mickey-gem

I Just recently finished my electric conversion for the Sig Kadet Senior ARF. I maidened it today
and was very pleased with the results. I bought this palne specifically for the e-conversion, I wanted a big
plane for nice relaxing flights! I also wanted a platform for using remote camera or video system for aerial
photography and video. I also converted this ARF to a tail dragger, because I find them aesthetically more
pleasing to the eye compared to the trycycle gear that came standard with the arf. I mounted the elevator
and rudder servos in the tail of the airplane because I did not like the large dowel pushrods that came with
the ARF. Components of the conversion are:

Sig Kadet Senior ARF 80.5 inch wingspan
AXi 4120/14 outrunner ( I Later decided on a 4120/18 better suited for 6S lipoly)
JETI Opto Advance 70 amp speed control
Model Motors Adjustable engine mount
FMA direct FS 8, 8 channel dual conv. receiver
Two Kokam 3s 3200 packs wired in series
Hitec HS 81 Metal Gear Servos. (x2 ailer. 1 rudder, 1 elevator, and 1 for steerable tail gear)
13X8 APC E prop ( Later settled on a Top Flite 13X8 wood prop)
Hanger 9 Dural HAN 160, 60 size main landing gear
Ohio Products tail gear assembly
AU weight is 7lbs 9 ounces !

I originally planned on using a UBEC to provide power to the servos but I ended up needing
to add weight to the nose, which I have read is not uncommon from previous posts on this model.
I wanted to add functional weight instead of dead weight so I added a JR 800 mah receiver pack
and switch harness to provide power to the servos. I mounted the receiver pack on the Model
Motors Aluminum engine mount. I still had to use 3 ounces of lead in the cowl to achieve the proper CG.

The maiden flights were wonderful, very smooth, scale, takeoffs were acomplished at 3/4 throttle
cruising was maintained at 1/4 to 1/2 throttle. Landing seemed to utilize a considerable amount of runway,
it is a floater! The landings are great, very smooth! I never really used full throttle 3/4 was sufficient for
climb performanc, but it is nice to know it is there if needed! I will post more pics of the cowl area tomorrow.

Enjoy!

Walt Thyng

My Feedback: (9)

Nice job! This one goes into my "Future Projects" file.
Walt

mickey-gem

Here are more pics of the nose, I had to take off the original shrink wrap from the Kokam pack
in order to expose more of the wire length, I then put on after market shrink wrap. Another helpful
point: I had difficulty tightening the prop adapter (MP Jet) so I Dremeled a slot in the end of the prop
adapter with a metal cutting disk, this does not interfere with the original threads on the shaft and allows
me to use a large flathead screwdiver to keep the shaft steady while I tighten the prop nut. Sorry The
pic for the prop shaft adapter is a bit blurry.

Enjoy!

mickey-gem

The only thing I have left to do is find or make some good wheelpants, and polish the aluminum landing
gear to a high degree of shine! Any suggestions on wheel pants? I would appreciate some leads!

In the last picture you can see that I completely took out the servo tray which was preinstalled, it came
out easily by cutting around the glue joints then pulling it our gently so as not to damage the fuselage sides.
This also leaves plenty of room for future payload options!

Originally the plane came with a plywood nose gear mount glued to the firewall, It came off very easily soaking
the area with CA Remover, then gently prying with a sharp flat razor blade, I then dremeled the area to slide in
the battery packs.

I cut and trimmed a piece of foam to place inside the firewall, I cut out a square piece directly in the middle
of the foam which the battery packs slide into neatly and provide security and impact protection for the packs.
In the front the packs fit fimly against the cowling.

Enjoy!


Thanks!

Tweet

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Nice job.

I'm planning to do one of these and am also in Colorado.

I have the motor (4120/14), receiver, UBEC, servos, etc., but am waiting for a Kadet Senior as Sig have temporarily ceased shipments while they move to a new factory in China or wherever. I am also planning a tailwheel conversion.

