mred

http://www.espritmodel.com/index.asp...S&Category=615

This is where I get my folding props from. They are good people to deal with and fast shipping. Either the Aeronaut or Graupner props will work, just make sure you get the 8mm props, because they have some 6mm too. That is the spacing at the hub of the prop. They should be listed as 10X6 8mm props. You can get the spinner here also, but I buy mine from Hobby City. If you need a 40mm spinner then you have to order two of them as the 40mm only comes in 4mm and above and you need a 3mm adapter. Get a smaller spinner with a 3mm adapter and use the adapter in the 40mm. They interchange with no problem. If you can find the spinner you are looking for at Esprit Models, you can get one there too, but they cost quite a bit more, but are good spinners. They are just out of stock every time I check. You can get two Hobby City spinners for less the one of the Esprit ones, but they are not quite as good, although I have been using one for the last two years and it's held up fine. I'll send you some pictures of the motor mount later today.

Ed

mred

OK, here is some pictures of mounting a brushless motor to a glider, but not the Vista. It's done the same way, but I cut a couple of fingers today and can't get the motor mounted in the Vista to show you. If you have any questions let me know and I'll try and answer them. One is on my Chrysalis 2M and the other is on my Spirit 100" glider. Both are mounted through the nose just like the Vista.

Ed

cbatters

Many thanks - exactly the info I was looking for.


Clint

Huffy01

I was wondering if you could buy plan's for a non-powered glider and fit a motor too it.Or is it better just to find one that is already made for power.I was looking at all the plan's on "Airbourne" and "RC" magazine plan's.Some of their non-powered model's are just better looking than the powered one's.I would like to upgrade from the Parkzone Radian I've got, one day.

Sky Sharkster

Hello Huffy,
I don't see why not. Many new gliders come in powered and unpowered versions, but the older designs (published before electric became feasible) don't. Just stick to the general guidelines on this thread or post the size and description, and you should receive some suggestions.
Ron

john339

I have added electric power to unpowered gliders a few times.
As long as the motor is mounted so it doesn't vibrate or wobble when running.
Try not to change the surface too much so it will still glide.
Go for it.

mred

The non powered gliders may be better for conversion to electric power then a lot of the powered gliders. Most of the low cost gliders use a speed 600 motor and it is very heavy needing a short nose moment. Building a non powered glider you have a longer nose and can use a lighter motor in it then the others. A 2 meter glider flies fine on a KD A20-22L motor, but it is to light for the speed 600 nose. You can make the nose 1 to 1 1/2" longer then the powered glider version and most of the time you won't need any nose weight to get the CG right. I use a KD motor in mine and at 3oz it is lighter then a speed 600 at 9oz. It also has more power and can swing a bigger prop. Normally a 10X6 or 11X6 prop on the KD motor verses an 8" prop on the speed 600 and it turnes it slower too. If you don't like the fast climb, you can throttle back and go up slow if you like, but it is much lighter all around then a speed 600 setup and with a smaller LiPo battery, you save weight there too.

Ed

Huffy01

I was looking around and noticed that the more expensive kit glider's tend to have less shapely, less like an actual aircraft with a pilot.
Is it a better design method to have a fuselage just big enough to fit the gear or to have it more "Meaty"!?

mred

Shape is drag. If you are looking for a scale type glider, then you are talking about added drag. The more "SHAPE" you can do away with, the more drag you can get rid of. Scale is great and some of them are very good looking, but we are not getting in these gliders and therefore don't need a nicely shaped cockpit to climb into. The more streamlined you make the glider, the more efficient it is and the better it will fly. Drag is a killer and the more you can get rid of the better off you are. Less sometimes equals more. Putting a pilot in a glider dictates the shape to some extent, but take the pilot out and you can get rid of a lot of drag. Also, some of it is done just because it looks cool.

Ed

PS. The more you add in the way of shape also adds weight and weight is the one thing you really want to get away from. Lighter is better and the more weight you can get rid of the longer it will glide.

AEAJR

MRED has it exactly right. The ideal glider would be wing and tail with a needle connecting them. But we need room for the electronics, although I guess we could put the electronics in the wing.

The competition gliders often have very long thin fuselages where the servos have to be set in tandem in order to fit. Battery packs have to be special shapes and micro receivers with end plugs are usually preferred.

The less wind profile the better.

Huffy01

I just had a scary thought and situation.
About a week ago I added a video camera to my Parkzone Radian.
I roughly worked out c.g.. Wired and taped the camera on and went about taking AV.
As I posted what I did. I had the reply (AEAJR) to check the c.g. so I did and found that the plane was level if it was on the ground but not in it's flying position.
It was handling beautifully nice level flight ,really smooth.
But once in a dive at about 30-45 degree's I could not pull out. I have video footage of this , Only until I got closer to the ground it actually pulled out.
I like to think ground effect did it.
My camera only weigh's 156grams(5.5oz)
If I add the weight of a motor ,esc and larger battery to an unpowered model will I need to think about enlarging control surfaces for the add weight.
I am very closing to buying plan's, next week if my car doesn't need expensive repair's?

AEAJR

Just some thoughts:

You say it was nice and level on the ground. I presume that means you set it on the factory recommended balance point and it balanced there. So we will call that properly balanced.

How is the camera mounted? High? Low? in the nose? under the wing? Where is it?

