|
|
|
James was nice enough to contribute a pair of KST245MG servos to the JW30. He has these in his ultralight JW36 and they perform well and have taken some serious abuse. The drivetrain on his servos is still tight after a year of flying so I think these are an ideal selection. See photo below.
I am also doing a small run of Tweety JWs for a few of the local pros for more comprehensive testing and analysis. If anyone else is interested in participating please send me a PM. We are building ultralight and heavy Tweetys to test the full wind and speed range of the planform. Some will use gyros and others won't as well. |
|
|
|
|
|
|
You and I are going to have to catch up in April. Will bring a second model box to take some stuff home haha
|
|
|
|
If you pot the fin, it could even be a friction fit.
|
|
|
|
|
|
Lots of progress on the tweety. Servos potted and installed. Receiver mounted. Spackle completed, wing taped and first layer of color applied.
I tried a new technique for blending the servos into the airfoil. I mounted the servos below the surface of wing by about the thickness of a business card. Then I smeared white gorilla glue on top of the servo and activated it with water. After it foamed up and cured, I sliced the top off the glue and sanded to shape. A coat of spackle resulted in a perfect continuation of the airfoil at the servos. Photos: ImagesView all Images in thread
|
|
|
|
|
|
Added some stripes this evening:
|
|
|
|
|
|
Man i need tweety, that looks nice!!
|
|
|
|
|
|
Built the battery tonight and installed it in the fuselage. A 4 cell AAA block pack fits in the nose. Bench fly weight at this stage is 9 ounces. It will need 1-2 oz of lead to balance out so it should come in around 11-12 ounces when completed.
ImagesView all Images in thread
|
|
Last edited by Aerogance; Feb 12, 2016 at 10:43 PM.
|
|
|
|
I like the way you cut the fuse to fit battery, I might go with just a cut out from one side of fuse to other side. I'm going to use a 450mah 1/3rd aa pack as this is an attempt to go as light and robust as possible, with what gear I have around the shop. The radio gear and rest of the kit (depron fin) came in at 4.15 Oz with fuze not sanded, and no covering, hope to be less then 6.5 Oz rtf
A quick test with everything taped in place including elevons and control horns and it was very nose heavy. Might have to get the wing done completely before cutting for the battery... Yes I'm lucky to live so close to Aaron to be in the loop ImagesView all Images in thread
|
|
|
|
|
|
I got the Tweety finished and just need to add nose lead. CG should be somewhere between 1 1/2" to a max of 1 9/16". AUW is looking to land at 10.80 ounces
|
|
|
|
|
|
Tweety
Looking Good Aaron,
Time to see what the mountain thinks of her. I hope she fits in the car. J |
|
|
|
|
|
Josh and I shot up to Parker this afternoon. Wind was 8 mph with gusts to 12 mph at first and lift was so-so. Despite this, I managed to maiden the Tweety JW. It was nose heavy with the CG at 1.5" as expected. I turned a few DS laps in the light air and then landed to do some adjustments.
I added about 1/16 oz of lead in the tail and relaunched. This time it was tail heavy but I turned a few laps and landed again. After a third CG adjustment, the plane much better but was still a tiny bit nose heavy. I left the CG alone and worked on the trim and throws. After getting everything dialed in, I flew the little plane for the rest of the afternoon. The plane weighs about 11oz and is very fast at this weight. On the front, the crows and ravens couldn't hold pace with it. On the back, it easily carved large circles but could also pull tight circles too. Josh and I furballed most of the time and found his 13oz Mini JW to be the best furball companion for it. As the afternoon wore on, the wind slowly picked up and eventually topped out with gusts to 16mph. In the better air, the Tweety JW really came alive on both the front and the back. The air was fairly clean so the little bird was able to get some speed going. Once on step, the Tweety JW locks in like its bigger brethren. Elevator only laps were very common. I am not sure how fast it went because we did not have radar, but the plane seems like it could do 150mph in better wind. A heavy tweety would certainly be faster still. The KST 125mg servos are a perfect match for this plane. With proper geometry, slop is very minimal. The only complaint about the KST's is the supplied servo arms have the closest hole to the hub very far out. It would be necessary to drill closer holes but on a plank if the holes are not exact then the handling of the plane is affected. I chose to use the factory holes for now and will drill new holes once everything is perfect with the CG and trim. The Tweety JW will be a very interesting plane for a few reasons. First of all, it can easily be built to beat the FAA weight limit. This is a proper epp DS plane and not some EPO fragile job so the FAA limit is compelling for those that don't want to register. Secondly, the plane should be able to be built heavy and attain very notable speed. Being small, you don't have to be going very fast to get all the thrill of high speed DS. I believe the plane can be a contender for the Tweety 200 race and could potentially break the 200 mph tweety barrier. Thirdly, with the new gyro receivers from Lemon and Orange, you can have a stabilized DS acro machine that takes up almost no room in your car. I haven't flown in quite a while so I was a little rusty. The Tweety JW was easy to fly and get my thumbs back with. By the end of the day, I felt really good on the sticks. The plane wasn't twitchy or squirrely as one would expect of a tiny airframe. The Tweety JW sounds just like a larger JW, but at a much higher pitch! I plan to get the plane back out again in better wind so I can fine tune the CG, rates and trim and then hopefully get a radar speed. Until then, a few of the local guys are working on Tweetys of their own so there should be more feedback soon. James is building an ultralight one that should come in around 6 oz. Bruce is working on a heavier build that will hopefully come in around 20 ounces. A few more kits are going out to local builders so there should be a good variety of weights, build styles and equipment choices to evaluate. Josh is uploading video from the maiden so I will post it here once it is available. |
|
|