Since you can get three 18650 trustfires(3-4A max discharge) for the price of an 18650 IMR(10A max), would it be reasonable to use three trustfires in parallel for the same current as an IMR but three times the capacity?
It would probably be impractical in a stryfe since you'd end up with 6 or 9 batteries, but I'm thinking of a homemade.

Depends on motors. Stock motors, those trustfires might be okay. Any sort of replacements, I would recommend a better battery chemistry.
Their current discharge rate will not increase, FYI, but their mAH will add up.

180 motors can pull A LOT of current, I think someone said 60A stall current? I forget. That's WELL past the current discharge rate of a Trustfire, thus you're not really getting any rev up benefits, and may even damage the battery.

There is definitely a limit to the capabilities of flywheels, as I haven't been able to hit significantly over 120 fps without either melting darts or melting flywheels lols.

A Trustfire charger will work just fine, I use one with my eFests. One great thing about IMRs is that they can't be overcharged.


Trustfires are just common because it was what people were initially doing. Plus, they're cheap. But because of their construction, there are many problems with trying to use them with a high current demand.
There are many alternatives which will provide the current motors demand when overvolted, IMRs, LiFEPO4, LiPo, NiCd, etc...

Hey guys, so for Christmas I'm trying to get myself a stryfe so I can start to learn modding for the flywheel blasters, and I'd like to experiment with putting a replacement motor in it. I have looked at nearly all the mod tutorials that i can find, and many recommend the "Pro 180" motors that coop tends to use, but I've also seen a thread on here about the "RM2". I was very interested in the "RM2"s, due to the price difference, but I saw someone post in the comments of one of coop's videos asking how well they work, and he said that he believes they don't perform as well as even the stock motors. I would really appreciate some clarification if you guys don't mind, and I apologize if this has been asked, or is posted somewhere already, I just could not find a comparison of both the motors. Thank you in advance guys.

RM2s are not that great. The brushes have been see to commonly just get obliterated when overvolted.

You can try just sticking with the stock motor and using better batteries. You can get a very stock look with 3 14500 IMR batteries (and a dummy battery), like eFests, and get very good performance out of them.

Very very cool. I have one thought, though...If it's 3D printed, why not design a more ergonomic handle? Is this just something designed to be universal, then? I know hand sizes vary a lot, so that would make sense.
Overall, very cool, really makes me think about building a homemade.

Sorry, I don't quite understand? Doesn't connecting batteries in parallel compound their current discharge? http://electronics.h...ch/battery6.htm (first paragraph).

Hmmm...that only talks about current supply. We are talking about discharge rate. The discharge rate remains the same.

But I thought about the math, and I was wrong, it does increase max discharge (not discharge rate).

For example, if both cells have 1000mAH, and 10C discharge rate, that means they have 10A max discharge, because 10C * 1AH = 10A. So if you connect them in parallel, you have a 2000mAH supply, but still 10C discharge rate. But 10C * 2AH = 20A max discharge.

So yes, that would work, but most people want overvolting, so you would have a pretty large pack to put 3 paralleled 18650s in series with 3 more paralleled in series with 3 more paralleled lol.

FPS tests have proven that simple overvolting of the stock motors gives much better performance than replacing the stock motors with RM2s and running at stock voltage. As long as you use good batteries, like eFest 14500 cells (not Trustfires).

I consider battery replacement and thermister removal to be MUCH easier than motor replacement...


If you want better performance, definitely do IMR instead of Trustfire. Trustfires do not have the current supply capability that we want for this application. They have relatively low discharge rates compared to other Lithium battery types. IMRs are also safer.

I believe commonly do two cell systems (2s) on Stryfe motors with no issue. I've done testing with 3s using Trustfires.

If you find 2s is high enough performance, I would rewire the battery box to have the two in parallel, for increased battery life.

LiPo is great but not necessary in your application yet, staying with stock.

For 18650s, right? I got a pair of 14500 eFest IMRs for 10 bucks or something. 4 of those, paralleled for 8.4V should plenty of current supply and discharge and keep a stock look.

Stryfes with stock motors on a 3s system get to average 110 fps, which is pretty close to the upper limits of flywheel performance:
https://docs.google....RWc&output=html

The voltage measures correctly when measured where? At the point where it contacts the Stampede?

And the solder isn't about age, it's about technique and what type of solder it is. Still haven't mentioned the type of soldering iron (wattage mostly) and solder alloy.
If your technique isn't good, your solder joints will not be good. I can't tell from that pic is your solder joints are good, but it looks like the solder did not wet on the contact at all. Meaning not really all that good.


EDIT: Wait, what batteries are you using? Are they unprotected or protected Trustfores? Protected ones will not work.

Pretty cool. Good ranges. I wonder how much more it could be boosted to?

You could, but they wouldn't work well. 180s require a lot of current. If you use old laptop cells, you'll be choked the current and stressing the batteries, since you'd be asking for more current than they can provide. You would probably see a lot of voltage sag (lower supply voltage - so motors would not be overvolted as much as you'd think), too, so the motors would not be working optimally.

