152 replies to this topic

[Langley]

Cool, are you going to share the files?

[Kilomona]

What's that sound? Oh... It's the sound of cintage blaster shell prices everywhere dropping. Both a good thing and a bad thing, but I think it's great! Expensive platforms can now be made and sold for much cheaper than the real thing. Only downside is collector prices, but still not super bad.

[The2ndBluesBro]

What's that sound? Oh... It's the sound of cintage blaster shell prices everywhere dropping. Both a good thing and a bad thing, but I think it's great! Expensive platforms can now be made and sold for much cheaper than the real thing. Only downside is collector prices, but still not super bad.

You know how expensive a print this size is right? Not to mention it's highly unlikely that anyone has a printer with a large enough bed at home. To make these, you'd need a larger, industrial scale printer, at which point you might as well mill them or cast them (like the Xplorer Xzeus) or injection mold them, all of which are very expensive and would probably require a crowdfunding campaign to get going. Further, I doubt there's enough people in the NIC willing to put the capital down for that. In short, prices for original shells won't be dropping anytime soon. 

[Pointman9]

Almost a month old, sorry about the necro.  Has anyone considered using vacuum forming to make shells before?  It may be possible.  I know that vacuum tables can be easily made, and I have seen some relatively complex vacuum formed objects.

 

EDIT:  Look what I have done.  Sorry!

Edited by Pointman9, 12 April 2016 - 11:42 PM.

[Spud Spudoni]

Has anyone considered using vacuum forming to make shells before?  It may be possible.  I know that vacuum tables can be easily made, and I have seen some relatively complex vacuum formed objects.

It really depends on the size of material you are vacuum forming, the thickness of the plastic/plastic type you are using to form something, and the amount of finite detail of a piece being vacuum formed. I've used our vacuum former in my studio's shop in school, but we always ran into problems with forming between two extruded sections that were very close to each other. Instead of getting, let's say, a clean form with sharp angles of two rectangular pieces 0.5" apart, we got a bowed section between the two pieces because the process couldn't get the plastic to form into the corners of the material. If this is applied to all of the ridges and dead space in the tornado/crossbow shell, you'd need a very thin sheet of plastic to allow it to get a decent form. And at that, it would be to fragile to do anything with.

Edited by Spud Spudoni, 09 April 2016 - 02:23 AM.

[Pointman9]

It really depends on the size of material you are vacuum forming, the thickness of the plastic/plastic type you are using to form something, and the amount of finite detail of a piece being vacuum formed. I've used our vacuum former in my studio's shop in school, but we always ran into problems with forming between two extruded sections that were very close to each other. Instead of getting, let's say, a clean form with sharp angles of two rectangular pieces 0.5" apart, we got a bowed section between the two pieces because the process couldn't get the plastic to form into the corners of the material. If this is applied to all of the ridges and dead space in the tornado/crossbow shell, you'd need a very thin sheet of plastic to allow it to get a decent form. And at that, it would be to fragile to do anything with.

 

 

I see.  Thank you for that.  Having never used one before, I had no idea.  Perhaps there could be a shell form that would be superior to a Crossbow while still being easily formable.  I'll have to ponder it for a while.

[Spud Spudoni]

 

 

I see.  Thank you for that.  Having never used one before, I had no idea.  Perhaps there could be a shell form that would be superior to a Crossbow while still being easily formable.  I'll have to ponder it for a while.

However, it could be possible to get a decent form with a very thin sheet of plastic with enough resistance to allow a resin cast to be made in it. If spaced out correctly, you could fill the resin between a form of the front of the shell, and the interior of the shell. But that all depends on whatever your molding material is, resin or something else, working properly and getting in every nook and cranny of every ridge in a blaster with a lot of ribbing like the tornado. But I guess if we mod a shell to remove any of the useless plastic on the inside, fill up the gaps between other ridges with putty, and just keep the interior ready for tornadobow swap, it could be possible.

Edited by Spud Spudoni, 09 April 2016 - 01:57 PM.

[Kilomona]

What about just a very basic shell? I don't know if that's what spud is talking about, but just a shell with no inside ridges or anything. Then people could simply put their desired internals inside.

[Spud Spudoni]

What about just a very basic shell? I don't know if that's what spud is talking about, but just a shell with no inside ridges or anything. Then people could simply put their desired internals inside.

