Stampede voltage question

Hello OzNerf...
I have a question about my stampede.
OK everyone, so I've been modifying both of my stampedes...the first one, I removed all the restrictors...and...that didn't turn out very well...
So for my second stampede I decided to stay on the safe side.
According to SGNerf's write up, I do not need to remove the electronic resistors, but I'm going to put a Nice 11.1KG spring into the Stampede, so I'm thinking of putting 6 Trustfires into the stampede (for a higher rate of fire). Will the stampede still work if I put 6 Trustfires into them?

- Jeremy.

I run mine on a 12v SLA with almost all the restrictors removed and with my Stampede Spring, which is an 11kg spring (but i have a slightly faster recoil spring in my own Stamp than i currently sell) - Because It IS MINE!

There's an exhaustive thread on NerfSG regarding Stampede batteries. Make that your first port of call.

I would personally steer clear of Trustfires, as their capacity and current delivery is somewhat lacking. If you're safety conscious and can be trusted to treat them right, a LiPo battery (such as they use in Airsoft) will deliver longer results, with less voltage sag, and are lighter and smaller than SLA's (which are also a good option).

Really up to personal preference.

Servulus wrote:I run mine on a 12v SLA with almost all the restrictors removed and with my Stampede Spring, which is an 11kg spring (but i have a slightly faster recoil spring in my own Stamp than i currently sell) - Because It IS MINE!

stoph wrote:There's an exhaustive thread on NerfSG regarding Stampede batteries. Make that your first port of call.

I would personally steer clear of Trustfires, as their capacity and current delivery is somewhat lacking. If you're safety conscious and can be trusted to treat them right, a LiPo battery (such as they use in Airsoft) will deliver longer results, with less voltage sag, and are lighter and smaller than SLA's (which are also a good option).

Really up to personal preference.

OK, so that answers battery preferences. Thanks
But If I use, say 12V or more, will I need to remove the resistors?

Nope. I've done a 12v SLA mod as Serv has outlined, and all I needed to do was attach wires to the battery sled terminals, and run them to the corresponding battery terminals. Obviously don't run full auto constantly, as you'll likely munch darts and burn things, but it should run without many issues.

stoph wrote:Nope. I've done a 12v SLA mod as Serv has outlined, and all I needed to do was attach wires to the battery sled terminals, and run them to the corresponding battery terminals. Obviously don't run full auto constantly, as you'll likely munch darts and burn things, but it should run without many issues.

OK, that's GREAT! One last question:
According to SGNerf's thread, 1.5V Alkalines have 3000mAh, causing a shorter duration for usage...but 14500 Trustfires (http://dx.com/p/trustfire-14500-3-7v-900mah-rechargeable-lithium-batteries-2-pack-19771) only have 900 mAh! So wouldn't the TrustFires only last for a short time?

- Jeremy.

Alkalines have a quicker voltage sag than lithium ion, if I recall correctly.

Also depends on how you wire the batteries, whether its in series (combines the voltage of all of the batteries in the circuit, but has the same capacity as one) or parallel (retains the voltage of a single battery, but combines the capacity)

A simple diagram that shows what I mean can be found here: Series vs Parallel

I would seriously recommend steering clear of Trustfires or any alkaline battery - you'll be recharging more often, and your peak performance (rate of fire, mostly) will be shorter.

Go down to a Jaycar or some other electronics store. Grab yourself a 12v SLA battery like this one 12v SLA battery and a charger like this one SLA charger, take out some of the plastic from inside the Stamp battery tray, use some aligator clips or solder the wires to the correct terminals, and BOOM! You have a very simple and reliable first battery mod.

Weight is the only downside to SLA. It'll feel a little back heavy, but no real difference between that and the 6D batteries you'd otherwise have in a stock Stamp.

Once you feel you're confident working with batteries, there's Lithium Polymer (LiPo). Same batteries used in RC cars and planes, due to their straighter voltage curves (read: don't die as quickly), high discharge rate (important for things under load like the Stamp motor/gearbox, esp. with a higher spring rate) and less weight (2A 12v SLA weighs 930grams, a near equivalent 2A 11.1v LiPo can weigh 200grams)

Good luck! And DO YOUR READING! Don't just try things out and hope for the best, you're playing with potentially dangerous electricity. If you're sensible and follow instructions, you have nothing to worry about, but if you're complacent and don't do your research you can destroy your blaster, batteries, waste money and hurt yourself/others. Not to worry you needlessly, just be smart, okay?

WOW, thank you for your input, you have really helped!
You have answered all my questions (so far).
Thank you very much!

- Jeremy.

Really very curious Stoph as why you would say to avoid 14500's.... You'd be disagreeing with over 65% of the NIC from what I've seen. I won't personally use Trustfire's, but there's other very reputable brands of 14500's on the market.

