Cris Handegard's KI-43 OSCAR

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combatgoblin
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Cris Handegard's KI-43 OSCAR

Post by combatgoblin »

Here's a link to pictures of a KI-43 OSCAR I built from Cris Handegard's
kit.
http://www.royfokker.com/KI-43a.html


I've flown it and it will get it trial run at Bushwacked.
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o1moregil
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Post by o1moregil »

Nice! whats the covering?
combatgoblin
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Post by combatgoblin »

Duct Tape and paint
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Ed Kettler
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Post by Ed Kettler »

Nice looking bird!
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Dane McGee
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Post by Dane McGee »

Nice Oscar[:D]
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Post by NeilD »

very nice plane.
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Don Holmes
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Re: Cris Handegard's KI-43 OSCAR

Post by Don Holmes »

How many KI-43 Oscars left ?
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Don Holmes RCCA #957
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Re: Cris Handegard's KI-43 OSCAR

Post by grasshpr »

12 Oscars left...
Chris Handegard
RCCA 481
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dditch
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Re: Cris Handegard's KI-43 OSCAR

Post by dditch »

I'm finishing up 2 of Chris's Oscars.
1 is Nitro and 1 is Electric.

For the Nitro:
I used a Hobbypartz .25 ASP AII (see my other thread comparing this to a Magnum .25XLS). I used a Dave brown mount. The mount is spaced out from the firewall about 1/2" or so. I used some cylindrical aluminum spacers from work. You could use oversized nuts. Sullivan 6oz round tank is covered in foam and I wrapped it with packing tape so it would slide into position easier w/o the foam comming off. I have a fill line run which goes to the bottom of the tank w/ tubing. That runs out the bottom of the cowl. I'm doing a Green on top and white on bottom scheme. Doing a test of the green packing tape, I see how it causes dark striping where it overlaps. So what I did was to paint the BiDi tape with green plastic Krylon, THEN put the green packing tape over it. This makes the finish darker plus more consistant and no striping. I still have not maidened it and need to still do some graphics w/ my vinyl cutter and mount the canopy. I will likely maiden tomorrow w/o the canopy cause I'm running low on time. I will need to check CG again when ready to maiden but I'd say I'm a TAD on the nose heavy side. I'll add a little bit of tail weight if needed cause I expect nose heavy, I won't be able to have enough elevator authority to make cuts.


For the Electric:
I have to say that the electric conversion of this kit is much better than I'd hoped for. My motor came with a standard X mount. It needs to be spaced off the firewall for proper distancing. I could have purchased a metal bracket for this but used some more of those aluminum spacers. Because I'm never doing it easy on myself, I opted to blind nut the firewall for a nitro mount so there is an adaptor plate in the middle. I put the ESC up front on the firewall. It BARELY fits w/ the motor mount. Maybe if I had to do it all over again, I'd allow space for the ESC to fit in the middle and have the Motor mount around the ESC. BEC is also up on the firewall. I cut a hole in the bottom of the firewall so I can push the battery cable out. This allows me to pre-load the battery into the fuse, then plug in when ready to go. I looked at making a hatch but felt that unless I cut intot he sides, I'd be messing with the integrety of the strength of the fuse. So I have to remove the wing to place the battery in. Because Chris has the center area of the foam fuse cut out, there is MORE than enough room for a battery to fit inside. I mounted my servos as AFT in the fuse as I could so I would have room to slide the battery FORE/AFT in order to get the correct CG. The amound of room I have is GREAT, more than I need. The battery is velcro'd to the TOP of the inside of the fuse, then I have a spare piece of blue foam that wedges the battery in place. I need to come up with something so that wedge does not slip out. I'ts pretty tight, but just to make sure it does not come off. I"m using a 900Kv motor from HobbyKing. It may not be the best choice, but it's what I had when I decided to do one electric and realized I probably did not have enough time to test electric motors and make my club's fall combat contest. I was able to get 14,500 RPM w/ the ATV set at about 95% and using a GOOD strong LIPO (Nanotech or Gens ACE). I have a Hobbypartz monster Power 25 on the way but it won't get here till the next contest. That motor will require some different spacing cause it's longer. The ELectric is weighing in at 3.70lbs which includes the heaviest battery I'll be using in place. With the lightest adequeate battery, it's about 3.5lbs. Both batteries I already had and I spec'd the motor to match those batteries (6S 3000mAh/3300mAh 25C Nanotech/GensAce). Those are used in a 500 size helicopter.

I will hopefully maiden both of them Friday morning with using 1 built up wing. I will build up the 2nd wing friday night, doing the canopy installation and graphics then. Hopefully, only minor tweeks will result from maiden. Then I can test the 2nd wing Saturday morning.
combatgoblin
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Re: Cris Handegard's KI-43 OSCAR

Post by combatgoblin »

I am just finishing up a P-39 I built it to see if I could get it light enough to do electrics.I figured you would need a 6s 4000mah
battery and this would put the weight at 56 ounces perhaps the nano batteries are more efficient.If I built another one I could shave about two ounces but it would still not come in at the minimum weight now to see if I can hit the minimum weight with a twin.Let me know how your KI-43 flies as I have a kit of one I could try to lighten to make the weight.
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dditch
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Re: Cris Handegard's KI-43 OSCAR

Post by dditch »

I did the maiden on the Ki-43's this morning before work.

