Keep a Tommy 20 From Jamming

Recently, I went to the store and had $30 to spend. I needed an automatic (non-chain fed) foam dart gun for another project. I should've bought the Nerf Rapid Fire, but instead I bought a Buzz Bee Air Blasters Tommy 20 gun. At the time, I was happy with it and I took it home to try it out. The results made almost made me weep. The gun uses two spinning wheels to "grab" the darts and throw them out of the gun. Whatever device pushes the darts out of the rotating barrel wasn't pushing them far enough, or there wasn't enough traction on the two drive wheels, or they weren't big enough, but the darts were jamming up almost continuously.

So, I sat and thought, and thought, and thought about what to do. Then it hit me- I should make it better myself!!! I took the cheap plastic gun to The Underground (our basement shop) and opened it up. Actually, I started to open it up, but my dad walked in, saw what I was doing, and told me NOT to open it up. Unless there was something wrong with it, I should LEAVE IT ALONE. Period. That night (in my room) after everyone was in dreamland (wherever THAT is), I opened it up anyway. I didn't have any idea what to do to keep the darts from jamming up, so I closed it up and did some research. What this instructable contains is the results of that research. Also, at the end of this instructable, I will post a drawing of me using the gun.

I would like to pleasantly note that unless you are skilled at opening such cheap pieces of....stuff, I would recommend taking care when opening up, and re-assembling this.....toy. It would also help if you had a trusted adult (don't ask my dad) to help you with this project-he/she probably knows more about fixing things than you do-if you get stuck ask him. Otherwise, proceed to the next page, get what you need, and let's get started!

Step 1: Gather Materials

You need the following items for the modification of this object:

-A Tommy 20 Air Blaster gun (DUH)

-A Dremel rotary tool

-A regular (+) screwdriver that will fit the plastic case screws

-12 rubber bands-I used bands that have a diameter of appoximatly 1"

-A hot glue gun

-Your "trusted adult"

Once you've found everything, proceed to the next step.

Comments

[theletterkay]

Is it ok to use E-6000 superglue instead of hot glue do you know? Hot glue is not meant to stick to plastic like this, but E-6000 sticks to anything. I of course would know to let it sit 24 hours before testing, just wanted to know if there was a specific reason you would HAVE to use hot glue.

[eyebot117]

Hot glue was what I had on hand. E-6000 would probably work. :)

[Gamer917]

i had the nerf rapidfire for a while, it never jammed but it took forever to pump and was as loud as a real gun, so i threw it out

[Pizzapie500]

I know this is 2 years and six days later, but, you should've given it to me! =)

[tom tom]

I noticed the globs of glue around the wheels. Did this affect the operation or did they have to be trimmed off?

[eyebot117]

Well, now that I've used this thing a while, I would use superglue on the bands rather than hot glue. The hot glue didn't hold and the bands were loose again. However, I would trim the globs off should you use hot glue.

[al9595]

cool pics!

[eyebot117]

I'm learning how to use a new program called Blender, which will allow me to make Pixar-quality animations that I'll soon use in place of these silly drawings... But it isn't easy to learn!

[tdawg309]

I agree. Blender is a pain. But not imposable.

[eyebot117]

It did take me approximately a year just to get the hang of using it though..

[Ellisthemodder!]

It's annoying my recon just broke, I am as we speak modding my nite finder!!!!!

[Ellisthemodder!]

It was a tommy 20 mod for a handle on the latch

[Ellisthemodder!]

Oh sorry my mod's instructable didn't post so i'll sort that out!

Ellis

[Ellisthemodder!]

Thats cool check out my mod!

[matstermind]

what mod?

[allan12345]

oh yeah go halo

[PikesPeak]

Ah the Dremel tool; if you don't own one of these by now, you aren't a modifying machine yourself.

[carpespasm]

What would you say is the practical distance the gun shoots now vs stock? What is the stock voltage it runs on?

[eyebot117]

Well, honestly this mod wasn't really to increase the range as much as it was to make it actually do what it was supposed to do (shoot without jamming). When I bought it, It would shoot about 10 feet and the darts would hit the ground. Pretty lame. It uses 3 AA batteries (1.5 volts DC each) to get 4.5 volts DC. Adding a battery will do one of two things, depending on how you add it. If you connect the battery in series (like the others), the speed of the motors will increase. If you connect the battery in parallel to the load, the torque of the motors will increase. But, don't add too many batteries, or you could burn up those cheap little stock motors! You might get lucky if you get more than an extra 5 feet by adding a battery. But again, I have not tried this yet.

[carpespasm]

You should be able to add batteries in parallel all day long and not have any worry about burning out the motors. The motors themselves look like they'd be the limiting factor in not maintaining torque when you shoot since they're kinda small in the axle momentum department. I doubt it's a lack of amperage to keep the motors spinning well that'd slow it down. I could be wrong there, but I think running a parallel set of AAs wouldn't help much. As for the voltage increase the little motors like the ones in that aren't too picky as to what power they're fed as long as it's not enough to burn up the coils. You might be able to find a close match for it online and see what it's rated max voltage is. You can usually go a little over even that without catastrophic failure.

[eyebot117]

Make sure that when gluing the rubber bands, that you REALLY secure them good! Mine keep coming loose!

[smashbro51]

Awesome drawing thats really good=]

[eyebot117]

Why, thank you!

[smashbro51]

your welcome

[Bodygard1117]

wtf?

[eyebot117]

What's wrong? You don't like my picture? Dang it.....I KNEW I should've drawn Chuck Norris instead! Oh well...Maybe on my next instructable!

[Bodygard1117]

its just a little random

[maxxnoodles1]

it would be nice if you posted a video of it shooting

[eyebot117]

Like I said below, my camera does record video, but for some reason that I don't understand, the video will not upload to my PC. I'm sorry for the inconvenience. I will say however, that it shoots great, at least better from when I got it. I still want the rate of fire to increase, and to do that, I'm thinking about adding one or two more batteries in series to increase the voltage, and increase the speed and power of the motors.

[Landon Sullivan]

Good job. 4 stars.

[eyebot117]

Thanks. Is there anything I need to improve on this instructable to get that last star?

[brunobl3]

I think u can make a video showing how it works. Cheers,

[eyebot117]

I wish I could. My digital camera does record video, and it does connect to my computer, but the my video editing program does not accept whatever format the digital camera video is on. I tried to do this multiple times, and I can't figure it out. So no movies until I can figure out how to upload/edit them, or until I buy a new camera.