If you use a 9v battery connector soldered to the terminals inside the battery sled, you can carry around 4xAA holder's loaded with fully charged batt's ready to be swapped out quickly when required. Add some quick release latches to the sled, and you could easily change out batt's in a matter of seconds without any tooling. Not to mention no weight compared to the SLA. And to be honest, spending $55 on 1 x SLA with a charger, than can't be utilised as much as 14500's, doesn't sound overly appealing. Remembering that li-ion's can be used in Barricade, Stockade, Stampede, Vulcan, Rayven etc etc, and for around $50, you'll get 16 TF's with a decent charger...

As for ROF, show me your SLA powered Stampede pushing out more than 5 darts a second, which most of us get with the li-ion's.

Now I'm not going down the road of which one is better, because all 3 power sources have their pro's and con's. But having to recharge a bit more often isn't much of an issue, and ROF is quite high.

Cheers,

clunk07 wrote:Really very curious Stoph as why you would say to avoid 14500's.... You'd be disagreeing with over 65% of the NIC from what I've seen. I won't personally use Trustfire's, but there's other very reputable brands of 14500's on the market.

If you use a 9v battery connector soldered to the terminals inside the battery sled, you can carry around 4xAA holder's loaded with fully charged batt's ready to be swapped out quickly when required. Add some quick release latches to the sled, and you could easily change out batt's in a matter of seconds without any tooling. Not to mention no weight compared to the SLA. And to be honest, spending $55 on 1 x SLA with a charger, than can't be utilised as much as 14500's, doesn't sound overly appealing. Remembering that li-ion's can be used in Barricade, Stockade, Stampede, Vulcan, Rayven etc etc, and for around $50, you'll get 16 TF's with a decent charger...

As for ROF, show me your SLA powered Stampede pushing out more than 5 darts a second, which most of us get with the li-ion's.

Now I'm not going down the road of which one is better, because all 3 power sources have their pro's and con's. But having to recharge a bit more often isn't much of an issue, and ROF is quite high.

Cheers,

Just wondering, what battery type do you personally use?

- Jeremy.

I've only used li-ion and SLA's, haven't personally installed li-po's, but have seen them used frequently.

From a commission-based perspective, I've modded around 30 Stampede's all using unprotected 14500 Li-ion batt's, and never had any issues.

Cheers,

Clunk07,
Are still open for commissions?
I've seen you're commission page, but it's not entirely active...

I go for simplicity and capacity. It's a personal preference, but I have my reasons.

1. Less batteries means less to charge
2. More batteries means more chance of unbalanced cells and less-than optimal performance
3. Less batteries means less weight (generally)
4. LiPo's and SLA's have higher capacities than 14500's (generally)

So whilst I respect where you're coming from, again it's just a personal preference - going longer between charging and battery swaps, avoiding the long winded death of smaller batt's and sub-par performance, and cutting weight are my aims with blasters like the Stamp. That, and I think the prevalence of the 14500's is because it's an easy gateway mod - accessible and doable. Not a bad thing at all, just not my preference. Personally, I just think an SLA mod is a better mid-ground mod and not that big a step up from using adapters and 14500's. Agreed on your points on cost prohibitive nature of SLA mod vs TF's.

I agree with stoph,
but in MY opinion, I'm going to stick with the 14500's.
It's light, efficient and is great for non 'professional' modders like me (even though I have 2 years experience).
Changing topic now...
what spring should I use for the stampede? An OMW spring?

Depends - do you want faster rate of fire? Or less speed for more power?

I'd like to get around 60' flat.
How many darts per second do you think 14.8V and an 11KG spring will make? And how many feet do you think it will shoot flat (with AR's removed and seal upgrade)?

JeremyArifin wrote:I'd like to get around 60' flat.
How many darts per second do you think 14.8V and an 11KG spring will make? And how many feet do you think it will shoot flat (with AR's removed and seal upgrade)?

If your using the spring that i sell, then you will see around 70ft flat, dont know the dart rate though as i rarely shoot more than burst fire.

Servulus wrote:

JeremyArifin wrote:I'd like to get around 60' flat.
How many darts per second do you think 14.8V and an 11KG spring will make? And how many feet do you think it will shoot flat (with AR's removed and seal upgrade)?

If your using the spring that i sell, then you will see around 70ft flat, dont know the dart rate though as i rarely shoot more than burst fire.

How many KGs is it? Is that 70' flat, with AR removed and 12V?

Yes 70ft with the AR removed. The voltage has no effect on the distance the blaster shoots, all the battery does is primes the plunger automatically, therefore higher voltage faster rate of fire.

^ This. Spring rate and breech setup is the only thing that will increase range in this case. That being said, another variable that can effect range and velocity are shorter darts. They are supposed to help due to less material to cause friction and slow down upon firing.

Xplorer do a drop-in breech setup that is supposed to be a pretty good seal (compared to the stock breech, but not 100% like homemade brass-breeches ala SGnerf). Here's the kit - Xpower Kit

It's SGD$75, so depending on shipping costs probably around AUD$80 to get it to you.

May also be worth waiting around for Pak Designs (Pak-Designs.com to develop their stage 2 and 3 Stamp kits. They're slow on orders but they've just employed someone to take over the admin side of things so hopefully the backlog of stuff will be tended to sooner than later.