DIY Motion sensing mine

[Drake]

Originally Posted by BGrail25

A solenoid is basically a motor that goes in and out, compared to spinning in a circle. You can buy solenoids, or even make your own. Unfortunately, from some of the solenoid's I've made, it is not very strong. If you Google 'solenoid' or 'homemade', you'll find a bunch of cool stuff. If you find out a way to make it very strong (like a stronger power source) it may just work.

Don't use a solenoid to try and depress the pin on the grenade: have a spring-loaded striker (strong enough spring to fire the shell) and have the solenoid actuate a trigger/sear.

[BGrail25]

Sorry I haven't replied to this sooner, I always seemed to forget.

I've been thinking about some alternatives to the grenade. I'm not sure how they would work out, but they might have some use.

1. You could use a buzzer, noise maker, or any other electronic sound to use as an alarm. This could be useful to snipers or CQB, where you will know where enemies are approaching. Plus, this would be easy and cheap enough, that many could be made to setup a perimeter of alarms. Or, if you want to get really technical, hook it up to some type of FM transmitter that could alert you when it goes off, or use earbuds so no noise would be made.

2. Smoke, anyone? If you could somehow hook one up to some kind of smoke device (whether homemade or not) and make it go off when someone goes past, I could see some possible uses as well. It could also be a 'tactical' smoke grenade. Throw it by an enemy base, when it senses movement, it goes off!

3. Or, some type of distraction device. I'd imagine you would paint it camouflage or disguise it somehow, but if you really camouflaged it (ie. leaves, bark, dirt, whatever) and then hooked it up to a buzzer or some other sound device, it could possibly make someone at least look around for it, leaving them a perfect target!

[lordnordeth]

Would one of the "shotgun shell" type units (like for the Goblin, or the various shotguns that fire airsoft) be easier to trigger than the grenade?

I know it wouldn't give as big a shower of BB's, but it might make for an easier build if it requires less pressure/force to trigger than the 40mm grenade.

Just a thought.

[baker_Jeff]

You could also use this to trigger the tripwire on a Claymore, perhaps?

[VooDooPeteK]

Originally Posted by baker_Jeff

You could also use this to trigger the tripwire on a Claymore, perhaps?

That would be a better idea IMO

If you could fine a way to have this unis set off the 40mm the BB's would just go up and the motion sensor would go off before anyone was right over top f it to get hit with a BB.

[Kos-Mos]

hehehehe

I am buying a bunch because I have 2 KA 168rnd shells that are waiting to be used....

And I also found a way to make the BB spread "claymorish"... with a bonus loud bang.

More this week, I will field test theses at a game on the 26th.

[coach]

You'll need a fairly strong servo and a some gears to set a 40mm off. Design it so you can adjust the gear ratio. The motion sensing device is sound if you use it purely for it's electronics.

If you want an easier way, make a trap. Won't be 100% horizontal but possibly at 30 - 45 degrees. Use the sensor but put the nade in a tube that it can be pulled backwards. Like a mortar round dropping on a firing pin but you can use rubber bands or bungies to pull it back. Use the motion sensor to actuate a lock pin. Once retracted the nade is pulled back or falls.

[ShelledPants]

Originally Posted by coachster

You'll need a fairly strong servo and a some gears to set a 40mm off. Design it so you can adjust the gear ratio. The motion sensing device is sound if you use it purely for it's electronics.

If you want an easier way, make a trap. Won't be 100% horizontal but possibly at 30 - 45 degrees. Use the sensor but put the nade in a tube that it can be pulled backwards. Like a mortar round dropping on a firing pin but you can use rubber bands or bungies to pull it back. Use the motion sensor to actuate a lock pin. Once retracted the nade is pulled back or falls.

Moustrap, firing pin / striker, electric trigger ... profit.

[Kos-Mos]

Back from the store.... no push-in-the-face thingy... but I did find some 38khz IR sensors I had lying around... And yes, I got 3 HS-645MG servos. 125oz torque on the shaft. But I am using the spring off a small mouse trap to make an hammer/firing pin that will shoot the nade. The servo will just be a "trigger finger"

I also am modding an RC car remote into a hand-held detonator.


I am placing the 40mm shell right up, and there is a 30deg angled metal plate right in front, shaped in a bend/twisted W shape to spread the BBs. Got to test it later today after I finish the fire mechanism...

And while I am at it, I bought 2 large rat traps to make a claymore. Have 3 ch. on the TX and RX... so why not use it?

[Kos-Mos]

hehehehhe

Here is my new toy: