davidchoate wrote:Why can't I see any photos.? It is just a small windows, 3 of them, with jpg numbers. 9 oz.? Holy ***t. I am also done with bricks, linear servos, and all that stuff. I have found that spending a bit more saves $ in the long run. Those 300 kits are all heavy, but nice. I think there are too many ribs in the wings, and a one piece wing (now that I know how) is a standard modification whenever possible.
For wing strength, a hair of beefing up certainly doesn't hurt this design. At least use a basswood stringer on the upper front center cabin cross support, with a hair of gusseting to tie it in to the wing mounting former. The external struts pretty much provide adequate reinforcement, other than the wing tearing away issue caused by a frontal hit at the tip or cartwheeling, which is the reason for the cabin bracing.
My issues with the bricks and micro linear servos are as follows.
1. The bricks are 3A rated, where a 6A ESC is not only more robust, but mounted in the serviceable cowling, where it can get some air exchange.
2. Like #1, the BEC chip can also get some cooling in the cowl, and is replaceable with the ESC.
3. Horizon micro linear servos blow H-bridges all too often. This is seen when the servo goes to one end on power up, and stays there.
4. Micro linear servos hang up, due to potentiometer issues. I understand the contaminant issues, but the problems I've had have occurred before contamination could be an issue. One would think that with something like 4 contact leaves, that this design would be more reliable than a small rotary pot, but that hasn't proven to be the case. Again you often can't get to the brick easily, for serviceability.
5. Mounting. The holes require porting for all but the smallest screws. I've come up with various serviceable mounting schemes, but they are more effort than simply mounting a standard servo.
6. I've used 3s with 6A ESCs with no problem, including ones rated for 2s. The bricks and micro linear servos are 2s max rated.
7. Cost. The last bl brick I bought was on sale at $30. I maybe should have bought a few more at that price, but not at the standard price.
Going back to the serviceability issue, this model will be fully serviceable, with standard design 1.7gm servos. The tail servos are mounted between the landing gear legs where they enter the fuse, and even allow for the plan landing gear scheme to be used. I could make a small access door, but irregardless cutting away a small patch of covering between the gear legs, from the center fuse keel to the first outward stringer on either side, will provide servo access from the fuse bottom. The servo arm holes were downsized with epoxy, for .020" pushrod wire. This setup worked out really well, as the pushrods could be installed into the servo horns, with the horns already installed on the servos. The laser cut slots cut into the fuse formers for the landing gear mounting just happen to work out perfectly, allowing the pushrods and servos to be fit into their mounts, with the pushrods going into the cut slots as you are installing the servos. Without those laser cut LG leg mounting slots, one would have to flex the heck out of the pushrods, to work the servos into their mounts, in the small area between the fuse formers. I'm not a fan of installing servo control horns after servo installation, as the horn should be held when tightening the screw, to avoid damaging the servo gears. Just a small notch, cut into the edge of each laser cut LG leg mounting slot, provides the pushrod entry hole in the fuse former halves, for each servo. Hopefully all this can be seen in the pictures.
The Park 180 motor came without a mount, which was fabricated from plastic tubing, epoxied to the motor mounting tube. I had a ply micro motor mount on hand, which worked perfectly for the mount base. I used this motor, since the 10gm Hextronic with mount included wasn't available at the time. Also just got a 2s-200 Hyperion lipo in the mail today, which will easily fit in the front fuselage bay, along with the receiver. Again using a tapped prop saver for the prop mount, as I have a number of them. They're otherwise useless to me, with a rubber band mounting scheme that would look terrible. The front is tapped for a #2-56 prop retaining screw.
Also shown in one photo below is the steerable tailwheel, with aluminum tubing bushing. The bushing will glue to the rear edge of the fuse, and the steering arm is bent 90 degrees, entering into a hole drilled into the rudder. All the clearances including tail surface hinge gaps have been worked out for this setup.
You do not have the required permissions to view the files attached to this post.