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Jul 05, 2002, 08:52 PM
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Dorme's Avatar
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Ford Trimotor/ Kavan


I bought this HL last week and put it together over the week. A fast build and most of the plane is already together. But there are a few things to look out for in the building instructions. I recommend you read it all first and think about it before assembly. For example, they have you installing the LG before the nacelles - wrong. You'll have to remove the epoxied LG to get the nacelles on. These are minor problems as the rest of the kit is very well done.

I took it out tonight to fly it and it wouldn't ROG. So I tossed it and it flew on the hairy edge of a stall out about 30 feet and probably would have gotten on step as it was gaining speed. But it started doing a dance from side to side and I put the elevator down to land it when I had nothing and it crashed. The front prop came off and I found that the elevator wire had broken. Easy repairs and was done in 30 min. My question for those that have Ecalc and the like, is this enough power? Mike Hines at HL said it was a good flier and I trust him.

WA 256 sq in.
AUW 19 oz.
Motors 2 280's with APC 5 x 3 props (no GB)
Bat 7 cell 600 AE
ESC Sprite

This is the recommended setup. Any suggestions before I fly it tomorrow would be appreciated. Thanks
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Jul 06, 2002, 06:24 AM
jah
jah
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Here is a Pic


Here is another shot I took at SEFF. Dorme, hope you get it to fly, but here is a pic.
Jul 06, 2002, 07:14 AM
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Dorme's Avatar
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One of the nice things that this kit has is a touch up paint.
Jul 06, 2002, 08:17 PM
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Jah, I don't know if you saw the tri fly, but here is my report from flying this evening. First I changed the CG to a little aft and with a fresh charge I ROG in 30+ ft. It was dead calm. It took a while to gain altitude and I was never able to go above 30-40 ft. It was operated at full power at all times as any reduction, unless straight ahead would cause it to head towards a stall. After 5 circuits and not feeling comfortable with this beast, I headed for a landing. With reduced power it started to lose height fast. Just as I was 10 ft above the ground, a small gust caused it to pitch up and it stalled before I could go out and and dig a 5 ft hole to give me enough room to recover. It has a stout wing and only the nose was knocked off. Easy repairs but this is going to the auction. It is not a good flyer and demands your devout attention. Too bad because if Kavan had made this a 5 ft wing (or bigger) the weight would not increase that much and it could be powered with 300's or 400's and have ailerons as well. Some planes just do not lend themselves to small scale. This is one of them. I did a check of my weight just now. 18.5 oz. Well within the specified numbers. The wing loading is high though - 10.4 oz. In my experience, this is too high for a plane of this size and dimensions. I had a similar problem with a P-61 and Farman in the same wing size and weight catogory. It should be around 9.5 which would put the AUW closer to 17 oz. Even though the wing span is 41 in., it has tremendous drag from the nacelles, thus it should be a bigger plane for more engine and bat to propel it easily.
Jul 06, 2002, 08:23 PM
jah
jah
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Sorry to hear about the crash. I did not see it fly at SEFF, I was only there in the AM Saturday, windy and rainy. Bummer.
Jul 08, 2002, 12:25 PM
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I fixed up the Tri and was getting ready to take to the store to sell when I found a battery pack I hadn't seen in a while (8 cell, 650 maH, NiMh). Because of its weight I wondered if it would make a difference. I weighed in the plane and found that it brought the weight down to just under 17 oz and balanced the plane nicely all the way fwd. I had to try this as the WL was now down to 9.56 from 10.4. BTW, I am using HS-50's and Hitec 555 with a Castle Creations Sprite.

It was blowing 7 mph with gusts over 10. I tossed it and it climbed with authority. Even with the gusts, it had the pull to handle it. Throttling back to half, it still had the power to maintain control, you just don't want to turn to severely in order to prevent a tip stall which this plane in its wing configeration is prone to. Power was used to set it down, but with the small wheels it always noses over when I land in grass. All in all, a much better plane with the weight reduced. It is like the difference between night and day with the weight reduction. Now I'm thinking that if you could change the motors from the 280's to a smaller motor that is geared for the 5 x 3 props, it would be an even better flier. It would fly slower as it is a speedy little beast right now. Any suggestions on a lighter motor out there?
Jul 08, 2002, 02:04 PM
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Kevin Murray's Avatar
I saw the Trimotor at SEFF. I don't know it it flew I did not aee it up.
I don't know why they would put a "dummy" prop up front. Why not just stick another motor up there or judt remove the center prop for flight.
It's got to be an awfull waste of energy just windmilling up there.

Looked like a nice plane though.
I would put in a third mill though
More hands less work
Sep 07, 2002, 02:24 AM
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Kavan Ford tri-motor


Quote:
Originally posted by Dorme
Now I'm thinking that if you could change the motors from the 280's to a smaller motor that is geared for the 5 x 3 props, it would be an even better flier.
What about making the third prop earn its keep by attaching it to a motor? Perhaps with three motors it would fly better at a lower throttle setting?
Sep 07, 2002, 07:43 PM
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Kevin Murray's Avatar
Quote:
Originally posted by Kevin Murray

I would put in a third mill though
More hands less work

that's what I would do.
Dec 02, 2003, 11:42 PM
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that is exactly what i am doing right now--the motor up front is another 280.

i figured that since Kavan also made this as a 3 engine float plane-----watch for the reasoning here----- then it could fly on 3 engines without the floats as long as the CG was correct and the AUW wasnt too high.
Dec 02, 2003, 11:58 PM
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The Johnson 250 motors are a pretty hot wind and would probably give some added thrust and reduce weight by a half ounce or so. There are also some hotter wind 280 motors available.

Do a search on the power systems forum for J250. Someone posted tests for the J250 a while ago.
Dec 03, 2003, 12:10 AM
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So how 're you wiring it, series or parallel? And what size / type battery pack are you using?
Dec 03, 2003, 12:56 AM
Registered User
parallel--and here is the picture with the cowling but not the rings yet. all the positives come to a point and all the negatives come to a single point, then hook up like any motor would.

280 size motor, same prop using collet style adaptor for nose. 2mm. found it at hobby lobby (the adaptor). I think this plane is discontinued there--i bought mine for 109.00 then they were gone i think.
i have seen them still avail at the sig web site but its the float version, looks nice though and seems to be engineered for 3 motors in use to begin with, but the down side is of course no wheels unless they throw that in.
i cant bring myself to put on all those cheesy decals..i was tempted to make it a Fokker.
the cowl rings will finish the build.

i am planning so far to use 700 mah 9.6 volt battery nimh..but i have to check to make sure its enough power. i am planning on using the 20 amp pixie or 30 amp gws,,any thoughts??
Dec 03, 2003, 01:00 AM
Registered User
my apologies to hobby lobby --i see it is there for 159.00 a very nice kit.
Dec 03, 2003, 01:05 AM
Registered User
right now its at about 400g even with the third motor, and the battery will put it at about 500g which is what the instructions say is the recommended AUW


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