Jump to content


Photo

High Volume Springer, Easy To Make And Cheap Version Of +bows And Snap

The Bargain - Anyone can make one.

22 replies to this topic

#1 Boot

Boot

    Member

  • Members
  • 90 posts
  • Location:Beijing, China

Posted 01 March 2011 - 06:24 AM

I know I said my next project would be the Mirage 2.0, but there's been a few issues that will set me back (including a shipment of brass I waited months for from the US, only to find it crushed beyond repair on arrival :wacko: ).

The goal with this project was to create a high volume springer on par or with greater performance than +bows or SNAP's for cheaper (in the case of the plus bow), and with materials that almost any one in any country should have.

Although I thought about putting this in homemades, you really aren't making anything from scratch, just assembling some easy to find items.

This build should allow more or less anyone with some simple tools to create a powerful, war worth blaster.

One thing to consider is that I have not included specific measurements. This is not (purely) because I was lazy, but because the combination of materials I used are specific to Beijing, but the concept of the build should apply everywhere. Hopefully people will be able to replicate this with all kinds of other materials.

Without further ado, here is the Bargain:

Posted Image

I DO NOT claim any sort of originality for this concept. it is little more than a plunger expanded Nitefinder that makes use of easy to find materials. Nothing is original about the firing system, what is original is how it is built, and what materials are used.

General materials:

-Ball pump
-Nitefinder
-Spring (or parts to make bow arms)
-Etape
-Hot glue (optional)
-Any square rod the size of a NF plunger rod, I used aluminum U channel, but something like nylon rod would be better.
-Assorted barrel components (you can improvise)

As with any other springer this blaster is composed of three parts: Catch, plunger rod and tube, and loading system.

The catch is simple. By using a NF catch shoddy build quality is not an issue. It will be reliable. Simply butcher a NF like so (and I DID butcher it, the whole thing was done with wire cutters :blink: ):

Posted Image

The loading system is completely to your preference. I used an RSCB for simplicity, and because it fits the blaster's form well.

Now the plunger assembly. This is where I think the stroke of genius is in this build. One of the biggest challenges (at least for me) has always been getting the seal right on springers. Unless you have access to precisely manufactured skirt and grommet seals, plunger seals are always a bit finicky until you get a system down.

By using a pump and the included plunger head, you ensure an absolutely perfect seal. All you have to do is reinforce everything to make sure it can take the pressure the system is under, and attach it to the rest of the blaster.

To prepare the pump cut off the BACK of the pump and remove the handle and plunger assembly. Widen the hole at the front, you can carefully remove the check valve for future use, or drill the thing to bits (you can probably do this with pliers, small wire cutters act as great reaming tools)

Simply fill any gaps in the plunger head with hot glue, and use a good deal of foam (mine is from a BBB missile) to pad the plunger head.

Posted Image

Saw off the head of the pump and glue it to your plunger rod. Because the pump head was not made to take any pressure, build a spring rest behind the plunger head like so:

Posted Image

This takes all pressure off the plunger head. Even if something breaks it will not be the plunger head (unless there isn't enough padding in front of it). TO prove how little stress the head is under I initially used hot glue to secure the plunger head to the plunger rod, after shooting well over 100 rounds it is still completely solid.

Then simply cut a catch notch,

Posted Image

and make a priming handle.

Posted Image

Assemble all the components like this.

Posted Image

Note the PPR (PVC looking tube) inside the spring. These pieces are very important. Cut them so that they equal the length of your spring when fully compressed. When your blaster is primed it should look something like this:

Posted Image

Then just slide the pump tube on and you're almost done.

Posted Image

To keep the whole thing together apply E-tape to the two places seen in the picture. You can also hot glue the plunger tube in place, but that is not necessary. As long as you're fairly generous with the tape the thing will NOT accidentally come apart, but is still easy to disassemble if required.

Posted Image

The performance of these things amazed me. On the basic version, with a 7 inch RSCB, about 5 inches of draw powered by a [k25] ranges were upwards of 100 feet. What I am really proud of however is how simple these are to build well. You can have next to no materials and make a perfectly functioning one of these. I think almost every nerfer has access to Nitefinders and ball pumps. Amazingly, when building my first version of this several months ago I still had not found a source for adequate lubricant, but by just preserving what was already on the pump head the whole thing functioned perfectly.