Vacuum forming is a one side process. For each side of the shell, you'll get an interior mold of the inside of the shell, and an exterior mold of the outside of the shell. You can just do one vacuum form and get one half of a blaster, that's not how it works. You either build an exact interior or cut out the interior half of the shell and secure it to the outside half of the shell, making it structurally unsound imo.

 

If you want just the outside of two pieces of a shell, then yeah it will work fine, but you'll have a hollow shell on the inside that you can't do anything with. Every shell on it's interior has a complicated system of screw ports, supports, and the like that keep a blaster together and functional. You can try to really pull the plastic in to try to get the shell formed, but you'll need to drill holes through the entire shell in order to allow the air in the liminal space to move through the vacuum process, destroying a shell to possibly get a vacuum form. And yeah, there are plenty of shells simpler than the crossbow and tornado but are those worth replicating?

 

TL;DR creating an exact replica in how the blaster looks and feels is the ultimate goal for recreating a shell. If a plastic shell 'looks' like a crossbow but doesn't have the same texture on the grips, lines, grooves, and detail of a crossbow and is just a smooth form, is it a crossbow? If so, than you can try out the +bow.

[Pointman9]

What about just a very basic shell? I don't know if that's what spud is talking about, but just a shell with no inside ridges or anything. Then people could simply put their desired internals inside.

This may be a possibility, even if not the ultimate goal of this idea. You could simply make it the desired width of the plunger tube you want, and then simply attach the tube to the inside with screws at the beginning and end of the tube, much like a plusbow.

[Spud Spudoni]

This may be a possibility, even if not the ultimate goal of this idea. You could simply make it the desired width of the plunger tube you want, and then simply attach the tube to the inside with screws at the beginning and end of the tube, much like a plusbow.

I could very well see this idea being applied to the homemade market more than the stock blaster market honestly. Groups like MHA producing homemade blasters with interchangeable outer shells that get screwed onto the blaster to bring homemades closer in looks to nerf blasters would change the game. I've had this idea for years, but never thought about using it with vacuum forming over 3D printing. Definitely would make the process much faster, easier, and cheaper to produce.

[Langley]

Based on my understanding of vacuforming, the kind of piece you can produce with an at-home hobby rig is not going to be rigid enough to use as the shell for a nerf blaster.  The result would be more or less like the clamshell packaging that electronics come in.  It's going to crumple in your hands if you try mounting internals in it.  And as mentioned by Spud, you need a crossbow shaped form to vacuform onto.  If you use a real crossbow shell, you would need to drill some air holes in it. 

 

I understand that it would be really difficult to vacuform the internal structure of a tornado or crossbow and then use the outside and inside piece to resin-cast a shell piece.  The piece would be too thin and complicated.  What if you build a solid mock-up of your homemade internals, and either vacuform that or just spray it with release agent and attach it to the vacuform of the outside of the shell? Then you pour in some resin, and you end up with a fairly solid (if somewhat heavy and possibly brittle) tornado/crossbow shell half. 

 

Mostly I just want someone to vacum form a crossbow shell so I can use it to make a full sized chocolate crossbow.  Either that or fuse a bunch of them into a big chair, making the nerf version of the Iron Throne.

[Spud Spudoni]

Based on my understanding of vacuforming, the kind of piece you can produce with an at-home hobby rig is not going to be rigid enough to use as the shell for a nerf blaster.  The  What if you build a solid mock-up of your homemade internals, and either vacuform that or just spray it with release agent and attach it to the vacuform of the outside of the shell? Then you pour in some resin, and you end up with a fairly solid (if somewhat heavy and possibly brittle) tornado/crossbow shell half. 

 

With an industrial grade vacuum form, I've been able to form plastic at the same strength and higher than that of nerf blaster plastic. The downside is that its thickness and composite just can't get hot enough to form into anything intricate, making blasters all but debunked. Plus, vacuum forming plastic can end pretty badly too. You could melt the shell you're vacuum forming due to the high heat of the plastic being formed. But a mock-up of the internals in a cast is a fantastic idea. Having a full cast of the inside of the blaster minus where the internals go would be the only way in my mind this thing could be structurally sound. You'd just need a way of centering the internals into the hollow shell half, which could be done with a wire hung over the cast going through the plunger assembly.

 

EDIT: Or you could just make a mold of one half of a blaster with a silicon mold, fill that with resin with your internals placed in the mold, coated in a non stick substance. Then when it dries, you can take the resin out of the mold, and you have a whole half of a shell, with a perfect mold for your exact internals, that you can bolt to the other half when it is formed. And btw, resin is clear, so having a clear tornado would blow my socks off.

