EJF Composite A-10 Construction - Page 5

Arthur Knowles · Apr 25, 2003, 04:52 PM

Thanks to all for the links and pictures. Wof, I wouldn't worry about the diversification, all threads spread around a bit.

With he pictures available, I guess I'll have to go with the rounded tips now. At least I won't have to cover them as I plan to paint it. Those tips would be no fun to cover with film.

drksyd · Apr 25, 2003, 05:11 PM

Arthur
What kind of lithium cells are you using? According to your calculations the cells are 950mah? The chart you're referring to is good only for the Etec cells, Kokams will only handle 5C in short bursts. If you have the new high output Kokams then they're good for 8-10C. The life of the pack should be good as long as you don't drop it below 10volts in the current config now, 4S6P.

Wof · Apr 25, 2003, 05:25 PM

Art do not forget the tip lights He He

Ed Waldrep · Apr 26, 2003, 01:38 PM

Quote:

Originally posted by Arthur Knowles
Thanks to all for the links and pictures. Wof, I wouldn't worry about the diversification, all threads spread around a bit.

With he pictures available, I guess I'll have to go with the rounded tips now. At least I won't have to cover them as I plan to paint it. Those tips would be no fun to cover with film.

Arthur, I thought I should pass on my experience covering my A-10. I ran out of Utralcoat grey so I bought some Ultracoat lite clear since I was going to paint it anyway. The stuff is thinner than regular Ultracoat and it will shrink more. I covered my curved horner wingtips with it and got it to stretch around the whole perimeter and shrink with no wrinkles! Amazing! I've never seen an iron on covering to that with the exception of fabric.

The key is to have two hands to pull on the covering while you heat it. A actually had my heat gun between my chest and my chin trying to hold it at the right angle and that worked somwhat. I kept heating and stretching the stuff and got it to shrink enough. This worked better than an iron I guess because the heat was spread out more evenly.

The Ultracoat lite takes paint well, I used Testors Model Master sprays and didn't even rough up the covering first, I was in a hurry. Some paint did come off when I was masking with newspaper but I only uses small doubled up tape loops to hold the paper off the surface a bit to get a soft masking edge. Sanding with steell wool or 600 grit might have prevented that.

Arthur Knowles · Apr 26, 2003, 03:21 PM

Quote:

Originally posted by drksyd
Arthur
What kind of lithium cells are you using?

They are E-Tech 1200 mah cells. 1200 * 6 = 7200 mah (that.s for the 4S6P pack). NipponDave has stated that others have pulled up to 10c in burst from the ET cells without damage. So, it looks like the 4S6P pack will be OK to use.

Based on the data provided for IR for single cells (.035) my motors & fans will pull 52 amps at full throttle - static. That's about 7C. In flight the motos & fans will pull 35 amps. That's 5C. I don't expect to fly at full throttle all the time. That's estimated at 90 mph.

All these calculations are based on Motocalc values and are just estimates. I'll firm up values as the plane is built and I can adjust the weight and wing loading accordingly. As it stands now, I'm going to put about 175 watts per pound into it.

Arthur Knowles · Apr 26, 2003, 03:24 PM

Ed,

Thanks for the input. As I have glassed the wing, there is no need to cover it with film first. I'll think about doing this with the elevator and rudder though. That may be better than glassing it as well.

Wof,

Lights. Hah, that's a good one.

On the serious side though, if the plane flies well I will be adding scale details to the fuse and wing. Lights (non operational ones) may not be too far fetched.

Art

Wof · Apr 26, 2003, 04:58 PM

The stage i am at excuse the poor building area no space

Wof · Apr 26, 2003, 04:59 PM

The fuse

Wof · Apr 26, 2003, 05:01 PM

Picture 1 just to make sue all flat and correct washout,picture 2 just drying

Arthur Knowles · Apr 26, 2003, 11:59 PM

Wof,

So, no operational rudder, huh? I've been thinking about that a lot. I have one HS-81 servo I could use for the rudder. If I could figure out a good way to make them operational without making it too ugly.

