Humbucker "Prusacaster" redesign

Hey! I want to share my project I have been working on the last couple of weeks. It is one of my first projects too.

I really liked the idea of the Prusacaster but I wanted more beef. 

So I present you, the purists absolute nightmare.

I decided for two active EMG 57/66TW humbuckers. 

They are able to switch between single coil and humbucker (coil split) which I thought could still retain somewhat the lighter Tele/Strat sound if wanted. Furthermore, I was hoping that the active powered pickups can mask the plastic tone of the body. 

This had a few implications:

Active pickups require a battery, so I had to add a compartment into the body. (Between the humbuckers). 

There was not enough room in the original pre-sliced Prusacaster model to cut enough space for the humbuckers, so I had to redesign it from the ground up. 

The Tele bridge simply does not fit. I also wanted to test if a normal strat bridge would work.

Those bridges are string through body types. This requires dedicated string holes in the body and string ferrules. I got very good results by just melting them into the body, exactly how you would melt inserts in.

As the strings are kept in place by the string ferrules in the back, I am confident that the body won't catapult into my face.

The design itself was kept close to the original as I really like the hexagon style. It is however a bit different and not compatible with the original design. 

Part list

M3 screw sets (0.6 - 2.0cm)

M4 screw set (0.6 - 3.0cm)

4x M4 screws 4.5cm

M3 inserts 3*4*5

M4 inserts 4*4*6

A lot of these parts on Amazon are just imported and sold with high markup. If you can wait a bit, you can save yourself quite a bit of money by just ordering from China directly. 

There are a few active pickup clones that are allegedly good and cost ¼ of the EMGs. 

Print settings

I printed everything with a 0.6mm nozzle at 0.32mm layer height on an MK4 with Input Shaper enabled.

The middle piece holding the bridge and strings uses 7 perimeters. All other pieces 3 perimeters. ~20-25% infill.

The middle piece was a bit tricky to print. It needs to be rotated 90° horizontally so the saw tooth side is facing upwords. Then rotate it 90° vertically, so it fits on the bed. It requires organic supports. 

You need to block a few supports depending on the rotation of the model, as some organic supports will be placed outside of the bed. Rather block the supports at the holes, not at the neck joint. This will make the holes a bit oval, but it does not break the functionality.

I had to add mickey mouse ears to all edges and use the standard steel sheet. The satin sheet was unfortunately not sticky enough and gave me adhesion issues.

All the other models printed fine without any issues.

Building

In case you are thinking about building this (which I find awesome) keep these things in mind:

You are printing a plastic guitar body with maybe expensive components. It is a fun project, but it is still plastic with all its downsides. Unless you are using used passive humbuckers, it can get a bit expensive. The original EMG humbuckers are 200€+. Just want to make sure you are not disappointed after 3 days of printing or so.

My guitar neck came without predrilled holes and I would suggest to search for those as you need to properly align the neck with the body. Even if the predrilled holes fit, it can still be that the neck will have some offset and your strings will be very misaligned which makes the guitar unplayable.

If you can get a cheap neck with predrilled holes, I would suggest to buy some wooden dowels, widen the holes in the neck, place the dowels in and glue the holes shut first.

Once the neck is ready, place it into the body, route two thick strings through the bridge into the neck tuners at position 1 and 6 (low, high e string). Add some tension and align the neck so both strings are properly centered on the neck. Mark the holes and predrill them carefully. (Maybe print a drill guide first.)

Similar to this video: 

Additionally, the edge where your playing arm is, needs a bit of fine sanding or hot air, otherwise it can get a bit uncomfortable after a while. It's not sharp by any means, but you can still feel it a bit.

EMG Pickup installation

The EMG pickup cables are not really suited for this body as they are way too long and take a lot of space in the electrical compartment. Try to stuff the cable back into the humbucker cutout once they are connected to the pots. It may require a bit of force but it passes fine. 

The black battery cable and jack cables are too short. I had to extend the jack cables with two common jumper cables. Like ~10cm. 

The black battery wire had to be extended with a thin cable as well. Similar size of the jumper cables. 

The pickup system contains a small connector pcb for the jack, pots and power. It should fit into one of the two small pockets in the electrical compartment if you remove the velcro fastener. 

Design

Sharing is caring, so I have attached the Fusion 360 project file. It is one of my first CAD designs, so there are quite a few imperfections in the CAD workflow and a lot could have been done better. But it works and the imperfections are invisible, so I won't continue the design further. Holes are all parametric. 

Result

Overall I'm happy with the result, but I should have taken more care while gluing the parts. The super glue really is super and I had basically no time to align the parts correctly. It's not heavily misaligned, but some parts could have been glued better. :)

I should have taken a glue variant that dries slowly. 2 minutes would have been enough really. 

Furthermore, I have a few glue spots over the body. Thankfully only behind the body. Still not great.

The neck still requires this “string down holder” metal piece next to the tuners I don't know the English word for.

Besides this, it plays much better than expected. The strings are aligned good enough, even at the last frets. Intonation was simple to adjust. The body feels nice on the leg. 

The physical balance of the guitar feels like a dead corpse though. :D

You can't lean it towards something as you might expect. It will turn around so the side is facing forwards. 

I haven't felt an imbalance while playing though. It is rather light compared to my other guitars. No extra force on the neck. Really fun to play. :)

Hope you like it!