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Hammy

Member Since 08 Nov 2011
Offline Last Active Nov 22 2013 11:30 AM

Topics I've Started

Rapid Strike and Stryfe VOltage Increase

05 September 2013 - 01:20 AM

I hope this is the correct sub-forum, apologies if not.

Last week, I made the following measurements on a Rapid Strike with 2x RM2 motors fitted (all the thermistors, capacitors, inductors and diodes removed), and

Voltage / Power Consumed
3V / 2.75W
4V / 4.45 W
5V / 6.8 W
6V / 9 W
7V / 13 W
8V / Insane, too scared to make a measurement.

Today I repeated the same measurements on a Stryfe, also equipped with RM2’s and all internalk components removed

Voltage / Power Consumed
3V / 2.5 W
4V / 5W
5V / 8W
6V / 12W

The measurements for both the RS and Stryfe were made with an R&S HAMEG Bench supply, and this can deliver 10A of current.

Making measurement with just the trustfires and a Fluke Multimeter (the yukki orange one)

The RS, with 4 trustfires when open, voltage measured 16.8V, but dropped to 6.5 V as soon as the flywheel motors engaged. (The pusher motor was disconnected at this time).

The Stryfe had 2 trusties fitted, and when open circuit the voltage measured 7.8V, and dropped to 6.25 V when the flywheels are running. 6.25 V means that more than 2A of current is been supplied by the batteries.

And both setups smell like an Ozone factory with the flywheels running.


I could obtain better measurements if I had more Stryfes and RS’s and more time, but I hope the above figures give an idea.


OK conclusions for now.
If you have Solarbotic RM2’s fitted, it is advisable not to use more than 2 trusties, even in a RS, otherwise expect burnt out motors and maybe the batteries to catch fire. Even 2 batteries is risky because of the high current been delivered.

When trusties are delivering large currents, they get hot, expect your battery compartment to melt if you are running on 4 trusties.

For a hand-held device, I think above 1-2 Amps, is well above the safety margin.

It is best to use a Lipo with a regulated supply to the RM2’s. And I will think of a solution for this in the coming weeks, unless someone beats me.
I am thinking to limit the operational voltage to 4.5V, but it is 6 V for the 1st few seconds of flywheel operation to get the motors up to speed, then the 4V switches in.

Air displacement of Night Finder Plunger

30 January 2012 - 03:38 PM

Can anyone tell me what the volume displacement in cc, of a night finder plunger is.

I need to know if it is larger than 38 cc. 50 cc and above would be good.

It is in consideration for a Brass Breech on a reverse plunger Nerf gun.