Check out the video here: https://vimeo.com/316969498
The goal of this project is to be able to print a functional skateboard without special materials or printer modifications. Does is work? Yes it does!
I am using a Volcano hot end for speed, but it is not necessary. The main part of the deck requires the full build volume of a 300x300x400 printer.
There are a few parts required that are not printable:
6903 bearings for the wheels.
Bolts for the kingpins.
Bolts, washers and nuts for mounting the trucks and connecting the deck parts.
See the "Required Parts" section below for details.
It is possible to print the smaller parts (trucks and wheels) on a smaller printer and use a conventional wooden deck. It is also possible to print the deck and use conventional trucks and wheels.
The trucks are reverse kingpin 50 degree. The hanger is reversible. Hanger width: 140mm. Axle width: 214mm.
The intent of the design is for cruising, and not doing tricks which would require stronger filament than the recommended PETG. I haven't tried printing any of the parts with Polycarbonate, Nylon, etc. but I'm curious to hear if you decide to try it out!
I recommend using a plastic bonding agent when attaching the tail (e.g Scigrip 16) as there is a lot of strain on the bolt holes without it. The nose is probably fine without being bonded as there is much less stress on it.
I've tried a few different TPUs on the wheels: Priline 98a, Sainsmart 95a and eSun 85a. See the results here: https://docs.google.com/spreadsheets/d/1oognSRkHh37sHCIzwKX4GOkM-d9Iz_LIPP12pA2XyIk/edit[hashtag gid]=0
Please let me know if you try other TPUs and what your results are. I expect Ninjaflex will perform similarly to the eFlex.
I've included my source files (Fusion 360) as well as .step and .iges so you can remix freely.
Caveat: I'm not a skateboarder or an engineer. Skateboarding is dangerous as flip. Always wear a helmet.
You will need some basic tools to put it all together.
3/8" combination wrench is helpful (optional)
small hammer to tap in the kingpins
I use a pair of channel-lock pliers to tighten the axles in the hangers. It's probably not a bad idea to use a thread-locker to make sure they don't unscrew, but I haven't had an issue with it. I wouldn't recommend glueing them together in case you need to replace a damaged axle.
It can be difficult to get the wheels over the wheel cores. Sometimes standing on it works, otherwise a clamp or vise will do the trick. If you try to print the Soft version of the wheels with a hard TPU, you're going to have a bad time.
Once you get it all together check the alignment of the wheels using a straight edge. I've had alignment trouble printing the axles and hangers at other than the recommended orientations, which I believe is solved now. But it's a good idea to check and be sure.
The tail needs to be bonded to the main deck with something like Scigrip 16. Bolts alone will cause too much stress and can lead to failure. Use bolts and large washers to clamp while curing. For the nose I'm just using the bolts without issue.
PETG is recommended for most parts. PLA+ (tested eSun) also has excellent layer adhesion and impact resistance, but lower melting point and less weather resistant 'cause PLA. Both brands of PETG I've tested have identical properties.
0.8mm or 1.0mm nozzle at 0.4mm or 0.5mm layer height.
The most important thing is getting good layer adhesion. Recommend nozzle temp 240-245°C. Fan 0-20%. Bed 80°C.
TPU is needed for wheels and bushings. I recommend a softer TPU based upon my testing but a 95a TPU will also work in a pinch.
eFlex: Speed: 3.0mm/s (!) Nozzle: 1.0mm @ 203°C. Layer Height 0.4mm. Bed 40°C.
SainSmart: Speed: 10.0mm/s. Nozzle: 1.0mm @ 218°C. Layer Height 0.4mm. Bed 65°C.
Support is included in the STL when needed. Most parts were designed not to need it.
Detailed Printing Notes
modjul-axle x4 - I have tried to print this laying down and had issues with warping which affected alignment of the skatebaord. Recommend printing this vertically with PETG. They are strong enough if you get good layer adhesion.
modjul-bushing lower TPU x2 - If using a softer TPU 85-87a (recommended) Try 2mm shell and 50-75% infill. If using harder TPU 95-97a. Try 1mm shell and 40-50% infill.
modjul-bushing upper TPU x2. Same as lower.
modjul-bushing pivot TPU x2. Print solid. Might need a smaller 0.6mm nozzle.
modjul-kingpin nut 13pitch x2. Print solid. Optional - could use a steel nut - but use nylon stop nut or it will vibrate off.
modjul-kingpin Nut Inset TPU x2. print solid.
modjul-kingpin washer bottom x2. Print solid.
