Another long, picture filled how-to. This time I am making crossbow pistols that shoot mini-marshmallows.
Click on the more link if you want to follow along.
I did the basic parts work on my ShapeOko mill, but there is still a bunch of hand-work.
I started by cutting the major parts out on the mill.
On the mill I cut out the handles two at a time, the bows three at a time and the lock work parts two sets at a time. That just the way it worked out.
The parts are held to the waste material with little tabs. This keeps them from moving around and getting jammed up in to the bit. The next step after milling is to cut the tabs and then remove the remnants with the belt sander.
The next step is to drill and countersink the holes for the screws to hold on the lock work cover. To the drill press!
As long as I have the countersink chucked up in the drill press, I might as well countersink the holes in the bows now.
Time to route the handles. First I chuck up a 3/8″ radius for the grip area, then I chuck up a 1/8″ radius for the rest of the handle and the bows.
Next I setup to route the rabbets to hold the guide rails. This is a bit tricky and requires a 1/2″ spacer and a stop block.
The guide rails are made from 1/4″ x 3/16″ strips of walnut. I rounded the ends on the belt sander to match the radius left by the bit used to route the rabbet. They are glued into place and clamped with rubber bands.
After those are dry, I trim them to length and sand them so there are no sharp edges to catch the pocket or the marshmallow.
Next I take some 1/8″ thick walnut and make the marshmallow keeper. This gets glued on and clamped with rubber bands again.
I need to make one more hole in the handles – there needs to be a hole for the end of the barrel spring. So I chuck up a 1/16″ drill bit and away we go.
After everything is sanded and fits the way it should I can glue the bows onto the handles.
For some reason, this looks like a flock of crossbow pistols to me. If you can count them you will see there are only nine. I started with parts for 12, but two had some tear out issues with the rabbeting, and I mis-counted some parts, so I only had enough for nine complete pistols. The other three will get finished up after this batch.
While those are drying, we can work some more on the lock work parts. I need to make two different springs for each lock work. One for the trigger and one to keep the barrel from rebounding and re-cocking when fired.
The barrel spring is made from .022″ diameter music wire. I made a simple jig with a hole and a pin to bend the wire around.
The trigger spring is just 4 coils from some 3/16″ diameter springs I bought at the hardware store.
Be careful making and cutting the springs. They are springs after all and tend to shoot off across the shop if you are not cautious. Make sure you are wearing your safety glasses.
The trigger needs a pocket to house the spring, so back to the drill press to chuck up a 13/64″ bit and make a hole.
After the glue dries I clean up any squeeze-out, sand any remaining rough spots and apply a boiled linseed oil finish.
After the finish dries, I can start assembling the lock work. First I insert the two dowels for the parts to rotate around.
Then I put a trigger spring into the pocket and insert them into the handle. In this picture I have also placed the barrel spring into position.
The next bit is tricky. I pull the end of the barrel spring around with a pair of needle-nosed pliers while depressing the trigger so I can fit the barrel into position.
And this is what it looks like when it’s cocked.
I screw the cover plate on again, make sure nothing is binding and the lock is working as it should and it’s time for the bands and leather.
The bands are made out of 3/4″ x 6″ strips of gold Theraband. I bought a 6″ x 7 foot strip on Ebay and it should be enough to last me for a while. I also cut a 5/16″ strip to use to wrap around the leather to attach the main bands.
The leather pouch (not really a pouch, but you know…) is just a 1/4″ x 3″ strip of leather. I bought 6 feet of 1/2″ leather strapping from Tandy Leather and cut it in half. I also cut some notches near the ends to keep the bands from slipping off – something learned from experience.
You can see here how I wrapped the small piece around the band and the leather and then used some nylon string to pull the end though to hold it.
Do the other end and done!
The marshmallows fly about 25-30 feet in a pretty straight line.