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        How did you set up your Electro Pulsar?

#1 Ron Williams Oct 07, 2002 10:07 AM

How did you set up your Electro Pulsar?
 
Trying to come up with a neat arrangement for the innards of my new 1.5 meter Pulsar electro, it occured to me that I might not have to reinvent the wheel. Anyone done it already and ready to share the their secrets? Pictures?

It's pretty tight in there and maintaining the CG and getting it all in is a little tricky. What's the best way? I'm using FMA s80 servos, a Hitec 555 Rx and a 16/15/3 or 4 with a gearbox. Mine's the v-tail, no ailerons. Thanks!

Ron

#2 Konratz Oct 09, 2002 10:55 PM

Hello Ron,
I set my servos in the V tail. I glued 3mm balsa on both sides of the V stabs from the root to the first slanting rib. I then added filler strips to the leading and trailing edges so that about 1/3 the span of tail is now 3 times thicker than stock. I then cut a notch in the root of the V tails between the wire struts for the servos to go into. I sanded the 3mm balsa to a streamlined shape (symmetrical). I added a .1 mm 3 ply plywood floor to the bottom of each V tail for the servo. The servos go in on there sides and are fully flared into the tail. Recover V tail with Oracover light. I ran 4 servo wires down the tail boom (servo shares the positive and negitive leads each servo gets its own signal lead). I place the receiver just under the trailing edge of the wing. This allows me to get to the RX to plug in the ailerons.
My setup is 1.8 meters, 610 grams. 4 servos (FMA 60), FMA RX, 4.5:1 Cosmotec GBX, 28 x 20 Graupner prop on a Speed 400 4.8V with flux ring timed to pull 17.5 amps with 7 Sanyo 500 mAh red cells. ESC is a Castle Sprite 25. Balance is at 63mm from the leading edge. Best climb is about 30.
Sorry I don't have any pictures, yet! No camera.
Konrad

#3 Ron Williams Oct 10, 2002 10:20 AM

Hi Konrad -

Thanks for the reply. I was beginning to think I was the only one alive with a Pulsar. Your solution to the tail servos is very ingenious, especially the use of just 4 wires to handle both servos. What did you do with your antenna? I've threaded antennas down carbon tube fuselages before without any problems but that doesn't stop me from wondering what will happen the next time.

I have the Pulsar with elevons only; no ailerons. I finally set it up with the carbon pushrods that came with the plane, attaching wire fittings at each end with rubberized CA and heat shrink tubing. I placed the servos at the back of the space under the wing, inline and the Rx ahead of them on a sloped bulkhead. The battery (7 cells, 500 mah Sanyo NiCads, folded with three on top and four on the bottom) is just in front of the Rx leaving just enough space for the motor, gear box and ESC.

Thanks, again.

Ron

#4 Konratz Oct 10, 2002 07:11 PM

Hello Ron,
I too have had no problems with running the antenna down carbon tubes (is it Carbon or just black fibers?). I make sure the tube length is NOT any fraction of the antenna that can be divided by 8 and is less that one wave length long. There is also a concern about reflective elements but with our small planes this is not much of a problem.

I like the folded battery idea. Can the battery come out the front for battery changes? I did not go this route as I use the same battery packs for my Speed 400 racers.

A note about setting up my V tails. On my "Simply The Best" 1.5m 2 channel V tail HLG I use a very aft CofG. I offset the sevro arm so that durring a turn the servo arm rotation would gives me more down than up. This gives me an little automatic down in a tun to keep from stalling because of loss of air speed due to drag at the start of the turn. With these very light ships any induced drag at max coefficient of lift manuvers (thermaling) can slow the ship into a stall. With rudder elevator ships and a rearward CofG this is a real problem. One could mix this into the TX, As a plus I need less forward stick to fly inverted:D.
This drag induced stalling is why some times you hear someone say that upping the wing loading helped the plane turn. The extra weight gives inertia to over come the drage induced by yawing the plane into the turn.
Konrad

#5 Ron Williams Oct 11, 2002 11:26 AM

Did it myself
 
1 Attachment(s)
Hi Konrad -

Here's the picture of how I did it. The folded battery has to be squeezed in, flexing the fuselage a bit. I haven't made a platform at the bottom of the fuselage to hold Velcro for the battery yet; I might just put the Velcro in right on the bottom of the fuselage and leave it at that. There's plenty of room for motor and ESC left and it all seems to balance just right at this point.

The servos are glued to each other and the rear one is about 3/16" higher than the forward one. The push rod connector for the rear servo is bent to put the push rod back down in line with the boom. Everything is real tight but moves smoothly without binding.

The idea of using differential elevator is interesting. I'll keep it in mind down the road after I've got some flight time on the plane.

Ron


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