I'm sure it's fine with stock motors, but I don't recommend them for 180s.

EDIT: Woops, double post.
Let's make it useful, at least.

Are you sure there's no corrosion or anything that could mess up the contacts? Have you considered that you may have a cold solder joint? Cold solder joints are a poor electrical connection.
What solder and soldering iron did you use?

.1 ohms is pretty huge, IMO.
I doubt that is what it is, though.
I don't know the dimensions of the spring, and I don't really care too much, but here's some math from a flashlight forum:

Looking at #24 gauge bare copper wire which has almost the same
diameter as 0.022 inch wire, the resistance for 1000 ft is 20.8 ohms.
For 1 foot, it's 0.0208, and for 1 inch it's 0.001733 ohms.

The length of the helix is approx:
L=4.5 turns times 0.375 inches times pi=5.3 inches.

The increase in length due to the helix over the
circumference is only about 0.2 percent, so this increase
will be ignored.

5.3 inches times 0.001733 equals 0.00918 ohms total for a copper spring.

Knowing that the resistivity of SS is about 42.4 times higher than
copper, multiplying the total resistance times 42.4 gives us an
estimate of the total resistance of the SS spring.

R(SS)=0.00918 times 42.4 which equals 0.39 ohms total.

This number indicates something went wrong with the previous
calculation done in the previous post. I suggest checking
it for an error involving the conversion factors. Since rho
is given in ohm-cm i suggest working entirely in cm and cm^2
and redo the calculations.

That should give you an idea, at least.

You are underestimating stall current, meaning the current that a motor uses when it starts moving. It can be pretty big, depending on how many volts you're feeding the motor. As you increase the voltage, the current demanded by the motor increases too.

It's a pretty well documented phenomenon in in flashlight forums. MY WIRE wouldn't catch fire under those circumstances, I use teflon insulated stuff, it's pretty tough stuff. Also, my spring HAS gotten hot enough to catch flame. I had to put out my Stampede - this happened to me. Why doubt me?
I don't know anything about yours. I've used slightly higher gauges of this teflon insulated wire in robotic builds that consume over 100A at stall current. And it was fine.
You might be fine because Trustfires are honestly terrible batteries that cannot supply the current that these motors need. They have a poor discharge rating. If you use something that actually gives the motor what it needs, it is a different story. My rate of fire is higher than most 4s (16.8v) Stampedes I have seen with a similar spring load (I am approaching 10-11kg).

FWIW, I don't recommend soldering to those springs. I guess you're limited by the Trustfire's crappy current supply, but one time, I was lazy - the battery spring got so hot that it turned red and started smoking.
Not that a AA tray's battery retention springs are any better haha.

Your most obvious test since you have a multimeter is to make the tray functions. Are you measuring 16.8 volts from it on a full charge?

Don't run 180s on 14500 cells. Go 18650 lithium or with a LiPo.

The issue is the spring, just don't use the stupid battery tray contacts hahaha. That's all it comes down to.
Or at least solder to the metal plate and not the spring. Or solder a crap load of wire or something to the spring to increase the area. That will reduce resistance.

As far as trustfires doing that, I would say that's more due to overdischarging the cell or shorting the battery. Trustfires have terrible current discharge rates. Well below what most powerful motors need at stall. When using any kind of powerful battery, you should always install a simple LED voltmeter to prevent overdischarge.

I'm using unprotected (gray) trustfire batteries.

Testing the solder joints, they provide negligible resistance alongside the metal plates, though I don't know if this is relevant.

When firing with 6 D batteries, the voltage across the two panels on the battery sled dips slightly from 9 to about 8. When attempting to fire with the trustfire batteries, it drops to 0 volts.

That is a VERY clear indication that your AA tray does not work, either because of your solder, or because of the tray.

Dude, as already pointed out, your battery connector is connected to the battery sled in the wrong polarity.

The black wire should go to the spring.
The red wire to the tab.

There is no thermistor in the battery sled.

It should not matter if you solder the wires to the spring and tab, so long as the join is good and clean.

No other electrical mods are needed unless you want to remove all of the locks.

Wrong, the spring has a high resistance, and should not be soldered to. Excessive current draw can cause it to light on fire. This is a well documented problem with battery springs. Ideally, battery trays shouldn't use springs at all.

Are you sure that the battery tray is even providing any power? Haven't heard confirmation that you measured the right voltage at the battery contact.

I can't believe you actually got a tube magazine to work. There was a thread by Shadow, and it lasted for two years, just barely touching on successful prototypes. And you managed to do it with just pvc and paint sticks.

Now, how many darts does the magazine hold? What flaws can you currently find in the design and construction of the blaster? How reliable is the tube magazine?

I think on Nerf Rev he said about 5 darts, of this particular length, any more or any different sizes and it gets wonky.

I've noticed that the darts are the important part in accuracy, streamlines will be shit from any length barrel, well made stefans will be lasers with almost any well-fitting barrel.

