13 replies to this topic

[Lordtac]

Hello everyone. So I'm posting because I've run into a problem that I'm sure most other Modders will eventually run into at one point or another. So I figured I'd kill two birds with one stone and make a helpful post for both me and others.

 

A month ago I changed out my Stryfe motors for these https://www.pololu.com/product/611known as the Solarbotics RM2

Today I received some batteries I ordered from wish (I'm sure you know where this is going by now) and installed them. (4 of them)

 

Here is the motors reference information.

Name: Solarbotics RM2

Form Factor: 130mm

Volts tolerance:9v max

Max amps draw: 300mA

 

Here is the batteries reference information.

Name: UltraFire 14500 Rechagable Lithium AA Battery 1200mAh 3.7V

Form Factor: AA

Amps: 1200mAh

Volts: 3.7v

 

I got them running for about a total of 15 seconds before smoke started coming from the motor cage and it stopped functioning entirely.

 

I'm not 100% sure why they failed. But my first guess would be that I didn't realize that batteries in a series increase voltage. So 3.7v x 4 batteries = 14.8v (right?).

Assuming the above statement is correct I over volted the crap out of them and it caused the internals to fry.

 

So i guess I'm asking if someone can confirm or explain what I did wrong here. I'm sure its the voltage. Also funny story, the stock switch didn't fry.

 

UPDATE

Thanks to the posts below we figured out that because of my lithium Ion ultrafire's I did indeed fry the hell out of my motors.

 

2nd we determined that the best motors for my setup (ideally running from a 3s Lipo) are MTB Rhino Motors http://www.containme...op/mtb/mtb-001/

 

3rd I intend to order and install these to see how things go. I don't know if I'll need anything else to work with them as my wiring is much thicker but we'll find out.

Edited by Lordtac, 28 January 2017 - 05:26 PM.

[shandsgator8]

I think your theory is correct and you might have given them too much voltage. Check this page out:

 

http://nerfhaven.com...ltage-increase/

Edited by shandsgator8, 26 January 2017 - 06:17 PM.

[Lordtac]

Yes upon inspection of this post (Thank you shand) I've narrowed it down to over volting. I pushed it way to hard. My next test will be with 2 new motors and 2 ultrafires with 2 dummy cells for safety.

According to my other research I've noticed that configuration matters. two parallel batteries will create more voltage with the same amperage while two batteries in series will allow more amperage at lower voltage.

[shandsgator8]

Yes upon inspection of this post (Thank you shand) I've narrowed it down to over volting. I pushed it way to hard. My next test will be with 2 new motors and 2 ultrafires with 2 dummy cells for safety.

According to my other research I've noticed that configuration matters. two parallel batteries will create more voltage with the same amperage while two batteries in series will allow more amperage at lower voltage.

 

You've got it backwards. 

 

Let's use a pair of AA Eneloops (1.2v nominal with 2,000 mah capacity) to illustrate.

 

Two AA Eneloops in series = 2.4v nominal and 2,000 mah capacity.

 

Two AA Eneloops in parallel = 1.2v nominal and 4,000 mah capacity.

 

I considered using the RM2 motors in my Stryfe so I could use 4 AA eneloops. But after some research, it looked like they weren't the more durable motors. I went with MTB Rhinos and a 6 cell Eneloop setup instead.

[Duke Wintermaul]

RM2 motors are made for Robotics, and are rated for a forward voltage of 4.5V; Less than the stock Nerf motors.

Running RM2 motors on their proper specs will give you ~100fps, with a decent spin-up time.

Don't use *fires, IMR's, Lipos, or dummy cells.

If you want to use a lithium ion battery RM2's are not the motor for you.

[Lordtac]

Aw I see, Taking that into account could you recommend a motor for the strife duke?

[shandsgator8]

MTB Rhinos work very well in the Stryfe, whether it's a 2s or 3s lithium setup. Too much FPS makes most darts very inaccurate, but that's another issue for another topic...

Edited by shandsgator8, 28 January 2017 - 10:17 AM.

[Lordtac]

I was actually just looking at the honeybadger at work and didn't see this one. Thank you very much. I'll update the original post to reflect what I decided.

[Lordtac]

So its been a few weeks now, and I said I would update. I'm still waiting on the motors I order over a week ago. So no progress.

[Airwolf13]

I just installed hellcats.
25c 3s so sucky lipo for now.
Stock fw
Have a artifact cage n fw combo and worker fw plus full auto kit coming.
Fps avg 105 with stock fw and new darts plus new fws.
Will be interesting with stage 2.
Will test stage 3 with brass breach/barrel

[SirBrass]

Brass breach will just slow the darts in a flywheel blaster. Hellcats should do great when they can draw enough current. 44A stall is what they'll want to draw (motors in parallel each with about 22A stall), so if your 3s 25C is 1000mAh and has a burst of 50C, it'll provide the current just fine. Otherwise it won't. Make sure the capacity multiplied by the burst C rating divided by 1000 is greater than or equal to 44.

Artifact cage + worker wheels should be great. That's what I have in my bladed stryfe and it shoots waffleheads AMAZINGLY.

Edited by SirBrass, 05 March 2017 - 09:09 PM.

[dB Zac]

I ran a very short dart guide/barrel in my artifact cage and did not get a loss of fps, I did end up with a smoother trigger pull, tighter grouping, and less (nearly none) jams

[SirBrass]

Details on that dart guide?

[dB Zac]

Details on that dart guide?

Your going to hate me but I don't have many details. It was a total experiment that I didn't expect to work. I can tell you it was a scrap piece of brass that almost fit the cage hole. I used a 40 grit flap disc on an angle grinder to take some material off to get the brass to tap into the cage.

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