HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jul 21, 2010, 08:56 AM
Registered User
twoplanekid's Avatar
Urbana, Ohio
Joined Feb 2008
303 Posts
Decided to try my Ember mods of wing fences and slats on the Champ.

Took the rig off the Ember and placed on the Champ. Boy, the Champ is now rock solid at slow speeds and can go very slooow. I just need to redo the mods to look better. Works as well if not better on the Champ than the Ember. Try it. You’ll like it!

Visit this old thread for my development trials and other mods.

http://www.rcgroups.com/forums/showthread.php?t=865438
twoplanekid is online now Find More Posts by twoplanekid
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 21, 2010, 09:48 AM
Still AWD, Subaru
St.Louis
Joined Nov 2006
884 Posts
i was thinking about flaps, but I like your slat mod
ShawnM4kq is offline Find More Posts by ShawnM4kq
Reply With Quote
Old Jul 21, 2010, 11:20 AM
Elfi Flyer
Doug Sipprell's Avatar
Rock Hill, SC
Joined Oct 2002
5,553 Posts
Will be interesting to see if the distance between the slats and the LE of the wing is critical. I would assume one would want some acceleration of the wind between the slat and the wing. In sailing, we used to refer to this at the slot, between genoa and main sails, and there was definitely a given setting in which the wind was flowing smoothly, according to the tufts we installed on the sails.

RD
Doug Sipprell is offline Find More Posts by Doug Sipprell
RCG Plus Member
Latest blog entry: Big Red Cadillac
Reply With Quote
Old Jul 21, 2010, 07:51 PM
Registered User
twoplanekid's Avatar
Urbana, Ohio
Joined Feb 2008
303 Posts
So many things to try. Larger slats seem to almost eliminate a brief wing rocking which developed under some flight conditions with the smaller slats. Cut the leading edge of a Citabria wing to make the new slats

It flies in half the space needed to safely fly a regular Champ. Only takes 1 minute to slide everything off to make it a factory Champ.

As I leave for Oshkosh on Sunday, I may not have time for more experimentation. I will take it to Oshkosh and fly it as is.
twoplanekid is online now Find More Posts by twoplanekid
Reply With Quote
Old Jul 21, 2010, 09:56 PM
Elfi Flyer
Doug Sipprell's Avatar
Rock Hill, SC
Joined Oct 2002
5,553 Posts
Are you using the stock Champ motor and prop? I would assume the slats installed as shown would add notable drag and possibly put more load on the stock motor when flying full throttle. Of course, the purpose of the slats is to be able to fly much slower, at reduce throttle settings, hence the additional drag might not be an issue.

RD
Doug Sipprell is offline Find More Posts by Doug Sipprell
RCG Plus Member
Latest blog entry: Big Red Cadillac
Reply With Quote
Old Jul 22, 2010, 07:51 AM
Registered User
twoplanekid's Avatar
Urbana, Ohio
Joined Feb 2008
303 Posts
Yes, I am using stock motor and prop. My power setting is about half power for cruise with plenty of power remaining to climb almost straight up.

Remember, I am use to flying my 46 J-3 Cub at about the same speed and power settings. Slooow!
twoplanekid is online now Find More Posts by twoplanekid
Reply With Quote
Old Jul 22, 2010, 08:09 AM
Elfi Flyer
Doug Sipprell's Avatar
Rock Hill, SC
Joined Oct 2002
5,553 Posts
Then I should not have a problem with "pull", being that my Champ now has the Mustang motor. Am seriously thinking about going back to a stock motor, as soon as I can get one, for longer flights on the 240 mAh 1S Lipo I am now using.

Have fun at Oshkosh. Been meaning to get up that way some time, I have customers in the state.

RD
Doug Sipprell is offline Find More Posts by Doug Sipprell
RCG Plus Member
Latest blog entry: Big Red Cadillac
Reply With Quote
Old Jul 22, 2010, 11:08 PM
Crash McNooblet
ci_phon's Avatar
United States, KY, Lexington
Joined Nov 2009
47 Posts
Wobbly bits....

I've got a couple questions....if anyone's willing to root through my horribly-long post.

Over the last few windy days I decided I would spend some time fixing and modding...breaking...crying...fixing...etc etc.. and I got around to modding my Champ so I could mount a keychain camera under the fuse and tucked inside a little, so I would have roughly a 45° forward/down angle view and still have ground clearance with the stock LG.

After cutting holes, padding, reinforcing, and buttoning everything up..my Champ came out weighing a bit more than I would have liked, but it's not any heavier now than it was the very first time I had taped a 'gumstick' camera the belly of the fuselage a few weeks back, or so I'm almost sure of...

(almost getting to the question...)

Originally...before offending my eyes with all my holes and missing paint...my Champ weighed 38grams, stock but without decals...and WITHOUT the battery. That was 5grams more than the listed/stated average weight. I still have no clue why it was heavier...there were no visible/obvious defects or explanations, but my guess is that the paint was/is thicker than it should be...which...I'm not sure if it's like this on all or most of them, but my paint peels off easily as if it were a heavy coat of latex based paint....anywho..

