16 replies to this topic

[Lt Stefan]

ATTENTION: REV. 2 (SEEN BELOW) TEMPLATES ARE AVAILABLE HERE.



This is my take on the pump action Plusbow, herein the PAPbow.

This thread will serve as a semi-writeup/overview.

First off, credit to Ryan for his original idea and credit to Split for his awesome way of connecting the priming to the plunger rod.

I have been working on this for quite some time. This is my second design, but I have waited until it was working consistently to post. It is still not complete; in the next version I plan on changing a few minor things. Now on to the goods.

Materials
-Normal +bow materials
-Materials for a grommet plunger head
-90402A148
-89755K41
-9245K531
-91780A123
-91780A132
-[k25] spring

Tools:
-Band saw
-Scroll saw
-Drill press
-Drill
-Taps
-Files
-Bench grinder (optional)

Templates: will be available today or tomorrow. I have to finish changing the things I mentioned earlier.


Now the writeup.

Step 1: Print the templates on legal sized paper, paste them on to the PC and start drilling cutting. I don't feel like labeling thicknesses/holes but it isn't hard to figure out. All the 1/4" T pieces are grouped, and all the 1/8" T pieces are as well. As for the holes, drill them to the same size that you would on a normal Plusbow.

Then mark, drill, and tap holes on the sides of the pieces as shown. Make sure to label which side is which so the holes line up when you put it together.


You should end up with this:

Step 2: Put together the handle the same way you would on a regular +bow. The only difference is a 5/16" standoff that goes between the two core pieces toward the front.

Step 3: Assemble your catch like you normally would, and attach it to the side plates. Also put ½" standoffs in the side plates where shown.

Step 4: Cut three stock rods. The length can be whatever you want it to be, except two have to be 1 1/2" longer than the other one. I used 10, 10, and 8 1/2, but I think that is too short for my tastes. Now take the two longer ones, drill and tap holes in both ends, and attach it to your frame piece like you normally would. Then attach the frame piece to the side plates/handle, and add your stock. Put everything together so far and you should have this:

Step 5: Now take your shorter stock rod and mark where to cut the sides off so it fits in the grip. Then attach the flat end to the stock, and slip the cut end into the grip. Now align it so it is parallel to the other rods and drill through the whole thing and put a bolt/locknut on it. It's hard to explain, so hopefully this picture will show you.

Step 6: Take a 1 ¼" length screw and a catch spring. Bend the last loop of the catch spring and put the bolt through the two holes as shown. Add a locknut.


Step 7: Cut your plunger tube/plunger rod/bushing and put them in the gun as usual. If you are using a [k25], you will need a 1-1/4" O.D. washer on the back of the plunger head.

Step 8: At this point you should have a completely functional +bow, save for the priming handle. So we will start working on that. Assemble the handle as shown.

Step 9: Take your PETG tube and cut it in half. Make the cut two inches.

Then angle the crosscut to free the piece from the tube. You will end up with this:

Step 10: Mark holes in the PETG and drill/tap them and attach them to the holes on the handle. You will get this:

Edited by Lt. Stefan, 29 May 2012 - 03:32 PM.

[Lt Stefan]

Step 11: Slide the grip over the gun. Take your aluminum bar and cut two 12” segments. If you want to make them look better, put a wire brush on your bench grinder and run the bars through it. It makes them shiny.

Step 12: Attach the bars to the handle/plunger rod. First, put the pieces on the plunger rod as shown. Then, one hole at a time, mark/drill/tap (if necessary) the aluminum. I did a hole, attached it, and then marked the next hole so I wouldn’t mess up.

Step 13: Attach the bars to everything with 1/2”length screws and you are done! This is what the finished product looks like, in comparison to another “regular” +bow:

Primed:

Rear-view:


Final thoughts/comments:

Instead of having bulky plates on the side of your gun to align the priming bars, I wrapped the handle around the plunger to align it. It is much easier IMO because it Is only one additional piece to the pump grip and doesn’t add a lot of weight. Also I put the stock on the bottom so you can actually aim down the sites. Those are probably the two main reasons I didn’t just call it a pumpbow.

Overall I am very happy with it. I am probably not strong enough to take full advantage of this gun's priming speed but it does prime very smoothly. I also love the new stock and the cosmetics of the gun are very appealing to me. I will be using it in a war with my friends tomorrow and after I will be able to post a better review of its durability.

I realize this writeup isn’t very clear so if you have questions, feel free to ask. I will make a video (eventually) and post up the templates soon.

Since this version works well, but is not the final version, I will be selling it at a much lower price just to cover materials cost and pay for my building of the next one. Keep an eye out for the thread.

[Split]

Interesting take on it. I like how much narrower the priming handle is. I don't like that there's no protection from "face diddle" from the plunger rod. How wobbly is the priming handle? I've noticed that adding foam to the grip makes it significantly easier to prime; perhaps that could help you.

I think you should make the connection between the two priming arms wider, with a sort of channel for the arms to fit into. It is much more stable and keeps it from turning that way.

Edited by Split, 05 August 2010 - 12:11 PM.

[Lt Stefan]

Interesting take on it. I like how much narrower the priming handle is. I don't like that there's no protection from "face diddle" from the plunger rod. How wobbly is the priming handle? I've noticed that adding foam to the grip makes it significantly easier to prime; perhaps that could help you.

I think you should make the connection between the two priming arms wider, with a sort of channel for the arms to fit into. It is much more stable and keeps it from turning that way.

