Radio Control Hobbies

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Re: Radio Control Hobbies

Postposted on Sat Sep 06, 2008 12:10 am

Well, I finished it off this evening. AUW is going to be 32oz. I had to add about 1.5-1.75oz to the nose to get the COG in the range it should be. A whole bunch of photos are here: http://s211.photobucket.com/albums/bb259/wpmcnamara/airplanes/Multiplex%20Gemini/

I made a number of custom decals just for fun.
Image

Image

In all it's un-flown glory.
Image

I'm planning on taking out to the local club airfield and flying tomorrow. Hopefully it comes back looking just as pretty. :)

--SS
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Re: Radio Control Hobbies

Postposted on Sat Sep 06, 2008 10:38 pm

Well, I didn't get to fly it at the field today. Too windy. Actually, most of the time it was very calm, but when the wind came, it was 10-15mph with little warning. Not good for a two pound foam biplane. I did get to fly it for just a bit, right before dark. I used the street in front of the house as a runway and flew in the park. Wow, it this thing sensitive, especially to aileron input. I suppose I shouldn't be surprised given that it actually has four fair size surfaces.

It was actually still too windy to really fly, and I wasn't going to push it. The CG and trim seemed good though and it looks like it will handle pretty well in calm air. I managed to get it down with only a minor scuff on one of the wheel pants. All in all, not bad.

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Re: Radio Control Hobbies

Postposted on Sat Sep 06, 2008 11:57 pm

This all looks pretty cool, but do any of you guys fly gas powered aircraft?
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 1:12 am

Gas as in gasoline or gas as in it has a motor on it so it must be gas but its really nitro methane ?
I have on nitro plane but i never fly it. Nitro and Electric both have their advantages. personally i lean towards electrics.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 10:46 am

Electric FTW.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 11:28 am

The thing I like about electrics is the ease of use. With my electric stuff I can grab the plane, radio, and batteries for the plane. With my nitro powered plane I need the plane, radio, battery for the plane, glow starter, battery for the glow starter, fuel, fuel pump, battery for the fuel pump and a spare parts box. Besides having to haul all the extra stuff around just to fly you have to take a roll of paper towels and half a gallon of 409 with you to degrease the plane once you are done flying.

Being able to grab a couple or three things and fly with no clean up after you get done flying is worth A LOT to me.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 12:10 pm

Hance wrote:The thing I like about electrics is the ease of use. With my electric stuff I can grab the plane, radio, and batteries for the plane. With my nitro powered plane I need the plane, radio, battery for the plane, glow starter, battery for the glow starter, fuel, fuel pump, battery for the fuel pump and a spare parts box. Besides having to haul all the extra stuff around just to fly you have to take a roll of paper towels and half a gallon of 409 with you to degrease the plane once you are done flying.

Being able to grab a couple or three things and fly with no clean up after you get done flying is worth A LOT to me.

Yep, it really simplifies the day. Casual flying is a lot easier with electric :D.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 12:25 pm

I have a couple of electric projects going right now. Some jerk went in our shop and broke the fuselage on my Slo-V on purpose. I am taking the remains and putting them on one of those little kid 5 dollar foam gliders. It should make for an interesting project.

The other project I have going is picking out something like a Slow Stick to replace the broken plane. I want extra long flight times though. I am going to try and get in the half hour flight time range with whatever I build so I need to do some research and figure out exactly what I need.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 12:39 pm

Hance wrote:I have a couple of electric projects going right now. Some jerk went in our shop and broke the fuselage on my Slo-V on purpose. I am taking the remains and putting them on one of those little kid 5 dollar foam gliders. It should make for an interesting project.

The other project I have going is picking out something like a Slow Stick to replace the broken plane. I want extra long flight times though. I am going to try and get in the half hour flight time range with whatever I build so I need to do some research and figure out exactly what I need.

Those foam gliders can actually be made into amazing airplanes. Their huge size and low wing loading makes them kind of majestic, but you need an abnormally calm day. You can also make their control surfaces large enough to give it a bit of maneuverability.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 12:58 pm

I actually got the idea from one of them I got to watch fly. My build isn't going to be all that radical but should be a good flier.

The one I watched fly had a good 250 dollars worth of stuff on that 5 dollar plane but WOW did it fly. Standard takeoff was aim the plane straight up punch the throttle wide open and let go :o When I first seen the plane it was sitting under the guys hood charging. I looked at it and thought what a hunk of junk. When I got to see it fly it was more like OMFG I have to have one of these.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 1:32 pm

Hance wrote:I actually got the idea from one of them I got to watch fly. My build isn't going to be all that radical but should be a good flier.