I thought about using a pull-pull cable with a tie between the two movable surfaces. I could mount the cable on the external (outside) surfaces. Maybe use fishing line (clear).

Or maybe use a pull cable on the inside surafaces with the external surface under tension. Though that one bothers me is the line snapped (i.e. the tension would pull the rudder out and possibly cause a crash). I think a passive system would better.

Anyone have any ideas they'd like to share?

Art

Wof · Apr 27, 2003, 04:55 AM

This will be quite a simple version no operational rudders you can just see the bungee hook on the fuse,the sites i fly from are grass with a nice long tarmac runway but i cant guarantee i can always land on it.
It maybe easier to have a stearable nose wheel i assume it will only be used for take-offs?
Mark

Arthur Knowles · Apr 27, 2003, 06:19 AM

Wof,

I will have a steerable nose gear. I will only use it for takeoff, landing, and taxi back to the pits. Unless it has problems taxing on the dirt runway we have.

I'll be using a micro servo for the steering. If I have functional rudders, it'll use another servo with a Y connector.

I just haven't decided on the rudder because of the complexity. Most likely, I'll skip a functional rudder. If I do, it means no stall turns. No snaps. No knife edge or 4~8 point rolls.

Art

Wof · Apr 27, 2003, 06:34 AM

I must get used to the fact that electric flight has advanced so much from when i got into it a good few years ago,it was an achievement to have a EDF that could fly let alone do a roll.
My first plane that surprised me was made by an english company called MFA it was the first plane that i had that could do a loop and a roll from level flight cant think of its name.
I am just getting back into electrics got quite a few planes ready for our two week summer when it arrives.

hoser · Apr 27, 2003, 11:51 AM

Arthur no need for rudders the plane is small enough that it only becomes and issue in severe crosswind conditions, where the nose gear can't correct the force of the wind on the rudder planes.

Wof, the plane hand launches pretty easy depending on the weight, for those who use a bungee like DR jet and jepe have uses fixed wheels in the nacelles like if the real ones were retracted and a tail wheel (I think) this would allow for landings on paved surfaces.

also this model will roll loop, fly inverted, split S and (by accident) do a hammer head)

Wof · Apr 27, 2003, 02:02 PM

Art more curly tips to see,got the wing 1/32 balsa covered now been sanded reinforcing the servo wells then to glass we go.

Apr 26, 2003, 04:58 PM	#67
Wof Registered User Join Date: Sep 2002 Location: London Southend, Great Britain (UK) Posts: 1,112	The stage i am at excuse the poor building area no space Attached Thumbnails 85.1 KB · Views: 260

Apr 26, 2003, 04:59 PM	#68
Wof Registered User Join Date: Sep 2002 Location: London Southend, Great Britain (UK) Posts: 1,112	The fuse Attached Thumbnails 75.1 KB · Views: 251

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Apr 25, 2003, 04:52 PM	#61
Arthur Knowles Registered User Join Date: Oct 1998 Location: Fallbrook, CA Posts: 1,113	Thanks to all for the links and pictures. Wof, I wouldn't worry about the diversification, all threads spread around a bit. With he pictures available, I guess I'll have to go with the rounded tips now. At least I won't have to cover them as I plan to paint it. Those tips would be no fun to cover with film.

Apr 25, 2003, 05:11 PM	#62
drksyd MultipleCrashSurvivor Join Date: Jan 2003 Location: Honolulu, HI Posts: 2,695	Arthur What kind of lithium cells are you using? According to your calculations the cells are 950mah? The chart you're referring to is good only for the Etec cells, Kokams will only handle 5C in short bursts. If you have the new high output Kokams then they're good for 8-10C. The life of the pack should be good as long as you don't drop it below 10volts in the current config now, 4S6P.

