Using OpenGrab as SFX


#1

Hi! I’m interested in using the OpenGrab as a theatrical special effect. We’re trying to make a prop shelf fall on cue while out on stage away from anyone. My thought was to find some sort of “always on” magnet and trigger it with a DC relay via Arduino to “OPEN” the circuit and make the shelf fall. Would this OpenGrab do the trick? Is it as simple as sending it a 5V DC signal to OPEN this circuit and break it’s magnetism?

Thoughts?


#2

Hello Marcelo,

Sure may I suggest to use PWM signal, there are plenty of tutorials for arduino and the like. The EPM works just like a regular RC servo with 3 states

Regards
Andreas


#3

Thanks for the info!! Any idea any other location to purchase the OpenGrab? There’s got to be some place other than Amazon…


#4

Yes we sell on Amazon as well;

amazon.com/NicaDrone-OpenGr … qWzF&psc=1


(Pavel Kirienko) #5

Marcelo, you can order it from NicaDrone here nicadrone.com/index.php?id_produ … er=product


#6

I just checked out their website - Thanks!

I sent them an email - I need to get (5) magnets in my hands by next week though… I hope they have more product in the US!

Thanks again!


#7

Got my toys!!! Thanks! Having trouble activating the magnet. It appeared in the video that it was just energized with voltage. Do i need a PWM to activate the magnet?

Currently it’s wired as follows:
7.2v RC battery > DMX relay board > Open Grab

The DMX relay board takes lighting control signal and outputs it into (3) control channels (RGB)

In theory, can’t I just activate the magnet with a battery?


(Pavel Kirienko) #8

You can activate the magnet using RCPWM, CAN, or a button. See docs.zubax.com/opengrab_epm_v3# … _interface