As usual, you can see this for your self:

Video

And I always love being able to fire rockets:

Video

One of the greatest things about this build however is that it is very adaptive. Just like the +bow or SNAP it can be built off of and customized for different purposes. Here is the same system with pump action priming and a stock.

Posted Image

Posted Image

Also, because my pump was not long enough to allow for a full length [k25], I made this extension with a similarly sized chunk of PVC.

Posted Image

The stock is simply bolted on.

Posted Image

Although I still don't use hoppers because it is difficult to get them to work with streamlines, I made up for that with a massive 15" RSCB.

Posted Image

The blaster has two power settings, one notch for pump action, and a second which you can manually engage for extra power. Both achieve over 100' for every dart in the RSCB. Ideal conditions (as in first dart in barrel) with 7.5" of draw results in a ridiculous 130'.

This is all shown in the Video.

I am hoping that this system will help introduce new members to the hobby with a simple build that yields high level results.

As usual, comments and suggestions both on the build and post style are very welcome!

Edited by Boot, 01 March 2011 - 06:59 AM.

  • 0
QUOTE
If you try to shoot over 45 feet with a magstrike accurately you fail

I beg to differ

#2 ahtanie

ahtanie

    Member

  • Members
  • 80 posts
  • Location:Singapore

Posted 01 March 2011 - 07:38 AM

Freaking mad props with the ball pump idea.
When I was scrolling down the page I was wondering how this differed from a NF rifle.
I love everything except the e-tape used to hold the plunger tube in place. You mentioned that if you're generous with the e-tape then there shouldn't be a problem but that would probably get very messy and sloppy...
Anyway great job! Can't wait to try it! :wacko:
  • 0

#3 taerKitty

taerKitty

    Member

  • Members
  • 883 posts
  • Location:98052
  • State:Washington
  • Country:United States

Posted 01 March 2011 - 07:48 AM

Great job! Can't argue with success, and 100' with the last dart of an RSCB is a success.
  • 0
Fugly is a feature.

#4 k9turrent

k9turrent

    Member

  • Members
  • 828 posts
  • Location:Brampton, Ontario, Canada

Posted 01 March 2011 - 10:04 AM

I like it!

Mind I was trying to the exact same a couple months ago, but my plunger rod and catch combo was agreeing so the project got the backburner.
  • 0
QUOTE View Post

That's about it. And thanks Angela who helped me with these pictures.. It looks huge in her hands.


HOLY CRAP!

FU ALL

#5 Y-Brik

Y-Brik

    Member

  • Members
  • 199 posts
  • Location:Elk Grove, IL
  • State:Illinois
  • Country:United States

Posted 01 March 2011 - 11:34 AM

I like the use of aluminum U-channel for the plunger rod, though I have a sinking suspicion that what works in metric won't work in Imperial. Worth looking though. As for the rest of the plunger, props for creativity but I think buying a slab of 1.25" PVC with the appropriate bushing will end up cheaper than gutting an $8-10 ballpump.

EDIT: I've been doing too many homemades lately, Jaybo's right to use 1" thinwall or PETG. Nerfgeek, don't forget the U-channel ($8-ish) and spring in your costs tally. And try Petco for your PETG.

Edited by Y-Brik, 01 March 2011 - 03:06 PM.

  • 0

As I said I have not not alot of testes yet but I will be once I finish the mod.

Why I am boycotting Hasbro

#6 NerfGeek416

NerfGeek416

    Member

  • Members
  • 151 posts
  • Location:12180
  • State:New York
  • Country:United States

Posted 01 March 2011 - 11:34 AM

This is great!
I have been trying to find 1" PETG or 1" thinwall for MONTHS.
This could have saved me so much time if you posted it in December!
I will be using this method on all future NF's.

EDIT:
Y-brik
This would probably cost $20
10 for a ball pump
10 for an NF.
It also has a seal, a catch, and a handle, which will greatly reduce build time. I can see building this in less than an hour.
I am also sure that you can get some cheap ball pumps which don't work for shit, but will be fine for this.

Edited by NerfGeek416, 01 March 2011 - 02:06 PM.

  • 0
 

#7 WicketTheModder619

WicketTheModder619

    Member

  • Members
  • 247 posts
  • Location:Northwest, Indiana
  • State:Indiana
  • Country:United States

Posted 01 March 2011 - 12:17 PM

This looks pretty cool and functions well too. I will definitely have to make one of these and do some experimenting.
  • 0
23:06 Buffdaddy: As long as they aren't doing it all night, don't care.

