hopkimf

My Feedback: (56)

I'm completing the Stinson Voyager from J-5 Enterprises. Wingspan is about 100 inches, and the weight is 20-27 pounds. I'm using a G-62 for power. It's an ancient Canadian kit dating to the '70s. Unusual in that there is no balsa. It's all mahogany plywood, with cedar and pine spars. (I was advised in another thread to throw it out and use the plan to build it in balsa. But I went ahead and built it anyway). The elevator is built up from mahogany sheets, top and bottom with several spreaders to get the airfoil shape. it's heavy, just like everything on the plane. I noticed the plans include a helper spring on the elevator to partly compensate for the weight. Maybe this used to be standard practice, but I've never seen anything like this before. Hitec servos for rudder and elevator are mounted in rear of fuse. Torque capacity is about 150 oz-in. For the size of plane this seems enough. But if I center the elevator with the servo and then turn the power off, the elevator will drop from its own weight if I bounce the model around a little on the workbench.

I could get out my fish scale, disconnect the servo, and compute the torque on the servo caused by the elevator weight. Or I could put on a helper spring. But I would rather just forget about it and let the servo hold it where it's supposed to be when powered.

Anybody else ever run into this or have any comments?

Thanks,
Mike Hopkins

BiplaneCrasher

Hey Hop,

I am no pro at this but I have head a few larger birds and have had friends with 50cc's and up. When you have the power turned on to your Rx and Tx, the power from your battery and certering info from your Tx is therefore centering your servo. When you turn ouf power there is nothing telling the servo what to do, so it will "sleep" and your control surfaces will droop. This is very normal, you do not need springs.

As far as the construction of your plane. Its sounds good and strong and should be a good flyer. The other fellas on this forum will tell you it will fly like a dog, but you will not be doing fast flying or 3D with this airframe and should fly realisticly. Maybe you could save weight by replaceing the spar with a carbon fiber spar, and/or substitute carbo where you can. I would try to save wieght by recommending a lighter engine so that you will noy be required to add tail wieghts to increase the overall wieght. Roto engines From First Place engine) are fairly light and are built very well. Plus they may be lighter than a G-62. I am also a big fan of HiTec servos, they have never done me wrong.