Originally Posted by GooberSB

Hello

I like this thread and see that it's pretty active with the same users so I want to share my creation with y'all - if you're interested.

While there is a brushless Champ thread already going, I don't feel it's the right place for this mod because the entire discussion is based on using the parkzone brick with brushless motors. This mod just doesn't fit there.

I took pictures during the build but don't have video yet. I hope to get some over the weekend...

My brushless Champ is completely redone with new motor, ESC, Rx, servos, pushrods, and battery. It flies good, but it doesn't float like a stock Champ because of the extra weight.

SB

Well i would sure like to see what you have done with your champ!

Post up some pictures!!


Ridgewalker

I want to see it too!

Here is my Champ mod for a brushless motor

Parts used -
HXM1400-2000 5g 2S motor from HK
Turnigy Plush 6A 2S ESC from HK
NineEagle 180mah 2S lipo from HK
2 x 2.5g servo from HobbyPartz
1 small paperclip
Champ airframe and pushrod accessories
Rx of your choice
2mm shrink tube
3mm shrink tube
5x3 prop from HK
GWS 5043 prop

Tools used -
Needle nose pliers
soldering iron
solder


I started by removing all the stock parts from my Champ's inside.

First, I soldered the motor wires to the 6A ESC and soldered on a JST battery connector.

Then I started with the servos with arms off. I removed some foam from both sides of the fuse near the brick location. I've uploaded a coupld of pictures taht show the servos up close.

After I had a nice shape for the servos to fit into I hot glued them in with one 2mm lower than the other. I connected the electronics and installed the servo arms. Then I discovered that they touched when centered so I had to cut the ends off. The center hole provides plenty of throw so that's ok. I installed the control arms and used my Tx sub-trim to center them.

I used the Champ pushrods and the U bend ends. But the z-bend that came with them is too small for these servo arms so I created my own using a small paperclip and 2mm shrink tube. These are shown in a few of the pictures.

When the servos and pushrods were in place, I attached the Rx in the end of the fuse with some velcro. This keeps the wiring neat.

The next step was to create a mount for the HXM 5g 2000kv motor. It comes with one that seperates from the motor. A stiff piece of plastic is suitable for this job. I wanted to use a thin piece of plexiglass but didn't have any. But I found a wall lightswitch faceplate so I used that instead. I marked a square slightly larger than the motor mount and cut it out with a scroll saw. I predrilled the pilot hols with a 1mm drill bit and mouted the motor mount to the plastic with 4 servo mounting screws.

The Champ fuse is designed for a motor mount that bites into the foam from the bottom so this motor mount didn't really work that well. After a few crashes the foam in the bottom was loose so I cut it away and hollowed out the bottom to be like the top half of the fuse.

Finally, I cut a block of some EPP type foam and cut it to fit into the bottom half of the fuse and partially into the top. I used hot glue to attach the plastic motor mount to the block of foam and then glued it into the lower half of the fuse. I cut a channel in the top of the foam block to keep the motor wires from moving around too much because they are pretty brittle.

I tried to position the foam block to have a little down and right angle while the glue was still hot. I don't know if I did enough angle, but it flies good like it is.

The last thing to do in the fuse was to cut a little channel for the battery wire and hot glue it in place so connecting and disconnecting the battery doesn't move the wiring around on the inside.

Cutting the battery area a little bigger and adding a bigger / stronger piece of velcro on the bottom was pretty much the final step. I made a spot in front and behind the landing gear wire so I could experiment with battery position. The optimal position for this battery happens to be between the wheels but it doesn't fit there. Behind the landing gear is tail heavy and very hard to control at the speed it's going. In fron of the LG makes it fly a lot better but it doesn't glide so well. It comes down a very nice angle with no power but it picks up speed. I can do some very nice landings by using some flare on the landing but the stock Champ lands great without it.

I't's windy today so I can't get any video. Should be able to in a few days anyway.

I've very happy with what I put together. Of course, I wouldn't go out and spend $40+ on these parts just to do this. I already had these parts and was only tinkering because the Champ brick went bad and it seemed like the thing to do for her.

I tried a 4x2.5 prop and it couldn't carry the weight all that good. Then I tried a 5x3 and a 5x4.3. Both really give it authority in the wind but I think the 5x3 is the best choice for this setup.



Videos:

My son flying the brushless Champ. It was a little windy but the Champ didn't even notice.

Champ Brushless #2 (1 min 43 sec)

This one shows it doing rudder rolls
http://www.youtube.com/watch?v=Oi7RdFP48zY

and this one is just fun flying
http://www.youtube.com/watch?v=SIGT1qinKTg



SB

That should move the champ right along!
Nice job with the pictures.
Any idea on the AUW?

Since you like to tinker..i do as well, here is a link to a plane i built and i'm using an e flite park 250 2200kv motor,overkill for the size of the plane,lol
It is mounted in some foam with hot glue.
The foam is a sleeping mat used for camping...EPP iirc...also makes great wheels,you just have to use a sharpie to make them black.

It provides a good cushion for the motor on nose in's...i have had a few.lol

Figured i would show you how i did it...might give you some ideas......https://www.rcgroups.com/forums/show...&postcount=101


Ridgewalker

Wow really nice work goober! Ridge I'm still closely following your thread and pkan to do a build up when I have some electronics laying around.

Originally Posted by ridgewalker

That should move the champ right along!
Nice job with the pictures.
Any idea on the AUW?

I did some rough calculations but I don't have a scale yet.

The stock Champ weighs in around 38g or so.

