Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
July 19, 2019, 11:37:57 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: 1 [2]   Go Down
Print
Author Topic: Baby Kadett  (Read 2047 times)
0 Members and 1 Guest are viewing this topic.
Pit
Palladium Member
********

Kudos: 127
Offline Offline

Germany Germany

Posts: 5,507


aka staubkorb


WWW

Ignore
« Reply #25 on: June 23, 2009, 07:55:31 AM »

Looking really sharp, Caley! I didn't note earlier that you were going to go with ailerons. Are you going to use a single set-up or a servo for each aileron?

One caution, tho. Even with a single ail. servo, you're going to be pushing the BEC of that 10 amp controller (min. recommended for that motor) at its BEC limit - not the motor limit. The BEC is probably no more than 1.5 - 2 Amps and only rated to drive 2 servos (maybe 3 on two cells). They'll usually have no big problem with 3 in a very light shockie (overall less weight), but with 4 servos, you'll be pushing the envelope. You DO have a bit more leeway by using only a 2-cell pack as there's less excess voltage to dissipate (7.4 V. down to 5 V. = heat). I would SERIOUSLY consider going with the 18 amp controller to get a bit more leeway.

The BEC on these small controllers (and most of the bigger ones!) are so-called linear BEC's which use a voltage drop-down circuit to get to the voltage required for radio operation - essentially putting a resistor between the batt. and the receiver. Works and is inexpensive, but is inefficient at best (produces lots of heat). The much better solution is the "switching" BEC that puts NO limit on the number of servos used - a bit more complicated and costly. Technicalities are beyond the scope of this thread.

Just a "heads-up" that you don't overdrive the capabilities of the controller.

Pete
« Last Edit: June 23, 2009, 08:47:57 AM by Pit » Logged

A Dedicated Convert to:
WWWoFF (Wonderfull Wacky World of Free Flight)

Comparing Spammers to a pile of organic waste is an insult to the organic waste!
crashcaley
Palladium Member
********

Kudos: 238
Offline Offline

United States United States

Posts: 5,161


Topic starter


Ignore
« Reply #26 on: June 23, 2009, 08:37:59 AM »

Hi Guys, not a problem with the speed control, as it is supposedly rated to take four small servos. I'm using Hitec 55s which, if I am operating all four at the same time, will draw less than an amp, and much less in the idle mode at. According to my model airplane program, I will be drawing around 5 amps with the motor full throttle. So the speed control shouldn't be overtaxed at less than 7 amps, as recommended max continuous is around 75 percent of a speed controls max output. This airplane supposedly will be flying around 18mph, so the servos won't be encountering heavy strain on them. I don't fly aerobatics, just putter around the sky.

Caley
Logged

What's stall speed?  Undecided
Pit
Palladium Member
********

Kudos: 127
Offline Offline

Germany Germany

Posts: 5,507


aka staubkorb


WWW

Ignore
« Reply #27 on: June 23, 2009, 08:56:39 AM »

Good work, Caley. Shows that you've done your homework and done enough reading up on the various subjects that you tackle (ie. your ref. to the 75% ratings). There are far too many out there who skip over the fine print in the instructions or on the discussion Forums and just don't realize the limitations of some of the stuff we take for granted.

Pete
Logged

A Dedicated Convert to:
WWWoFF (Wonderfull Wacky World of Free Flight)

Comparing Spammers to a pile of organic waste is an insult to the organic waste!
crashcaley
Palladium Member
********

Kudos: 238
Offline Offline

United States United States

Posts: 5,161


Topic starter


Ignore
« Reply #28 on: June 23, 2009, 08:38:59 PM »

Pete, I've used this system in another model, that met its untimely demise. Pilot error. But the equipment survived. I'm just happy I've got the program MotoCalc. It really helps me match the pieces of the drive system, instead of hit and miss, like when I first started into electrics. That's when I lost most of my airplanes due to mismatches, etc.