#8 shmmee

shmmee

    Member

  • Members
  • 467 posts
  • Location:West Valley, Ut.
  • State:Utah
  • Country:United States

Posted 01 March 2011 - 02:04 PM

Simple and extremely effective, deffinately a Boot creation! Great work as always.

Based on the plunger diameter and such, It almost looks like an unshelled xbow!
  • 0
"and we should respect the people who make our blasters. Even if we do molest the hell out of them..."
~BritNerfMogul


#9 jaybo1996

jaybo1996

    Member

  • Members
  • 110 posts
  • Location:Peabody, Massachusetts

Posted 01 March 2011 - 02:36 PM

I like the use of aluminum U-channel for the plunger rod, though I have a sinking suspicion that what works in metric won't work in Imperial. Worth looking though. As for the rest of the plunger, props for creativity but I think buying a slab of 1.25" PVC with the appropriate bushing will end up cheaper than gutting an $8-10 ballpump.


1 1/4 PVC doesn't fit with a NF, I've tried, the pipe is too wide and the plunger rod ends up way off center and not making a seal. You need 1 inch PETG, or 1 inch Thinwalled PVC. I've personally used 1 inch thinwall PVC and it works really well, but it involves much more shell diddle, I recomend using 1 inch PETG, for ease of construction, and for clearness.
  • 0
01:15 N9> The problem with nerfers: We're around plastic. Plastic contains estrogenic compounds, so we're more feminine than the rest of the world.

WTF, are you in Tony Stark's basement!?'


#10 Blue

Blue

    Member

  • Members
  • 2,222 posts

Posted 01 March 2011 - 03:11 PM

I have seen the type of ball pump he used at a few local "dollar" stores awhile back for $2.50. I have a hard time believing that the electrical tape only on the back part will hold the plunger tube in against a [k25] spring for very long.
  • 0

#11 NerfGeek416

NerfGeek416

    Member

  • Members
  • 151 posts
  • Location:12180
  • State:New York
  • Country:United States

Posted 01 March 2011 - 03:14 PM

Blue, I don't think the PT is under any stress. Judging by the size of the parts in the pictures, the [k25] is not precompressed, so it sin't pushing on the front of the PT.

Boot, do you have an ID/OD for that pump? I'd like to know how much volume it has in relation to a +/Snap bow.
  • 0
 

#12 taerKitty

taerKitty

    Member

  • Members
  • 883 posts
  • Location:98052
  • State:Washington
  • Country:United States

Posted 01 March 2011 - 03:32 PM

Unless there's a way to stop the PH from traveling beyond the length of the PT, there will be the chance that momentum will carry the plunger assembly beyond the length of the spring and put stress on the PT/handle attachment point.

That said, e-tape is dirt cheap and readily available, so it's not a huge issue. And, you can throw a hose clamp in its place if it keeps breaking repeatedly.

I'm more concerned about torque from the weight of the barrel and magazine on the handle and attachment point, but, as above, e-tape is cheap.

Great job!
  • 0
Fugly is a feature.

#13 Seven7h Man

Seven7h Man

    Member

  • Members
  • 147 posts
  • Location:Long Valley
  • State:New Jersey
  • Country:United States

Posted 01 March 2011 - 03:49 PM

This looks like something I built a while ago, not as clean, but defiantly more plunger volume. Nice work!
  • 0

#14 utahnerf

utahnerf

    Member

  • Members
  • 339 posts
  • Location:Grosse Pointe Park, Michigan in summer; Aspen, CO for school.

Posted 01 March 2011 - 04:16 PM

Loving that extension idea, it looks awesome. Great work!
  • 0

#15 durka durka

durka durka

    Member

  • Members
  • 364 posts
  • Location:Durkadurkastan
  • State:Delaware
  • Country:United States

Posted 01 March 2011 - 05:53 PM

Two words: Flea market. If I got lucky, I could find a ball pump and nf for <$5. I love the creativity behind this. I am definitely going to have to make one of these in the future. Nice Job.
  • 0
"The warrior who cultivates his mind polishes his arms"

#16 Green Wing

Green Wing

    Member

  • Members
  • 68 posts
  • Location:Vancouver, Washington
  • State:Washington
  • Country:United States

Posted 01 March 2011 - 05:59 PM

Great job. I love how this can be just as good any Snap in performance, yet so easy and cheap to make. This will definately help me a lot, seeing that I have to always provide all the blasters with the group I usually nerf with(To keep things fair).
  • 0

#17 Boot

Boot

    Member

  • Members
  • 90 posts
  • Location:Beijing, China

Posted 04 March 2011 - 06:16 AM

Wow, I'm glad this is generating so much interest! Sorry for the lateness of this reply but I've been fairly busy at school.

