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Jun 14, 2018, 09:56 AM
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Oh Yeh! That's a mighty fine build! Now I get what you mean by "crude." I used to have a few MS Composit EPP profile planes (1" thick fuse), and their wires hanging out all over was what prompted me to finally replace them with full-fuselage foamies. And I hear you about the tail. I'm thinking about making special "antennae" (thread) that run from the fin to the wingtips on both sides to stiffen up that wobbly tail.
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Jun 14, 2018, 11:46 AM
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Hey Jeff--I was up to the stage yesterday where I could play pretend zoom-zoom with my wings temporarily attached to the fuselage. In the process of that I fitted the 70mm fan unit into the fuse. I remember that before the April club meeting when we groupies started building the Panther from your kits, you and I had an email conversation where I said that I was going to use a 70mm fan, and you said that you were going to process the kits with 64mm fan cutouts, and that whoever wanted to use 70mm fans would then enlarge the cutout on their own afterward for their particular fan. Well, yesterday I discovered that you had cut my fan cutout for 70mm. Wow, that was really nice of you to do that for me! I remember how impressed I was at the April meeting when I saw all those kits that you produced and realized how crazy much work you put into that project for us guys in the club, and now, on top of that, you custom-cut that 70mm cutout for me, just makes me think how much above and beyond the call of duty you went. No words to describe that soaring degree of integrity from a man, so I'll just say "Thanks!" I did have to trim the backside of the cutout by about 1/16" because of my slightly longer unit, but 1/32" ply is easy to cut with a #11 blade.
Jun 15, 2018, 09:46 AM
Jer. 29:11
jeffsch's Avatar
Jay, thank you for assuming the best.

I cut all the club kits the same. Since I didn't have precise dimensions for the EDFs, I went with the dimensions provided on the original plans. Very glad it worked out well for you!
Jun 15, 2018, 12:00 PM
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OK--Got it. I also noticed you're using an FMS 64mm EDF. I checked that out online, and it says it uses 4 cells. If you're using 3 cells, just put a bigger ESC on it, and it should go like a bat out of hell.
Jun 15, 2018, 03:09 PM
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Jeff; received your package today. Thanks muchly. I will (try to )make good use of them.
Jun 18, 2018, 01:52 AM
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Well, I botched up my build tonight. I was gluing the port wing to the fuselage with 5 minute epoxy, and I thought I had the wing root fully against the fuse as I was holding it for 5 minutes. But it didn't seat properly, so when I put on the starboard wing, I had to bend it up to compensate for the higher port wing. Luckily, the fuse ended up pretty square in the middle of the two. I now have a 6.5 degree dihedral instead of a 4 degree one. I remembered that a Piper Cherokee has a 7 degree dihedral, and it's known to be a sweet flying plane.
Jun 19, 2018, 04:56 PM
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I modified Dick Sarpolis' control horn shape from his plan, so as to balance the correct position of the clevis hole with the correct position of the tab insert fully behind the bottom of the 45 degree angle on the leading edge of the control surfaces.
Jun 19, 2018, 08:58 PM
Jer. 29:11
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Love the attention to detail.

I found that I had the recommended throws (and a bit more) with the pushrod on the innermost hole at the servo end and the outermost hole at the control horn. The outermost hole on my control horns [1] is 0.5". Something to consider when you size your control horns.

Jun 19, 2018, 10:15 PM
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Jeff, the control horns you supplied in our club kits are these kind. Was that a mistake, 'cause they're scary big!
Jun 19, 2018, 10:20 PM
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What I usually do with my control throws is set low rates to about 9 degrees, and high rates to about 15 degrees. I work that out in inches in Photoshop with the model's control surfaces images.
Jun 21, 2018, 07:25 PM
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I was looking closer into my control throws, and also referenced the control throws for a Tower Hobbies Corsair, which is about the same size. 15 degrees high rate and 10 degrees low rate for the ailerons and the elevator correspond very well with the inch measurements for the Corsair: 3/8" for high rates, and 1/4" for low rates. The rudder is a different animal for me, as I rarely use it in flight. Some people say you can never have enough rudder throw, and I assume that's for doing things like stall turns, which would benefit from large rudder throws. The Corsair's rudder throws are 1" for high rate, and 3/4" for low rate, so I'll just follow that for the Panther. I'll be using 30 % exponential for low rates, and 50 % for high rates. And my plan for the maiden is to launch on high rate. I feel very comfortable with these measurements as a starting point. And I also feel very comfortable about my ability to control my plane even if the rates are not so good. This is due to my launch procedure. You can see my launch tutorial on my blog, entitled: "Why it's OK to launch your planes with your left hand". Just to let you know, I throw a baseball with my right hand, which makes me right-handed.
Jun 22, 2018, 04:46 PM
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Finished Control Horns

Yes, I really did the old-school thing here! Bob Benjamin (or Dick Sarpolis?) would approve.
Jun 24, 2018, 03:39 AM
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Hey Dave, I've got a question for you. You said in post 15 that you used 1/2" up and 3/8" down on your ailerons (on high rate). Will you please tell me why you used differential on your ailerons?
Jun 24, 2018, 03:33 PM
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I did a quick search on "aileron differential," because I needed to refresh my memory about its effects, and I came up with this quote from gooniac33, posted 6/11/2018: "Adverse yaw is caused by the down aileron having too much throw. It creates drag that makes the plane yaw in the direction of the down aileron. . . . " I was actually more concerned with the short tail moment, but I couldn't find enough info on wing-to-tail coupling, and I don't understand the topic very well, so the best thing is to just get the initial flight on the plane, and see what it needs.
Jun 24, 2018, 09:27 PM
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Battery Placement

Well, my battery placement doesn't look like Dick Sarpolis'. Anybody else have a forward battery placement like this?

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