TIW Clickable Brass Pen

In this instructable, you will make your very own clickable pen out of brass! We will be using both the manual lathe and manual mill to do this. If you are making this project at Texas Inventionworks (TIW), all materials can be found in the machine shop. If you're interested in following this instructable but don't attend UT Austin, no worries! All supplies are listed in the following section. If you haven't worked with brass before, it's quite similar to aluminum just slightly harsher. In addition to the machining practices you've learned from the lathe and mill trainings, you will need an understanding of how to operate a tap and die for threading certain parts. If you're curious about threading but haven't learned how yet, I would advise you to check out the following videos:

https://www.youtube.com/watch?v=WRuJ3k0V-fA

https://www.youtube.com/watch?v=4keGTpaZ7nk

Let's get started!

Manual JET Mill w/ DRO

1. Edge Finder
2. Collet Set

Manual Baileigh Lathe w/ Tailstock

1. Live Center
2. Drill Chuck

Drills

1. Standard set of pilot/center drill bits
2. Standard set of drill bits

Brass

1. 1/2" diameter
2. 3/8" diameter
3. 1/8" diameter

You will need 1/2" diameter brass stock for the body. If completing this instructable at TIW, ask if you can use some stock in the machine shop. Otherwise, order some from onlinemetals.com.

First, we need to cut this giant piece of stock down to a usable length that you can put in the lathe. Since the body is 5.5in long, cut off a 8in long piece on the horizontal bandsaw (dropsaw) so you have some material to put inside the lathe chuck jaws.

The body is fairly long relative to the diameter. So, you need to use a live center. A live center holds onto the end of your stock to minimize chatter when machining. Before you can use the live center, you'll need to make a hole using a pilot drill bit that the live center can fit into. Using a 1/4" pilot, run the lathe at low gear, 115rpm, and drill a 1/2" deep hole.

Now, you're ready to put your live center into your stock. Make sure its snug inside the body and then turn the lathe at a low RPM to see whether the live center turns with the body. If it isn't turning, there's a good chance either you need to make your pilot drill hole deeper or you need to move the tailstock closer.

If it's turning, then you're ready to use the turning tool to turn the body down to a diameter of 0.45in. Turn the lathe at high gear, 460rpm for this operation. Once you've turned the diameter, you can optionally buff the body or use high grit sandpaper to polish the body. I opted to use sandpaper in the setup you see in the picture but it's not required.

Finally, go ahead and use the parting tool at 5.5in and part your body off the stock.

For the drilling process, we need a 3/8" diameter through hole. Start with a pilot drill bit followed by a normal 3/8" drill bit. However, this piece is long, so our typical drill bit won't cover the distance. To complete this operation, you'll need to use an extended 3/8" drill bit. If doing this instructable at TIW, the extended drill bit set will be in the bottom drawer of the gray cabinet. Once you've done that, you're ready to start tapping.

The tap and die sets are in the gray cabinet located opposite of the machine shop. For tapping the body, you will need a 7/16-20 tap. The tap guide is located in the top right drawer of the brown cabinet that sits atop the computer desk, and you can choose a tap handle from the blue cabinet next to the gray cabinet. Once you've finished your scavenger hunt in finding all your tools, you can start tapping!

If you haven't tapped before, visit the video listed in the introduction of this instructable.

For tapping, you can never use too much tapping fluid! Make sure to start with the tapered end and finish with the non-tapered end (bottomer).

The nose is a bit tricky, but also the coolest looking part of this pen. Before you start machining it, you'll first need to establish your set up.

When you cut the conical shape of this pen, you will be using the compound feed which is controlled by the angled crank. Since we need to cut the profile of this nose at 14 degrees, you will need to change this angle. To do this, take a hex key and untighten the two screws that are holding the compound slide down to the plate. Now, rotate the plate until the hash mark on the compound slide lines up with the hash mark at 14. Once you've done that, make sure to tighten both screws fully.