Freaking mad props with the ball pump idea.

I love everything except the e-tape used to hold the plunger tube in place. You mentioned that if you're generous with the e-tape then there shouldn't be a problem but that would probably get very messy and sloppy...

I have seen the type of ball pump he used at a few local "dollar" stores awhile back for $2.50. I have a hard time believing that the electrical tape only on the back part will hold the plunger tube in against a [k25] spring for very long.
I'm more concerned about torque from the weight of the barrel and magazine on the handle and attachment point, but, as above, e-tape is cheap.

Thanks! A lot of people seem to be concerned with the E-tape, both in terms of strength and in amount. I just want to make clear that what is shown in the picture is ALL the tape that is needed! I have fired many many times, including dry fires and it is completely solid. No chance of failure. I think this is for two reasons. The first is, for structural reasons, the spring is glued down on both ends. This means that for about 5mm before the plunger head ends it's stroke, the spring is actually pulling back, counteracting the force. Even without this though, a combination of thorough padding and proper placement of tape (as seen in the picture) will hold fine. I think this is because of how the tape actually grips the tube. I did a little test, and found that a fairly sharp, quick tug will not dislodge the E-tape, while a continued tug of lower force will. I am no expert but I think this has to do with the nature of the actual adhesive.

In terms of torque, although there is only one loop of tape, it is several layers thick, and so acts more like a thick zip tie.

And yes, I am very happy with the pump idea, since it is one that should work everywhere!

Also, remember this is just how I did it, and I am very lazy. If you don't think the tape is strong enough (although I assure you it should be) then glue, bolts, or zip ties will all keep this in place. One thing to keep in mind is the majority of work done throughout is for the sake of taking stress off the pump parts, and plunger assembly in general. I think the large amount of padding is a must. In an early test I put too little padding, and after one collision with the front of the pump, the pump head was deformed, and no longer created an entirely perfect seal (this will be different if you're pump uses an Oring, rather than a skirt seal).

Mind I was trying to the exact same a couple months ago, but my plunger rod and catch combo was agreeing so the project got the backburner.

This looks like something I built a while ago, not as clean, but defiantly more plunger volume. Nice work!

Nice! I am happy other people have picked up on the pump idea, that's the main change here, everything else is more or less a standard PT replacement. Most of the work revolves around taking stress off the pump parts.

I have a sinking suspicion that what works in metric won't work in Imperial. Props for creativity but I think buying a slab of 1.25" PVC with the appropriate bushing will end up cheaper than gutting an $8-10 ballpump.


The main merit in the ball pump is that you guarantee a perfect seal. I am not sure about this, but I believe skirt seals cost around $10 off McMaster. Just a standard PT would make for a standard plunger replacement, which makes it harder to get a perfect seal without either some extra experience or materials.

Also, although I do only speak for myself. The ball pump here cost me 20RMB, about $3. If you can get the same seal with PVC parts though its definitely stronger, and probably more reliable.

Also, remember the NF itself is designed in the empiricist system I'm sure you'll find an adequate part (remember, plastic is probably better, the aluminum may eventually wear at the plastic NF catch. That worries me :( )

This is great!
I will be using this method on all future NF's.

This would probably cost $20
I can see building this in less than an hour.
I am also sure that you can get some cheap ball pumps which don't work for shit, but will be fine for this.


Wow! thanks! it's great to know this method will get used! you are right about the cost. I'm not sure about the prices in the US, but in Beijing the NF and pump cost 20RMB each, a total of $6 for both. The U-Channel was another 20RMB, but for 3m of the stuff.

You can definitely do this in an hour. Especially with dremel and drill (I now have a drill! Yay!). I'd say with a dremel the pump and NF could be prepared in 10mins, then marking all the PVC and plunger material carefully another 5, and finally another 15 to cut drill glue and assemble. I built the Pump action one in two hours without a dremel, but in that case I had to experiment with all the pump action and plunger tube extension components.


This looks pretty cool and functions well too. I will definitely have to make one of these and do some experimenting.


