Nice! I love the use of the surgical tubing. Also could you use a powerful extension spring? I have seen then at my local hardware store and they seem more common.
Yes, extension springs are possible to use in this design. The only draw back is your are limited to whatever tension the spring gives you, plus you have to add the length of the spring to your blaster. With surgical tubing, you can theoretically make the blaster shorter. Right now with the horizontal pumpgrip, I'm not taking advantage of that aspect.
What's the part number for the tubing? Did the brass and aluminum have to be lubed? What's the ring at the top of the PR? Great job on this blaster!
See below for parts list. The bronze bushing is self-lubricated, so in theory you don't need to lube either. The front end of the plunger rod has a nylon "eyebolt", which is used to attach the latex tubing to the plunger rod.
Alright, I've several.
1: What advantage does using the funky Y serve over the elbow-in-a-hole method of the rainbowpups?
2: Does that piece extend a ways into the plunger tube, or did you cut it down to allow the plunger head to move farther forward and eliminate some dead space?
3 & 3.5: What stops the plunger? Does it hit the above mentioned piece?
4: How smooth does that catch operate? I've never been too fond of snap-style catches, and prefer the catch-in-notch style used in rainbows and most actual Nerf-brand guns.
5: Are you expecting any friction/binding problems with the vertical pump grip? I remember Kane said he had trouble with this with the earlier bullpups he worked on.
6: Observation, not question: That catch looks like an unergonomic mess. Lots of corners and such everywhere. (This is more about hitting the wrist of your priming arm on it)
7: How well does that bushing seal?
8 & 9: How long does it take to make one of these, and how many do you plan to make?
The funky wye is much easier to replicate and easier to get a perfect seal. It does however have slightly more deadspace, but it could be filled with hot glue or something else if you really desired. Also as Zorn mentioned, the wye parts gives it better airflow that the standard method.
The wye piece does extend roughly an inch into the plunger tube, which is wrapped in e-tape to seal in the plunger tube. I did cut down the front of that piece that extends towards the front tube in order to reduce deadspace.
Right now, the wye piece does stop the plunger rod. I haven't noticed any fatigue and I think this should be fine. In the next iterations I'll be adding a rubber chunk to the front of the plunger head to reduce the noise it makes slamming against the swing wye.
As for the catch, it works really well. The trigger pull is a little harder than your average blaster, but if you've ever used a sceptor, it's a lot less harder than that pull. This catch style is way easier to replicate than a Rainbow catch granted you have already made the templates for all your components. This was one of the reasons I switched over for this blaster, plus having the catch as far forward as possible makes the blaster shorter towards the back end where the plunger tube would be. If I were using a rainbow catch, the blaster would have to be about another 2" longer where the stock is.
No problems at all. I'm not sure what Kane's problems were related to, but if your bushing is straight and your plunger rod isn't bent, you shouldn't have any problems.
The front part of the handle is less of a disaster than your think. Since the pump grip is 7" long, your hand has plenty of space to grip. There is also roughly an extra inch before it hits the handle when at full draw. Your hand never hits the handle at any point. In the next versions they'll have vertical grips which will negate this problem anyway.
The bushing seals close to perfect. If you put your mouth on the air output and blow back when the plunger rod is in there, it'll make it move backward. With these bushings, your seal is pretty much as good as it's ever going to get without sacrificing for some friction.
This particular blaster took a while to complete but now that I've figured it out probably only a couple hours of labor when made in a large batch. Majority of the time spent is making the plunger rod, the handle, and milling out the slots. I plan on making a large number of these.
This was really cool at YANO. The handle was very large and comfortable. You seemed to have a lot of fun using it at YANO. How easy is one of these to make, minus the 3D printer part? This was one of those blasters that I got hit in the head from. It was pretty cool.
All of the parts are repeatable without the use of a 3d printer. Bare minimum tools would be some sort of drill and a scrollsaw, aside from basic hand tools. I wouldn't say these are easy or difficult to build, but if you've built any pump action blaster in the past, this is probably about the same difficulty.