The one I watched fly had a good 250 dollars worth of stuff on that 5 dollar plane but WOW did it fly. Standard takeoff was aim the plane straight up punch the throttle wide open and let go :o When I first seen the plane it was sitting under the guys hood charging. I looked at it and thought what a hunk of junk. When I got to see it fly it was more like OMFG I have to have one of these.

They fly a lot better than a lot of kits I've seen, that's for sure. The modification doesn't take that long and the bodies are so cheap that it's not the end of the world if you crash.
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 2:35 pm

SpotTheCat wrote:
Hance wrote:I actually got the idea from one of them I got to watch fly. My build isn't going to be all that radical but should be a good flier.

The one I watched fly had a good 250 dollars worth of stuff on that 5 dollar plane but WOW did it fly. Standard takeoff was aim the plane straight up punch the throttle wide open and let go :o When I first seen the plane it was sitting under the guys hood charging. I looked at it and thought what a hunk of junk. When I got to see it fly it was more like OMFG I have to have one of these.

They fly a lot better than a lot of kits I've seen, that's for sure. The modification doesn't take that long and the bodies are so cheap that it's not the end of the world WHEN you crash.


I fixed that for you LOL
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Re: Radio Control Hobbies

Postposted on Sun Sep 07, 2008 3:12 pm

Hah! yeah!

http://www.youtube.com/watch?v=fVGaY4ASDOQ
The one I saw was similar to that, but a lot bigger with less wing loading. The super-slow flight of it coupled with the great T/W and excellent stall and stability characteristics made it great to fly around. I think the AUW was about 200 grams, it flew about 10mph.

edit: one more thing: if you're going to be buying these at wallmart, or a dollar store or something, really look around for the straightest subjects. The way they store these things can really bend them up. Also, get a few so you can mix/match the straightest parts you can find.
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Re: Radio Control Hobbies

Postposted on Mon Sep 08, 2008 8:16 am

Wind was calm right at sunrise this morning and I got to take the Gemini out and fly. In calm conditions, it is quite a joy to fly. I buzzed around at about 60% throttle for two battery packs. Two ok takeoffs, one so so landing, and one nice three point right side up landing. :) My problem is that the closest place to fly has concrete on which to take off, but hitting a 4ft wide walk in the 40 ft where it is straight is kind hard so landing is in the grass.

I backed all the rates off by 20% and with the ailerons on low and the rudder and elevator on high, it flies quite well and is very controllable. I haven't tried and rolls or loops yet -- I put enough work into the plane I don't want to make a mistake yet. ;)

For anyone learning to fly on a high-dihedral aircraft (or anything that tends to self right) it takes a bit of transition to re-learn the ailerons in turns. I still have to consciously remember to let the ailerons come back to neutral once I have started into a turn. I'm not sure where I picked up the habit of staying on the ailerons through the turn though, as I have never flown a classic "trainer" style plane.

--SS
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Re: Radio Control Hobbies

Postposted on Mon Sep 08, 2008 8:54 am

Here's my 2 heli's side by side. The CX2 is in the back and the CP Pro is in the front. I couldn't believe the size difference. The blade span on the Pro is longer then the entire CX2.

Image

And something I noticed this morning that I'm not sure if it's causing the right lean problem. I noticed the blades on the CP Pro lean to the right when they start spinning. I know Hance said that it's normal for the heli to go to the right, but the blades are about half an inch lower on the right side as opposed to the left. Is this normal? I'll see if I can get a good pic of it. It's a pretty good day out today so I'm gonna take the Pro down to the park and see how things go today.
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Re: Radio Control Hobbies

Postposted on Mon Sep 08, 2008 9:22 pm

Well something really isn't right with this thing. I took it to the park found a nice open spot that had a row of trees to break up the light wind that was kicking up. I brought a 3x3 piece of plywood with me for a makeshift heli-pad. I took Hance's advice and idled up quickly to get it off the pad and in the air. When I did the thing went up to about 5 feet and then into an aggressive nose down position and went into a kind of death spiral nose first into the ground. I panicked when this happened and was throwing the controls all over the place trying to get it to level out and nose up. Thinking that was the problem and knowing that it was gonna take off to the right I prepared myself for that on the second attempt. I trimmed it a bit more for some compensation and set it on the pad again. Slowly idling up I got it so the heli was jumping on the pad and then gave it more power to lift it off. Same result. It goes up to about 5 feet and then goes into this death spiral type thing again. I would say the nose is angled down about 35 degrees. Somethings not right and I'm going to contact eflite about it. There is no way this thing was set up in any way at the factory. Luckily there was no damage of any kind as the grass wasn't cut and provided a soft crash landing.