Also, I had used a "gumstick" camera that ALSO weighed more than the average "stated" weight due to it having a much larger battery than most of them came with. The stated weight for those is 18grams...mine weighed 23grams.

So, my first camera attempt made my Champ weigh a whopping 66grams! It flew pretty decent considering the extra weight and that everything was stock. (plane=38g, batt=5g, camera=23g). Now my "current"...post-mod weight with a much lighter "keychain" camera...is 60grams even, making it 6grams lighter than before, and properly balanced versus it just taped on in a hurry. (plane=38g, batt=5g, camera=17g). For this recent mod, I was originally planning on mounting the new camera to the top/center of the wings/fuselage... using a light "wedge" of foam to form-fit to the curve of the wings on the bottom side, and form-fit to the camera which would be ontop of the wedge...attached with hook&loop. I changed my mind on that though because I wasn't sure if that extra weight on the top of the plane would cause instability by making the plane more top heavy... worse than I already have. I posted a pic of this foam wedge idea for reference.

*here's getting to the point:

My Champ is wobbly as all getout! If I'm not on the stick a good 95% of the time....the plane will tumble like it's going out of style, and will easily "roll" during the most gentle of turns as if it had overly sensitive ailerons on it. It does however maintain altitude as well as can be expected...as in, if I go below say...30% throttle, it stays level but will steadily lose altitude. I'm fine with the altitude issue I suppose, I can't have "extra toys" and not expect to have some sort of consequences. But the whole flip flop turn and drop thing is rather unexpected. I should mention that there was also some wind blowing at a steady 2-3mph with gusts up to about 5...as was actually monitored with an anemometer at that time. (5mph is a lot more than most think it is when simply guessing, you'd be surprised!)

Now, there's a good chance that I simply may have just not noticed this during my first few camera flights a few weeks back... there was no wind whatsoever, the camera was taped completely to the underside of the fuse, whereas after my mod and with a difft. camera, the camera is partially up and inside the fuse...which slightly raises the vertical center of gravity. I'm not sure if I've even watched anyone else's videos that show their Champ being all wobbly. I could be experiencing something I've just not noticed before, which leads me to a few questions.. (Finally...man...long post... Right? )

Is this normal behavior considering the extra weight, or is it a result of the extra weight PLUS the minor wind? -or- Is it possible that the wings are 'flexing' too much because of the extra weight and is the cause of the instability?

I'm not all that knowledgeable yet, but I am learning quickly. If the upward flex of the wings is what's causing the plane's desire to roll, I could either spar the wings to help reinforce them, which would prevent the flexing, or design some sort of stall strip and apply to both wing's roots. (or both spar and strip?) My guess is that a stall strip wouldn't be all that effective on the Champ's wings due to the curvature of both the top and bottom of the wings, again I don't know, but the strip would have to be pretty darn tiny...maybe a square wooden toothpick split/sliced length wise to make two...semi-triangle shaped toothpicks. Trial and error?

I only slightly offset the original COG, making it a bit tail heavy...which was easily fixed by cutting/notching out the battery tray to allow the battery to be moved even closer to the nose.)

**Almost forgot to mention, I have also swapped out the motor and replaced it with the Mustang motor, I felt I needed that extra strength to help with the weight. The Champ still didn't climb all that well, but I was fighting the wind considerably more than I am used to...as this was actually my first Champ flight with any wind. Also I had only slightly offset the original COG, making it a bit tail heavy...which was easily fixed by cutting/notching out the battery tray to allow the battery to be moved even closer to the nose.

Well, if anyone has any thoughts to offer, I would greatly appreciate it! I've posted some photos for reference, and when it's done uploading...I'll post again or edit this one to include a link to one of the videos I have that (to me) shows this wobbling and rolling effect. I still have to finish repairing all the areas where the paint is missing from...so it's a bit...beter when viewed from afar! Aren't they almost always?!

I didn't go up all that high considering my first Champ+wind+new mod flight...I'm also afraid of the plane going out of range on me. (Oooh... BTW, (roughly) What can I/should I expect the range to be if I'm using a DX6i? I've watched some videos where it "appears" as if those Champs are flying 1200feet or more, although the cameras typically make things seem farther away than it actually is.)

If the instability is inherent with this much weight...I'll get used to it, but it would be awesome if there was something I could do to correct it and still use a camera.

Again, thanks in advance for any input, and sorry for the lengthy post!
ci_phon is offline Find More Posts by ci_phon
Reply With Quote
Old Jul 23, 2010, 12:30 AM
Registered User
United States, WA, Woodinville
Joined May 2010
336 Posts
That is a pretty portly Champ. My cam-Champ is less than 50g, and the weight is all inside the fuse so it handles pretty well.

The keychain cameras are pretty cheap now. I got one for $9 shipped... if you want to pursue a camera Champ, I suggest getting another camera and taking it apart.