I removed the motor, brick, and battery so I figured those were worth maybe 20g. Then I added about 10g for the motor and wire + 8g for the servos + 5g for the Rx + 10g for the ESC + 18g for the battery. I suspect it weighs around 65-70g AUW with this setup.

A good indication is that HK claims the Hextronik puts out about 70g thrust. User reviews support that within reason. A 5x3 prop has been shown to output over 60g.

With both the 5x3 and 5x4.3 prop, the Champ will hover so the motor is at least putting out 1:1 thrust / weight ratio. The ratio could be greater if I shortened the battery and motor wires, used only 1 piece of velcro, etc.

But that supports my estimate of around 65g.

Originally Posted by ridgewalker

Since you like to tinker..i do as well, here is a link to a plane i built and i'm using an e flite park 250 2200kv motor,overkill for the size of the plane,lol
It is mounted in some foam with hot glue.
The foam is a sleeping mat used for camping...EPP iirc...also makes great wheels,you just have to use a sharpie to make them black.

It provides a good cushion for the motor on nose in's...i have had a few.lol

Thanks for showing me that. I'm surprised that it works and works really well. As you say, it provides a cushion and it's really been a money-saver. The Champ has hit some things pretty hard with this new speed. The stock motor mount would have torn loose with just one of these and when that happens there's no foam left to put it back.


I also have a Mini Super Cub mod that I did with a large Tower Pro brushless that I power with a 3S 800mah. It flies better than the stock MSC so sometimes it pays off to tinker with them.

SB

Originally Posted by jlcamp7

Wow really nice work goober! Ridge I'm still closely following your thread and pkan to do a build up when I have some electronics laying around.

Thanks! I'm proud of the way it looks inside and happy that it flies.

SB

GooberSB...

So far so good with the motor mounted that way,makes for a cheap motor mount that provides some protection.

I have also used that same foam for mounting a mustang/champ type gear box and it worked well.

Hope you have some good weather to get some video!

That motor you have in the champ would have no trouble hauling the champ with a set of floats.
Also would be good for carrying a keychain camera.


Ridgewalker

Hi all

The storm passed by and this evening it was calm outside so I took my brushless Champ out for a spin. My son is the rc pilot - I'm just the repairman - but he didn't want to fly today so I had to do it. My wife is the cameraman and had a little trouble keeping it in the frame. This is to say that the video isn't as good as I wanted it to be but it is what it is.

Champ Brushless #1 (2 min 35 sec)

You'll see a few hand launches. After I get above the trees and power lines I cut the trhottle to 1/2 or less and just cruise around. I wanted to show you all that replacing the PZ brick with 2 2.5g servos and a Rx doesn't turn it into a brick.

I'll try to get a better video with loops and faster flying.

Oh, BTW, in this video I'm using a GWS 5043 prop. After flying for a little while I brought it in and put the 5030 back on. The motor seems to like it better.

Edit:
This is a follow-up to my post here
https://www.rcgroups.com/forums/show...postcount=2718


SB

Goober...

The champ flew great!
You certainly had the speed as well as nice and slow flight.
What kind of run time are you getting with your battery?

Good to see that the larger servos esc and rx fit well in the champ and still retain the champs great flight characteristics.

Wonder how it would do if the dihedral was removed from the wing...similar to how people make the wing flat on the super cub lp.

And then adding in ailerons..

You would be able to knife edge the champ! lol

Great video and nice work with the champ.

Ridgewalker

Goober, this is awesome! I love to fiddle with stuff too so I just might try this.

In the future, you might want to try this RX, as it's only 2.5g compared to the 8g RX you chose. Hey, every bit of weight helps.

https://www.hobbyking.com/hobbyking/s...dProduct=11972

What is the best process for taking wing dihedral out?

Originally Posted by ridgewalker

Goober...
What kind of run time are you getting with your battery?

I can fly at half throttle for 15-20 mins. I haven't needed to use the 350mah battery at all.

Originally Posted by ridgewalker

Wonder how it would do if the dihedral was removed from the wing...similar to how people make the wing flat on the super cub lp.

And then adding in ailerons..

You would be able to knife edge the champ! lol

Great video and nice work with the champ.

Ridgewalker

Thanks for the support. I've seen a couple of aileron mods and think it would work really well. Since this mod doesn't use the PZ brick, the best way to go about it would be to use either 1 2.5g or 5g servo in the top half of the fuse or 2 of the HK micro linear servos that are very similar to the ParkZone linear servo. HK has some with JR plugs.

It would be funny to see the little Champ doing stunts

SB

Originally Posted by mxandrews1

Goober, this is awesome! I love to fiddle with stuff too so I just might try this.

In the future, you might want to try this RX, as it's only 2.5g compared to the 8g RX you chose. Hey, every bit of weight helps.

https://www.hobbyking.com/hobbyking/s...dProduct=11972

What is the best process for taking wing dihedral out?

Yes, you're right about that. HK was selling some 6ch DSM2 Rxs with no cover. They were very light too. I got a couple and put shrink tube on them but they are in other models for now. If I do a 1S mod like this I'll probably use one of them though.

I can't answer the dihedral question though.

SB

I think this is the angle or it should be near enough

Originally Posted by SENTRY 62

I'm gonna head to the store to get a protractor so I can get the angles down for you guys. It's just made of cereal box (LOL) and taped on.

My son flew the brushless Champ yesterday. It was a little windy but the Champ didn't even notice.

The video is short because he doesn't being filmed and I had to sneak off to get the camera

Champ Brushless #2 (1 min 43 sec)

SB