227 replies to this topic

[CaptainSlug]

Cost was not a foremost design consideration for this project. The only way to make it more expensive would be to make it entirely out of aluminum.

You can only make the gun parts out of a material that you can add a #6-32 thread to. Polycarbonate is the cheapest, most durable, and easiest to machine material that I could possibly recommend. It can take far more abuse and mishandling than most other plastics.
Hardboard or any other kind of cheap fiber or wood byproduct material is not going to be able to hold a thread.

A band saw will let you do external cuts, but not internal ones. Half of the parts require a square hole be cut in the center of the parts for the plunger rod to pass through them. These cuts can only be done correctly using a scrollsaw since the cuts are inside of parts that are too small to safely work on with a jigsaw. I used a bandsaw to roughly trim the parts to size, but did all of the more intricate using a scrollsaw.

If you want to save money on materials you'll have to find a local supplier (plastics shop) that sells plastic off-cuts.

If you skimp on materials and tools you're not going to end up with the same gun. Sure it will be cheaper, but it won't be at all usable in a War. This gun has a GIGANTIC spring inside of it and alternative construction methods just won't be able to contain 25lbs of force.

Edited by CaptainSlug, 28 December 2007 - 01:56 AM.

[General Cole]

Hey, what size CPVC is that? It looks more like Electrical piping.

[n-strike]

Hey, what size CPVC is that? It looks more like Electrical piping.

1/2" I suppose...

[CaptainSlug]

I generally get the best results with my darts using barrels between .525" and .535". I then pick the barrel based on the power source.

My preferred barrel for plunger guns is either 1/2" SCH80 Dark Gray Type I PVC (.526" ID mcmaster part# 48855K21), or PETG (.532" ID).
For Air-powered guns I tend to prefer Aluminum (.527" ID) because it has an extremely low friction coefficient, and it's cheap and durable.
I've pretty much ditched anything other than those three options.

1/2" I suppose...

Kindly shut it. I don't need anyone to answer questions for me. Let alone in a flippant and unhelpful manner.

Edited by CaptainSlug, 28 December 2007 - 02:36 AM.

[General Cole]

Okay, I was wondering how you got PTEG in CPVC. Thanks.

[CaptainSlug]

As was stated in the post with the images I had to use the lathe at work to bore out the ID of the PVC pipe to match the OD of the PETG tubing.

Edited by CaptainSlug, 28 December 2007 - 02:30 AM.

[n-strike]

Sorry CS.

[Z-man12]

The othe day when I was looking at this I was thinking you could add a pumping forgrip to the gun along with a slide breach. Effectily making it a high powerd pump version. Are you planning on doing this?

And on a side note, I am slowly working on getting the things together to make my self one of these.

Edited by Z-man12, 28 December 2007 - 01:16 PM.

[elf avec gun]

Well CS, you did it again. I had stopped nerfing for awhile and back then xBows were going for $60 bucks. It is sort of insane that the price has ballooned to the point where they are going for upwards of $100. Inflation has certainly hit the nerfing industry haha. Thank you so much for making this, perhaps it will bring down the price of the actual xBow or atleast slow it down.
Just a few questions about the spring:

1.) Is the spring you used in the prototype actually the spring on your ordering list: "9637K26 - Continuous-Length Compression Spring Spring-Tempered Steel, 11" L, .844" OD, .08" Wire - $10.12 per Pack of 5" Or is the ordering list spring what you plan on using?

2.)How does it compare to a normal xBow spring?

Although these questions will make me sound like a bit of a noob, my curiosity wins out over my pride. You mentioned a "laser cutting tool" you said you are considering leasing, I have a few questions about that.
1.) Is the purpose of the laser to actually cut the plastic? (or is it just to serve as a guide?)
If so:
2.) Wouldn't that compromise the integrity/strength of the plastic sheeting a bit due to the heat?

[CaptainSlug]

The othe day when I was looking at this I was thinking you could add a pumping forgrip to the gun along with a slide breach. Effectily making it a high powerd pump version. Are you planning on doing this?

I have no plans to do this because it would add more parts and wouldn't really make it any easier to prime.

1.) Is the spring you used in the prototype actually the spring on your ordering list: "9637K26 - Continuous-Length Compression Spring Spring-Tempered Steel, 11" L, .844" OD, .08" Wire - $10.12 per Pack of 5" Or is the ordering list spring what you plan on using?

2.)How does it compare to a normal xBow spring?

Although these questions will make me sound like a bit of a noob, my curiosity wins out over my pride. You mentioned a "laser cutting tool" you said you are considering leasing, I have a few questions about that.
3.) Is the purpose of the laser to actually cut the plastic? (or is it just to serve as a guide?)
If so:
4.) Wouldn't that compromise the integrity/strength of the plastic sheeting a bit due to the heat?

1. The spring in the part list is the spring in the gun. And I am using the whole spring, not a section of it.
2. I don't have any specifications on the stock X-bow spring. But the spring I am using is even strong than the Defender T3 spring that manner use as a replacement xbow spring.
3. A laser cutting table does just that. It burns through the material in a very narrow width path (.010" inches) based on the .DXF drawing supplied to the machine.
4. Heat does not affect the structural integrity of plastics. Mechanical stress however does. And the heat is so localized that it's only affecting the very edge of the cuts.

