SpudFiles

Multi-chambers.jpg
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Here are my different chambers so far. 4" softball barrel, 2.5" tennis ball barrel, and 1.5" potato barrel

Ehm??

Nice cannon! I like the interchangeable barrels with PVC->ABS conversion.
Good job!

I took my GPS and measured the distance the softball traveled while fired at about a 40 degree angle (eye measured)

DISTANCE = 686 feet!

It was too far for me see where it first bounced in the grass but I was happy with the results.

Jeff

great gun there Jeff, 686 feet is insane. btw i used to have a gun just like that, big chamber, small pipe and big barrel, worked really good, built up the pressure needed to launch baseballs way out there. g/j.

So I cut the barrel down 6" to improve the C:B ratio and the ball is shooting about 50' less on an average.

Chamber = about 3770ml
Barrel (now) = about 6570ml

So what's that now? Chamber divided by Barrel for my ratio?

.57/1

If that's my ratio, I was doing better at .48/1

Is my math wrong? Also, I use Gumout Carb & Choke Cleaner and I'm a pro at spraying in the proper amount. (professional spray & pray-er) Haha.

Jeff

Well... a larger chamber would have given you more power for that barrel which is how I would look at it, not the other way around.

-B

Boom_erang wrote:Well... a larger chamber would have given you more power for that barrel which is how I would look at it, not the other way around.

True. But this is my universal chamber for all my other barrels so I was just trying to maximize distance without having to make another combustion chamber.

I cut off the 6" in case the pressure was dropping too low the last 6". Apparently not.

I have been thinking about setting up a propane meter. Home Depot didn't have the part that screws onto the propane bottle. I have to hunt around for that.

Jeff

xpitxbullx wrote:So I cut the barrel down 6" to improve the C:B ratio and the ball is shooting about 50' less on an average.

Chamber = about 3770ml
Barrel (now) = about 6570ml

So what's that now? Chamber divided by Barrel for my ratio?

.57/1

If that's my ratio, I was doing better at .48/1

Is my math wrong? Also, I use Gumout Carb & Choke Cleaner and I'm a pro at spraying in the proper amount. (professional spray & pray-er) Haha.

Jeff

Interesting! That's a noticable drop in performance. Might I then suggest you build yourself another softball barrel, maybe 2' longer than your original....measure your performance. Assuming it's less than your original, saw the end off in say 4" chunks and measure performace each time. Stop sawing when you hit a peak. Shoot 2 or 3 times at each length to get a good average.

Given a softball will not air tight fit in that barrel, you may be getting some advantage from a longer barrel.

I'm using a rag to give it a tight fit.

I may have to go with remaking the barrel and finding the optimum size.

Jeff

Do another latke test
It seems that other C:B ratios are required for other sizes... interesting!

I decided to make the propane meter. It's built and later today I'll fasten it to the chamber.

I couldn't find any low pressure psi gauges so, for now, I have a high pressure gauge that's harder to read.

Thanks for the ideas!

Jeff

think u will have another vid up this weekend? would like to see the performance, although i would never complain about the distance your getting already. i know the C:B ratio is important but even with the current chamber a longer barrel would give more distance i would think.

I'll be testing out barrel lengths for the softball attachment after I get paid this weekend. If the wind dies down, I'll get a video of it and measure it accurately with a GPS

Looking at my C:B ratio I don't see it being more than a foot longer. The barrel is currently 32" from where the ball seats to the tip.

EDIT: I took my GPS and tested it today. 885ft!! Woohoo!