Serv's Spring Sales: Stampede & Vulcan

I do happen to have another set of 4 TrustFire Li-on batteries never used before, so I'll charge them and try them later on. If they still don't work, it's unlikely to be batteries problem.

Clunk, btw where do you get these so-called AW branded Li-on batteries from? Do you sell themm too? Cheers.

That will be your best bet mate.

I do sell the Andrew Wong branded batteries, but I only order them in by special request.

Cheers,

I'll second the use of AW's batteries. Testing by other people have shown that the capacity of his batteries are more likely to be what's stated on the wrapper, compared with quite a few other brands which overrate theirs.

Sigh, tested the Stampede with different set of 4 TrustFire Li-on batteries, and the problem is still the same.

238232 wrote:I'll second the use of AW's batteries. Testing by other people have shown that the capacity of his batteries are more likely to be what's stated on the wrapper, compared with quite a few other brands which overrate theirs.

110% agreed. They're definitely worth the extra money.

That's not good Akimbo, it's got me stumped...

Cheers,

I've just received my today, i will make a back up with my 14500 cell Li-ions tomorrow and give them a test.

I have tested it with the SLA and works a treat.

My thanks to serv for the spring of stampede pwn.

Gooni.

gooni wrote:I've just received my today, i will make a back up with my 14500 cell Li-ions tomorrow and give them a test.

Cool, let us know how it goes.

I'm now considering buying a few AW batteries for testing, however if the same problem still persist even with AW batteries, I'm gonna be really pissed off.

Update on Li-Ion testing, a 4x3.7V 900mAh pack will not move a serv spring.

Under load that pack was only dropping around 0.5v (although it was a light load and not measured in the stampede) There is just not enough current from the 900mAh.

I will be getting some 1.2amp cells in the coming weeks and will test with them and post results when I have them.

So until we get some better Li-ion's it is SLA all the way people.

Now that part is over, onto the range results.

I did both flat and slight angled ranges.

Stampede with Serv spring running 12v 2.2Amp SLA.

PTG with heavy sili tips = average of 55ft, max was 65ft.

ATG(30deg ish) with heavy sili tips = average of around 80ft, max was 100.

This was my results , others may find their results different to mind.

Gooni.

Thanks for the info Gooni, it'll be interesting to see what kinds of currents we need.

While we're on the subject of Li-ions, maybe it's time to step up to using the big boys. 18650s are pretty much the standard Li-ion size for many commercial/industrial applications, everything from laptop batteries to the Tesla Roadster. Any improvements in Li-ion technology also make their way into them first. Highest capacity ones at the moment are 3100 mAh, so the safe discharge rate is a tad over 6A.

Okay, I'm a little confused now. My 4 x 14500 li-ion's easily compress Servulus' spring, and they're only 900 mAh, and were only charged to 16.4v. I'm interested to see what I've done differently...

Not that there's anything wrong with SLA's, but before we write-off li-ion's, maybe someone can suggest how a simple redneck like myself can get them to work...

And I've run mine on Trustfire's, Ultrafire's and AW branded li-ion's.

Whilst I agree about the performance of 18650's, the size and cost (I pay $25 ea) are highly prohibitive for Nerf in my particular case.

Cheers,

What charger are you using?

Also, maybe you've got less resistance in the wires for your system? If things are really borderline then it might make a difference. Less friction in the plunger tube -> less force required from the motor? (Can you tell I'm starting to pull ideas out of my ass by now?)

Gooni and AA, how far did the plunger move when you were testing the Li-ions? If it's nearly pushed all the way back then you just need a bit more power, while if it's only going half way back or something then you really need a lot more.

I'm using a WF-139 charger. I normally monitor the charging with a Multi, and stop at around 4.1 to 4.2v.

I've removed the wiring to 3 of the 4 inter-lock's, and have used 2 bullet crimp's to connect the wiring from the on/off switch (makes it alot easier when you have to open up the blaster).

Maybe my plunger-seal isn't as tight as AA's and gooni's...

Cheers,

Interesting, so Gooni has similar result like mine, our Li-on batteries just not powerful enough to prime Servulus spring. Yet Clunk managed to get his working. I use the same UltraFire WF-139 charger to charge my TrustFire batteries. I don't believe Clunk's plunger seal is any looser than mine, because outherwise he won't get that kind of firing range (50-60ft at flat angle). Maybe his wiring has less resistance I don't know, I assume Clunk has the 4-battery holder, however how his is connected to the battery terminals I'm interested now.

I reckon it's something other than the spring causing your issue. Have you had a look at the Stampede trouble shooting thread over at NerfSG? Lots of good info there.

AA - I've connected the 4 x AA holder to the battery sled via a 9v snap cable, soldered directly to the terminals in the sled. It actually took a fair bit of time to solder it, as I really roughed up the terminals with the dremel, to ensure a really solid solder joint. (This was due to some advice from Phuong, who had some teething problems with his, before he diagnosed that he didn't have a good connection with his solder).

Cheers,

Could be the soldering connections, double check to make sure there aren't any cold joints, especially if you're using thick wire. Now that it's mentioned I have had a couple of cases where the resistance over a joint was high because of that.

oxymoron wrote:I reckon it's something other than the spring causing your issue. Have you had a look at the Stampede trouble shooting thread over at NerfSG? Lots of good info there.

Well, like I've said earlier, if I changed Servulus spring to stock spring, the TrustFire batteries fire fine But when I changed it back to Servulus spring, it won't fire.

