Epoxy Resin Cast Blaster Parts - Build Guide!

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.

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:




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! :)
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Custom Weighted Foam Darts - Tip Seal Guide!

I have been receiving many queries on custom weighted foam darts from modders. This guide will answer 2 of the popular questions:

How to ensure dart tips never split or detach during firing or impact?

How to make consistent flat tips for attaching the soft padding?

Here is one of the methods i use...



From left to right (top row):

- Remove the original tip from the foam dart.

- Insert the tip weight.

- Use a short section of 17/32" brass tube as a mold and sleeve it over the foam dart tip, allow 1-2mm of clearance from the brass tube edge.

- Apply hot glue into the brass tube mold, this will seal the tip weight and the foam dart together.

From left to right (bottom row):

- Put the mold tip first on a cool surface and press down on the foam dart to compress the hot glue and get rid of any bubbles. This will create a molded flat tip. Wait around 20-30 seconds for the hot glue to cool down and solidify.

- Remove the foam dart from the brass tube mold, trim the sides of the flat hot glue tip so that it is aligned with the foam dart outer diameter.

- For safety, attach a piece of soft padding to the flat hot glue tip. This helps to absorb the foam dart impact.

- Close-up of the completed custom weighted foam dart.

Hope that helps! :)

Custom Calibrated Foam Darts - Conversion Guide!

Most modders naturally find stock Nerf foam darts inaccurate and inconsistent. They are basically not designed with the proper weight balance required for straight and consistent dart flight when used in blasters that have been modified for more power.

To improve accuracy and range, there many methods to custom make foam darts, either from foam backer rod (FBR) or converting existing foam darts into customized versions.

The main feature in most customized foam darts is a heavier tip, this additional weight in front of the foam dart helps increase performance . But having too much or too little tip weight can also have adverse effects too, it all depends on the power of the blasters they are used in. Thats where proper calibration comes in.

In this guide, i will cover one of the conversion and calibration methods that has been popular with modders at the NerfSG forum. This method is based of the "Sabot" design by SixShot.

It is one of the more effective techniques of adding more weight to the foam dart tip, yet allowing calibration for different blaster power and still ensuring that all the materials used are of a safe nature (ie. no metal or hard plastic/resin parts).

Note that the outer diameter (OD) and length of foam darts that users choose will determine the specific dimensions of breeches and barrels that are suitable for them.

For example, wider OD foam darts that fit well into 9/16" brass barrels will be too tight for 17/32" brass barrels, which would cause chambering issues. Whereas narrower OD foam darts that fit well into 17/32" brass barrels will be too loose in 9/16" brass barrels, resulting in air leaks around the foam dart as its fired, which reduces power and range. So its all a matter of testing to find the right combination.

For my own custom calibrated foam darts, i prefer to use either 3rd-party SDL brand foam darts or custom FBR which have slightly wider foam bodies. Their "fatter" OD creates a much better air seal when chambered in both normal stock breeches and brass breeches which use 9/16" brass barrels, offering optimum overall performance in those particular barrel and breech dimensions.

The choice of foam dart type and brand is up to the user's preference, so there is no "best" foam dart, just the most suitable and customized for the user's application.

Here is an example of how Custom Calibrated Foam Darts can be made...

Step 1: Remove the original tips from the foam darts.

Get soft eraser stick refills (commonly found at most stores) and cut them into the desired lengths.

In this example, i cut them into 4 different lengths (5mm, 10mm, 15mm and 20mm) to create 4 different calibrated foam darts with varying tip weights.

The longer the eraser stick refill, the heavier the tip weight. So its up to users to find the best length (and consequently weight) combination to suit their particular modded blasters .

I would recommend making a "calibration" set as shown below for initial testing.




Step 2: Slot the cut lengths of eraser stick refills into the foam dart tips.

Use general-purpose glue or "contact cement" glue to permanently attach them into the foam darts. Make sure the glue is completely dry and the dart tips are secure before firing the foam darts.

In the photo below, the numbers on the tips indicate the eraser stick refill lengths used within each foam dart, these are an example of a "calibration" set used for testing the suitable tip weights for various modded blasters.

It is common for users to have seperate batches of different tip weighted foam darts allocated to each of their different modified blasters. Do remember to indicate the tip weights somewhere on the foam darts, so they don't get mixed up.




Step 3: Safety and further customization.

As custom calibrated foam darts are commonly used in more powerful modified blasters, the impact of hits will naturally be harder and the chances of welts or bruises occurring would also be higher, therefore it is important to cushion the impact of the dart tips.

To reduce the foam dart impact during Nerf games (while still maintaining accuracy and range), i attach 12mm diameter soft foam padding to the tips of all my customized foam darts. These soft foam padded tips help to prevent welts or bruises occurring even if accidentally fired at close range.

The soft foam padding also keeps the dart tips intact over multiple shots, reducing the heavy wear and tear that usually occurs with constant Nerf game usage.

In addition, i also wrap a layer of tape just behind the tip of each customized foam dart, this helps to reinforce the tip as well as to slightly narrow the front section to aid in smoother dart chambering within modified breeches.



This is just one example, there are many other methods to customize your foam darts, try them out and find the most suitable techniques for your usage... and make sure you have the safety aspect in mind too!

Enjoy better calibrated accuracy and range from your modified blasters! :)