modjul-truck baseplate x2. Print solid. I had to make this tight to the metal kingpin to avoid sloppy handling. It may require a little cleanup inside to get the kingpin in.
modjul-truck hanger x2. I ran into an alignment issue with one I tried to print vertically. Print in the given orientation with a brim, and you shouldn't have any issues. Also had an issue with the threads when "Check Thin Wall" was on in ideaMaker. Recommend at least 8mm shell. This is a 4 hour + print for me with 0.8mm nozzle.
modjul-wheel nut 16x10 x4. print solid.
modjul-wheel washer 17 thin x4-8. print solid. I use one thin washer on the inside of each axle. It's nice to have a few extra to get the spacing just right so the wheel isn't too loose or too tight.
modjul-wheel washer 17x1mm. x4. print solid. use on outside of wheel between wheel and nut.
I have tested a few different TPUs on the wheels and found that the harder, faster to print TPUs don't roll as well as the softer eSun eFlex 85a.
See results here: https://docs.google.com/spreadsheets/d/1oognSRkHh37sHCIzwKX4GOkM-d9Iz_LIPP12pA2XyIk/edit[hashtag gid]=0
I would guess that Ninjaflex is similar to the eFlex. The downside of the softer TPUs is that they're slower to print (very slow) and more expensive. I still recommend them though, as they roll faster and more comfortably.
There are two wheel designs included. The larger 306436 wheels with cores and the smaller, rounder core-less 305834. The smaller one's are more for tricks, which the deck isn't really strong enough for, but these would make sense if using a wooden deck.
If using softer TPU
modjul-wheel 306436 85a core x4. Print solid with PETG.
modjul-wheel 306436 85a TPU x4. Print solid with TPU.
If using a harder TPU
modjul-wheel 306436 95a core x4. Print solid with PETG.
modjul-wheel 306436 95a TPU x4. Print solid with TPU.
modjul-wheel coreless 305834 TPU x4. Print solid with any TPU.
modjul-wheel nut tool x1. Print solid. This is just for fun.
modjul-deck nose x1 or x2. Similar to main: 3mm shell. 15-25% infill to support top layers. No brim needed. warning: I had too much adhesion on one of these and pulled up glass. ~250 grams of filament.
modjul-deck tail x1 or x2. 3mm shell. 10-15% infill. ~400 grams of filament.
modjul-deck main x1. I recommend 3.0mm-3.2mm shell. 10-15% Grid infill. This takes me about 32 hours with the volcano hot end, 1.0mm nozzle. I have had trouble with the corners pulling off the print bed - the print still finished, but with anxiety. Recommend printing as much brim as possible, in a warm room (or enclosure) with PVA or some other way to maximize bed adhesion. This needs more than one kilogram of filament, which means a filament change in the middle. I recommend printing about 250-300 grams first then doing the swap to a full spool, in case of failure with the swap. ~1200 grams of filament.
modjul-deck main NO SUPPORTS x1. This is for someone with a larger printer who wanted to try a different orientation.
modjul-deck tail NO SUPPORTS x1. If you want to experiment with a different orientation.
6903 bearings x8 for the wheels. The ones I purchased came with a very heavy industrial grease which rolled slowly. I replaced this with 3-in-1 oil, and removed the inner seal from each bearing, which is a huge improvement if you want to roll fast. I got mine on amazon.com
1/2" x 2-1/2" long bolt x2 for the kingpins. This is a standard bolt (in the US) with a coarse 13 tpi pitch. (ANSI 1/2 - 13 UNC) I got mine at the local hardware store.
10/32 or 10/24 screws (bolts) x16 for attaching the deck parts and trucks. Conventional skateboards use 10/32 but I think the 10/24 is nice as there is less risk of over-tightening them. When using the Modjul deck these will need to be 1-5/8" or 1-3/4" long. I bought a pack of 2" 10/24 screws (too long!) and cut them down with a multi-tool after they were mounted. Unfortunately 1-1/2" seems to be too short.
10/32 or 10/24 stop nuts / lock nuts x16.
For tail: Recommending 1/4" washers x4 for top. [see images]
For deck: #12 washers x8 [see images]
Optional for trucks: #10 washers x4.
You like Cults and you want to help us continue the adventure independently? Please note that we are a small team of 3 people, therefore it is very simple to support us to maintain the activity and create future developments. Here are 4 solutions accessible to all:
ADVERTISING: Disable your AdBlock banner blocker and click on our banner ads.
DONATE: If you want, you can make a donation via PayPal here.
WORD OF MOUTH: Invite your friends to come, discover the platform and the magnificent 3D files shared by the community!