Doing a quick Google search found that Lowes (And I assume Home Depot) sell the latex tubing. I think the stuff they sell would work, but I don't know what size you used. (So could you let us know?
This blaster looks awesome though. I love the smooth action of a bow powered blaster, but I hate the size. I think this is a win situation here.
The latex tubing I used was also purchased at Home Depot
For those interested here is the parts list. I think everything is included. A lot of the materials including the PVC were purchased at Menard's which I know a lot of people don't have access too. The one thing that you would need to order off the internet would be the swing x wye, which can be found here.
This parts list includes the materials I'll be using the the next blasters which the only difference will be a vertical instead of horizontal pump grip.
Menards - Schedule 40 Solid Core Pipe-1 1/2"x10'
Menards - Schedule 40 Solid Core Pipe-1 1/4"x10'
Menards - Schedule 40 Solid Core Pipe-1"x10'
Menards - SDR 26 PVC Pipe-1 1/2"x10'(thinwall)
Menards - CPVC Pipe- 1/2"x10'
4880K44 - Standard-Wall White PVC Pipe Fitting 1-1/4 Pipe Size, Tee
Menards - 1"PVC WYE X SWING
Menards - 1" PVC Plug
6338K412 - SAE 841 Bronze Flanged-Sleeve Bearing for 1/4" Shaft Diameter, 3/8" OD, 3/8" Length
8619K461 - Rigid HDPE Polyethylene 1/4" Thick, 12" X 12"
8619K431 - Rigid HDPE Polyethylene 3/8" Thick, 12" X 12"
94639A333 - Nylon Unthreaded Spacer 5/16" OD, 5/16" Length, #6 Screw Size x 100
5233K63 - Masterkleer PVC Tubing 3/8" ID, 1/2" OD, 1/16" Wall Thickness x 1'
8974K31 - Multipurpose Aluminum (Alloy 6061) 1/4" Diameter X 6' Length
9686T74 - Nylon Eyebolt with Nut-Not for Lifting, 1/4"-20 Thread, 1/2" Eye ID, 1" Shank, 7/8" L Thread, Packs of 25
94812A116 - Nylon 6/6 Hex Nut, Off-White, 1/4"-20 Thread Size, 7/16" W, 15/64" H, Packs of 100
2614T52 - Extreme-Temperature Silicone Rubber Plain Back, 3/16" Thick, 2" Width x 1'
5234K33 - Super Soft Latex Rubber Tubing 1/4" ID, 3/8" OD, 1/16" Wall, Semi-Clear Amber x 1'
9691K56 - U-Cup Seal 1/4" Height, 7/8" ID, 1-3/8" OD x 5
8572K55 - White Delrin ® Acetal Resin Rod 1/2" Diameter x 5'
93135A459 - Nylon Pan Head Machine Screw Phillips, 1/4"-20 Thread, 2" Length x 100
92311A144 - 18-8 SS Cup Point Set Screw 6-32 Thread, 1/4" Long x 100
92311A148 - 18-8 SS Cup Point Set Screw 6-32 Thread, 1/2" Long x 100
90272A146 - Zinc-Pltd STL Pan Head Phillips Machine Screw 6-32 Thread, 3/8" Length x 100
90272A155 - Zinc-Pltd STL Pan Head Phillips Machine Screw 6-32 Thread, 1-1/4" Length x 100
91772A158 - 18-8 SS Pan Head Phillips Machine Screw 6-32 Thread, 1-3/4" Length x 100
90480A007 - Zinc-Plated Steel Machine Screw Hex Nut 6-32 Thread Size, 5/16" Width, 7/64" Height x 100
4880K977 - Standard-Wall White PVC Pipe Fitting 1-1/2 X 1 X 1-1/2 Pipe Size, Reducing Tee
All the parts come out to about $20 per blaster, minus the few 3d printed parts. I also put u-cups in the parts list as this is what I'll be using in the future.
Thanks for the questions, comments, and compliments. Keep them coming.
Edited by Ryan201821, 13 December 2012 - 01:25 PM.