Looks like I'm stuck with the CX2 indoors until I get this figured out.
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Re: Radio Control Hobbies

Postposted on Mon Sep 08, 2008 9:47 pm

Welcome to the wonderful world of CP heli's hoser.
Have you checked the swash plate and made sure that its level with the heli powered up and the controls in a neutral position ? Also have you check the servos to make sure there is no stripped gears in them ? CP helis are totally different than what you are used to. The CX2 will fly itself. The Blade CP on the other hand is notorious for being a hard SOB to fly. I think I posted this a few pages ago but its even more important with a CP heli so go here http://www.dream-models.com/eco/flying-index.html it should help.
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Re: Radio Control Hobbies

Postposted on Tue Sep 09, 2008 10:42 pm

That stinks Hoser. I agree, something isn't quite right, though a collective pitch heli is a whole different beast to fly than the CX2. It should respond to stick input, even wild, uncoordinated stick input. If it really is just pitching forward and spiraling down, something is broke. I agree with Hance, check the servos. Carefully move each one by hand through it's range of motion and see if it binds or skips anywhere. If so, you have stripped gears. Replacement gear sets are a couple of buck and a 10 minute job to replace. Best of luck and don't get discouraged. Even if you have a perfectly setup heli, expect it to take a couple of weeks before you get a good stable hover and feel in control.

I got to go fly again this morning and a bit this afternoon. I found out I get 12 minutes of mild aerobatics on a 1800mAh LiPo. I found this out because I wasn't paying attention to the flight timer on my radio. I looked down and it was at 12:15. I was making the circuit to land and found out how it behaves when the low voltage cutoff kicks in. Not fun. I also, earlier and intentionally, found out how the plane dead sticks. The nose drops a bit if you don't have enough airspeed, but once the speed is back up, it is quite well behaved. Loops are quite tight and clean so long as you go in with enough speed and it rolls like it's got a rod going trough the middle of it. On high rates it will roll 360 degrees in 3-4 plane lengths at 60% throttle. All in all, very fun to fly.

I did learn something this evening: if you land with flaps, remember to reset them before you take off. I spent about 5-10 minutes flying around with flaps down this afternoon. I kept wondering why the trim seemed so off and the ailerons were sluggish even on high rates. Luckily, no damage done.

I like the foam glider conversion idea. I may just pick one up and make a project of it (something like this http://www.lifoam.com/gliders.htm). I'm considering selling the heli too. Planes are so much easier to fly...

--SS
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 1:13 am

Don't wuss out on us and go back to planes SS. I have fun with my B400 but its WORK to fly the dam thing and trying to make sure it doesn't do the dead chicken dance.

Those are the gliders I am talking about. The next time I go shopping I am going to see what I can come up with. It should make an interesting project.
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 6:15 pm

I am very curious how much they weigh. Four and a half feet is a lot of foam.

I was thinking the Ultra Flyer would look spiffy with a couple of EDF nacelles either slung under the wings or molded in at the fuselage, but then I got to looking at EDF thrust to power ratio. Man does it suck. Based on reading you need at most a 2/1 weight to thrust ratio and preferably higher. Looking at a pair of basic EDF units, 350W gets you about 28 oz of thrust, exactly what I get out of my 160W prop setup. Perhaps pusher nacelle or a standard tractor setup then.

--SS
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 6:54 pm

SecretSquirrel wrote:I am very curious how much they weigh. Four and a half feet is a lot of foam.

I was thinking the Ultra Flyer would look spiffy with a couple of EDF nacelles either slung under the wings or molded in at the fuselage, but then I got to looking at EDF thrust to power ratio. Man does it suck. Based on reading you need at most a 2/1 weight to thrust ratio and preferably higher. Looking at a pair of basic EDF units, 350W gets you about 28 oz of thrust, exactly what I get out of my 160W prop setup. Perhaps pusher nacelle or a standard tractor setup then.

--SS

A T/W of .5 is kind of "standard", although many airplanes (including RC) fly with less.

The problem with these foam conversions is balance and alignment.