I decided to work on the battery mounting area and access. I'm trying something different, as I dislike access from the bottom, because the panel usually falls out while in the air. I also dislike having to take the wing off each time to change a battery. So I decided to install a door. On the fuse, all I did was install two gussets on the forward section and a strip with a magnet on the rearward section of the door frame. These keep the door locked in without worrying about shoving the door into the fuse. The door is built up with tabs in the front and a magnet in the rear. I added a little handle covered with shrink tube so I can have something to grip and pull to remove the door.

I just need to do some sanding along the perimeter of the door in order to allow for the plastic covering.

Caley
Attached files Thumbnail(s):
Re: Baby Kadett
Logged

What's stall speed?  Undecided
crashcaley
Palladium Member
********

Kudos: 238
Offline Offline

United States United States

Posts: 5,161


Topic starter


Ignore
« Reply #29 on: June 28, 2009, 02:03:28 PM »

Finally got the BK done and is ready to maiden next week, winds permitting. It's a hodgepodge of plastic covering colours, as I had to do with what I had on hand. And my ability to apply plastic covering still leaves something to be desired. Still can't figure out how some people put it on without a wrinkle, bubble or any other imperfection using just a pair of hands. I could have used another pair to help me. Smiley

I did a bench check of all the control surfaces and only needed to reverse the rudder servo. One of these days I will learn to orient the servos properly, so I can avoid that.

I also did a bench check of the power. The motor is a HET Typhoon 6/20 1800rpm outrunner motor. I'm using a HET Tsunami 10 amp speed control and a MaxAmps 1100mAh 2-cell lipo battery pack. My Whattmeter gave me a reading of 7.67 amps full throttle at 8.36 volts. Oh, the prop is one I found in a parts drawer made by APC. It's a 7x4 electric prop, and ended up being a perfect match for my system. Unfortunately, I don't think this size is made anymore. I can't find it anywhere on the web. Will keep trying, as I always like to have a spare, just in case.

So, my MotoCalc program was pretty close to what I got with my Whattmeter. I'm hoping that his puppy will fly. Won't know until next week. Hopefully I didn't build any warps into the flying surfaces that will be its death.

Caley
Attached files Thumbnail(s):
Re: Baby Kadett
Logged

What's stall speed?  Undecided
crashcaley
Palladium Member
********

Kudos: 238
Offline Offline

United States United States

Posts: 5,161


Topic starter


Ignore
« Reply #30 on: June 29, 2009, 12:29:48 PM »

The BK maidened this morning. Karl took it up and it was absolutely squirrely on the first flight. He managed to keep it in the air and tame it enough to allow him to land. Upon looking things over I saw one big mistake. I goofed on wing alignment, with on side about 1/4 inch leading the other. I fixed that.

Karl took it up again, and said it was much better behaved. He did the trimming again, and it now flys very nicely at about half throttle, which is what I expected of this setup.

I will try to fly it this sunday. Couldn't fly it anymore, as I didn't want to take a chance of the battery pooping out with me on the sticks. Grin I'm not a very good pilot, and need every advantage I can get. Power is a definite advantage. Grin

Caley
Logged

What's stall speed?  Undecided
Dimeflyer
Platinum Member
******

Kudos: 55
Offline Offline

United States United States

Posts: 1,349



Ignore
« Reply #31 on: July 30, 2009, 07:20:13 PM »

Caley Ann, you amaze me some times with how fast you adapt to the different types of power systems and how to balance them !!!!

George
Logged
crashcaley
Palladium Member
********

Kudos: 238
Offline Offline

United States United States

Posts: 5,161


Topic starter


Ignore
« Reply #32 on: July 30, 2009, 08:00:17 PM »

George, Well, thanks, but, it really isn't me doing the figuring out. It's my computer program called MotoCalc.

I'm more than willing to run someones airframe through the program to determine what drive system would be optimum for it. All I would need is the following:
1. Name of aircraft
2. Number of electric motors
3. Wing Span
4. Wing Area in square inches or centimeters
5. and lastly, the weight of the airplane, without motor, prop, speed control or battery. But do include the weight, the receiver and servos.

