AirSharp

How to build a motorized hicap magazine for airsoft

One Hitec HS-322HD servo, cheap, as you can see.
www.rccountryhobbies.com
Get a high-speed if you want fast,
get high-torque if you have a long feed to the hopup. This procedure uses about $20 in parts to make.
Although these instructions do not allow dis-assembly of the finished unit (considered disposable in the event of malfunction),
simple planning would allow a unit that can be completely broken down.

1/8" drill.

With the servo still assembled, drill the hole out slowly with a variable-speed drill.
All servos have 1 screw holding the wheel/arm on. Remove this screw, and drill the hole out to 1/8".
This is much easier to do at this stage. don't panic, I'll show you why we
do this in a bit.
Make SURE you use a drill no larger than 1/8"/.125""!
You only need to go in about 3/8" or so, but if it bottoms out, no harm.
take care not to crack the tube you're making here.

Remove the bushing/bearing, middle gear, and output shaft in order numbered.

Under the output shaft location will be the pot shaft sticking out.
Lop it off flush, sand smooth with top of hole.

Another view. Two chops usually work better than one.
On brass shafts, you may need a small file to take it down flush.
As long as the shaft can turn freely when temporarily placed, that's good.

Like this.

BE CAREFUL HERE- Make a small nip at the outside end of this tab.
Repeat again coming in from the top.
THEN snip it off completely. Try to do this too ham-fisted, and the shaft will break.
I know, so use little nips to work the stop tab off.

The little speck below the cutters is what we've removed.
Place the shaft through the bushing/bearing, and temporarily place it in the servo cover. Make sure it turns freely.

Re-assemble the geartrain, slide the cap back on. Some alcohol will remove any gear goo.
Tape the cover on if it won't snap on and stay.

Just chop off the wires. Don't worry about being careful about the connections, they won't be reused.
If you're fastidious, you can desolder them.

I chop them off flush with the trusty Sandvik cutters I've owned for almost twenty years.

Positive and negative hooked up on the motor leads themselves.
Servos vary as to which is which.
A test connection to a drycell battery for a moment (hold the cover on to avoid gear damage)
will show you which way to hook up. this of course depends on which way your servo needs to turn.
Screw the cover back on, it may not go flush where your wires come out,
if you went with bigger wire (no problem reusing the stock harness), but this is OKunless you shoot underwater a lot.

Snap the nub off the winder key from your mag,
or use a Dremel to make a 1/2" length of 1/8" allen key.
This becomes the drive shaft.

A pair of Vise-Grips, push the shaft 1/2 way into the servo shaft.
Again, take care to push straight in, or you may crack the output shaft of the servo.

And we have our finished drive unit.

Now to rework a normal M14 magazine:
about $10 online, and proven reliable.This will be a magazine for one of my Brownings.
It goes into an ammo box, and needs a way to feed the gun a few feet away.

Milsim folks, look away. My trusty band saw took the "un-need" part right off.
Yes those are latex gloves. Latex gloves are great, so much hand-scrubbing time eliminated.

NOTE: If you are building one of our miniguns, skip the next 8 pictures, as parts to replace the putty are in the design.

A chunk of normal 1/4" aluminum rod stock is pushed into the BB-hole, after a mild deburring.

5/16" coil spring from McMaster-Carr slides right over the aluminum shaft.
This keeps the feed tube (spring) aligned with the mag body while the Oatey #31270 epoxy hardens.

Use a chunk about the size of a bon-bon.

Kneaded into a rope shape...

Wrapped around the spring somewhat evenly this way.

And pushed into shape with a small card.

Let set for about 8-10 minutes .

Then stretch the spring slightly, and (use the Sandvik's you ran right out and got)
pull the aluminum rod free. Work it up into the spring, it will fall out.

Works every time.

Wiggle the spring loose by tugging and twisting.
Look close at the spring you use, one direction will make
the spring shrink as you twist, the other will make it grow.
You want the spring to shrink, so it can move in/out of the hole you've made from cast putty.

Make sure you get any loose particles!

So much happening here*. The epoxy has been smoothed over a shop vac, so no dust got inside.
The hole has been slightly chamfered. Fingerprints are from the cheap latex gloves. A little alcohol on a paper towel takes them right off.
*See the sandpaper? It's six months old. I spray-adhesive'd it to plastic sheet. I score the back and pop off any shape "nail file" I need. Lasts almost forever.

A test-fit to the now painted servo.

A 1/8" hole, drilled in line with one of the servo ears. Make this hole
in a spot where it is outside of the BB path. Looking at the edges of the servo, you will find a good spot.
Location will depend on clearance for your needs.

A #6 screw self-threads into the new holes.
Adjust so the servo does not bind while turning.
It is OK to turn the wheel slowly to check. A little wobble is just fine.

Another view.

Hot melt glue WON'T come off, like nuts that vibrate free.

This picture is biggest for a reason. take care not to glue the wheel to the servo case or the mag body.
If you get sloppy, DON'T touch it. Let it harden, and trim it off later.

Add 36" of new spring, you could feed ????
McMaster-Carr #9664K49, 5ea for ~$14.

Same principle applied to M4 magazine.

Use a rubber tire from a toy car if your mag has a tiny wheel.
You'll need to devise a bracket of sorts. Larger tire=faster winding.

Sorry, we do not sell motorized units, except with finished gun packages. This information is provided for entertainment only, and no warranty of suitability to your needs is implied. Use of this information is at your own risk.