Edited by Spud Spudoni, 10 April 2016 - 06:17 PM.

[Langley]

EDIT: Or you could just make a mold of one half of a blaster with a silicon mold, fill that with resin with your internals placed in the mold, coated in a non stick substance. Then when it dries, you can take the resin out of the mold, and you have a whole half of a shell, with a perfect mold for your exact internals, that you can bolt to the other half when it is formed. And btw, resin is clear, so having a clear tornado would blow my socks off.

 

It sounds like silicone might be easier to work with, although for something the size of a blaster it could get expensive.  I think for the internal shape of the shell half, I'd still want to make a solid mock up of the internals, with extra material added on to account for the range of motion of moving parts, air flow, clearance, and any shrinkage that occurs.  If you think about just the stock crossbow internals, you need space for the trigger to move, you need a cylindrical cavity for the trigger spring, you need a space that allows the full range of motion of the catch, and you have to provide enough space for the plunger rod to move back and forth without binding up.  You can't just spray that stuff with release and dunk it in.  But you also don't need nearly as much space as the original shell allows, the only reason that space is even there is to make the blaster cheaper and lighter. 

Edited by Langley, 10 April 2016 - 08:45 PM.

[Spud Spudoni]

You are right about moving parts. The plunger tube could just be set in, but if the crossbow is the example, you'd need room for the trigger, catch, and priming bar to move. Resin is a cool material because it can be done in layers (allowing one layer to dry, then putting more resin on top) and it still makes a complete mold. With that in mind, you could fill a cast to a certain amount, where the trigger and catch could sit. Once that is dry, 3D printed molds of the whole catch area (side profile of catch +length for spring to sit) and trigger area (side profile of trigger +length for spring to sit) could be printed with its side profile extruded to a desired length. That way, you could place this mold negative standing up in the first layer of dried resin, then fill the rest up until the shell's half is complete. Here's a quick sketch of what I mean to help explain: 

 

 

The semi circular portion would sit right on the inside of the trigger guard, and would give enough room behind it for a complete trigger, and spring to be just glued to place with hot glue. This negative mold will of course be extremely difficult to remove, even with a coating of some non stick substance as you've stated about the plunger assembly Langley. But if you can clear coat those pieces, it can help in removing; same with the plunger assembly. As far as the priming bar goes, using a table saw or a router saw could easily cut a channel out in the resin that would do the job.

[Langley]

I was envisioning two shell halves that can be screwed together.  That seems way easier than trying to cast an entire blaster all at once, and leaving a cavity for internals.  I'm assuming this is what you're talking about as far as doing it in layers and putting the actual internals in as you go.  I'm not sure how it would be for a tornado, because I'm not as familiar with it, so I don't know how that would be different from a crossbow.  

 

So lets say you make a mold of a crossbow shell piece.  You would put the piece so the center line of the crossbow is against the table, so you're looking at the outside of the shell-half, and seal it to the table with clay or whatever, seal off screw holes etc.  Then you attach a mock up of the plunger rod and the barrel, but you'd have to cut them in half lengthwise because you're only casting one shell-half at a time.  Build a box around it, pour in latex, and you have a mold for half a crossbow. 

 

Then you flip it over, and place your mockup of your crossbow internals into it.  The plunger tube is a solid cylinder instead of an open tube, and it has rods coming out of it for the plunger rod and barrel.  There's a piece attached to the plunger rod that represents where the catch and spring go, and a space for the trigger attached to that.  Since the internals go straight through the center line of the blaster, and since you included the parts of the internals that stick out in your cast of the shell, you should be able to just place them right into the mold.  Pour in resin until the mold is full and the internal mockup is half-submerged, and you're done with that half.  Repeat for the other half.  You just have to make sure your molds are very close to level when your pour the resin in, because if you make it crooked the shell will be thicker at one end and the internals might not fit or align properly. 

[Spud Spudoni]

You are right, my idea would entail screwing two resin halves together once they are cured. And your idea of the plunger assembly, barrel, priming bar, and a mock piece for the trigger and catch is what I was floating around too. The only thing that I was trying to figure out, is how possible would it be to remove the internals after the mold has been cast? I'm thinking if you created a full mold pf the internals out of silicon of a mock trigger with the room to move and spring rest connected to the back (basically a really long trigger with a stem for the spring), a mock catch piece with no hole in the middle, extended upward for its movement for the actual catch, and the plunger assembly and priming bar. Then when the silicon mold dries, you'd pour in more silicon into the mold, creating these pieces. That way when the resin dries, you can just peel the silicon internal molds out, and peel the resin half shell out of the silicon mold. Then repeat. This might be a little expensive, but I may be able to try this out in the coming year.