Thanks! I encourage you to do some experimenting. As with most of my builds, this is just an unpolished project. You can make it better!

Simple and extremely effective, deffinately a Boot creation! Great work as always.

Based on the plunger diameter and such, It almost looks like an unshelled xbow!


Hehe thanks, I have no experience with xbow's, but I do have to admit most of my mods seem to follow my "hack and slash" methods of construction. :P

1 1/4 PVC doesn't fit with a NF, I've tried, the pipe is too wide and the plunger rod ends up way off center and not making a seal.


This is true, but a simple solution would be to cut the NF differently. Put the entire plunger tube in front of the trigger guard. This would allow the PT to be positioned differently, and be centered better (although attaching the plunger this way may require a bit more effort that slapping on E-tape :P ). I have a bit of a suspicion that my PT is just too large, as the plunger rod dips down by about 1/4 of a cm when the blaster is primed. Luckily the seal still is perfect though.

Blue, I don't think the PT is under any stress.

Boot, do you have an ID/OD for that pump? I'd like to know how much volume it has in relation to a +/Snap bow.


You're completely right. Most of the components are made to keep the plunger head from slamming into the PT too hard. Also, the pump is used is 3cm in diameter, just over an inch.

Loving that extension idea, it looks awesome. Great work!


Thanks! This is a very flexible system!

Two words: Flea market. If I got lucky, I could find a ball pump and nf for <$5. I love the creativity behind this. I am definitely going to have to make one of these in the future. Nice Job.


Yea. Funny, because the prices in all of Beijing make it like a giant flea market. With the exception of the spring (which cost a fortune to ship) the rest of the blaster, including U-channel and PVC cost less than 60RMB, or $10

Again, thanks, I'm really glad others will actually be trying this out!
Great job. I love how this can be just as good any Snap in performance, yet so easy and cheap to make. This will definately help me a lot, seeing that I have to always provide all the blasters with the group I usually nerf with(To keep things fair).

Interesting, this has kind-of become out standard blaster too (even though "we" only is around 10 people now...). Again, nice to see that others will be trying this out :)

I'd love to see any improvements on this. I'm sure there's room for much more!

Edit: Sorry, I have no idea whats going on with the quotes. I will try to fix it, but so far I can't see what I've done wrong... I've bolded all my responses so that this is easier to read.

Edit 2: Thanks to Captain Slug the post is fixed, I've looked over the code and hopefully won't get it wrong again. I'm guessing it had to do with some sort of quote limit (like Blue stated). I've also gotten rid of the bolds so this post won't kill your eyes.

Edited by Boot, 04 March 2011 - 07:23 PM.

  • 0
QUOTE
If you try to shoot over 45 feet with a magstrike accurately you fail

I beg to differ

#18 Blue

Blue

    Member

  • Members
  • 2,222 posts

Posted 04 March 2011 - 10:05 AM

I'm pretty sure there is a quote limit. Just split them in half and make another post.
  • 0

#19 BrokenSVT

BrokenSVT

    Member

  • Members
  • 128 posts
  • Location:Southern Ohio

Posted 04 March 2011 - 10:08 AM

Try using: Left Bracket Quote=BrokenSVT Right Bracket TextYou'reQuoting Left Bracket /quote Right Bracket

Sorry for the confusing context, but I can't actually use the brackets or it defaults to the finished product.

Edited by BrokenSVT, 04 March 2011 - 10:11 AM.

  • 0
REVOLUTION Be there or be square.

#20 taerKitty

taerKitty

    Member

  • Members
  • 883 posts
  • Location:98052
  • State:Washington
  • Country:United States

Posted 04 March 2011 - 11:14 AM

Try using: Left Bracket Quote=BrokenSVT Right Bracket TextYou'reQuoting Left Bracket /quote Right Bracket

Sorry for the confusing context, but I can't actually use the brackets or it defaults to the finished product.

Try
[quote=BrokenSVT]TextYourQuoting[/quote]
And to write the above text, try
[code][quote=BrokenSVT]TextYourQuoting[/quote][/cоde]
===

Back to the mod:
  • Skirt vs. O-ring. By definition, a pump has to have a perfect seal, skirt or o-ring. This is sheer genius.

  • I'm glad I'm wrong about torque on the tape.

