PETG
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 240-245ยฐC. Fan 0-20%. Bed 80ยฐC.
TPU
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 @ 203ยฐC. Layer Height 0.4mm. Bed 40ยฐC.
SainSmart: Speed: 10.0mm/s. Nozzle: 1.0mm @ 218ยฐC. Layer Height 0.4mm. Bed 65ยฐC.
Support is included in the STL when needed. Most parts were designed not to need it.
Detailed Printing Notes
TRUCKS
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.
WHEELS
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#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.
Optional
modjul-wheel coreless 305834 TPU x4. Print solid with any TPU.
modjul-wheel nut tool x1. Print solid. This is just for fun.
DECK
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.
Optional
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.
REQUIRED PARTS
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.