Rollergun roller idea

[ka-chink]

I've been thinking about this idea for a rollergun, as i'm thinking of that being my next build. I'm just wondering if anyone has done it, or your thoughts, seeing as you guys are experts as far as i'm concerned. :thankyou

I've been thinking of drilling a 1/2" hole in approx 1 1/2" square by 12" long wood block, and doin an epoxy pour in there. when it's cured i'll put that on a lathe and turn out a couple rollers in the style i'd like and then cutting them up on the band saw to get the individual rollers. i'd then drill a 9/32" centre hole and put em on the gun with SS pins.

i did a mini test and they seem strong in compression, and they spin nice enough (didnt do the epoxy pour on the mock up though). i'm not sure how they'd function underwater or on a gun, so asking for your thoughts :king

 

[Tin Man]

The main problem that I foresee is that it will be hard to get any bubbles out of the epoxy. When guys pour epoxy tracks, the tracks are long, but only 1/2" or so deep. And still, they use a variety of tricks to get the bubbles to rise to the top and pop. In your case, you will have a pour that is 12" tall and only 1/2" in diameter. So I think you'll end up with a lot of porosity in your epoxy.

Maybe you could minimize that by cutting the rollers just slightly oversized first, and then pouring them individually, and then turning to final dimensions.

I have only built one roller gun, but I can tell you from that experience that the main challenge is in what the wishbone does after the shaft is fired, so that it isn't a pain in the arse to reload.

 

[ka-chink]

The main problem that I foresee is that it will be hard to get any bubbles out of the epoxy. When guys pour epoxy tracks, the tracks are long, but only 1/2" or so deep. And still, they use a variety of tricks to get the bubbles to rise to the top and pop. In your case, you will have a pour that is 12" tall and only 1/2" in diameter. So I think you'll end up with a lot of porosity in your epoxy.

Maybe you could minimize that by cutting the rollers just slightly oversized first, and then pouring them individually, and then turning to final dimensions.

I have only built one roller gun, but I can tell you from that experience that the main challenge is in what the wishbone does after the shaft is fired, so that it isn't a pain in the arse to reload.

Yea I know I'll get a lot of bubbles. I just realised that I wasn't very clear. The rollers are gonna have a wood exterior, with the epoxy just forming the core. I figure it'll have less friction that the wood on the SS pin, and also should waterseal the inside of the rollers. Its just that to me putting yachting rollers on a wood gun sticks out. And yea I'm sure they're a beast to load.

 

[foxfish]

I think you would be better off just buying some rollers!
I have only built two roller guns, they are very difficult to balance being nose heavy, the system seems to work better on big guns with plenty of bulk!
However there are some amazing examples on db - try the search button for pages of inspiration & ideas.
I found some great rollers complete with brackets & bearings in a boat chandlery shop, they are used on sail boat rigging. In fact my local chandlery shop sell just the replacement rollers in lots of different sizes.