The first operation will be turning 0.25" length of the stock to a 3/8" diameter. Once this is done, you will need a 3/8-20 die along with a die handle which can be found in that blue cabinet. Just as with tapping, you want to start with the tapered side and finish with the bottoming side.

Once you've threaded your nose, turn 0.7in length past the threaded section down to 0.45in. Then, at the end of 0.7in, use the grooving tool and make 2 channels side-by-side at a diameter of 0.15in. This will serve as our "free-space" so that with every pass of the compound slide we stop once we reach the free-space.

Now, with your angled compound slide and turning tool, zero the turning tool roughly 15 thou from the far end. Turn your compound slide until you reach the free-space. Back out, and come down another 15 thou from where you just were. Zero, the turning tool, and turn the compound slide until you reach the free-space. Repeat this process until you are 0.1in away from the threaded part. With this final compound slide pass, you will have a 14 degree taper cut out of the nose! With the taper cut, you're ready to move on to drilling the nose.

The nose requires 3 different diameter holes. One for the tip, one for the spring, and one big enough for the cartridge. Start with a pilot drill bit before going in with the 7/64" drill bit and making a through hole. Now, use a 3/8" drill bit to make the hole that the spring will sit on, preventing it from falling through the nose hole. This hole should be 0.85in into the part. Lastly, use a 1.4" drill bit to go 0.7in into the part. With these holes drilled, your nose is complete and you can part it off the stock using a parting tool or a metal saw.

For the clicker, you'll need to use the live center again so start by making a pilot hole.

You will need to turn the clicker diameter down to 0.27". If you try this starting from the rightmost part of the stock you may accidentally hit the live center. So, use the grooving tool to make a groove that clears the live center and turn to a 0.27" diameter for 4in from this point.

Once you've turned this diameter, part the stock off and drill a 15/64" hole 1.95" into the clicker.

Lastly, you'll need to tap a small hole for the clicking rod to thread into. Just don't clamp down too hard on the manual mill or else... well see picture 5...

For this thread, first drill a hole using a No. 50 drill bit through the clicker. Then, carefully run a 2-56 tap through the entire hole. Make sure you're doing this on the solid end of the clicker - not the hollow end.

This part is quite small, so find the smallest diameter brass stock you have and take a 0.5" piece off to put in the lathe. Now, turn 0.15" of the stock down to a diameter of 0.08" and thread 0.10" using a 2-56 die. With that done, use a metal saw to take your part off the stock.

This step will truly make you feel like a manual CNC. I would highly recommend having a Desmos graphing calculator out for this (not joking). You will need a 7/64" drill bit for this job.

First edge find the size of the body to zero the x. To determine the zero in the y, edge find on the closer side of the spacer which is in line with the top of the body.

The slot is 45 degrees down for a length of 0.38" followed by a 45 degree angle up for 0.17". Since these are 45 degree angles, to create this slope, you will need to drill at (0.109", 0.795") go down 20 thou and across 20 thou, and drill again. Repeat until you reach (0.290", 0.980"). This is where Desmos is quite handy as a sanity check. Plot a graph of the line and for every point that you drill, verify that it falls on that line so you know you're on track.

You'll notice that with every hole the radius of the drill bit leaves a ridge between passes. To get rid of these, use a thin file to smoothen the slope and allow for a more satisfying click.

Congratulations! You've finished making your very own clickable pen. Assembly is fairly straightforward. For the clicking portion, take your G2 Pilot 0.7mm ink cartridge and slide it into the clicker - it should be a fairly tight fit. Place the spring onto the tip of the ink cartridge and slide this assembly into the body. Now, rotate the clicker to where the threaded portion is facing out of the slot drilled into the body. Take your rod and thread it into the clicker, and your pen should be fully assembled! If you run out of ink, just twist out the rod holding the clicker in place, switch out the ink cartridge, realign, and twist the rod back in. Now, go write something!