39 replies to this topic

[VelveetaAvenger]

They make threaded street elbows if you're still thinking about screwing that part in. Actually, I found this thing too, no tapping required!

Looks really cool already though, can't wait to see the streamlined version.

[Ryan201821]

Well, this was way easier than I thought. I decided to switch back to a coupler and see if I could do a better job this time around. Turned out pretty well, and literally took about 15 minutes to swap out and replace the tee.









Seals perfectly, even without any glue. I guess drilling the 5/8" hole for the CPVC made a huge difference when I drilled it through plunger tube and coupler. The CPVC fits in there super nice.

It's dark out so I can't see how far it's shooting, but I can hear it hit the shed which is the rough 90' mark in my backyard.

Here's also a rough cost estimate sheet. Not as cheap as I though, but it's still not bad.

I love this thing, and it's pretty easy to make. Plan on seeing a lot of these built.

Edited by Ryan201821, 12 June 2012 - 01:58 PM.

[Ambience 327]

Your cost estimate sheet link is asking for a Username and Password.

[HasreadCoC]

Will the final product be made with clear parts? Most particularly the plunger tube? I always think they really add to the looks of a project.

[Zorns Lemma]

Your cost estimate sheet link is asking for a Username and Password.

He left in the ftp link
http://ryan201821.ne...upcostsheet.xls

[Ryan201821]

Your cost estimate sheet link is asking for a Username and Password.

Fixed now.

Will the final product be made with clear parts? Most particularly the plunger tube? I always think they really add to the looks of a project.

Nope. All opaque.

EDIT: Just crudely range tested it in daylight this time and it's right around 90'. I'll probably add a half inch more draw for the next versions.

Edited by Ryan201821, 12 June 2012 - 02:13 PM.

[TxNerfer]

As for the barrel being essentially taped on to the front of the blaster, why not drill a 5/8" hole under the tee, run a piece of cpvc through the bottom side, and cap it off underneath? Just a thought.

[atomatron]

New update amended my concerns, Looks good.

Edited by atomatron, 13 June 2012 - 01:50 AM.

[Bchamp22795]

Just had an idea. There is quite a bit of space at the front of the blaster where you put the pump grip, it may be possible to modify the design slightly to use an extension spring. I recall carbon saying in his SNAP-9 that extension springs are better performing because they have less friction or something. This may allow for people to use extension springs they find at Lowe's or locally instead of buying long compression springs from mcmaster.

Also, I think this will allow you to make your plunger rod shorter which means less weight.

Edited by Bchamp22795, 17 June 2012 - 12:34 PM.

[thesoxfan1234]

Awesome! Would you be able to get some measurements? The 2 pieces of 1 /14 inch PVC? That would be great.

[Ryan201821]

Just had an idea. There is quite a bit of space at the front of the blaster where you put the pump grip, it may be possible to modify the design slightly to use an extension spring. I recall carbon saying in his SNAP-9 that extension springs are better performing because they have less friction or something. This may allow for people to use extension springs they find at Lowe's or locally instead of buying long compression springs from mcmaster.

Also, I think this will allow you to make your plunger rod shorter which means less weight.

This is a good idea, and what I was originally do, but decided it would be easier with a regular compression spring. The blaster wouldn't be really any shorter however, since the extra space in the front is for the pump grip. For a grown person, 6" is really the minimum length I consider comfortable for a pump grip. Kane has already been building a variant of my blaster with rubber bands, same concept as use an extension spring. Maybe he'll post it here sometime.

Awesome! Would you be able to get some measurements? The 2 pieces of 1 /14 inch PVC? That would be great.

I'll do a writeup at some point. Probably my next batch of blasters. The lengths of everything are very specific to the stuff I used, so either figure it out for yourself or wait for the writeup.

=============================



Just need to make plunger heads and barrel spacers.

[Bchamp22795]

This is a good idea, and what I was originally do, but decided it would be easier with a regular compression spring. The blaster wouldn't be really any shorter however, since the extra space in the front is for the pump grip. For a grown person, 6" is really the minimum length I consider comfortable for a pump grip. Kane has already been building a variant of my blaster with rubber bands, same concept as use an extension spring. Maybe he'll post it here sometime.

The plunger rod could be shorter, yet not the entire blaster, allowing someone like me to use less nylon. This is because when a compression spring blaster is fully primed, you need extra plunger rod in front of the rainbow catch to give space for the compressed length of the spring. This isn't the case with an extension spring blaster. You'd have to make your slots further back, and cut a piece of the pump grip to allow for the rainbow handle. Also, to stop the grip from spinning, you'd need a guide like Kane's that slips over his barrel. But I agree, a compression spring is easier.

[HasreadCoC]

I'm glad you decided to make those barrel holder things, it was what I was thinking i would make if i ever bought/built a rainbowpup, it just looks so much cleaner like that.

[Meaker VI]

The plunger rod could be shorter, yet not the entire blaster, allowing someone like me to use less nylon. This is because when a compression spring blaster is fully primed, you need extra plunger rod in front of the rainbow catch to give space for the compressed length of the spring. This isn't the case with an extension spring blaster. You'd have to make your slots further back, and cut a piece of the pump grip to allow for the rainbow handle. Also, to stop the grip from spinning, you'd need a guide like Kane's that slips over his barrel. But I agree, a compression spring is easier.

IIRC, most tension-springs have longer draw than the draw on typical compression springs. Alternatively, they might need pre-tensioning; I built a hand-cannon one time that used tension springs, and it was still 12" long before priming.

Regardless, I'm not sure how you're planning on mounting tension springs so that you would save plunger-rod length, unless you were making a floating plunger head (which you can do with a compression spring anyway). Are you thinking you'd just make a PR that's the length of the plunger tube, and cut slots that start behind the plunger head for the length of the draw? Then wouldn't the tension springs be exposed? If nylon is too expensive, I use wooden dowels for plunger rods and they work fine.

[Ryan201821]

So I finally finished up a couple of RBPs.



Took me forever to figure out why they were only shooting 70'. It actually turned out that the problem was the seal between the catch and the air output.

The grommets were apparently causing too much friction so I swapped them out for o-rings. I'll have to get some picture of it sometime because most of you probably have no idea what I'm talking about. I still have two more left that need the same thing done to them, so I'll take some pictures when I do that.

Now that I've swapped for the o-ring, they don't get a perfect seal which is perfectly fine with me. They leak enough I don't need a check valve anymore which is generally a giant pain in the ass. They still shoot very consistently around 90-100' which is plenty. If I got some wider o-rings that fit in the bushing better, I would probably get a better seal, but I'm not sure it's even worth dealing with having to use a check valve. I know most people think check valves are unnecessary but they definitely are if your blaster seals perfectly and you want it to shoot consistently without pooping or vacuum loading.

I also swapped out the super 16" CPVC barrels with some optimal barrels. Now they fire a lot more reliably. The other part is obviously aluminum, with a CPVC coupler holding it together.