What kind of control scheme are you thinking? The one I saw was simple 2 channel left/right control. I would not suggest a super high T/W without elevator control :D
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 7:20 pm

The one I am going to build will more than likely be a V tail because that is what the setup is currently on and I don't know if I can unmix the channels or not.
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 7:45 pm

Hance wrote:The one I am going to build will more than likely be a V tail because that is what the setup is currently on and I don't know if I can unmix the channels or not.

You mean your receiver is set up to mix for Vtail? None of those foamy gliders have a Vtail. A lot of the time, if you can't reprogram the receiver you can reprogram the radio.
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 7:49 pm

Yeah the plane I am stealing parts off of is a V tail set up. I know none of the foamy gliders are a v tail but thats part of my project or it might be. It just depends on if I can reprogram the radio or not. I am guessing its going to be a not its a simple cheap radio setup. I am going to look at it tomorrow and see what I can do with it.
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 8:16 pm

SpotTheCat wrote:
SecretSquirrel wrote:I am very curious how much they weigh. Four and a half feet is a lot of foam.

I was thinking the Ultra Flyer would look spiffy with a couple of EDF nacelles either slung under the wings or molded in at the fuselage, but then I got to looking at EDF thrust to power ratio. Man does it suck. Based on reading you need at most a 2/1 weight to thrust ratio and preferably higher. Looking at a pair of basic EDF units, 350W gets you about 28 oz of thrust, exactly what I get out of my 160W prop setup. Perhaps pusher nacelle or a standard tractor setup then.

--SS

A T/W of .5 is kind of "standard", although many airplanes (including RC) fly with less.

The problem with these foam conversions is balance and alignment.

What kind of control scheme are you thinking? The one I saw was simple 2 channel left/right control. I would not suggest a super high T/W without elevator control :D


I don't do anything half-a**ed so I figured I go ahead and go for full control plus speed brakes if I had enough weight allotment. I figure that at less than $10 for the basic airframe, I can afford to experiment. I'm thinking a push-pull setup using music wire on the rudder and elevator. I would like to do the wings the same way to keep all the servos in the body, but that makes detaching the wings difficult so I'm thinking that if I use separate servos for each aileron I can embed them near the wing root and run music wire out to the surfaces. Unfortunately than means I have to accept the extra servo weight and power.

--SS
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 8:21 pm

For anybody else that might want to try my project I forgot to mention something. The one I seen had a 1/4 carbon rod to reinforce the leading edge of the wings. Guy told me he folded up a couple of sets of wings until he added that mod.
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 8:38 pm

I was thinking that I would put an aluminum tunnel through the center of the fuse, larger in front and smaller in back then embed CF rods in the wings that would mate to the tubes to provide a rigid wing mount and stiffen the inner portion of the wing.

I am mentally planning on a power budget of 90-150W with a thrust range from 18-25oz. Aiming for the low end, a 1000mAh 3S LiPo would give me about 6.5m at wide open throttle and if I can handle the weight of an 1800mAh then I can almost double that.

I haven't been able to find anywhere online what these things weigh out of the box so I will likely have to completely change my figures if they are way heavier than I vaguely remember.

*edit* Just found this video: http://www.youtube.com/watch?v=3IKkEFN64a4

That's the glider I'm looking and and the motor prop combo he used produces about 12oz of thrust at 90W. So it looks like I'm on the right track. :) Funny note, he bought his motor the same place I did. It's chinese, but it's pretty high quality - replaceable shaft and bearings. The weakest point on the motor is where the leads transition into the windings.
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 8:47 pm

Hance wrote:Yeah the plane I am stealing parts off of is a V tail set up. I know none of the foamy gliders are a v tail but thats part of my project or it might be. It just depends on if I can reprogram the radio or not. I am guessing its going to be a not its a simple cheap radio setup. I am going to look at it tomorrow and see what I can do with it.



Check this out: http://www.rcgroups.com/forums/showthread.php?t=63253
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 9:35 pm

Hance wrote:For anybody else that might want to try my project I forgot to mention something. The one I seen had a 1/4 carbon rod to reinforce the leading edge of the wings. Guy told me he folded up a couple of sets of wings until he added that mod.

Another slick way to keep everything together in powered flight while maintaining take-apart-ability is to put a bracket (I've seen aluminum and fiberglass) in a.... erm... bracket, [, shape with the tips hanging out of the wings as motor mounts. It's a lean solution that puts a spar and motor mounts in one part.
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Re: Radio Control Hobbies

Postposted on Wed Sep 10, 2008 10:16 pm

I don't care about being able to take it apart. I drive a 4 door 3/4 ton truck LOL
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