eddieoctane

Strength is definitely an issue in any FDM part, but there's always a solution. I know metal FDM parts can has extra liquid metal wicked into the spaces. I'm wondering if some kind of resin could be used in an ABS part that could reinforce the air spaces. It's a theory, but it might be worth looking into if that's the direction you're going. I'm not too familiar with FDM, so I don't know what the options are.

What were you considering in terms of capacity, barrel arrangement, trigger placement, and overall shape? If you have some kind of baseline design, I can throw together something in SolidWorks and email it to you.

One last thought: have you considered putting joints at the points where individual parts connect? I feel like gluing the surfaces in the mock-up you showed alone wouldn't hold up under any half-decent spring, but even a simple joint just to increase the glued surface area would improve the strength of the blaster significantly, assuming the part itself can handle the stress.

I still think the loss of inertia from extended contact is negligible. There is still only a fraction of a second total contact. Conversely, the more inertia lost by the wheels means the higher maximum velocity on the dart, and the total energy between the two systems (counting both wheels as 1 and the dart as the other) can only balance out, meaning the angular velocity of the wheels can only drop to the maximum speed of the dart.

And if you're really worried about it, you could increase the speed of the motors. My primary concern with stefans would be weather a shorter dart can still be pushed out far enough to make contact with the wheels. If not, you need to find a way of effectively extending the reach of the push rod without preventing the cylinder from turning. This seems like an inordinate amount of work to use stefans in a Barricade, unless you're ok with using longer than average stefans.

Cyphre, on Sep 18 2010, 07:19 PM, said:

Now I know you could easily increase the diameter of the flywheels or make any sort of adjustment necessary, BUT I am wonder if it will reliably fire darts of the wheels contact all of the dart itself. In it's stock format, the two flywheels engage the wider head of the whistler darts, as opposed to the main, foam body of the dart. One such concern would be whether or not the wheels would get bogged down from the additional contacting mass of the dart being pushed (in regards to follow-up shots).

Bogged down how? You would obviously need to increase the space around the wheels to house a larger diameter wheel (just so nothing rubs), but I don't see them slowing down that much firing stefans or streamlines as opposed to whistlers. The rotational inertia of the flywheels wouldn't really change with the added mass of the tape or rubber bands, so the acceleration of the wheels is going to be basically the same. The only remaining issue would be a dart twisting if the motors aren't going at the same speed if it contacts both wheels for longer. But a properly wired system shouldn't run into this problem either.

The buckles for getting easier access to the battery tray is genius. Swapping out batteries is always a huge pain in the ass dealing with electric blasters. I'm not so sure about modifying the battery tray in a way that prevents using plain D cells. A fairly fat wooden dowel with a hole down the center to match the battery of choice could have a terminal down one end making them the same size as 3 D cells, ensuring you could still drop in normal batteries should you run out of other options. With stretched out contacts, you will have to re-compress and re-stretch them if you end up going back and forth between batteries, and that will eventually crack the contacts.

Fome, on Sep 16 2010, 04:28 PM, said:

making it stefan compatible is probably a different story, however.

I don't know about that. It looks like, when opened up at least, the whole cylinder can be removed fairly easily. If that's the case, removing that pegs to fit stefans shouldn't be much of a process at all. If the distance between the flywheels is the issue in using stefans, a little bit of electrical tape should increase the diameter enough to grip your ammunition of choice.

For any game where being able to put rounds down range matters more than stealth, I can see this thing doing serious work. A semi-automatic handgun is something that has been missing and I think people may change their minds once we really get our hands on this thing.