Oh yes, please provide the temperature, barometer reading, and altitude of your flying site. These help refine things much better to come up with what will work. The reason is that a power system that is just enough to fly a model at say 200 feet above sea level, won't work if you are flying at 2500 feet. I discovered this by trying to fly minimumly powered models that flew very well down the hill, but just can't hack it up at my flying field. The consequences of trying was to lose a couple of airplanes.

You could also provide the motors, speed controls, props and battery packs, to see if I can come up with a combo that will get the airplane in the air with what you have on the shelf.

I probably should be using a 12 amp speed control to be safer, but I never fly full throttle, so I never approach the limit of the one I have.

Anyway, my offer is open to anyone wanting help.

Caley
Logged

What's stall speed?  Undecided
applehoney
Titanium Member
*******

Kudos: 278
Offline Offline

Canada Canada

Posts: 3,148




Ignore
« Reply #33 on: July 30, 2009, 10:46:53 PM »

Wow, Caley ... after reading all that I'm so glad I'm just flying rubber, glider and gas models .. they're so simple !
Logged
crashcaley
Palladium Member
********

Kudos: 238
Offline Offline

United States United States

Posts: 5,161


Topic starter


Ignore
« Reply #34 on: July 30, 2009, 11:06:57 PM »

Jim, You could just mix and match components for a radio controlled model, but that usually takes someone with experience to get things right. MotoCalc makes doing the mixing and matching easier for someone like myself.

I like radio control because I can be a pilot of an airplane, even if it is only a model. Just wish I had the money, and health to be a pilot of a full scale airplane. Will just have to be happy standing on the ground and getting a crick in my neck as I watch my airplanes fly. Smiley

Hey everyone, what about getting together and purchasing a ready to fly radio controlled airplane for Jim. Grin

Caley

Jim, are you still there? Or did you run waving your arms in the air and screaming incoherently. Grin
Logged

What's stall speed?  Undecided
applehoney
Titanium Member
*******

Kudos: 278
Offline Offline

Canada Canada

Posts: 3,148




Ignore
« Reply #35 on: July 31, 2009, 01:47:49 AM »

Aaaaaghh ......

Freeflight exercises the body.
Radio control exercises the thumbs.

Who needs fit thumbs Huh
Logged
hermit
Gold Member
*****

Kudos: 52
Offline Offline

Canada Canada

Posts: 702




Ignore
« Reply #36 on: July 31, 2009, 08:43:54 AM »

I like your Kadet Caley, specially the colors! Good job, and the trimming does take some time sometimes. Wether you realize it ot not you've got a good basis of trimming experience with your free flight models to get the Kadet trimmed out okay.

Hey Jim, I can get some pretty good exercise retrieving RC gliders too! Spot landings, Hah!

Doug
Logged
crashcaley
Palladium Member
********

Kudos: 238
Offline Offline

United States United States

Posts: 5,161


Topic starter


Ignore
« Reply #37 on: July 31, 2009, 09:20:58 AM »

Jim, You've got some pretty fit thumbs, if you didn't know. Have to hold onto the rubber motor winders for a long time. Builds up extraordinary thumb fitness. Grin

Doug, Gliders sound fun. True spot landings? Well, I saw an article once, on that. Apparently the competitors try to hit the bullseye by sticking the nose of their glider in the grass. Must have a kevlar/fiberglass/carbon fiber nose to do that. Kind of funny seeing one sticking into the ground at a 45 degree angle.

Caley
Logged

What's stall speed?  Undecided
luizsouza
Nickel Member
*

Kudos: 0
Offline Offline

Brazil Brazil

Posts: 1



Ignore
« Reply #38 on: May 23, 2014, 08:26:18 PM »

good model - great construction
this is a model that I intend to build
Logged
Pages: 1 [2]   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!