  • Sorry to be dense, but could you give a closeup of how you prevent plunger over-travel? I see the PVC (cut to the spring's compressed length) at the NF end of the spring in this pic (no point wasting space to repost a pic he's already posted), but I don't get how you keep the plunger head from contacting the front of the plunger tube.
  • Re: stock spring catch? I'm sure you can get NFs for dirt cheap ($3?!? I get the NF alone for $9, much less the U-channel) so it can be treated as a 'consumable', but am asking to see if it shows any wear after the 100+ test fires. Hell, I'd pay $3 for a new spring catch each war (and get a spring, trigger, shell, LED, etc. out of it)

  • Re: Aesthetics: I'm of the anti-polish mindset. If your blaster looks slick, that means your focus isn't on performance. That's great if that's what you mod for, but I'm for performance (however low my bar is). Besides, I can't make something purty worth a damn. For me, the fuglier, the better. I mod for the lulz, and fugly-but-functional gets lulz.

  • To build on your answer to Y-Brik's comment: the only sizing issue he needs to worry about is dart-barrel fit. If he has metric PVC (say, 13mm) and 13mm foam, it'd work great. If he has 12mm foam and PVC, it'd work great. (For reference, 1/2" is 12.7mm, or so close everyone accepts it as same.) Metric, imperial, or Jovian units, if dart-barrel fit works, this will work.
Re: pump cost vs. skirt seal (or rubber washer, or even wood block) Remember, these are cheapie ballpumps, not bike pumps. They're high volume, (relatively) low pressure. Other advantages:
  • you don't have to rely on McM's measurements and your PVC sizing (remember, PVC OD is standard, PVC ID is 'common', but not standard). Also pump tubes are smooth, but PVC internals aren't polished smooth.

  • you don't have to use a credit card (such as for our 'fledgling' members, many of whom are more advanced modders that I am)

  • you don't have to pay for their (insanely great shipping to the US)

  • you don't have to be in the US (for those north of the border, or in SG, or the UK)
(Re: springs: you can get by with two NF springs, or springs from any other blown mods. This removes McM from the equation completely.)

HOLY CRAP! Sports Authority has a ball pump for $3.98 shipped (Y-Brik, thankYouThankYouThankYOU for nudging me to look for data on prices - I'm gonna get me a load of them once I'm done with this reply!!!)

Boot, what do you propose for a name for this? PumpFinder? NightBall? MinusBow? It deserves a name better than HVS.

===

In conclusion, Boot, I think this will be a new standard, not just for your crew, but to the NIC. I know I'll be making a few to war with, loan out, and, hopefully, resell.

===

Edit: Double holy crap!! When I said $3.98 shipped, that's because it's $2.99 for the pump, and $0.99 for shipping. For. The. Whole. Order. So long as you buy stuff that is eligible for this special, that is. BTW, Pistol Splats are eligible.

Edited by taerKitty, 04 March 2011 - 01:24 PM.

  • 0
Fugly is a feature.

#21 Ozymandias

Ozymandias

    Member

  • Members
  • 201 posts
  • State:Texas
  • Country:United States

Posted 04 March 2011 - 05:25 PM

In case anybody is interested...

Posted Image

The inner diameter is about 4in. I started working on one last fall, but shit came up and I never got back to it.

It is at Walmart and less then $10. My plan is to attach it to a nitefinder a la The lord of fish via a combination of couplers, bushings, hot glue, and ducttape.

It is a 2-way pump, which means hot glueing (sp?) the 'plunger head' is required.
  • 0
If you wish to post anything HvZ related, here ya go.

"...if you've ever suffered the effects of a fucking faggot retard overpopulation, you'll understand what devistaiting effects it can have on one's psyche." - Talio

#22 Boot

Boot

    Member

  • Members
  • 90 posts
  • Location:Beijing, China

Posted 04 March 2011 - 08:01 PM

Thank's for all the help with the quote's, the problem seems to be fixed now (thanks to CS) :lol:

Skirt vs. O-ring. By definition, a pump has to have a perfect seal, skirt or o-ring. This is sheer genius.

I'm glad I'm wrong about torque on the tape.

Sorry to be dense, but could you give a closeup of how you prevent plunger over-travel?

Re: stock spring catch? I'm sure you can get NFs for dirt cheap ($3?!? I get the NF alone for $9, much less the U-channel) so it can be treated as a 'consumable'.


Re: Aesthetics: I'm of the anti-polish mindset. fugly-but-functional gets lulz.

