carbon fibre pen gun build log

[jackssmirkingrevenge]

I've been commissioned to build a pen gun similar to this and though I would document the build process for those who are interested

First step is rather basic, the CF body is cut to size and the ends are squared up on the lathe using a carbide tool at high rpm:

[mark.f]

Sweet. Should be interesting to see your construction methods in use that don't involve epoxy. :p

[jakethebeast]

I bet JSR used epoxy somewhere

[jackssmirkingrevenge]

Sweet. Should be interesting to see your construction methods in use that don't involve epoxy. :p

Don't worry, epoxy will feature here too

[JDP12]

this looks awesome! Been absent from the forums for awhile, but this looks interesting, can't wait to see it.

[yodabeast14]

How much psi are you planning to operate at?

[jackssmirkingrevenge]

How much psi are you planning to operate at?

Should be able to take 400 psi safely.

Here's the front endcap, threaded 1/8" BSP to allow a 0.177" barrel adapter to be fitted to the 0.22" barrel. Note the grooves to improve the adhesive grip.

[jrrdw]

Arrow shaft?

Message toooooo short!

[jackssmirkingrevenge]

Arrow shaft?

10mm ID 12mm OD tube sold as outriggers for quadcopters.

Here's the barrel setup, note the delrin sleeve at the breech end which increases the area on which the piston seal pushes, reducing wear. The OD of this sleeve is 8mm, you would think that it leaves too small a gap between barrel and chamber for air to flow but in fact, the cross sectional area is greater than that of the 5.5mm barrel.

Also illustrated is the schrader valve prepared for attachment, along with a "virgin" example.

[jakethebeast]

Hehe nice work, your almost finished, now all you need is... epoxy

[Oxy]

This looks awesome! Can't wait to get it, great work.

I'll post a video of it in action when it arrives

[jackssmirkingrevenge]

Here's the piston and rear endcap, hopefully this thing will be ready for testing tomorrow.

[jackssmirkingrevenge]

Worky bits all put together and polished, will do some high pressure testing later in the day.

[jackssmirkingrevenge]

Here's the triggering assembly before being epoxied in place, with the threaded part to fit the schrader cut from an alloy cap.

[jakethebeast]

Nice one! How´s the power?