Apr 25, 2003, 05:25 PM	#63
Wof Registered User Join Date: Sep 2002 Location: London Southend, Great Britain (UK) Posts: 1,112	Art do not forget the tip lights He He

Apr 26, 2003, 03:24 PM	#66
Arthur Knowles Registered User Join Date: Oct 1998 Location: Fallbrook, CA Posts: 1,113	Ed, Thanks for the input. As I have glassed the wing, there is no need to cover it with film first. I'll think about doing this with the elevator and rudder though. That may be better than glassing it as well. Wof, Lights. Hah, that's a good one. On the serious side though, if the plane flies well I will be adding scale details to the fuse and wing. Lights (non operational ones) may not be too far fetched. Art

Apr 26, 2003, 05:01 PM	#69
Wof Registered User Join Date: Sep 2002 Location: London Southend, Great Britain (UK) Posts: 1,112	Picture 1 just to make sue all flat and correct washout,picture 2 just drying

Apr 26, 2003, 11:59 PM	#70
Arthur Knowles Registered User Join Date: Oct 1998 Location: Fallbrook, CA Posts: 1,113	Wof, So, no operational rudder, huh? I've been thinking about that a lot. I have one HS-81 servo I could use for the rudder. If I could figure out a good way to make them operational without making it too ugly. I thought about using a pull-pull cable with a tie between the two movable surfaces. I could mount the cable on the external (outside) surfaces. Maybe use fishing line (clear). Or maybe use a pull cable on the inside surafaces with the external surface under tension. Though that one bothers me is the line snapped (i.e. the tension would pull the rudder out and possibly cause a crash). I think a passive system would better. Anyone have any ideas they'd like to share? Art

Apr 27, 2003, 04:55 AM	#71
Wof Registered User Join Date: Sep 2002 Location: London Southend, Great Britain (UK) Posts: 1,112	This will be quite a simple version no operational rudders you can just see the bungee hook on the fuse,the sites i fly from are grass with a nice long tarmac runway but i cant guarantee i can always land on it. It maybe easier to have a stearable nose wheel i assume it will only be used for take-offs? Mark

Apr 27, 2003, 06:19 AM	#72
Arthur Knowles Registered User Join Date: Oct 1998 Location: Fallbrook, CA Posts: 1,113	Wof, I will have a steerable nose gear. I will only use it for takeoff, landing, and taxi back to the pits. Unless it has problems taxing on the dirt runway we have. I'll be using a micro servo for the steering. If I have functional rudders, it'll use another servo with a Y connector. I just haven't decided on the rudder because of the complexity. Most likely, I'll skip a functional rudder. If I do, it means no stall turns. No snaps. No knife edge or 4~8 point rolls. Art

Apr 27, 2003, 06:34 AM	#73
Wof Registered User Join Date: Sep 2002 Location: London Southend, Great Britain (UK) Posts: 1,112	I must get used to the fact that electric flight has advanced so much from when i got into it a good few years ago,it was an achievement to have a EDF that could fly let alone do a roll. My first plane that surprised me was made by an english company called MFA it was the first plane that i had that could do a loop and a roll from level flight cant think of its name. I am just getting back into electrics got quite a few planes ready for our two week summer when it arrives.

Apr 27, 2003, 11:51 AM	#74
hoser Registered User Join Date: May 2001 Location: miami springs Posts: 2,561	Arthur no need for rudders the plane is small enough that it only becomes and issue in severe crosswind conditions, where the nose gear can't correct the force of the wind on the rudder planes. Wof, the plane hand launches pretty easy depending on the weight, for those who use a bungee like DR jet and jepe have uses fixed wheels in the nacelles like if the real ones were retracted and a tail wheel (I think) this would allow for landings on paved surfaces. also this model will roll loop, fly inverted, split S and (by accident) do a hammer head)

Apr 27, 2003, 02:02 PM	#75
Wof Registered User Join Date: Sep 2002 Location: London Southend, Great Britain (UK) Posts: 1,112	Art more curly tips to see,got the wing 1/32 balsa covered now been sanded reinforcing the servo wells then to glass we go.