14 replies to this topic

[TheAbused]

I've been working on this version off and on since I posted the last one, keeping suggestions and comments from the community in mind. I thought I could have knocked this one out in about 2 weeks, but winter temperatures and uninsulated working environments are not conducive to working with plastic.

The big new feature? Variable Speed Control Trigger.



BAM!



I managed to find a couple matched drills closer to an 18V rating. I'm a little paranoid about driving too much power through stuff. I've seen a lot of things get too hot and burst into flame at work. Also pictured: DeWALT drill shell and trigger.



This trigger is pretty important. It plugs directly to the battery, whereas many other cordless drills have two separate pieces for battery connector and trigger. LIFE LESSON: If you dig a power drill trigger out of a dumpster, check with a voltmeter for electrical shorts before you connect your $90 battery to it. I managed to burn one of mine up in less than 10 seconds, complete with smoke, red-hot glow, melting plastic, and probably a few toxic fumes. Luckily, I didn't burn out the motors.

Speaking of motors, if you're lucky enough to find some that come with a plastic mount on them, save the plastic mounts as templates for later.

Motor size comparison.:


On the other blaster, I had an awful lot of ball spin. My strongest suspicion was angle of contact on my fly wheels. The original setup had parallel surfaces. When I mounted my flywheels to my motors, I had flipped one flywheel over. I made sure not to repeat that mistake.



Some details on removing the puny motor and making way for the manly motor.



The gaps between the housing and the flywheels are important if you don't want anything to rub. Note the lack of gap in the red circle (Boooo!). Later I'll put a 1/8" disc of Lexan on the top of my flywheel so I can epoxy everything directly to the gear mounted on my motor. (If I want to get really fancy, next time I'll get a gear puller and order a couple shaft collars.



Here I've used some 1/8" Lexan between my drill motor and flywheel housing to get the spacing I need for my flywheels.



Using the plastic motor mount as a template...



To preserve the proper orientation of my flywheels while keeping both motors on one side, I needed to build a standoff in one flywheel. And to make sure both flywheels would spin at the same speed, I needed to keep them the same weight. So I built standoffs in both.

For some reason I felt the need to use as much of the original parts as possible in this mod, so I Frankensteined some unnecessary plastic in my flywheels. The mounted motors with no flywheels, running at full 18V speed, were whisper quiet. The mounted motors with one properly balanced flywheel, at full speed, were whisper quiet. The mounted motors with one properly balanced flywheel and one almost properly balanced flywheel, were about as loud as a regular drill.



It's entirely possible to make this a virtually silent ball blaster, but I would need to rebuild that flywheel. I've already rebuilt one 3 times, and any rebuilding at this point will destroy the flywheels. So what I really need to do is either turn some new flywheels from scratch, or find a donor Ballzooka. My advice would be to use 1-1/2" or 2" PVC as a standoff, and cap the end with Lexan.

Once again I coated my flywheels with Plasti Dip to guarantee decent grip on my balls. NOTE: I used a disposable BRUSH to apply the Plasti Dip.

Some pictures of the drill handle attached and reinforced:



I was going to mount a small spring blaster in the drill handle for extra Nerf Community Points, but I'll save that for the next version. Actually, I really want to mount a Blast Bazooka chamber in there, so I can fire balls, darts, and arrows, thereby creating a near ultimate Nerf blaster. (The ultimate Nerf blaster would also grant you sexual favors.)

A few angles of the unpainted finished product.



Ranges: up to 60 feet
Weight: 6.75 pounds without battery, 9.125 pounds with battery
Length: 20 inches
Width: 18 inches
Ammo Capacity: 16 balls

I haven't done a whole lot of test firing with this one yet, but it appears my ball spin is under control. Instead of veering off to one side, the ball does this cool spiral through the air.

Added Feature #1: Variable speed trigger gives greater control on ball speed/distance
Added Feature #2: Fore-grip handle redistributes weight better, making a shoulder strap less necessary

Planned Fix #1: Properly balanced flywheels for whisper quiet operation

Future Feature #1: Additional spring blaster mounted on side
Future Feature #2: Cool lights?
Future Feature #3: Fog machine?

Videos:

Previous Version (Christine)


Version 2 (Carrie)
http://www.youtube.com/watch?v=ng-f48C6EGU

I'm off to sleep for now, though I might wake up in the middle of the night to answer questions and read comments.

Final Paint:

Edited by TheAbused, 28 May 2010 - 10:45 PM.

[hummer]

And I thought the first version was sexy...damnnnn

[Samzilla]

I love it... while originally i was gonna say adding a spring gun would be better as it would provide a quick reloading backup shot, i realized with 16 balls you can fire whenever you want heck shove the most ridiculous air gun you want there. (a jobar seems like it would fit nicely there)

[fallinouttadabox]

What brand are those red drills? I've always found DeWalt drills have higher RPMs than other drills of similar voltage levels, and usually are more durable (I dropped one off a 2 story roof into the mud, it was completely comsumed except for a small yellow patch, and it still works fine). Also, $90 a battery is not worth it, Home Depot has deals on DeWalt drills 2 or 3 times a year, a few weeks back they had 18v Variable Speed Drills with an extra battery and charger for $60 (I got 5), and although they aren't the XRP you're using, they're definitely worth it in my opinion.

Other than my OCD about the drills, this is wonderful, I love ball guns, and not only did you make a ball gun primary worthy, you made a flywheel gun primary worthy. Wonderful.

[Broderick]

God damn, tha thing weighs nearly 10 lbs. with a battery in it? That's gonna get a bit tiring to carry around for more than 1 or 2 rounds. However, the awesomeness outweighs the weight drawback.
To tell the truth, I'm lost for the most part when it comes to mounting the motors and where the flywheels are placed, but nevertheless fantastic job; I can't wait to see it painted.

