Pepper Cannon

All these parts are now on thingiverse at Pepper Cannon Accessories

The pepper future and the pepper past:

I've retired my old Unicorn Magnum now. It worked great, but it is no match for the pepper cannon.

The tracking info for my Pepper cannon finally advanced beyond "label created", so perhaps it really will arrive soon, I therefore need to get to work on all the accessories I want to print for it. [Update: Delivered! Sep. 18, 2021 3:00 PM].

Drill

First is the adapter to use an electric drill for grinding mass quantities of pepper. Here's one part I can print while waiting:

I used my drill press to (as precisely as possible) enlarge the printed hole to exactly 1/2 inch for the shaft, glue the aluminum shaft in place with super glue, then drill the 1/8 inch hole through the side of the shaft (using the printed hole as a guide) and screwed in the 30mm M3 bolt.

That piece will go on the drill like so:

Spinning the drill up seems to indicate this is properly centered with no wobble. It is also vastly over engineered :-).

It will fit in a matching hole and drive a separate adapter which I can't print till I can see how well my model matches the real pepper cannon, but I can print a test slice to check the fit and see if the model needs tweaks once I get it:

I can print just the bottom section of the adapter though to make sure the parts join correctly:

Looks like it fits perfectly. It also still fits on the drill.

Measuring cup

I also want to print an alternate cup for the bottom to allow me to observe exactly how much pepper I've ground. No more guessing when a recipe wants two teaspoons or some such thing. I've managed to produce a test ring that correctly screws on to the centrifuge vials I ordered from amazon:

Getting the threads printed is the trickiest part, and that is now done. Just need to see the best way to connect it to the cannon once it arrives.

I've done a little more work, creating a complete cap that screws on and has a hole. This will become part of the funnel that connects to the bottom of the cannon once I come up with the best way to do that.

I've got the pepper cannon in my hand now, and I see the cup is simply press fit with an O-ring to hold it, it even comes with a spare O-ring, so if I can get the dimensions exactly right, and can use the O-ring on my measuring cup attachment.

Loader

Finally I want to make a funnel for filling the cannon that fits on the top, but there isn't anything I can print before I can measure it. I have created a generic funnel module in OpenSCAD ready to use when I get that far.

I created the pepper loader module with some dummy numbers I can use just to see what it looks like. Here's the preview:

Once I can measure the real numbers I can plug them in and print it.

Credits

I picked geometry data off the STL file from another drill adapter from thingiverse to make my openscad model. I eliminated the need to print with supports (by turning it into two separate pieces).

Results

After getting the pepper cannon in my hand, the first thing I printed was the simplest, the loader funnel:

Here's the cannon about to be filled:

Here's how the funnel fits on top:

The very first pepper I put in the cannon was using the funnel, and it is able to grind out pepper once filled, so it definitely works. In fact it is so easy to dump in pepper, I overfilled it and had to pour some back in the jar. I'll keep that in mind the next time.

I'm now in the process of printing the drill adapter. The test slice I printed earlier was too small, so after measuring the difference in diameters I was able to scale it up a bit and produce a new test piece that fits perfectly. Not hard to get on or off, but definitely able to grab the top and rotate it:

The complete adapter has now finished printing, and the top slides right in nicely:

I haven't glued the two adapter parts together, but they fit so well I figured I'd give it a try:

Holy cow! That blast of pepper was a single pulse of the drill. If I need mass quantities of pepper for a rub or something, I know how to get it now :-). I don't think I'm likely to use it in normal day to day operation.

It does make a good effort to rip the pepper cannon out of your hand, so hold on tight, and I wouldn't use anything but low speeds.

For the final part, after a test print, I've gotten good dimensions for the O-ring groove and threads to make the the measuring vial attachment:

The vial screws in like so:

The whole thing pushes into the bottom of the pepper cannon:

And with a few turns of the top you can see it grind out a teaspoon (which is about the same as 5ml):

That concludes the pepper cannon accessories for now (till I think up something new I want to add).