23 replies to this topic

[SgNerf]

Wouldn't it be useful to be able to easily replicate and make your own replacement blaster parts? or perhaps even custom make parts too?

The common method to make replacement parts amongst modders usually involves cutting shapes out of polycarbonate sheets, but that requires a fair amount of work with special tools, along with lots of polycarbonate dust flying everywhere.

The other method is to contract a custom parts fabrication company to do it, but that requires dealing with minimum order quantities and higher monetary expenditures, not really cost efficient for simple blaster parts.

Therefore i was looking at an easier (and cost effective) method to make detailed parts as and when required.

With this objective in mind, i looked into a technique that is commonly used in many scale model hobbies to make replicated parts = Epoxy Resin Casting.

I've seen modders use epoxy resin to reinforce joints or to fill up empty spaces in blaster casings, but i've not yet seen anyone actually make working detailed blaster parts using epoxy resin.

So i tested out the epoxy resin cast method and it works!

Here is the build process...


- Make the Casting Mold -

In my example, i use EasyMold Silicone Putty to make the casting mold, so my process will be based on this particular product. Here is the product link for reference: http://eti-usa.com/e...silicone-putty/

Once a silicone mold is made, the same mold can be used repeatedly for casting many parts.

There are other similar silicone mold brands that can also be used too, just follow the instructions specific to those products.

Step 1:

Mix 2 equal parts of the silicone putty components. Knead the mixture until the color is uniform.



You will need to work fast as the EasyMold Silicone Putty compound has a very short working time.


Step 2:

For this example, i will be casting a PAS trigger.

Press the original plastic PAS trigger into the prepared silicone compound, make sure it sits completely in the putty and creates a detailed impression.



Note thats this is a one part mold. For functionality and simplicity, i only needed to replicate the right side of the trigger as thats the side that requires part detail for the catch spring to mount on.

For more detailed molds, 2 part molds can also be made by creating the mold in 2 stages with enclosed mold pieces.


Step 3:

After 20+ minutes, the silicone mold will cure enough that you can remove the original part.



Leave the silicone mold to cure further for a minimum 24 hours... then its ready for usage.


- Make the Epoxy Resin Cast Part -

For the casting material, i used high strength 2-part epoxy resin. The epoxy resin does not adhere to the silicone mold so its suitable as a casting material.

I've tested various epoxy resin and they all vary in strength depending on the intended application. Since the part i intend to make undergoes high mechanical stress loads, i found that Devcon "Plastic Steel" Epoxy worked well, as it has good tensile and shear strength.

Step 1:

Mix the 2-part epoxy resin and hardener until it has a uniform color, then apply the mixture into the silicone mold in layers until it is completely filled.



Make sure to fill up the mold completely so that there are no unfilled spaces or air bubbles trapped inside.

Let the epoxy resin cure for 6-8 hours (cure time will depend on environmental conditions).


Step 2:

After the epoxy resin cast part has cured, remove it from the mold. Just flex the silicone mold slightly and the part will pop out.

Trim off any mold lines or excess epoxy resin material with a hobby knife or sanding file.

Here is a comparison of the epoxy resin cast trigger versus the original plastic trigger.



If the cast part comes out with lots of holes (looking like swiss cheese), then it's probably due to too many gaps and air bubbles introduced during the mold filling process.

Just mix a small amount of epoxy resin again to fill in those holes and let it cure further.


Step 3:

Fit the epoxy resin cast part to the blaster, it should have a perfect fitment.



Do any further trimming or adjustments as required, then you can start using it.

Since you can re-use the silicone mold many times, just cast a new part anytime as and when needed!


Application Demo Video:

http://www.youtube.com/watch?v=X2icfOn8DMk


Summary:

So far, i've tested the epoxy resin cast PAS triggers and they were able to handle up to 20+ kg load main springs. The catches worked perfectly over hundreds of shots, so it looks like they can be suitable and durable replacements for other load bearing parts too.

Yes... its indeed possible to make epoxy resin cast blaster parts!

Edited by SgNerf, 23 September 2011 - 05:54 AM.

[andtheherois]

This is completely awesome. Great job once again SGN. Have you tried other things, like say a 4B trigger or anything else that tends to break?

