curtisrands
Member
Hi all, I'm new to Arrma, new to RC, and new to the forums.
My son got an Arrma Granite Voltage Mega 2WD a month ago and we've now experienced the dreaded rounding out of the plastic differential outdrive. I ordered new diff outdrives but they are on backorder, so I decided to test out a 3D print of the part. I modeled the part from scratch with the relevant features and printed it on a Markforged Onyx One printer at work. I used the standard Onyx material, described as "Nylon mixed with chopped carbon fiber offers a high-strength thermoplastic with excellent heat resistance, surface finish, and chemical resistance." I think the normal part is probably ABS; the Onyx nylon claims 1.4 times stronger and stiffer than ABS. We haven't done any hard testing yet, but I think the killer is when my son hits full fwd and then goes into full reverse, which he loves to do. I've told him he's got to lay off that a bit unless he wants to be fixing it all the time. We are using Li Ion batts on dirt and asphalt, with everything stock, for reference.
Anyway, the part fits and spins really well, we'll get out a drive it around a bit this weekend and see how well it holds up. I can print 4 of them in a few hours and the material cost is about 75 cents a piece, using solid infill (infill is a 3D printing term - a lot of 3D-printed parts are mostly hollow if you don't need the strength and want to save time and material). I wanted the best strength and don't care about the weight, cost, or time here.
I'm want to attach STL file of my modeled part - anyone can use this to print from any 3D printer in any material - but the forum won't let me because it's an unrecognized extension (.stl). Thus, I have placed the files on Thingiverse (https://www.thingiverse.com/thing:3414192). This is my good deed for the day. If you print it in the standard 3D printer PLA material, it probably won't last one acceleration. But you can probably do well enough printing it with ABS or Nylon on any printer that can handle those materials. I would strongly suggest you use 100% infill (solid). And let us all know your results, please!
If this ultimately doesn't work, I might try to make some metal ones. I have connections. Should be a pretty easy part to turn and then add the shaft slot and dogbone slots on the mill.
I've also attached 2 pictures of the printed part (left) compared to the OEM parts (one damaged, one in tact). I've also attached a picture of the part installed. Spins freely, dogbone stays in nicely and articulates well.
My son got an Arrma Granite Voltage Mega 2WD a month ago and we've now experienced the dreaded rounding out of the plastic differential outdrive. I ordered new diff outdrives but they are on backorder, so I decided to test out a 3D print of the part. I modeled the part from scratch with the relevant features and printed it on a Markforged Onyx One printer at work. I used the standard Onyx material, described as "Nylon mixed with chopped carbon fiber offers a high-strength thermoplastic with excellent heat resistance, surface finish, and chemical resistance." I think the normal part is probably ABS; the Onyx nylon claims 1.4 times stronger and stiffer than ABS. We haven't done any hard testing yet, but I think the killer is when my son hits full fwd and then goes into full reverse, which he loves to do. I've told him he's got to lay off that a bit unless he wants to be fixing it all the time. We are using Li Ion batts on dirt and asphalt, with everything stock, for reference.
Anyway, the part fits and spins really well, we'll get out a drive it around a bit this weekend and see how well it holds up. I can print 4 of them in a few hours and the material cost is about 75 cents a piece, using solid infill (infill is a 3D printing term - a lot of 3D-printed parts are mostly hollow if you don't need the strength and want to save time and material). I wanted the best strength and don't care about the weight, cost, or time here.
I'm want to attach STL file of my modeled part - anyone can use this to print from any 3D printer in any material - but the forum won't let me because it's an unrecognized extension (.stl). Thus, I have placed the files on Thingiverse (https://www.thingiverse.com/thing:3414192). This is my good deed for the day. If you print it in the standard 3D printer PLA material, it probably won't last one acceleration. But you can probably do well enough printing it with ABS or Nylon on any printer that can handle those materials. I would strongly suggest you use 100% infill (solid). And let us all know your results, please!
If this ultimately doesn't work, I might try to make some metal ones. I have connections. Should be a pretty easy part to turn and then add the shaft slot and dogbone slots on the mill.
I've also attached 2 pictures of the printed part (left) compared to the OEM parts (one damaged, one in tact). I've also attached a picture of the part installed. Spins freely, dogbone stays in nicely and articulates well.