Added: Actually SgNerf is the guy who first solved my trouble in that thread earlier this year when I used the wrong batteries. Turned out there are two different versions of grey TrustFire Li-on batteries, there's the protected version I purchased from somewhere I can't remembered now, and there's the unprotected version from DealExtreme. They both look the same, except the protected version is slightly longer with the PCB added at the bottom.

Well it is revision time.

I have just pulled my cells out of the charger and put them in my serv'ed stampede, and it fires.

The pack is reading 16.something volts and is firing fine.

AA, there might be something wrong with your li-ion's. I found one of my cells was on its way out yesterday. Fresh charged fully working cells are working fine.

I use the undranded blue cells with "+ICR 14500 900mAh 3.7V-" printed on them, I no know what brand they are, and I am using the unbranded charger that came with them.

Gooni.

Use lipos, they far exceed even SLA output current capability -low end batteries from Hobby King start at 20C.

gooni wrote:Well it is revision time.

I have just pulled my cells out of the charger and put them in my serv'ed stampede, and it fires.

The pack is reading 16.something volts and is firing fine.

AA, there might be something wrong with your li-ion's. I found one of my cells was on its way out yesterday. Fresh charged fully working cells are working fine.

I use the undranded blue cells with "+ICR 14500 900mAh 3.7V-" printed on them, I no know what brand they are, and I am using the unbranded charger that came with them.

Gooni.

Gooni:

Hmm, puzzling. I have tried two different sets of four TrustFire Li-on batteries, and it won't fire in both occasions. I can't be that unlucky to get 8 dodgy batteries, can I? Do you know if your unbranded blue batteries protected or unprotected?

Try mixing the two sets around. All you really need is one out of the 4 to be stuffed and then things start going down the drain.

@ AA , the cell's I use are unprotected, They come from Ebay somewhere.

As numbers said, it only takes one out of the four to make things fail. test each cells voltage after a full charge, that might give you an idea of what one might be the troubled cell.

Gooni.

Just checked those 8 batteries.

The first set was charged a week ago: 4.09V, 4.07V, 4.02V, 4.10V.

The second set was charged over the weekend: 4.11V, 4,13V, 4.11V, 4.14V.

gooni wrote:@ AA , the cell's I use are unprotected, They come from Ebay somewhere.

As numbers said, it only takes one out of the four to make things fail. test each cells voltage after a full charge, that might give you an idea of what one might be the troubled cell.

Gooni.

I can see a nickname sticking out of this one gooni!!! haha

But, yeh, good advice, it will only take one to drag the output down. I'd still suggest looking in to the AW's or another reputable brand.

Let's all use li-po's and blow ourselves up/burn our houses down....

Cheers,

clunk07 wrote:Let's all use li-po's and blow ourselves up/burn our houses down....

I'm up for it!

clunk07 wrote:
Let's all use li-po's and blow ourselves up/burn our houses down....

Cheers,

Ok i must be the only one who can safely use LiPo's then. Well me and the Kahkinator. I have never had one catch on fire, and only had 2 go pop nothing more than a little smoke for a few seconds and then it no work no more. I personally think there are too many people who dont know what they are doing, that have given LiPo's a bad name.

I just detest people saying that they're the be all, end all of batteries.

I tend to err on the side of caution, and my electrical ability is more than adequate to charge batt's. I just see their reliability as inadequate against various other power sources.

Cheers,

clunk07 wrote:I just detest people saying that they're the be all, end all of batteries.

I tend to err on the side of caution, and my electrical ability is more than adequate to charge batt's. I just see their reliability as inadequate against various other power sources.

Cheers,

Highest power density, fastest charge rates, highest current output. Yep, LiPos are definitely the be all and end all. Feel free to stick to your old technologies.

Servulus, just want to confirm I'll be buying a Stampede spring off you at the Glenunga war on Sunday for $10?

My "old technology" seems to be pumping out 5 rounds per second in a Stampede, so, yeh, I think I'll stick to that. Plus, I have next to nothing to worry about when it comes to public liability issues, by using li-ion's.

I think you guys have failed to see that I'm talking from a business perspective.

clunk07 wrote:
I think you guys have failed to see that I'm talking from a business perspective.

I wont say they are the be all end all, they do the job with my RC vehicles very well, i do find they need very good ventilation and i dont use them in my Nerf guns.

From a business perspective its best to go with what you like to work with and what you feel is safe. That is the way it always has been and always will be.

I knew you'd understand Serv, being in a similar - but more full-on - situation.

Yes, I agree Li-po's are brilliant in any application where they can receive adequate ventilation.

cheers,

Bump

Still have plenty of stampede springs available.

Also on the vulcan spring, it may appear that a 11kg spring might be the go. The 12 kg spring broke the plunger arm after only 4 belts, but i have fed through 48 belts full auto feed with the 11kg spring and the vulcan still lives. I will give this spring testing over a few more wars yet and if it still doesnt break then i may have found the spring. Ranges coming later (after testing).

have you thought of reinforcing the plunger rod?

I have, but the it is better to find a spring that wont cause the arm to break, especially when i am planning on selling that spring. Many people would rather just buy a spring and install it, rather than having to reinforce their Vulcans plunger arm just to use the spring.

I will one day look into having the plunger arm cnc machined, but until that day, finding a suitable spring is a better move.

Bump

Stampede Springs still available.