[SgNerf]

This is completely awesome. Great job once again SGN. Have you tried other things, like say a 4B trigger or anything else that tends to break?

Yup, a 4B trigger would be an ideal part to replicate in epoxy resin too... i guess that would be one of the various useful molds to be made.

[Daniel Beaver]

Neat.

I wonder if it would be possible to increase the strength by mixing in some sort of fibers? Might be tricky to keep them for settling, though.

Edited by Daniel Beaver, 12 September 2011 - 02:08 PM.

[ChaosPropel]

Lol, I was just thinking about something like this a few days ago! Nothing up to the scale which you have achieved, though. Great job!
What's the tensile/impact stength on the resin?

[Blue]

I'm sure this is obvious to people who know what they are doing, but is this epoxy resin actually noticeably stronger than the plastics themselves?

Awesome job on the molds and actually making something both easy AND useful, looks like a very fun thing to do too. I'll add this under random things in the mod directory.

[Curly]

That is sheer awesome. Would this work with any 2-part epoxy, or are some varieties useless in this regard? Also, can you use any putty-like substance for the mold or do the properties of epoxy putty influence the product?

EDIT: Another advantage to this method is you can slightly change the parts to suit your liking. If you didn't like the bend in the PAS trigger, unbend it!

Edited by Curly, 12 September 2011 - 03:10 PM.

[Jilliop]

For people whose parts have already broken, you ought to make/sell just the molds. Like any part that shatters typically. Then, the piece can't really be cast, can it? And since the molds are so easy to make, let the recipient use their own epoxy resin!

[KatanasPWN]

Nice! If you could find a clear drying epoxy then you could make an almost entirely clear nitefinder! I've got a few questions:
1. Could you color the parts to some extent with dyes or something
2. Are there any kinds of epoxy that you should generally stay away from that are too fragile or that will attach them self to the mold?
If you've already broken the part you can probably just attempt to glue it back together, follow the regular mold making process and just fix up the mold a bit with a toothpick.

[Zorns Lemma]

I'm sure this is obvious to people who know what they are doing, but is this epoxy resin actually noticeably stronger than the plastics themselves?

Awesome job on the molds and actually making something both easy AND useful, looks like a very fun thing to do too. I'll add this under random things in the mod directory.

Epoxy resin when mixed correctly has around the same strength properties as concrete. Also can avoid the ridges found in the stock pieces that are probably there to save on plastic when injection molding.

Also, can you use any putty-like substance for the mold or do the properties of epoxy putty influence the product?

2. Are there any kinds of epoxy that you should generally stay away from that are too fragile or that will attach them self to the mold?

Silicone is used for negative molds like this because nothing really adheres to it besides more silicone.

[Curly]

Silicone is used for negative molds like this because nothing really adheres to it besides more silicone.

Thank you sir, I'll add that silicon grease can be used on a non-silicon mold to have the same effect, but it must be re-applied.

[Zorns Lemma]

Thank you sir, I'll add that silicon grease can be used on a non-silicon mold to have the same effect, but it must be re-applied.

They probably make silicone-based mold release agent. I'm wary about directly applying grease because that can develop in a relatively thick layer perhaps interfering with the resin. But since resin is pretty cheap and molds are reusable it's worth a shot.

[chavez guy]

This is really friggen cool. Imagine the possiblities!
You can steal someone's key, make a copy, and get into their house.

Oh, and I'm sure this could be applied to nerf uses as well.

With a large enough mold, I could possibly see barrel spacers.

Or it could be used to make decorative parts and items and whatnot for those concerned with blaster cosmetics. Although seeing the rather phalic decorations used before, I am hesitant to look forward to the decorative items people will make.

Regardless, this definately got me pretty excited. Good work as usual!

[IrishMonk]

This is really friggen cool. Imagine the possiblities!
You can steal someone's key, make a copy, and get into their house.

Oh, and I'm sure this could be applied to nerf uses as well.

With a large enough mold, I could possibly see barrel spacers.

With large enough molds, someone who has one could mass-produce Crossbow shells!

And in non-Nerf related talk, I kind of do want to try this with my key and see if it works.

Major props, SG Nerf!