Edited by Spud Spudoni, 11 April 2016 - 08:04 PM.

[DjOnslaught]

Drac recently posted that he got the white crossbow shell back and was sending it to a friend he had made who was gonna scan it (hopefully successfully this time)

 

The earlier reference made to cnc'ing the crossbow shell out of something more sturdy.  I worked in a manufacturing environment for 12 years (plant shut down last year) and that option would not be cost effective for mass reproduction at a reasonable cost to anyone.  Part of the reason is that you would need a complex program for it as well as someone to stand there and change the tooling several times, you would further have price of machine rental or purchase and the coolant needed.

[Meaker VI]

The only thing that I was trying to figure out, is how possible would it be to remove the internals after the mold has been cast?

 

Langely's suggesting you make a fake set of internals that are similar to your real set, but solid. For a trigger I'd just make it a solid block the size of the trigger + any movement it can possibly make. It'd mean you'd need to accurately machine them once though.

 

 

The earlier reference made to cnc'ing the crossbow shell out of something more sturdy.  I worked in a manufacturing environment for 12 years (plant shut down last year) and that option would not be cost effective for mass reproduction at a reasonable cost to anyone.  Part of the reason is that you would need a complex program for it as well as someone to stand there and change the tooling several times, you would further have price of machine rental or purchase and the coolant needed.

 

Yeah, so far none of this is really cost-competitive. Even vaccuforming and filling with resin is going to produce shells that, accounting for any value in time and materials, you'd need to sell starting in the low hundreds of dollars.

 

However, CNC would produce a better shell mold; and you don't need a manufacturing CNC machine. Something like a shopbot would do just fine if you CNC'd the outside surface out of wood (or something similarly cheap & easy to CNC) you could vaccuform to that.

[xXD3V1LXx]

A would crossbow would be really cool. I'm thinking use like blood oak or something because they tend to withstand a lot of pressure so the spring won't break it.

[The2ndBluesBro]

Nobody said CNC was the cheapest way, but as the xzeus proved, it's the best way barring finding a company willing to injection mold a large batch of them, which requires more capital than any of us probably have available. A wood crossbow is a terrible idea, since it would be really heavy and ABS can be thinner and lighter while still having enough tensile strength (although some design changes should be made like a thicker spring rest, in the case of the crossbow). I think the best way would be to crowdfund enough cash to CNC a mold and have an injection molding company make a bunch, which we could then sell to recoup the costs. To be honest, I think this is a cool development in Nerf but the technology just isn't cheap enough yet, and it's unlikely to ever be.

[Spud Spudoni]

 

Langely's suggesting you make a fake set of internals that are similar to your real set, but solid. For a trigger I'd just make it a solid block the size of the trigger + any movement it can possibly make. It'd mean you'd need to accurately machine them once though.

 

 

Yes, I know. I think I've mentioned the mock trigger thing a few times, and even have a sketch of it a few posts up. Hell, the next sentence in the post you quoted says exactly what you said. Thanks though

 

 

 

Yeah, so far none of this is really cost-competitive. Even vaccuforming and filling with resin is going to produce shells that, accounting for any value in time and materials, you'd need to sell starting in the low hundreds of dollars.

 

However, CNC would produce a better shell mold; and you don't need a manufacturing CNC machine. Something like a shopbot would do just fine if you CNC'd the outside surface out of wood (or something similarly cheap & easy to CNC) you could vaccuform to that.

I don't like how quickly we are jumping to mass production off of a concept that is barely past the idea phase. This is all apart of prototyping. At this point, it isn't about how cheap it is to produce a shell out of resin or any other material, but is it possibly. As also mentioned above, resin and casting is obviously expensive. No one is saying it isn't. But as of right now, it stands as the easiest way to produce a shell accurately, and strong enough to work for a nerf blaster with little threshold to create (no need for CNC, 3D printers, Mills). That's what is important, not the money.

[Meaker VI]

A would crossbow would be really cool. I'm thinking use like blood oak or something because they tend to withstand a lot of pressure so the spring won't break it.

