I just got a Sig Kadet Senior ARF and I have a couple of questions. With everything that I have read about having to add a lot of weight to balance this plane, especially if it is converted to a tail dragger (which I am going to do), what do you think about putting a Magnum 80 four stroke on it? I can always throttle back! Any advice on the size of the main gear for a tail dragger conversion? This is my first plane after a 6 year break, it's good to be back....

Wilinfla,
I built one of these this summer and converted it to a tail dragger. I used a Saito 65 for power,more than enough. If I tried to fly with more than 1/2 throttle, it wanted to go left and up. That was with washers behind the motor mount to offset this. I think your Magnum 80 might be overkill. This is a light plane ; t doesn't need much power. With the Saito I didn't have to add any weight, just moved the battery up under the fuel tank.
Sam

Sam, thanks, maybe the Magnum .61 4 stroke would be a better choice insted of the .80.

Will

If you haven't read this thread already, I've posted pics and info on my Kadet Sr ARF taildragger conversion here:

http://www.rcuniverse.com/forum/m_13...tm.htm#1349468

I just maidened it this morning and it flew beautifully. Unless you're a rank beginner, I'd say the taildragger conversion is a must. I especially like the wheel pants I added. Mine came out right at 8 lbs and balances perfectly with an ASP .75 2stroke. The darn wing is so big, a couple of lbs is nothing for it. The Magnum .80 4stroke will be perfect for it. I doubt you'll have balance problem with that engine. Go for it!.

I gotta question for you guys too.,
Just picked up my Blue Kadet Sr ARF and a TT Pro .61 and Volfly you may be ablel to answer this.
Sitting here looking at that wing and the attachment system and remembering the old Indy RC Robinhood 80 that stated you need struts.

Do you think this plane needs struts. Specially if you plan to do some hard training and float flying.


Thanks

JDS

I don't believe struts are necessary. If you wanna hang a 1.20 on the nose, I might start to worry. Mine flies beautifully as is. I did drill a small hole on the LE mounting tabs and put a 4x40 bolt through it to keep the two wing halves drawn tight together. The wing mounting method is plenty strong. It is more imporntant that the aluminum joiner fits snug in the pockets. I lightly coated the pockets on mine with finish epoxy resin while I was fuel-proofing the wing root rib.

Having said that, I can visualize how the Kadet would look with struts, along with the wheel pants I have on mine. Should look marvelous, as Billy Crystal would say. I remember seeing in a Saito brochure a giant Telemaster that was modified with struts, wheel pants and a round cowl. It had a wonderful 30s cabin cruiser look to it. Struts might be a worthwhile addition just for esthetics reasons. Should be easy to do with the double spar wing the Kadet Sr has.

Oddly enough, of all the ARFs I have put together since I got back into RC a couple of years ago, this Kadet Sr has given me the most satifaction. It truly reminds me of why I loved the first Kadet Sr I'd built long ago, and how I regretted having to sell it.

Sorry to veer off-topic, but... JDS, I noticed your nickname is CAP10b. I happen to be putting together one of the prototype .60 size CAP10b from VQ model aircraft. Looks to be an interesting sport scale airplane.

Volfly
No problem, I campaigned a Yellow A/C Cap10b with a Brison 2.4 for a couple of seasons, Great plane lots of stories. I saw that VQ Cap10b............I want one of those.........get some pics....please!!!

Getting back to the Kadet. I don’t blame you for adding that 4-40, looking at it and knowing all the knocks and dings one takes when training students. I would feel more comfortable with something besides that hook into the forward bulkhead. But experience is why I am here you guys know more about this model than I do. I know SIG stuff builds like a Brick House and their ARF's seem to be designed along those lines. Knowing that I would trust SIG before any other ARF's, with maybe the possible exception of Kangke USA. I guess its up to the individual. Wouldn’t take much to add them. I guess the best thing to do is get some flights in and go from there.



Thanks

JDS

Just use Throttle Control I had a Saito 72 on mine and it flew great ,but I did a slight dive at the runway at full throttle inverted and the Large Barn door ailerons were fluttering like a humming birds wings, I broke both servos. Good luck and you'll love the plane

I assembled mine with a K& B .61 and was very happy with the way it flew but since it has gotten cold here the .61 has started to have cutoff issues. On a whim I removed the cowl and bolted on a .91 Surpass. Now the plane flies with serious authority but the only flight issues I had was having to add some down trim into it and having to make a perfect landing due the ground clearance issues with the prop. I will admit the plane spends most of it's time at 1/3 throttle with this engine. When the weather improves I will probably put a Saito .72 on it because the 4-stroke sound is what this plane deserves. Mine is still a trike wheel setup but that will be changing soon as well and even though the struts are not needed it really makes the plane look so much better. I would suggest hard points be installed in the wings to reduce the strain on the wing ribs from the rear strut, not from flexing but from possible contact with high grass or whatever.

If you have seen the Warbirds over Delaware video from this past meet, does anyone know the type of floats that were used on the Kadet in the video? That plane really looked sweet!!

Thanks Guys,
All good suggestions and yes I am interested in knowing what size floats to purchase when I get ready to use them. The club is getting a new field off Lake Grapevine and WOW Float Fly here I come !!!


JDS

Thanks for all of the suggestions, I see that Magnum has come out with a new .70 4 stroke, so I think I am leaning towards that. Any ideas on the amount of right and down thrust for the engine? The assembly book doesn't seem to address that issue.

Thrust is prebuilt into the firewall and you will not need to adjust for the .70 4-popper. Just sguare the engine in the mount and you should be fine. good luck!

I fly a blue KSA myself powered by a Super Tigre .51 ringed engine. It is also carrying a wireless video system which includes a 10 cell AA nicad pack for power.
The plane is still overpowered. One thing I would do (and have since done) would be to add some tri-stock to where the tail meets the fuse. I have had my fin try to remove itself twice so far. Can even see it waving merrily back and forth in one of the videos when I had the cam aimed to the rear.
Forgot to mention that even with the overkill engine and the added weight of the video system, it doesnt need any struts. If I was gonna do it over, I would have used my .46LA instead of the .51ST.

Yes I saw that Vertical fin in the back and all I could do was shake my head. but your right I aint gonna be screaming out of a 1/2 cuban eight with a half roll and a snap. So no need to worry about it I guess. And the TT Pro .61 is more for STOHL purposes than for top speed. I plan to use a 12x6 or 13x6 wide blade Graupner coming off the water or out of golf course first cut rough, that’s about what our grass field is like. Also I plan to tow some gliders if I can find anyone in our club to use as guinea pig. Thats what I meant by hard use. But let me get it airborne and go from there if I see things bending, flexing and flapping thats a different story.

Thanks

JDS

Excellent advice. I did that on my Kadet Sr from the getgo. The tristock went on either side of the vertical stab, over the horizontal stab and extended a little into the the forward sloped section. I tapered the forward section of the tristock and then covered them with the same transparent blue Ultracote. It looks like a factory job.