You can see some pics of my project here:

http://www.rcgroups.com/forums/showp...postcount=1506

But, I have to say, the 45 degree down angle ends up not being that interesting. I think a more forward view would be better, but YMMV.
horseflesh is offline Find More Posts by horseflesh
Reply With Quote
Old Jul 23, 2010, 02:10 AM
Crash McNooblet
ci_phon's Avatar
United States, KY, Lexington
Joined Nov 2009
47 Posts
Quote:
Originally Posted by horseflesh View Post
... the 45 degree down angle ends up not being that interesting. I think a more forward view would be better, but YMMV.

Several times now I've watched the few videos I took this morning with the camera at that near 45° angle...and I agree, a more forward/up angle would surely be better. I wanted to be able to see the horizon but only just enough to better tell what's going on in a video, I thought the angle I used would be fine, but I underestimated just how small the camera's field of view was.

I have room to work with in that gaping hole I made, so I'm going to try to angle the camera up a considerable amount, and I'll give it another try.

Your mod was pretty much what prompted me to do what I did, I had read your posts and thought that it'd be a good idea to mount the camera inside but I wanted to leave myself the option of removing the camera easily...so I did what I did for that purpose. I do have more than 1 camera and gave part of your mod some though...I however am not very "steady" with my hands when it comes to soldering small circuitry...and would most likely end up with both a fried camera and brick. I may give it some more thought and leave the buttons alone, use some sort of poking stick through a small hole cut out in the top of the fuse or something like that.

What's the most that would happen by trying to remove various parts and improve my current build?....I might make my plane "lighter" than it is right now and get better flight times and handling? Heheh
ci_phon is offline Find More Posts by ci_phon
Reply With Quote
Old Jul 23, 2010, 02:37 AM
Registered User
United States, WA, Woodinville
Joined May 2010
336 Posts
I actually had a problem with the camera cutting out when powered off the plane's battery. In the end, I decided that it was better to suck up the weight of the camera's battery, which wasn't all bad as the plane needed some weight up front anyway.

If soldering isn't your thing then dissecting the camera isn't the way to go, yeah.

Looking forward to see what you come up with.

I'm waiting for these sunglasses-style cameras to get cheap... I figure the sensor will be on the end of a few inches of cable, which will make for a lot more plane mounting options. When these hit $20 I may order one to take apart.

http://www.bigboxstore.com/wholesale...lasses-cameras
horseflesh is offline Find More Posts by horseflesh
Reply With Quote
Old Jul 23, 2010, 06:47 AM
Incorrigible
Nunja Business's Avatar
USA, AL, Silverhill
Joined Jun 2010
150 Posts
Quote:
Originally Posted by horseflesh View Post
I actually had a problem with the camera cutting out when powered off the plane's battery. In the end, I decided that it was better to suck up the weight of the camera's battery, which wasn't all bad as the plane needed some weight up front anyway.

If soldering isn't your thing then dissecting the camera isn't the way to go, yeah.

Looking forward to see what you come up with.

I'm waiting for these sunglasses-style cameras to get cheap... I figure the sensor will be on the end of a few inches of cable, which will make for a lot more plane mounting options. When these hit $20 I may order one to take apart.

http://www.bigboxstore.com/wholesale...lasses-cameras
How about $28.99 shipped? http://www.meritline.com/sunglasses-...--p-45792.aspx
Nunja Business is offline Find More Posts by Nunja Business
Reply With Quote
Old Jul 23, 2010, 09:24 AM
220 221 Whatever it takes
captdave221's Avatar
USA, IL, Belleville
Joined Dec 2009
276 Posts
msr brick in a champ??

I have a brick from a MSR micro heli. Do you think it will be usable in a Champ airframe?? Will the gyro cause me grief? Or is there a way to disable it?
captdave221 is offline Find More Posts by captdave221
Reply With Quote
Old Jul 23, 2010, 12:51 PM
Registered User
United States, WA, Woodinville
Joined May 2010
336 Posts
Quote:
Originally Posted by Nunja Business View Post
Hey, good find!
horseflesh is offline Find More Posts by horseflesh
Reply With Quote
Old Jul 23, 2010, 01:42 PM
R.C. Aviation Fanatic
Razors edge 29's Avatar
Canada
Joined Aug 2009
21,026 Posts
UM P51 Motor with GWS 5043 Prop

My new Mustang motor arrived today, so I installed on the Champ with GWS 5043 prop which should be a great combo.
Will test out later today hopefully; see pics below
Razors edge 29 is online now Find More Posts by Razors edge 29
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Article HobbyZone Champ RTF Review dee-grose Micro Ready-to-Fly 888 Dec 01, 2013 12:11 AM
Discussion HobbyZone Champ On-board Video VasMan Aerial Photography 2 Jun 25, 2010 02:47 PM
Alert HobbyZone Champ RTF Group Buy in Middle TN: $87.80 per plane (including tax) PerlAddict Hot Online Deals 5 Jun 16, 2010 06:00 PM
Wanted Hobbyzone Champ pmass23 Aircraft - Electric - Airplanes (FS/W) 0 Jun 01, 2010 01:17 PM
Video Hobbyzone Champ - Short Glide Video VasMan Electric Plane Talk 0 May 16, 2010 10:01 PM