Airsoft Canada - Make a Thompson Electric Mag Step by Step

http://www.air-sharp.com/Thommy_mag_...ed_0030CAD.JPG

YES, I know there's off-the-shelf ones now...I guess I'll have to throw away the patterns I worked so hard on...
http://www.air-sharp.com/Thommy_mag_motorized_0001.JPG
Yes, there IS a way to fit a servo into a Thommy mag, without it sticking out.
Tamiya Lunchbox diff gears #9115010. Enough to do TWO drum mags, SWEET!!!

http://www.air-sharp.com/Thommy_mag_motorized_0001a.JPG
http://www.air-sharp.com/Thommy_mag_motorized_0002.JPG
Arrowed: An M14 mag winder is cut off, turned smooth, and bevels cut to serve as "indexes" for the Oatey putty to lock into.
We need a new "lug" on the mag winder, that is .315" dia. The putty ball is slightly bigger than this.

Remember my Golden Rule here!

Walk away, just, walk away.
It needs to harden up without being disturbed. I put a lamp on it to warm it, I'll come back in an hour, and turn this down on the 9x20 Harbor Freight lathe.
http://www.air-sharp.com/lathe.JPG
An electric drill, a file or emery board, and the same op could be done.

http://www.air-sharp.com/Thommy_mag_motorized_0010.JPG
The drive lug after turning on the lathe.

http://www.air-sharp.com/Thommy_mag_motorized_0009.JPG
A closeup.

http://www.air-sharp.com/Thommy_mag_motorized_0012.JPG

http://www.air-sharp.com/Thommy_mag_motorized_0011.JPG
Pressed into the gear, and a plug of putty locks it to the hex-shaped recess.

http://www.air-sharp.com/Thommy_mag_motorized_0008.JPG
Turning to the drive gear, a shallow slot is cut across the bottom. This allows a keyed lug to be formed into it.

http://www.air-sharp.com/Thommy_mag_motorized_0007.JPG
A 3mm screw is wrapped with blue masking tape, and used as a mandrel. A small "snake" of putty is mixed...

http://www.air-sharp.com/Thommy_mag_motorized_0006.JPG
And wrapped around the screw, and mashed into place.

http://www.air-sharp.com/Thommy_mag_motorized_0005.JPG
A short while later, it can be easily pulled apart, and trimmed up.

http://www.air-sharp.com/Thommy_mag_motorized_0004.JPG
Drive parts completed.

http://www.air-sharp.com/Thommy_mag_motorized_0003.JPG
Now to mount the servo like this.
The whole assembly is 1.49" thick -less than the servo is deep, measured from the shaft end to case back.

SERVO-MOD DIRECTIONS:
http://www.air-sharp.com/magmod.html

http://www.kapowwe.com/Merchant2/mer...s&Store_Code=R
Thompson lo-cap, Marui-compatible.

http://www.air-sharp.com/Thommy_mag_...ed_0013CAD.JPG
And hack the poor thing as shown.

This will hold about 3,000 rounds or so.

Making the drum from scratch, CAD for that and how to make the outer band coming.

http://www.air-sharp.com/Thommy_mag_...ed_0014CAD.JPG
To make the outer band for this, the computer says cut a strip 20.82" long, by 1.70" wide.
ASK YOUR MOM FIRST IF YOU ARE UNDER 35.
Preheat over to 325deg, find something "about" 6-7" diameter to use as a form.

http://www.air-sharp.com/terminator_...rowning007.jpg

http://www.air-sharp.com/Thommy_mag_motorized_0018.JPG
Find my forming plastic tutorial, and then, still don't try this yourself:
http://www.air-sharp.com/Thommy_mag_motorized_0017.JPG
The main and front cover bands. My uncle said he was in a cover band once.

http://www.air-sharp.com/Thommy_mag_motorized_0015.JPG
Mocked up over the CAD at actual size. Approximate locations of components.
http://www.air-sharp.com/Thommy_mag_motorized_0019.JPG
Servo Mounts.

http://www.air-sharp.com/Thommy_mag_motorized_0020.JPG

http://www.air-sharp.com/Thommy_mag_motorized_0022.JPG
The back panel, and the abbreviated Thommy locap.

http://www.air-sharp.com/Thommy_mag_motorized_0023.JPG
The Dremel was used to create the "spotwelds" in the front cover.

http://www.air-sharp.com/Thommy_mag_motorized_0028.JPG
The locap slides into these slots on the back.

http://www.air-sharp.com/Thommy_mag_motorized_0027.JPG
Fully seated.

http://www.air-sharp.com/Thommy_mag_motorized_0025.JPG
These were robbed from a Kappowwe springer drum mag- virtually the only parts of it left worth using!

http://www.air-sharp.com/Thommy_mag_motorized_0026.JPG
Getting closer!

http://www.air-sharp.com/Thommy_mag_motorized_0024.JPG
Some sanding, and a bit of paint, and oh yeah, wiring!

This will get a tracer illumination circuit added next.

I should point out- all the plastic parts for the drum were made with and Exacto knife, a Dremel, and a band saw with a dull blade. Note all pics taken in the kitchen -NO SHOP NEEDED!