I'm working on the face diddle part. The priming handle isn't wobbly at all. It has about 1-2mm of wiggle room on all sides. If I had cut the side plates unevenly, it wouldn't go back. That's how tight it is. It can even prime the gun without one of the aluminum bars.

I tried adding foam yesterday, but it seemed to want to pull out. I'm thinking if I make the stock normal length, and extend the grip another inch forward, it shouldn't be a problem.

I don't think I understand your second part. The whole point of wrapping the priming handle around the gun is so I don't have to make a channels. It is very stable how it is. Since the part that attaches the two arms sits right on the stock, it sort of aligns it anyway.

[Split]

I think you should make the connection between the two priming arms wider, with a sort of channel for the arms to fit into. It is much more stable and keeps it from turning that way.

I don't think I understand your second part. The whole point of wrapping the priming handle around the gun is so I don't have to make a channels. It is very stable how it is. Since the part that attaches the two arms sits right on the stock, it sort of aligns it anyway.

I'm not talking about channels to keep the arms straight, I'm talking about little nubs that keep the connection part straight. I could be wrong, but it looks crooked in this photo:

Notice the same part on mine:


Not a big change at all, good benefit though - if that part gets turned, it could add some unnecessary friction to the plunger rod, and possibly get stuck in the notches. Just a suggestion, take it or leave it.

Edited by Split, 05 August 2010 - 04:14 PM.

[Lt Stefan]

I see what you mean. It isn't really that crooked, and doesn't cause any friction either. However I do have an idea to keep it better aligned.

Edited by Lt. Stefan, 05 August 2010 - 04:49 PM.

[Zorns Lemma]

I must disagree with your choice of priming guide. Since you are using bars to ultimately transfer the pump action, you're going to have to deal with the side bulk anyways. Using rails for it to ride on rather than wrapping the pump over the entire blaster results in 1) easier fabrication 2) slimmer vertical profile and 3) more surface area to stabilize the motion of the pump.

Pimp stock though.

Also, the solution to Split's problem is pretty simple. I can already think of multiple solutions that would take minimal refinements: 1) do it his way and channel the priming plate with the pump bars 2) double up on priming plates RTP plunger head style 3) thicken the priming plate either vertically or coaxially and add another set of screws.

[Lt Stefan]

I must disagree with your choice of priming guide. Since you are using bars to ultimately transfer the pump action, you're going to have to deal with the side bulk anyways. Using rails for it to ride on rather than wrapping the pump over the entire blaster results in 1) easier fabrication 2) slimmer vertical profile and 3) more surface area to stabilize the motion of the pump.

Pimp stock though.

Also, the solution to Split's problem is pretty simple. I can already think of multiple solutions that would take minimal refinements: 1) do it his way and channel the priming plate with the pump bars 2) double up on priming plates RTP plunger head style 3) thicken the priming plate either vertically or coaxially and add another set of screws.

I will be redoing the priming on the next version. It will be similar to what you described but will be a lot less bulky too.

Thanks. I would however like so help for ideas on how to prevent check diddle. I can't use a half pipe because it would not fit over the rectangular priming mechanism. I put a bar over the stock, but I don't like how it looks.



And I see what you mean. I added those notches, as well as a groove that slides in the stock rods.

[BustaNinja]

Run a nylon rod from the catch area to the back of the gun ala +bow. Sure, it won't look that original, but with the reduced size of the plunger rod, it'll be enough to protect your cheek.

[Lt Stefan]

I find that unnecessary considering I only need about three inches of material to rest my face on coming from the back with a shortened stock, and close to none with a lengthened stock.

If I ran a rod all the way from that point, it would look something like this and that's just not good:

[flamingeyes245]

You could put a U channel over the top of the priming plate so that it slides under it. The thickness of the metal channel would be so minimal that it would not affect aiming capabilities or looks, imo.

[VelveetaAvenger]

I'm no +bow expert, but wouldn't it make way more sense to turn that piece on the end of the plunger rod into a circle instead of a square with really sharp corners? It shouldn't be too hard to cover it in a bit of foam either. Then if it does hit your face at least it probably won't slice you open.

[Lt Stefan]

You could put a U channel over the top of the priming plate so that it slides under it. The thickness of the metal channel would be so minimal that it would not affect aiming capabilities or looks, imo.

The thing is i would have to put a big u channel over the entire priming mechanism to allow the aluminum bars to slide inside it. I'll look into it.

I'm no +bow expert, but wouldn't it make way more sense to turn that piece on the end of the plunger rod into a circle instead of a square with really sharp corners? It shouldn't be too hard to cover it in a bit of foam either. Then if it does hit your face at least it probably won't slice you open.

Rounding the edges probably is a good idea.

[Merzlin]

Something like that would provide a bit more relief on the cutting of a cheek. I think an oval maybe even be a better solution, if you were to change the design.

[alugilaC]

If you still have the templates, could you post them, i'm very interested in that handle design.

[quertyman]

Do you think that there is maybe another material that you could use for the priming handle? Because that petg is about 7$ per foot now! I was thinking maybe the polycarb tube or like 2" pvc. Any other suggestions?

USER WAS WARNED FOR THIS POST

Don't post in month old threads, especially when the months old thread is because someone posted in a years old thread. Do read the New Members Guide

Edited by Zorn's Lemma, 19 September 2012 - 11:53 PM.

[Zorns Lemma]

Dude this is from August 2010.