I have also considered trying to take most or all of the dihedral out...how does it fly with it in?

I guess if you found a way to leave the elevator/rudder servos forward you could alleviate some of the aft CG problem...

What kind of flight times are you getting?

mickey-gem

The kadet flew well with the stock dihedral, I was able to perform mild aerobatics, loops and slow rolls.
Note, on this ARF much of the dihedral has already been taken out per the original design. The Kadet Senior KIT
has much more dihedral.

The longest I have flown is about 15 minutes, but I only used about 2000mah of the 3200 packs, so I probably
could push to around 18 minutes with another 2-3 minutes of reserve time left.

I had to call numerous hobby shops in the area before I found one. Colpar East in Aurora Co. had two, I believe
they still have a blue one.

Regards.

Tweet

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When I look at your picture I don't see much dihedral...

I was thinking of using a 5S Thunderpower (6000mah or 8000mah) as has been done by others. That would put me down 3.7V versus where you are at.

I also have standard size servos. I hadn't considered going to the mighty minis...I am using those on an Accord R&R but that airplane is a bit lighter. They must be working just fine for you though. By putting them in back that was the only way to go.

My standary servos put out 61 ounce/inches of torque versus 42 for the HS-85MGs and weigh 1.6 versus .77 ounces.

Tweet

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Actually, the AXI I have for this airplane is a 4130/16, but this should do fine.

mickey-gem

I think Sig made a good call when they decided to produce the ARF version without much
dihedral. I have read many post here in RCU in reference to making modifications to the dihedral on the
KIT version as well as adding ailerons. ( The kit verson only has elevator and rudder)

So Sig did a wonderful job of bringing the ARF version up to date by minimizing dihedral and adding
nice large ailerons, in a very big package! 80 inch wingspan and 64.5 inch length is a nice size plane!
It looks much more scale without the dihedral.

I would definately suggest 5s lipo, I am only using 6s because I already had the two 3s packs. I
have programmed an end point on my throttle so I cannot use the full voltage of the pack. The Axi 4120/14
is only rated for 5s, although the Model Motors web site does give test numbers with an 18cell nicad pack
which is roughly the equivelent of 6s.


Good luck with your e-conversion endeavors!

Tweet

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It looks like a lot of fun and I can't wait to get one. You have a lot of ideas I plan to copy. Thanks for the feedback on the battery voltage.

I was thinking of going with the 5S 8000mah but that gives ridiculously long flight times so may go with the 6000mah. With the 8000mah battery I get 32 minutes of flight time at 75% throttle.

Planning to use a 16x10 prop with the 4130/16. That'll give me 33amps at 5500 RPM with 97 ounces of thrust at 5000 feet altitude.

Tweet

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Mickey-Gem,

Couple of questions:

* Why the decision to go with the HS-81MGs rather than full size servos? Were (are) you at all worried about the available torque?

* Where do you fly (what part of the state)?

mickey-gem

Well, I have been using the metal gear HS 81's in many of my electric applications with great results.
I am impressed with there torque, size and weight. I wanted to save as much weight as possible all around
since I was adding the tail gear components. I replaced the glow throttle servo with the tailwheel servo,
and in doing so still saved 4.15 oz of weight all around, 5 servos., (also the weight from The very large dowel pushrod
system that came with the kit, probably only one oz. ) I was originally going to use inexpensive Futaba
standard servos which weighed 1.5 oz ( .83 0z heavier than the HS 81) and they produced 42 oz of torque
so the HS 81's are not far off, which at 4.8 v yield 36.1 oz of torque and at 6.0 v yield 41.66 oz of torque.
If you go with the 6V UBEC you will be able to experince the full torque benefit of the very compact servos.
Unfortunatley since I needed more weight in the nose I did away with my 6 volt UBEC. Eventually if I get larger
capacity packs I can take off the nose weight I added (about 3 0z) and replace it with say 4000 mah packs
And my 6 volt UBEC and I should still be at the same weight ( 7 1/2 lbs.) with slightly more flight time.