To build on your answer to Y-Brik's comment: the only sizing issue he needs to worry about is dart-barrel fit.

you don't have to rely on McM's measurements and your PVC sizing (remember, PVC OD is standard, PVC ID is 'common', but not standard). Also pump tubes are smooth, but PVC internals aren't polished smooth.

you don't have to be in the US (for those north of the border, or in SG, or the UK)

(Re: springs: you can get by with two NF springs, or springs from any other blown mods. This removes McM from the equation completely.)

Boot, what do you propose for a name for this? PumpFinder? NightBall? MinusBow? It deserves a name better than HVS.

===

In conclusion, Boot, I think this will be a new standard, not just for your crew, but to the NIC. I know I'll be making a few to war with, loan out, and, hopefully, resell.


Thanks a lot! I was also happy with the pump idea simply because it makes all the original issues with getting a good seal null. In terms of performance this is no different than a well made Snap or +bow, but it is NOT well made :P . Many of the minor braces (like the spring rest behind the plunger head) take pressure off the more fragile parts, and increase life span.

I too was actually surprised with the strength of the E-tape. I put it on as a brace for excess glueing and bolting to come, and fired a single shot as a test... Then realized it was rock solid!

You're not being dense about the plunger, I may have been unclear. It DOES still contact the front of the pump, however is slowed down before doing this. In the picture you posted, notice the mounds of glue at the two ends of the spring. These keep the spring in place, and so after it reaches the end of its stroke the glue keeps the spring in place, and the spring is slightly stretched, and acts against the momentum of the plunger. This combined with the excess padding means that very little force is put on the front of the plunger tube. Try out taping this thing and you'll see what I mean. The E-tape holds surprisingly well.

Hehe, dirt cheap is right. One of the benefits of living here is that all the factories are here, and so we often get what are called "水货" or "water supplies" These are often factory rejects, or extras that no one ordered so they are sold for much less.

The catch has worn a bit, but the wearing seems strange. After the first 10 or so shots, a tiny bit of the catch was worn away, and since then, in the other 400 or so shots no extra wear has occurred. I think this is partially due to the fact that the [k25] isn't an overly powerful spring. More importantly however, I think the wearing is a result of the slight misalignment I spoke of earlier, this would explain why no additional wearing has occurred. Remember, there won't be with problem with a softer plastic plunger rod.

Most of my projects are based on performance, and in reducing the size of the blaster by as much as possible. The Mirage 2.0 might be my only good looking build (but that is still to be seen. I have a completed design, but no materials...). The ugliness of my builds seems to be my standard now :)

I think Y-brik's comment was pointed towards getting a plunger rod that fit well. But I'm sure the sizes can all be worked out. As stated before the NF is designed on an Imperial standard.

And yes, the whole point of the build was to make the build more accessible to those with fewer tools and materials. I'm glad I succeeded :)

Your point on the springs is interesting, but I think NF springs would be much too weak. What would also remove McMaster from the equation however would be bow arms, which really seem to have a future in Nerf.

On to the subject of names, I thought "the Bargain" was fine. I wanted to stay away from the large number of "bow" names (like Cheapbow which would fit well), but I am entirely open to suggestions.

And finally, thank you very much. It is high praise to say that this will be a new standard, and I'm just happy people will be trying this out for themselves. It's a really fun blaster.


In case anybody is interested...
The inner diameter is about 4in. I started working on one last fall.


The only response I can give to that would have to be something like: :blink: . I knew people would develop the design, but with a plunger that size I can see the end product having comparable strength to a XXL Bazooka... Awesome!

Edited by Boot, 04 March 2011 - 08:03 PM.

  • 0
QUOTE
If you try to shoot over 45 feet with a magstrike accurately you fail

I beg to differ

#23 taerKitty

taerKitty

    Member

  • Members
  • 883 posts
  • Location:98052
  • State:Washington
  • Country:United States

Posted 04 March 2011 - 08:35 PM

I tried one of those 'air mattress pumps' as well. The two problems I faced were

- The plunger rod IS the airway. The PR needs to be replaced anyhow, but this means we'll have to vent the pump out a way it wasn't designed to go.

- Moving that much air is slower than moving a smaller diameter. I grew convinced that it was too big a diameter, and too short a stroke for it to build up enough pressure in the barrel unless the dart was twist-fit.

I'd love to see an implementation, though. I've been wrong more than right on this hobby.
  • 0
Fugly is a feature.


0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users