends of the wire together it would he it would help prevent it from expanding.
    As a experiment, thisbwas great to watch. I hope you might try different methods and designs

  • Could probably take this further and easier with larger parts. Print hollow with 2-3 shells. Drop the wire in. Finish printing. Drill 2 small holes. Pour in resin, cheap at HD or crafts stores.

  • You missed one important part.
    Splice the ends of the cable together.
    It is really easy to do for low strength applications, and with practice not hard for full cable strength.

    The easy way, you basically cut half of the strands short on each side, leaving every other strand long, and then interwrap the two ends.

  • Interesting, thank you. I have lots of stainless steel cable left over from my bike gear cables that would be ideal. If anyone watching this wants to do the same, I suggest asking at your local bike shop for old gear cables, no doubt you’ll get them free.

  • Nice idea. But if you are looking for better results you should consider this:

    If you joining two materials soft and hard you should maximize contact area of both peaces. You should make additional cavities in the printed peaces and then use some filler. It can be anything mixed up with a glue (baking soda, sand, whatever). So the resulting softness would be between plastic and steel.

    p.s. in general its the same idea how japan sword is made, – where to types of steel are joined, you can easily find smth on youtube

  • Not bad thinking, but this is really only useful for increasing elongation resistance in one direction. Adding composite encasement would also buff the torsional rigidity.

  • Very interesting. Thanks for sharing the results. It would have been interesting to compare the strength to weight ratios of the two parts.

  • This doesn't reinforce the print. It just means it will hang from something inside when I breaks.

  • I've done many prints with reinforcement from metal rods, or screws… But never tried steel wire, should try it soon.

  • Wouldn't a non-braided wire work better because it stretches less? It may be weaker on its own but I bet you a solid single core wire would show even better results.

  • Doesn't bending the surrounding surface while introducing the wire also introduce defects into the print's structure?
    I wonder how the printer deals with that, if at all.

  • Very cool video. I think this would be even easier with ABS, where you can print the part in two pieces, add the wire, and use acetone to weld the top on. This would also let you to solder the ends of the wire together to form a closed loop.

    I'm also interested in using 0.3 mm thick sheet metal as an integrated part between layers. Leaving room for a piece of sheet metal would be even easier, and you could incorporate multiple pieces easily within the same part. The sheet metal could be cut using a laser CNC machine.

  • What was the failure mechanism? Did the wire break, or did the end of the wire pull out of the plastic?

    Also, if you could pre-tension the wire, you might be able to increase the strength of the part before the plastic breaks.

  • At 6.10
    You start to add the wire in the wrong place…
    The wire should start 180° further around… So the curve takes the strain
    I would print a spiral recess on the curved ends, so no wire is pulled straight, but around the curve, this will give more grip to the wire
    Or did you do a double run of the wire, hard to see

  • This is very similar to the Markforge printer and it's use of carbon fiber. It would be Insanely cool if we could all come up with a cool automated way to mimic that process. Of course, simply embedding Carbon fiber every few layers works too and would probably be super strong. I need to try this.

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