[sllewgh]

This is re-god-damn-diculous. You are a man after my own heart. Anyone who thinks that a 10lb blaster with a fog machine in it is awesome and not stupid earns my respect. If you were in the MD area, I'd buy you a beer.

On a more constructive note, have you considered using an air-compressor with an airtank? It's been done with a titan airtank and a quick on-off button switch, and you'll already have lots of battery power at your disposal if this thing is going to be war-worthy. You could even keep the compressor in a backpack. If I saw someone at a war with that giant, monstrous thing, attached to a backpack air compressor, and heard the noise you'd be making, I'd probably have to go home and change my underwear.

[Draconis]

Better MBZ overhaul? I love you, man.

[moosa]

This is a monstrosity. Put a freaking Vulcan tripod on it.

P.S. I Love You.

[TheAbused]

What brand are those red drills? I've always found DeWalt drills have higher RPMs than other drills of similar voltage levels, and usually are more durable (I dropped one off a 2 story roof into the mud, it was completely comsumed except for a small yellow patch, and it still works fine).

The drills are old 18V Craftsman Limited Editions I picked up at a flea market for $5 each. I couldn't bring myself to tear apart two working DeWalt drills.

God damn, tha thing weighs nearly 10 lbs. with a battery in it? That's gonna get a bit tiring to carry around for more than 1 or 2 rounds. However, the awesomeness outweighs the weight drawback.
To tell the truth, I'm lost for the most part when it comes to mounting the motors and where the flywheels are placed, but nevertheless fantastic job; I can't wait to see it painted.

The shoulder strap takes the weight pretty well, but its still fairly easy to lug around with just my (scrawny) arms. I'll post a more detailed picture and description about the motors and flywheels a bit later (after food).

On a more constructive note, have you considered using an air-compressor with an airtank? It's been done with a titan airtank and a quick on-off button switch, and you'll already have lots of battery power at your disposal if this thing is going to be war-worthy. You could even keep the compressor in a backpack. If I saw someone at a war with that giant, monstrous thing, attached to a backpack air compressor, and heard the noise you'd be making, I'd probably have to go home and change my underwear.

I would worry too much about the blaster being banned if I hooked up a compressor to it. For me, there isn't a whole lot of appeal being a one man Nerf wrecking crew (though the thought of the potential certainly is appealing).

[TheAbused]

To tell the truth, I'm lost for the most part when it comes to mounting the motors and where the flywheels are placed.

Before I could mount anything new to the housing, I had to shave off the original motor mounts. I don't really have a picture of that step besides 6th picture in my first post.

The Lexan piece is glued to the housing for two reasons: 1) to give me the flywheels proper axial spacing, and 2) to have a strong/rigid enough section to mount the motors. All that is required to mount the motors are (in this case) two screws and holes drilled in the right places (Usually I can get the holes to be in the right spot on the first try, but every once in awhile I have to try again). The center of the new motor needs to be as close to the center of the original motor as possible. Otherwise, the flywheels might be too close together to allow a ball to pass (and knock off the flywheels), too far apart to grip a ball (and the ball will sputter), too far forward to grip the ball when you pull the trigger, too far back so they grab the ball even when you don't pull the trigger, or offset in a way they throw the ball at an odd angle.

My flywheel is glued to a Lexan spacer. The spacer has a hole in the center for the motor shaft to sit. The gear on the motor shaft is eventually epoxied to the spacer. All of this is a result of circumstance. I could have just as easily (well, not just as easily, or else I would have done it this other way) pulled the gear off the shaft and mounted shaft collars. I could have then epoxied the shaft collars directly to the flywheels.

Is that clearer? I could try again, just let me know where I lose you.

[Chadpuff]

I bet it would suck to be hit but that thing! Very nicely done. For a battle cry you gotta scream out "Feel the awesome power of my balls!"

[bourbon]

And I thought the previous version was cool. Do you think if you weighted the balls somehow they would fly even further? I mean it has two drill motors powering it... just something to consider.

[TheAbused]

Do you think if you weighted the balls somehow they would fly even further? I mean it has two drill motors powering it... just something to consider.

I haven't done many experiments with weighted balls yet (I had a very limited supply until a little while ago). I put a 1/2" diameter ball bearing in one ball and tried that, but I got pretty crap ranges. Like, 10-15 feet ranges. Drill motors run at high speeds with low torque, and rely on a transmission for low speeds with high torque (so you can drill holes or drive screws). The way I'm using the motors here, I have very high speeds with very low torque.

A regular Nerf ball is about 6 grams (0.2 ounces). My experimental ball bearing ball is 36 grams (1.3 ounces) and definitely too heavy. I'll probably add smaller bearings (or buck shot or something) to see if 12 grams works better. Or 8 grams or 10 grams.

If I were feeling really industrious, I would build a transmission (or modify the existing one from the donor drill) so I could throw those heavier balls at a lower speed and a higher torque. Its likely I could see better ranges that way, since air friction will have a tougher time of slowing the mass of my ball.

[bourbon]

Whoa, 36 grams is pretty intense. I have a scale and a copper BB weighs 0.6 grams, too little. Maybe a 1/4" slingshot weight? I don't have any of those to weigh but I'm willing to bet that somewhere around 8-9 grams would be perfect. The fact that it can throw a 36 gram ball at all is good news, that means it can definitely handle it.

[nerf mafia]

Seeing the original in person was great can't wait to see this one on the battle field.

Edited by nerf mafia, 28 March 2010 - 05:00 PM.