Actually, lately I've been doubting the accuracy of standard size stefans. I've been making darts that are 50mm long, and seem to have better luck with those, at least in my partial brass breech setups. Perhaps stefans made with metal weights are pretty accurate, but I prefer not to use those. 50mm darts with a rubber/silicone tip seem to be the optimum amount of length for proper drag stabilization in dart flight. The metal washer type stefans just have such an overwhelming weight that it doesn't matter how long they are.

Anyway, off topic!

Regarding HvZers' experience, It might be an effect called muzzle blast.

Link to a Chicago style hopper?

How to add a barrel if you went AT2k route, though? Fired straight from the dart turret, I would think it would be wildly inaccurate.

Dang, I think it looks kinda cool. Shame ranges are poop.

I slut myself between a bunch of different blasters as the rounds progress. You don't have to commit to a single blaster and only use that. It's much more fun to switch it up...
1)RSCB'd full tank panther (small, light, huge range, insanely accurate, simple 10 min mod, a near perfect rushing blaster, great for CTF. Currently it's my go-to primary)
2)hoppered marshmallow crossbow. (the huge pt allows for an equally huge feed tube, quick easy mod)
3)pteg barreled, pump replaced marshmallow Mforcer (naturally semi-auto 15 rnd rear loading turret! Only 80' range, but the rof compensates)
4)trustfired Rayven (it doesn't get simpler than buying 4 trustfires and dumping them in. Accuracy is abysmal but the rof and clip swapping is pretty fun)

I bought an MForcer the other day on your recommendation haha. Stoke to get it in the mail. 80', according to some data conducted hereis actually pretty solid. Most blasters apparently don't actually hit 100' flat.

Is the crossbow you mean?
http://www.amazon.co...o/dp/B0036QFKTG

Also, in terms of deadspace, how is an RSCB that different from a hopper?

Printed ABS is not that strong.
I have a significant amount of experience with different filaments, and it is definitely not in any way impact resistant.

I'll second the thought that it could break.

Elite is much better than the N-Strike line, that's for sure..

The cocking mechanism is certainly new for Nerf, as far as I know. That alone makes it worth picking up and stripping down, especially if it lies in the >$15 range.

Resembles the Dart Tag Snapfire 8, actually, IMO.
I like it because it's actually a viable secondary, being that it be primed with one hand. I wouldn't mind carrying that around in one hand, with a Stryfe in the other.

Dual Wielding should be cool, too! For those who do indoor or office wars, should be neat.

Too OP for the style of gameplay I usually have hah. So I usually have the Stryfe and something that's primed for at least one shot so I don't have to keep motors revved.

Hotlinking my holster, just because I really don't think sewing is hard or complicated. Worth a try, if you have a machine available.



Again, first time using a sewing machine.

I just remembered MLD's first post about the Centurion. He mistakenly described it as a full auto blaster with a 3 round burst option - then retracted that info and corrected himself.

This could be that blaster, and that might be what the secondary trigger is! This gives me hope that it's not flywheel.

A lot of people have successfully taken Retaliator internals and put them into a Longstrike.

From looking at the image, I can see the bulges near the front of the blaster that are much akin to those on the Stryfe and Rayven. Right where the orange tac rail on the side is. These "bulges" are the cavities for the flywheel compartment. I am pretty sure this is a flywheel blaster. I personally love flywheels.

True, I see that now.

I like my Stryfe a lot, I suppose my main issue is this: What separates this from the Stryfe, really? I get a really nice RoF with my Stryfe, full auto isn't a big selling point for me.
With a reinforced Recon stock, it's pretty comfy, too.

Made my own using materials from Walmart. First time using a sewing machine, too. It's not hard, once you read up on how to do edging and the proper X stitch at tactical websites.
http://nerfscience.b...ot-holster.html

I would think it's easier to center a washer than a ball bearing.

What kind of foam and washer are you using where you have exposed metal? 3/8" OD #6 washers should not be exposed with 1/2" foam.

Tbh, the "twirling edges" as you call the rifling, help dart stability, as far as I can tell. Darts are typically drag stabilized, but I do see crappy shots get corrected by spin sometimes.

If your real issue is shooting while turning, then you're better off using a blaster with no barrel. Of course the darts will hit the barrel if you turn. Your blaster continues moving with you, while the dart is moving in one direction, along one plane.

I don't really understand the seemingly strict rules on HvZ I've seen. I feel like modifications should be limited by measuring fps with a chronometer, not by simply banning modifications outright.

What's the composition? I don't deny that there are legit hard solders out there, but it's important note exactly what you used if others are to use this as a guide.

https://en.wikipedia.org/wiki/Brazing

Which isn't soldering.
Look at all the filler metals listed, and then look at solder. It's made of lead/tin, usually. He says he's using silver solder, which usually contains maybe 3% silver.

Solder requires more of a mechanical connection/joint for it to be anything close to trustworthy for putting pressure on.

Solder is not an adhesive. Let me know how well that works out in the long term.

er... these spring blasters don't push enough air for a tight barrel fit to help... It just makes it lose a lot of power.

How well does it work with your strip barrel design? There have been theories on the possible positive effects on porting barrels.