Wolffie

I print models 3D for work (when we need them), and I've recently printed the front suspension arms for a Losi 22S SCT. I used my "tough resin" for a G3D printer, and it broke right away. I'm looking at getting a FDM printer to use to make these parts instead. Questions I have are below;
1) Will any 3D printed part hold up to the torsion and movement for a front suspension arm?
2) What material would hold up to these?
3) Is there a specific infill, or structure that you all have found to hold up better?
4) I created the model myself, but are there specific websites to look for rc models and parts?

Riketsu

iTrader: (33)

You should be looking at either ABS or Nylon. PLA might get you so far depending on where used (not suspension or rotational parts).

For ABS, you definitely need an enclosure for your printer (and even move the electronic components to the outside).

Not all FDM printers are capable of printing ABS/Nylon out of the box. Many will do with modification and aftermarket parts.

Check this video, has some great information about printing 3D parts:

andreas78

Hey Wolffie,

the video from Riketsu is nice and there are some truths in there. But I would also disagree on some points. For example, I wouldn't recommend ABS in the first place due to a few reasons. ABS doesn't really have very high layer adhesion. At least not compared to Nylon or PET-G. Some might say, with some Acetone postprocessing the layers can be kinda fused together even better, but from my experience, that's merely an optical thing and doesn't really add to stability. ABS is also rather tricky to print due to a high chance of warping and cracking, especially if you have an open printer like all those Prusa based designs.
I have printed some parts including arms for 1:10 offroad cars and I can share my experience.
One thing is the chosen material, another thing is the way you print it. Always keep in mind, as said in the video, the strength between layers will never be as high as within the continous plastic extrusion. Only about 60-70% I would guess. So you must print your part in the right position. Arms I always print upright so that the holes for the bolts that are holding the arm to the chassis are within a loop of plastic. If you print it flat, which is the easiest way, the arm will surely break right at the hole very soon, because there's not much material there and the layers are not strong enough. It also the area with the highest stress in case of a crash.
The only problem with printing it upright is, that torsional stress might be able to crack the arm along its lenght, but with a material with good layer adhesion you can get away with that. At least I never had one fail yet. Another thing is, if it fails at that point, the car will probably be still driveable, because the two halves of the arm will still be hold together by the upright and/or the arm holder of the chassis. The car might handle differently, of course, but you're probably gonna be able to finish your run. The tipp to print things so that the layers are at an 45° angle to give strength to two directions simultaneously is also a good one, but cannot always be done.

So my recomendation for materials is, use PET-G (because it's cheaper) to make some new "first try" parts. Depending on the part, the strength of PET-G might already be high enough and it's much cheaper than Nylon. It's also easier to print. If the parts work as desired and you only need them to be stronger, print them using Nylon. I had good luck with Taulman 910, very nice finish and strength, although a bit flexible compared to original parts. It's also not too hard to print. As I live in Europe I also used Nylon with glass fibers filament made by Eumaker. It's a bit harder to print as Taulman 910 and it's abrasive to the nozzle (use a steel one or even hardened steel), but it's stiffer and layer adhesion is also very strong. Removing support is quite a PITA.
For infill I always use triangles. It easy to print and mechanically, triangles are always a good structure, loadwise.
For parts, there's lots of parts on thingiverse. Grabcad is also a nice resource, but more for professional cad designs, not focused on 3D prints. But you can find complete, well made cars there, an first generation SC10 for example.

So my verdict is, it is possible, but you have to gain a bit of experience with materials an designs and you might come across some parts, that cannot be 3d printed reliably. But I'm quite glad I have a FDM printer.

Andreas

Lone Racer

I'm new to 3D but there are alloy filaments on the market that seem like they might hold up. They require hotter temps to print but so does nylon and ABS.

Metalsoft

iTrader: (75)

When it comes to 3D printing, how you print it ( Extruder temps, table temps, filament size and splicing have a huge and I mean a a huge impact on your prints. Proper design and splicing from the STL file will make a good print. Ignore those and you can have a good print go bad quickly. PLA can be used, but needs to be designed and printed properly ( More layers ) to use. I have used PLA for suspension and everything under the sun. ABS is fine, but will stink up your printing room quickly.

Make sure to research the in and outs of printing. It is not as simple as designing something and just printing it.

2wdMod

iTrader: (42)

So much spot on here already. Only thing I would add is design for the process.. Dont design a part that should be injection molded and print it and expect it to hold up.. This may sound a bit odd , but , I have found that designing parts for printing specifically is similar to designing parts made from wood due to having to pay close attention to the "grain" of the lay up.. Working in 1/24 scale I get away with a TON you 1/10 guys would never dream of.. Hell I can use silk PLA's for my 1/24 drag car wheels and pull 50 mph runs on them and get away with it because my car weighs under 150 grams RTR..But I wouldnt dream of printing some 1/10 wheels out of silk pla..

andreas78

I like your example of "..designing parts from wood..". From an engineering stand point, designing parts for 3D printing is quite similar than to design parts for fiber reinforced composites. They share quite the same "problems". Layers that are glued together and therefore nonhomogenous behavior of the material. Just like wood, too.

Andreas

derevles.ru

Kym, I like the "...within reason" part.

Just a question, there are now places for specific Subeta/Neopets/Club Penguin discussion. Will you be making similar areas for discussion of other online games?

duckinduck

I found these sites:
https://grabcad.com/library?per_page=20&query=rc%20car
https://www.3dcontentcentral.com/Parts.aspx
I have not come across this yet, but I found these articles, I hope they will help you.
https://www.craftyhangouts.com/best-...1000/#nitem_18
https://www.sharrettsplating.com/blo...d-3d-printing/

Jeremywhipkey99

Nylon, ABS,Delrin all will work here with different flex/fracture properties.

Daksh

Any reason resin printing is not preferred? I have an ABS like resin that seems to hold up quite well, wondering if there's any reason one would not try to print things like wheels and a arms using resin.

DynaMight

ABS like Resin is still really brittle, nothing like real ABS/PETG filament. I've tried some myself, well not on RC stuff but bought it to see if it could be used. Your best bet would be to mix it with a flexible resin, people are mixing with ABS Like to get good results that are not brittle. It takes some messing with the mix rate but the results seem pretty good. The flexible resin is really expensive but would go a long way if mixed.

here, but that was with a 90/10 mix, seems like 85/15 or 80/20 is probably a better mix. Not sure if there would then be too much flex?

2wdMod

iTrader: (42)

Resin is more brittle than FDM compounds.. There are many vids on you tube making comparisons between the 2 for durability in a variety of functions.. For example one was testing material wear when used for gears.. standard old PLA or PETG was way more durable than resins.. The resin prints tended to leave a fine powder residue from wear in the gear train shortening the life compared to the same part printed out of FDM materials.