 

Doing it the way I suggested would result in a nearly-solid blood oak crossbow that would cost and weigh way too much. Using pine or fir (2x's) would be more manageable.

 

 

 A wood crossbow is a terrible idea, since it would be really heavy and ABS can be thinner and lighter while still having enough tensile strength (although some design changes should be made like a thicker spring rest, in the case of the crossbow). I think the best way would be to crowdfund enough cash to CNC a mold and have an injection molding company make a bunch, which we could then sell to recoup the costs. To be honest, I think this is a cool development in Nerf but the technology just isn't cheap enough yet, and it's unlikely to ever be.

 

Doing full-wood isn't actually such a bad idea: it's cheap, readily accessible, depending on species not *too* heavy, usually stronger than plastic, and tooling is cheap. I could get/make a copy-router and copy (the outside of) a crossbow shell for a few hundred dollars in tooling and an hour or so of my time. Then you could vaccuform or make a mold off of the copy and fill the form with resin or whatever to make additional copies, but personally, I'd be fine with the wood one.

 

Crowdfunding a mold could mean raising 10s-100s of thousands of dollars. Injection molds aren't cheap; but we'd then get the inside and the outside all at once.

 

Missed this:

 

I don't like how quickly we are jumping to mass production off of a concept that is barely past the idea phase. This is all apart of prototyping. At this point, it isn't about how cheap it is to produce a shell out of resin or any other material, but is it possibly. As also mentioned above, resin and casting is obviously expensive. No one is saying it isn't. But as of right now, it stands as the easiest way to produce a shell accurately, and strong enough to work for a nerf blaster with little threshold to create (no need for CNC, 3D printers, Mills). That's what is important, not the money.

 

No no, you misread me. It's both definitely possible to create a strong part and definitely 'expensive' to do this. It's possible to mass-manufacture, it's possible to micro-manufacture. It's possible to 3d print. Each method will have pros and cons. In this context, the cons of CNC and resin casting it that the material costs are high. Every method we're talking about requires specialist machinery (CNC, 3d Printer, Injection mold) which serves as a high threshold to the individual, so the cost of the part produced is what matters. 3d Printing and injection molding will both use plastic, so the cost of the part should be more marginal, except that I don't expect 10,000+ people to want to purchase these things so injection molding is right out IMO.

Edited by Meaker VI, 12 April 2016 - 02:49 PM.

[Langley]

You are right, my idea would entail screwing two resin halves together once they are cured. And your idea of the plunger assembly, barrel, priming bar, and a mock piece for the trigger and catch is what I was floating around too. The only thing that I was trying to figure out, is how possible would it be to remove the internals after the mold has been cast? I'm thinking if you created a full mold pf the internals out of silicon of a mock trigger with the room to move and spring rest connected to the back (basically a really long trigger with a stem for the spring), a mock catch piece with no hole in the middle, extended upward for its movement for the actual catch, and the plunger assembly and priming bar. Then when the silicon mold dries, you'd pour in more silicon into the mold, creating these pieces. That way when the resin dries, you can just peel the silicon internal molds out, and peel the resin half shell out of the silicon mold. Then repeat. This might be a little expensive, but I may be able to try this out in the coming year.

 

Sorry, I misunderstood. Based on your diagram and what you said about layering and standing the trigger up, I thought you were talking about casting the whole shell in one piece. 

 

I haven't worked with resin before, so I'm just talking out of my ass at this point, but I had thought that a rigid mockup of the internals with maybe a couple of coats of glossy paint and some mold release would pop right out of the resin. You could probably taper and bevel the square parts slightly so that they come out more easily.  I've seen videos of people making parts out of fiberglass using a rigid mold coated in wax, but the fiberglass is flexible enough to work off the rigid mold, so maybe that's the key difference.

 

Edit: another alternative would be to apply fiberglass to the inside of the mold instead of pouring in resin.  Then you end up with something lighter and closer to a nerf shell, but you would have to add internal structures to reinforce it and provide a place to mount the internals. 

[xXD3V1LXx]

To be honest I think an oak crossbow would look so cool stained and coated. You can always reinforce the internals with copper plates like drac did on the Lilith. If it only cost you like 300$ for the tools the wood is extremely accessible I'm pretty sure if you would be able to get a ton of money from crossbow fans to make wood shells with copper reinforcements and would probably pay you back after 3 or 4 crossbows.