hey guys im having trouble understanding how to assemble the actuators with my RFFS stuff. im not quite sure what the instructi0ons are telling me and i dont want to start clomping arround with these delicate things. does anyone have pictures or instructions on how to assemble them? thx chris

They are a handful, aren't they?

Be sure not mount them with CA. Use UHU or another good rubber cement if you are going to use the hingeline surface method. If you are then some of the following won't apply. Spacing the mags closely and using the insert bearing for an actuator arm to drive a pushrod helps keep the weight amidships, not back on the tail- which would require a longer nose, heavier motor or battery to balance.

Put the arm assy into the black round insert first and check to see it rotates freely. Now slip it in the coil and note the arm's plane of rotation relative to the circuit board as shown in the manual. Only the barest of CA is needed to secure the insert to the coil but UHU would be better. Use a toothpick and the pointiest end for the smallest amount of medium- thin is too dangerous here- don't ask me how I know!

Here's a picture that shows a critical part of the setup- their orientation to one another.

Mutual magnetic centering and non-interaction is vital to these spooky lil guys. I had them offset in my original Micro Pitts. Aileron caused some elevator interaction- and the elevator, likewise, induced an unwanted reaction from the other! Not fun to fly! Lets see you program THAT outta your TX! Moving the rudder servo into alignment with the aileron servo fixed it.

Get it right, like in my Super Skeeter and my balsa Skeeter ultraslowflyer variants, and mags handle as good as motor servos but at 1/100th the power- and at airspeeds slower than anything you've ever enjoyed before due to the low system weight!

The KP-00 motor (like others in its class) is a joy that sips power from a tiny 250 ma lipo and its all you need to haul the RUFUS and those lil mags around with plenty of reserve power to loop and kick up your heels.

Rubber powered rc would be a blast- Rudder Only would be interesting again at 1 or 2 mph... but I understand that a motor MUST be connected- or an equal resistor, perhaps? The motor is roughly equal in weight to rubber power and thrust is similar- and you dont have to wind it- so I remain electric!

On the basic actuator I made the wires wrap around the round magnets a full turn to make it more secure before gluing it w CA. The magnet floating on the hinge wire within the center of the coil is a delicate thing to install on the basic hingeline actuators. The magnetic actuators are more difficult to install than conventional servos but are a bit simpler than the pushrod method. Either one will get you slower, lighter flight than you've ever had.

I have another question about actuators, what do you connect them to? I know that servos have a ciruit board, but do actuators have these? Can you connect the actuator directly to the radio?

The actuators connect to the RFFS-100 receiver by two wires from each coil. The RFFS-100 is a 3 channel receiver with built in speed control good for up to 2 amps. If the actuators movement is reversed, simply swap the 2 actuator wires in their sockets in the receiver and its done. The tiny circuit board on the coil is a place to attach wires as well as a reference for orienting the actuator properly for mounting.

The picture shows the RFFS-100 with both actuator's wires plugged in with their 4 wires. The tiny crystal is to the left on the board. The black connector strip on the right feeds the motor from the center two holes and battery power is connected to the two outside holes. There is no switch. Get the polarity right every time- there is no protection for reversed polarity.

The actuators are mainly a coil with a magnet held in it's center The moveable magnet is driven by the coil's steerable magnetic field which is varied by the stick position for the rudder and elevator controls. Completely proportional. 3 channels, very long flights- for mere grams! The lightest and the slowest.

Also pictured is a new actuator with an output arm for driving a pushrod. These have larger coils, making them more powerful- and heavier. They are for mounting near the center of the fuse to keep the tail light- but require careful setup for magnetic non-interference with one another.

Would it matter that I have an electron 6 that I am wanting to hook an actuator up to? I just do not want to screw up my reciever.

Also, how much torque can an actuator usually put out? Are they comparable to, say, an HS-55?

thx deltageek. i think i found the problem with mine.......the magnets didnt fit in the arm and they were binding on the side and not centering. i ordered a better set of hardware now and i think it will fix the problem.

YW, EVOL. Glad you got it sorted out. I had no such problems- they were hard enough my first time working with these atom sized units. Let me know how it goes. Were you using "Battery Holddown magnets" instead of the others? Cant imagine how they would be wrong size. They wrap the mags up in the label- took me awhile to find them first time!


Quote Hatty- "Would it matter that I have an electron 6 that I am wanting to hook an actuator up to? I just do not want to screw up my reciever."

The magnetic actuators are completely different than motor servos- and are not compatible with anything but the RFFS-100. The Electron would weigh so much more than the RFFS that it would be pointless even if it were possible. I'm sure it would fry both!

Quote Hatty- "Also, how much torque can an actuator usually put out? Are they comparable to, say, an HS-55?"

The torque of these guys is just a few percent of the geared motor units. Most servos provide far more torque than is needed- in medium and low performance models.

Compared to an HS-55? Divide by 100 and you are getting close. With the load on a surface of a micro measured in grams, it is all you need for this application and they handle great. Understand that a complete 1 ounce plane with this system weighs only a bit more than 2 HS-55s!

Being super light, the airspeeds are super slow and the loads generated are also miniscule.