Edited by IrishMonk, 12 September 2011 - 09:35 PM.

[Blue]

Amazon:
Rubber Silicone
Silicone Putty

Pretty cheap stuff. Maybe the rubber silicone could be used for larger pieces. Also, you can't really do shells with this method because you fill the entire mold up to create a solid piece, so you would have no space for internals.

[SgNerf]

Amazon:
Rubber Silicone
Silicone Putty

Pretty cheap stuff. Maybe the rubber silicone could be used for larger pieces. Also, you can't really do shells with this method because you fill the entire mold up to create a solid piece, so you would have no space for internals.

Thanks for posting up those Amazon links for reference.

For those who are wondering, i got the EasyMold Silicone Putty 1/2 lb Pack (their smallest volume pack) and only used a fifth of that amount to make my PAS trigger mold example. So its possible to make 4-5 one part silicone molds for trigger sized objects with just their smallest pack.

Therefore in terms of mold material costs, it works out to just a few dollars for each small re-usable mold... quite cost effective.

[Demon Lord]

It would be tricky, but a person could do a two part mold to create shells and other complex pieces like that.

[Darksircam]

I've been making molds with silicone caulk. It's cheaper than silicone putty... and available in smaller amounts for smaller projects. While new silicone may adhere to cured silicone a bit, a little bit of force is all I needed to separate them.

[moosa]

This is pretty fricken neato.

Blaster shells would require injection molding, like they do in the Nerf factories, so you can forget about your mass-produced xbow shells (which would destroy the value, novelty and coolness factor of xbows effectively).

[PVC Arsenal 17]

Very nice. I'd even implant some music wire or similar "rebar-like" reinforcement to keep things good and strong, especially on a trigger like that.

[balisticjoe]

For those already wondering, and those who are about to ask, it would be completely possible to replicate much larger items (specifically speaking, the x-bow shell) using a method similar to this, but notably different. First, you would probably wind up using smooth-cast products, because they make just about every thing you would need for such a project. To make the mold, you would use something like Oomoo 25 to make the main mold (to halves of a mold per half of a part to be replicated). then you would have to cover each side with a hard mold (to make it keep shape/rigidity). In order to actually cast it you would have needed to build up a lot of the thinner parts (using the x-bow example, the catch rest, the trigger area) with clay (non-sulfur based) so that when pouring the plastic it will fill in. The plastic you would use would probably be 320 or 321 liquid plastic, or even task 4 for the thinner walled sections. As you can probably tell, I spent alot of time looking into this, the method I recommend is based largely on replica prop making, and seems to be the best (quality, not cost effective) way to go about doing this. The end product would be very similar (externally) to the stock x-bow, but the internals would be noticeably different (albeit better). The problem with this method is that it would cost a significant amount of money to invest, just to see if it is possible. I know bob and I chatted about this a while back, so he may have found some alternative way of doing it, but he may not even remember discussing it. Feel free to look into it tough, and if you have that kind of disposable income to spend on a chance, I'm not stopping you. If you have any more questions regarding the topic, feel free to ask/message me.

On topic-Nice job, a lot easier and safer than meticulously measuring and machining parts to make a polycarb replica.

Tl;Dr: How to go about replicating large objects like the x-bow shell, but it would cost a lot to do.

Edited by balisticjoe, 13 September 2011 - 09:09 PM.

[stuffstuff]

Could you make a plunger out of epoxy?

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Edited by Zorn's Lemma, 21 June 2013 - 08:44 PM.

[Kronos Nerf Mods]

I have to say that this is big. I would never attempt to make a trigger on a printer as it would probably break, especially one for a pas. Anyway, great job sg!
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Edited by Zorn's Lemma, 22 June 2013 - 09:02 PM.

[SolarFusion]

Nice! If you could find a clear drying epoxy then you could make an almost entirely clear nitefinder!

This is a boatbuilding supply retailer however they sell large amounts of clear epoxy for decent prices considering the amount you are getting.

http://duckworksbbs....epoxy/index.htm

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Even if you have something to add, this thread is so long dead that it is probably better off starting a new one.

Edited by Zorns Lemma, 21 August 2014 - 02:47 AM.