ON a 30 ounce plane, 5.5 ounces adds 18% to the plane's weight. That is significant. Where it is placed could be very very important to handling.

Did you have to put in any up trim to get it to fly properly?

Was the elevator parallel with the H-stab?

How high were you when you did this dive and what was the reason for the dive?

Was this a power on dive or power off?

Ground effect is a situation where you are flying parallel to the ground and you are within one win span. If I understand the effect properly, this can result in a build up of a pressure cushion that will lead to a very shallow glide path, more shallow than would be seen at higher altitudes. So I don't think ground effect had anything to do with your situation.

When you went into the dive, how high were you?

How long was the dive?

What were you doing during this dive?

Nothing?

Pulling up?

Pushing down?

Motor on?

If you lost control of the plane, there must be a reason. I am trying to understand what happened.

maguro

Huffy, you will absolutely have to enlarge the control surfaces. The easiest way to do this is to add balsa rudder, elevator and ailerons (if you plan to use them).

Take a look at what has been done over at RCGroups. There is a lot of great advice in this thread: http://www.rcgroups.com/forums/showthread.php?t=832717

Roger

AEAJR

Maguro,

Why such a requirement for surface expansion? I often ballast my gliders 20% and have never found the need to expand surfaces. As long as the plane is properly balanced, and the weight is centrally located, expanded surfaces should not be needed. This assumes that the plane flew well with the stock surfaces before adding the weight.

Having said that, expanded surfaces shouldn't hurt.

Huffy01

I had the camera mounted on the top over the wing.
It was unintentional dive coming out of a turn, crosswind, no power.
I could not give you a very accurate altitude as there is nothing in the backround where this happened.
I did pull up and you can see it in the video, the plane moves but continue's diving.
I did loose any controls of the plane
I have the video on the computer but I cannot upload to site ,too many done already but could do it next month.

AEAJR

Unintentional dive tells me you stalled the plane, so you had no surface control as a result of the stall. You were flying too slowly and/or turned too sharply and too flat. You did not have enough speed to keep the plane flying. During a stall there is little or now surface contol possible till you gain airspeed.

Having all that weight above the wing will make the plane top heavy. Combine that with a stall and you will have little control and can not pull out till you have allowed the plane to gain speed. The extra weight plus the high mounted weight simply means you need more speed.


Were you 10 feet high? 20? over 100? What is your guestimate?

How long did it take to pull out? 10 feet, 20 feet, 100 feet?

maguro

I assumed we were talking about hand launched foam gliders. This type of glider was never intended for anything other than a back yard toy. The need for movable control surfaces was never figured into their design.

Look at the link I supplied. There are others as well on RCGroups. Many types of gliders and many configurations were tried. Some were successful, some not so. I am just passing along the experience of many over the years. Yours may vary.

Roger

Sparky Paul

I've seen this occur with high-mounted cameras. The turbulence around the camera reduces the effectiveness of the tail surfaces, so that power-off, you have much less command of the airplane.
Lower the camera.

AEAJR

This is a real good point. Pilots experience this same "blanking out" of the tail when flying RES gliders where one big spoiler may divert air past hte tail surfaces or create turbulance. Depending on the turbulance this can be a minor issue or a major one.

It is more of an issue on an R/E plane than an aileron plane but if you blank out the elevator or create so much turbulance that the elevator doesn't function well, you have a real problem.

I don't know if that is the case here. More likely you just had a normal, everyday stall caused by the pilot letting the plane fly too slow, turning too sharply or perhaps applying too much up elevator for the speed at hand.

Nothing mystical about stall. 90% of the time it is caused by pilot error.

Huffy01

The camera is mounted just behind the canopy(see photo), I did move it a little further forward.
I have been looking at the video.
The plane is flying over 100 feet. There is no sign of a stall ,it is flying fast and loosing altitude before the turn.
as the plane turn's it sharply turn's and start's to dive.
During the dive the plane is in a shallow turn, it continues of 8 second's before I input elevator up .There is a slight deviation of the nose up then moves back to oringinal path .
3 second's later there is another input of elevator up the plane moves out of it's flight path and shallow turn becomes a medium turn.
At the 13 second of the dive the plane is parallel to the ground in a medium bank.

AEAJR

Thoughts:

Elevator stuck - not centering

Rudder stuck - not centering

Receiver problem

Those are my current thoughts.

Huffy01

I haven't had in flight control problem's yet.
Only a light breeze on that day.
?

Huffy01

Well I chopped the section out of the full video.
This the footage from the plane .

[media]http://www.vimeo.com/3638126/[/media]

AEAJR

Based on the bank angle of the plane it looks like it went into aturn and did not come out. I can see you fighting to come out using the elevator but I don't see any atempts to level the plane till the very end.

My gut says you gave it a left rudder command and the rudder did not come back tocenter. Either a rudder problem or you held rudder during the entire dive.

I don't think the top weight effect would hold that bank angle like that. And the camera is not all that high off the fuse.

Hands off, the Radian will not hold a bank angle like that. The dihedral in the wings will naturally bring it back to level.

I suspect the rudder. Check the hinges, the linkages, etc.

Huffy01

I received plan's for a 2 metre glider which I wish to convert to electric assit.
It's an aerobatic model, semi scale. Mid-wing with standard tail configuration.
The wing span is of course 2 metre's and the fuselage is 1.13 metre's.
I will try to post a picture but at the moment ,the batteries in my camera are flat.