Electric:
Using a plug attached to a string and aluminum bar (at other end) I fished the plug from the front, plugged it to the battery and then pulled as I inserted the battery. Otherwise, it's hard as heck to get the battery wire out the front pushing from the other end. I ran the motor up and adjusted the ATV for 14,500RPM. One thing I really love about electric is you KNOW it will start and you KNOW how it will perform. You also get to walk up to the flight line w/ the prop not spinning and you can take your time and relax. My CG was near perfect with no nose-weight or tail-weight added. I now have a point of reference for the battery placement. I flew with the 6S 3300mAh 25C Gens Ace battery (the heavy one). Overhand hand launch was good. 13mph wind and gusting so the head wind helped. It flew great. I had too much throw on the ailerons and it was twitchy in the wind. After I landed, I took some throw out mechanically. I did a 5 minute flight and will measure the mAh I put back in tonight. I was pleased with the maiden. I don't think I have any significant tweaks to do before tomorrow. More flight time getting used to the plane would help, but I won't have that.

Nitro:
I was not that happy w/ my RPMS. I'm wondering if my fuel is bad or something. I'll have to try some different fuel tomorrow. I was only getting 13,800RPMS. Wonder if it has to do with the cowl vs. test stand? I have some 20% I can try in order to get the right RPMS. I don't think I should have to. I'm using MAS 10x4 prop. The fuse was slippery and I did not have any sandpaper on the fuse to grip so I underhand launched it. Trim was mostly good, I needed just a little bit of right aileron. Considering the amount of wind, it was not too bad. I could stand to add some differential and/or reflex. I had none on maiden. I think the Electric seemed faster, but can't really tell. I have them on 2 different radios so at some point I could get some help and do a flight test seeing which is faster. The Nitro is just at the required weight, maybe a couple ounces over. I went for ruggedness and put BiDi all over the fuse and wing.

Tonight, I need to add graphics and the canopy.
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dditch
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Re: Cris Handegard's KI-43 OSCAR

Post by dditch »

Pictures:

Note that on the electric, I put in an exhaust port on both sides of the back fuse. I staggered them to reduce weakness. This is so that the air comming into the fuse to cool the battery has a place to escape. Note the color of the fuse how dark and somewhat consistant in color due to the paint under the packing tape. I"m still rifeling through color schemes. I think I'll try to keep it simple though.


http://www.mycoolrc.com/PICS/KI43ElectricMaiden1.jpg
http://www.mycoolrc.com/PICS/KI43ElectricMaiden2.jpg
http://www.mycoolrc.com/PICS/KI43ElectricMaiden3.jpg
http://www.mycoolrc.com/PICS/KI43NitroMaiden1.jpg
http://www.mycoolrc.com/PICS/KI43NitroMaiden2.jpg
http://www.mycoolrc.com/PICS/KI43NitroMaiden3.jpg
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Don Holmes
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Re: Cris Handegard's KI-43 OSCAR

Post by Don Holmes »

dditch wrote:I did the maiden on the Ki-43's this morning before work.

Nitro:
I was not that happy w/ my RPMS. I'm wondering if my fuel is bad or something. I'll have to try some different fuel tomorrow. I was only getting 13,800RPMS. Wonder if it has to do with the cowl vs. test stand? I have some 20% I can try in order to get the right RPMS. I don't think I should have to. I'm using MAS 10x4 prop.
I have 2 of the ASP .25 AII ( last years model ) and I only get 13,800 with 10%.
You need to go 25% nitro and add some castor oil and that should get you to 14,500
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Re: Cris Handegard's KI-43 OSCAR

Post by grasshpr »

Looks great David, nice job! Without the canopy they have that unpiloted drone look. For my nitro engines that struggle to get a MA 10-4 up to 14.5k I switch to an APC 10-3 before going to too much trouble, or hit it with 30% but don't get set too lean and overheat. The APC has less pitch but is more efficient and lets the motor spin just a bit more easily and unload in the air. Seems to work pretty well. The added castor Don mentioned is also a good idea that I use with every gallon of store bought fuel I run.

Another source of overheating in cowled situations is insufficient openning for outflow of cooling air around the cylinder head and muffler. The opening in front is large so if there's not enough outflow opening to let it pass freely the air gets stalled a bit in the cowl and may rob a few rpm.

You're the first I know of to electrify one of my kits, nice work! I hope they serve you well, take no prisoners!
Chris Handegard
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dditch
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Re: Cris Handegard's KI-43 OSCAR

Post by dditch »

Had a great test flight on the electric this morning with a new wing. Unfortunatly I need more time than 2 test flights to familiarize myself with 2548 planes. After flying SSC, I was depending on tight turns too much. The Oscar did turn tight but I did a split S coming out downwind and plowed into one of the few trees in the foreground. I was hoping I was this side of it, but smacked into it and luckily the wings hit first. Battery pushed the firewall off sending the electric motor, cowl and firewall all as one piece about 30'. The battery went about 60'. I was lucky to find it. I made the mistake of cutting back the BiDi that was wrapped around the firewall to get to see where I'd drilled the mounting holes. I'll do that differently on the rebuild. I think I'll also put a crossbar on the inside of the fuse in order to keep the battery from doing this again. Hopefully I'll remember to take pics. I forgot to take pics this morning after I did the graphics.
I then flew the Nitro powered Oscar.
The Oscars finished 3rd just behind Don's Handegard P-47.
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