The Printacaster

When i saw the original Prusacaster, i immediately ordered the hardware kit from Thomann and started printing the core piece that accepts the bridge and pickup, but when the kit arrived, none of the holes aligned with the printed part(s), and some of the cutouts were not deep enough.
It would have required substantial drilling and cutting to make it work, so i decided to update the design. Unfortunately i was not even able to properly align the STEP files of the original design, so instead of updating the Prusacaster model, i just started my own version of a 3D printed guitar.

My main requirements for the redesign were:

• Fits the current Harley Benton T-Style Kit by Thomann
• No glue, only threaded inserts and M3 bolts
• Parts are easily replaceable (see above)
• Strap button mount holes
• Fit a 250mm² bed

The layout of the hardware is based on a photo of the guitar body of the kit - with a few peeks at the drawing used by the Prusacaster - and a heavy priority on ignoring all the asymmetric routing required to cut holes and passthroughs into a wood body, and taking advantage of the fact that this will be a 3D printed design.

Required Vitamins:

• Soldering Iron with the right tip for heat set inserts
• M3 Threaded Inserts (M3x5x4), a.k.a “M3S (short) inserts"
  • Core: 26
  • Core Tail: 8
  • Lower Right: 3
  • Lower Left: 20
• M3x10 bolts, minimum count:
  • 17 * DIN 7991 (pickguard, bridge, knobs, jack plate)
  • 13 * DIN 912 (connections between core and lower parts & tail)
  • 30 *DIN 34805-1 (connection between core and upper parts)

Yes, the number of inserts and bolts doesn't add up. Just get enough of each, i'm too blind to find the ones that are missing. ;-)

In theory pretty much any bolt head type should fit everywhere, it just may not look as nice as when using the intended head type.

Printing Instructions:

Please consult the Prusacaster Blog article for the details about which material to use for which part and why, but if you're too lazy: print the Core from PLA, and the other parts from whatever your prefer (i went with PETG). Again: Core = PLA. (unless you've got PC-CF).

There are 2 versions of the Core, one that will fit a 250mm² bed ("Short") and needs its tail printed separately, and another one that's ~320mm in length ("Full") and will definitely not fit a 250mm² bed in any useful way. That's the version for the big boys. Pick whatever fits your bed, and put the emphasis on printing it laying flat.

For the core, i'd also recommend using more perimeters/walls than usual, to make it as sturdy as possible. As this is a pretty huge part, picking a non-linear infill like “Adaptive Cubic” or even “Support Cubic” can save you a lot of filament, time and weight.

Assembly Instructions:

Before getting to the part where you stuff all the guitar hardware into the printed parts, you'll need to bring them into a shape that generally resembles the pictures above - and then make sure that it stays in that shape.

There are plenty of holes allover the contact surfaces of the parts, and there is one Golden Rule (as golden as those threaded inserts): In the end there's gotta be a threaded insert in exactly one of each of those holes on either side of the contact surface. There is no situation where you would end up with two holes facing each other with both of them having a threaded insert in them. Well, it may of course happen, but that's not how this was supposed to be done then.

To figure out which hole receives the threaded insert, have a look at the X-Ray Vision™ image provided, and keep in mind that all connections are structured like this:

• a 6mm wide entryway of varying length, into which you put the bolt including its head
• a 3.5mm wide and 3mm long neck, on which the bolt head will rest when tightened
• a 4.7mm wide and 4mm deep hole in which you've melted a threaded insert
• a 3.3mm wide and 6mm long place for the bolt to screw into

So in short, you put the threaded insert into that side of the contact surfaces where it fits. ;-)

For the hex grid parts, there's only a 1mm recess for the bolt heads, to ensure that there's still enough material for structural integrity below the bolt head. That's why you should go with DIN 34805-1 (a.k.a. button head) bolts there. Unless you like the look of black DIN 912 as much as i do, and are going to use those everywhere! ;-)

I would suggest this order: 

• Tail to Core
• Lower Left to Core and Tail
• Lower Right to Core and Lower Left
• Pickguard
• Top Hex Parts

Do not attach the Neck before the Pickguard. You can try, and it is possible, but it's easier if you wait with attaching the Neck until the body is mostly done.

The hole for the grounding wire (below the bridge plate) may be a bit tight, depending on how accurate your printer is calibrated, so if you can't get the wire through that hole, just take a ~2mm drill bit and clean it up until the wire can be massaged through.

Pretty much all access holes to the bolt heads are a bit hidden, which helps with not making the finished guitar look like a swiss cheese, but also makes assembly a bit more difficult. A regular Allen key is the only tool you'll need, though. And lots of elbow grease, as there are lots of bolts, and some bolt locations will only allow you to make quarter turns with the Allen key. Sorry for that.

Assemble the whole body on a flat surface, to make sure the parts are aligned properly, then add the Pickguard and the rest of the hardware.

This is more of a redesign than a remix, as everything was created from scratch. The only similarity is the outline of the body, which is based on a sketch created from the Prusacaster models.