Other scale planes in the size range of the Kadet Senior, generally weigh in at about 8-10 lbs, and their
control surfaces are much heavier. The Kadets control surfaces are very light in comparison. By mounting
all the servos where I did, the connections are much more solid and the potential for control rod slop
and binding are virtually eliminated.

Also, I purchased this plane for it's very slow, relaxing flight characteristics, so I was not planning to
put to much stress on the control surfaces during flight.

I live in Littleton Colorado, I genarally fly in large open soccer fields near my house. I live near Chatfield
resevoir which has a very nice AMA sanctioned flying field which I would like to fly at in the near future.

Regards,

Jesse

Regards

Yak18

My Feedback: (11)

If you are still looking for wheel pants try here http://www2.towerhobbies.com/cgi-bin...p?&C=ATH&V=GPM You're sure to find something that works and they are already painted!!!

Yak

mickey-gem

Thank you for the link, I appreciate it greatly!

By the way Tweet, I purchased an AXi 4120/18
for the Kadet today, it is better suited for my 6S setup. I will use the 4120 /14 in another project
(WM 5-51 Mustang Rockwell version) with 5S.

Hopefully I will get to test the 4120/18 tomorrow with my 6S setup, I should be pulling much lower amps
as well with the 4120/18

I also programmed flaps and a landing mix into my Hitec eclipse 7 that I will experiment with. I hope will help
decrease the long landing aproaches, and bring it in a little slower.

Tweet

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Hi Mickey-Gem,

I have a 4130/16, which on Motocalc looks very nice for this airplane using a 16-10 prop and 5S I am planning to buy. The 4120/18 should be great for the 6S. Let us know how it works for you tomorrow.

I'm curious to hear how your flap and landing mix works and just how you did it. I will be landing on the street in front of my house (rural area) and am interested in cutting the float down. I have seen the Seniors fly and they really do float quite a bit (part of their charm).

Let us know how it goes tomorrow.

loone

Ive been flying the KSA for about a year with the AXI 4130/16 and a 18/10 prop. flys really good.

wilinfla

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mickey-gem, gerat thread,

I have a Kadet Senior ARF that I have been flying for a while with an OS65LA in it and it flies great, but I want to try electric. This will be my first time dealing with electrics so I have a couple of questions. I was looking at Hobby Lobby and they have both the 4120/14 and 4120/18 that you mentioned with speed controller for the same price. If you were buying a system just for this airplane which one would you buy? I also can't seem to locate the battery size that you were talking about, at least not in the mah you specified, can you tell me where they are available? What would the best battery system be for these set ups? Do you charge at the field or swap out battery packs? I have not used Lipos before, so they are new to me as well. Thanks for any information you can provide, I'm looking forward to some clean flights with this airplane

Tweet

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Here are some more threads:

http://www.rcuniverse.com/forum/Kade...2528461/tm.htm

http://www.rcgroups.com/forums/showthread.php?t=233468

Thunderpower makes a 5S battery at 4000, 6000, and 8000mah capacities.

I went with the 4130/16 purchased just for the Kadet Senior because I figured it could use the extra weight in front and I already have a 4120/14 on another airplane.

wilinfla

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Tweet,

Thanks for the information, do you have a good place to purchase the Thunderpower batteries? I was wondering what kind of price range they go for. Can you use NiMH batteries with these motor set ups?

Tweet

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Here is the Thunderpower web site with prices. You shouldn't pay any more than this and probably less. I get mine for a good price at my LHS "Things With Wings" in Greeley, Colorado.

http://www.thunderpower-batteries.co...batteries.html

Looks like they just came out with a new series with balancer connectors.