It's going to take me more than 6 or 7 months to save up enough money to buy the particular model I want. Leasing would take too many years to pay off and cost far more.

[General Cole]

If thats the case, I would start taking money now to get the cutter faster, then everything happens faster.

[CaptainSlug]

If thats the case, I would start taking money now to get the cutter faster, then everything happens faster.

If it's not something that requires a significant investment to start making, and is not ready to be put in a box and shipped to the customer, then I wouldn't feel comfortable accepting payment.

That's my policy, and it won't be changing anytime soon.

[CaptainSlug]

Good News: Second gun is finished and I took 40 pictures of the fabrication and assembly process. I'll get to making the write-up once I've finished making a batch of darts.

Bad News: Considering that this gun took me close to 10 hours to make it's not likely that I will be making these in bulk using the tools I have now. It just takes too long to make this many pieces.
Now that I'm a College graduate and I work full time I'm no longer in the situation of limitless free time that I used to be in.
So two things might happen. Either I save up enough money to buy a laser cutting table ($13,000), or I make ten of these slowly over the next 6 months with the intention of selling them in auction format for a price higher than $90.
Unfortunately there's no way to make these at a reasonable price without significant investment on my part. Either financially or in time (that I wouldn't be reasonably compensated for).

[Jtcm]

Hey CS have you ever considered this site http://www.ponoko.com/ ? If i understand what they do correctly i believe they can cut the parts you need and ship them to you. I don't know all that much about them or there rates but I thought I'd let you know.

[CaptainSlug]

Their prices are pretty high for that type of service. The other problem is that I am making these out of polycarbonate, which most laser cutting services are not willing to cut.
The amount of money I would have to spend outsourcing the manufacturing of these would end up being close to simply buying the tool myself, and the price per unit would still end up being absurdly high.

ANY kind of machining service inside this country will be too expensive for a low-volume order such as this. By comparison, I would have to make and sell 230 kits to pay off the purchasing of a laser-cutting table.
But in order to break even having someone else cut out the parts I would have to sell over 600 of them.

Edited by CaptainSlug, 04 January 2008 - 10:43 PM.

[six-five-two]

1/2" I suppose...

Kindly shut it. I don't need anyone to answer questions for me. Let alone in a flippant and unhelpful manner.

Sorry for the minor de-railing, but I couldn't help it...

SHUTTTT DOWNNNNNNNNNNNN


Back on topic, CS I bet you can make quite a bit of those if you sell it auction style on eBay, didn't someone's modded Longshot (was it FA_24?) that sold for $200 or so? I bet you can sell your +bows for atleast $200.

Edited by six-five-two, 05 January 2008 - 02:18 AM.

[n-strike]

Hey CS, could you possibly show us the pictures of your 2nd +bow?

Edited by n-strike, 05 January 2008 - 03:22 AM.

[CaptainSlug]

Second one looks pretty much the same as the first one. Only some very tiny changes like a more generously padded grip.

If I make them myself I would have to sacrifice all of my Saturdays to this for 2 months and I would have to increase the price by at least $50. I'll have to do some more accurate accounting for supplies and time. I need to figure out where I need to set the price in a way that won't make this a huge drain on my life for the next year.

If at all possible I would prefer to avoid eBay, because quite frankly the average eBayer is much dumber or rather more frustrating than the kind of customers I prefer to deal with.

It's doable that way, and if there are enough people that want these then it might be feasible. Not sure yet. For now I'm going to concentrate on getting the construction write-up done so those that can will be able to make their own.

Edited by CaptainSlug, 05 January 2008 - 08:36 AM.

[Prometheus]

Would a plasma cutter cut polycarbonate? I don't know how hot or how concentrated it is compared to a laser cutter, but I've considered buying a CNC plasma cutter, as they are around $5000 for a decent-sized one for my purposes. I would assume though you've already researched this already though...

[CaptainSlug]

Plasma cutters should only be used to cut metal. Using one with plastic would result in a fire and lots of toxic fumes, or would not work at all. There's also no way to make this gun economically out of aluminum because aluminum costs 3 times as much as polycarbonate.
Plasma cutters also do not produce cleanly cut, dimensionally accurate holes. So they're really only used to shape parts that you plan to weld together.

Edited by CaptainSlug, 05 January 2008 - 12:19 PM.

[Cannonball]

I don't know if someone already asked you this or if you already did cover this ( if you or someone else did then sorry for waisting your time) but would it be possible for you to build, I guess, kits where all the pieces were provided and the holes were already cut in so that the only thing the person would need to do would be some cutting on their part and the rest just assembly? I imagine that in any possible scenario producing a lot of anything and cutting holes for that matter would be a major drain on you.

Kits would definitely be easier on some of the nerfers who would rather not go out and buy equipment just to cut and build one gun. Just a thought though.

[CaptainSlug]

That wouldn't save me any time. Assembly is the shortest step.

[Peter]

I think he means the plastic sheets with the holes drilled and tapped with the template on it already, and that being the only part sold.

[Forsaken angel24]

Sluggy I love your work.

[CaptainSlug]

Construction write-up
Mirror version at Instructables

It's done, and massively long with 37 images. I also added the link on the first post.

Edited by CaptainSlug, 06 January 2008 - 01:04 AM.