You can use NiMH or Lipoly (or even Nicads). It is not the type of battery that matters but the amount of voltage they provide. Forget Nicads...no one uses them as they are too heavy. Each NiMH cell provides 1.2 volts of power. Each Lipoly cell provides 3.7 volts of power.

Lipolys are much lighter than Nimh for a given voltage and capacity and do not lose their charge on the shelf (you can charge today and fly next week). They are also much more expensive and can be hazardous if not handled properly (read all the precautions and follow them).

In my mind brushless is the only way to go. Right behind that is using Lipoly batteries. I have only brushless motors and Lipoly batteries. The up front investment is more, but unless you damage them in flight the brushless motors will essentially last forever.

Some of the best investments you can make (and they don't cost that much) is Motocalc or something similar and a Wattmeter or something similar. Then there is the free and good advice you get on RC Universe and the other place (Matt Kirsch and Greg Covey are very active moderators).

wilinfla

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Tweet,

Thanks for the help, I appreciate it.

mickey-gem

Will,


I purchased the Kokam 3200 mah 20C (64 amps max cont. discharge) from Tower Hobbies
they come in 2S and 3 S configurations. This is the cheapest I have found Kokams, and Tower
often has deals such as; take off $30 from your order of $200 or more, I believe they currently offer
$25 off an order of $175 or more. Most of my LHS's do not carry these larger packs, but they smaller
packs they do carry are much more expensive than on Tower, and with the extra $$$ off your order it makes
it that much sweeter!

I have three chargers, two Triton chargers which I use on my bigger packs and a small E-flight Celectra
for my smaller parkflier size packs. I usually try to keep all my packs charged and ready to go, my large
Kokam packs can take up to 1 hour and 30 min depending on how far I discharge them. Smaller packs
anywhere from 30 min to an hour. When I come home from flying, I genarally began charging them at
that time, with 3 chargers running I can have about 3 or 4 packs charged in about an hour.

All three of the motors we were talking about would fly it fine, this plane does not need alot of power
to keep it airborne. The 4120/14 and 4120/18 are the same size and weight, the 4120/ 14 will spin a prop
faster on less cells (volts) but will also pull more amps (less flight time) I beleive the 4120/18 or 4130/16
would be better choices. Generally for me the deciding factors are future applications. The 4120/18 weighs
11.28 oz the 4130/16 weighs 14.42 oz, a difference of about 3.14 oz. If you think you will use the motor in
future projects requiring you to plan for less weight and size overall, the 4120/18 will be better and provide
you up to about 750 watt output range on about 14- 22 cells or 5S to7S Li poly . If you think you may want to
get into larger models requiring more power the 4130/16 can perform in the 1000 watt output range on 16-
24 cells or roughly 6S to 9S Li poly and will spin larger props with less amp draw. As Tweet mentioned, you likely will
not have to add weight to the nose to balance the Kadet Senior, depending on how you set it up. The cell numbers
and output watts I listed are from model motors web site.

Then there is one more element of choice that I will throw in; the 4120 series motor with Jeti 70 amp ESC Combo on
Hobby Lobby's web site is $265, The 4130 series with the Jeti 77amp ESC Combo is $388

I hope this info helps!
Good luck!

Regards

wilinfla

My Feedback: (5)

mickey-gem,

Thanks for the information, that really helps. I am leaning toward the 4120/18 as a motor. In your erlier post you had said that a 5s pack was sufficient, would I hook up a 3s and a 2s in series? By the way your kadet looks great!

mickey-gem

Yes, a 2 and a 3 cell pack in series, you can purchase series connector modules which
makes it very easy to connect the two packs. Just make sure the mah ratings and C ratings
are the same, example: One 2cell 3200 mah 20 C rated and one 3 cell 3200 mah 20 C rated
connected in series. Also make sure they are charged equally.

Regards,

Jesse

Tweet

My Feedback: (1)

Also, Thunderpower makes 5S packs you can buy in 4000, 6000, and 8000 mah configurations.