Hi I'm Jim, here to request some help...........

[Canada_Jim 0]

I am not a skydiver, nor do I have any experience being around the discipline at all, so really green.

I do not intend to be a jumper at all, what I am is a 30 year scratch building radio controlled modeler with an idea in my head.

To build the worlds first; remote control, animatronic, skydiving Teddy Bear!

I have purchased this traction kite; this container; This 36" Teddy Bear; This signal flare chute..........

and all the stuff necessary to install 3 degree of freedom robotics into the teddy to give him humanoid arm and leg movement, linear actuators to deploy chute, telemetry radio system to provide remote control........................etc.....etc....

I have some scale ppg building experience including re-string a chute from a cad model.

I lack the practical full scale experience necessary to really be successful, but believe all the products are now available to do some really cool things like this..............imagine a wing suit flying animatronic teddy bear..............PPG bear.............etc.

So I got all this stuff coming in the mail, and while I'm waiting I'm curious to hear some thoughts from experienced divers, and would like to ask some aeronautical engineering type questions, such as what is the purpose of the slider on the lines?

I am not a skydiver, but a radio controlled modeler seeking information about building a radio controlled skydiver.

[Lawndarter 3]

In simple terms the slider slows down the opening of the canopy so that the opening shock transmitted to the jumper is lessened. It essentially delays the inflation of all the cells slightly by holding the lines together until it comes all the way down to the slider stops.

[dthames 0]

The slider had air pressure on it during the initial inflation phase of the canopy. The slider is forced up to counter the inflation, thus controlling the canopy inflation until the speed is reduced. With less pressure on the slider, the inflation force wins, forcing the slider down.

You need to make your bear fall at 120 MPH so a skydiver can fall relative to the bear and take docks on it.

Instructor quote, “What's weird is that you're older than my dad!”

[dthames 0]

Just looked the photos. You need to plan for a ram-air type parachute and have the bear's arms move to steer it. I saw someone do this with a large GI Joe back in the 80s. He could fly around, controlling direction and landing location to a fairly good extent.

Instructor quote, “What's weird is that you're older than my dad!”

[Canada_Jim 0]

Thanks for the swift replies guy's,.........so I'm thinking slider is not necessary and bear can endure the forces.........

Hames, I'm think I'm gonna convert the kit in photo to the chute for this project.

I will sew a bag and attach the 36" signal flare chute in one of the pics for a pilot, to mimic full scale system. I will ground test and maybe anticipate re-stringing for increased angle of incidence...............thoughts??

I am not a skydiver, but a radio controlled modeler seeking information about building a radio controlled skydiver.

[Canada_Jim 0]

The 3DOF animatronic stuff I will use and my 32 channel computer transmitter that uses open source software which allows me to write custom algorithm's for the human like control this model will have......in these attachements.

I am not a skydiver, but a radio controlled modeler seeking information about building a radio controlled skydiver.

[piisfish 135]

Do you want to do something like Mini Gibolin ? https://youtu.be/Dv_uqRGGO8Y

scissors beat paper, paper beat rock, rock beat wingsuit - KarlM

[Canada_Jim 0]

In a lot of ways yes exactly, piisfish, like that model only larger. My design will have more flexible limb movement and will be much larger scale........but the concept is based on the tried and true type of rc skydiver you depict.

I am not a skydiver, but a radio controlled modeler seeking information about building a radio controlled skydiver.

[sirenoremac 0]

I think this is awesome. One thing I think might not be obvious to a non-jumper: for modern pilot chutes that are not spring loaded (as it appears you are planning to use), in a real skydive the pilot chute must be thrown clear of the jumper to get away from the turbulent air immediately above. I imagine teddy will have this need as well if you are going with this type of pilot chute, which seems challenging. Cool if you can make it work, but using a spring loaded pilot chute seems like it would be much easier. That can be compressed into the container on top of the bag, then the container can be closed with some kind of release mechanism (ripcord). When the release is triggered, the container opens and the pilot chute pops free into the wind stream. Perhaps you've already considered this, but it seemed like a not entirely obvious pitfall so I thought I'd mention it. I want to see this thing in action!

[obelixtim 100]

How do you propose to get your bear to his launch point?. What altitude? what vehicle? Landing zone?

Be aware that there might be problems to overcome with authorities when you go into the air with this toy. Like CAA, local councils etc.

My computer beat me at chess, It was no match for me at kickboxing....

[Canada_Jim 0]

Siren, thanks for the heads up on this condition, it was not something that I had considered, and it now has me brain storming a bit.......

Obe, I intend to install a drop pin mechanism on a radio controlled aircraft called a Pilot RC Skywolf, it can be seen here;[url]https://youtu.be/G4FP7ZBdgC4
I have oversize landing gear for it, that will buy me the space between ground and underside of fuse.
I am a 30 year member of The Model Aircraft Association of Canada and follow their protocols for safety at all times. The equipment I will build with allows for GPS downlinking and barometric sensor information to provide a real time sense of location, and it will be used at a MAAC sanctioned field after passing all safety inspections required of it. My goal is to obtain Nav Canada special exeption licence and private insurance to be able to display it at airshows..........

I am not a skydiver, but a radio controlled modeler seeking information about building a radio controlled skydiver.

[obelixtim 100]

OK, that is all good, you are familiar with the various requirements for flight and dropping objects.

Also to take into account.

What is the weight of the bear? That will have an effect on both the opening and the flight of the canopy, depending on the wind strength. So the size of the canopy will need to be matched with the weight of the passenger to get optimal flying performance.

There is quite a bit to consider.

My computer beat me at chess, It was no match for me at kickboxing....

[Canada_Jim 0]

Yes, Obe, so much to consider...........I'm thinking of this as a quarter scale project, but have been unable to decipher the full scale parachute sizing numbers. They don't equate to anything I can compare kite size to. My gut tell me to start out in the 20kg range and I'm thinking some ground testing might garner information that has it pretty light on the wing at that weight and may suffer from lack of penetration, especially due to high angle of incidence of a kite compared to parachute. My research indicates kites around 2-3 degrees, and parachute up to 7 degrees.

Another question I have is about the pilot chute.........the ones I've seen you guys use have an apron extending at least partially around the strings. This differs from the signal flare chute I got, so does this serve a special purpose, should I expect to add?

I am not a skydiver, but a radio controlled modeler seeking information about building a radio controlled skydiver.

[obelixtim 100]

Not sure what you mean by "apron". Not part of our terminology.

I've done drop testing with dummies before, and the best opening method is a static line type system...does away with pilot chutes completely. Then of course you'll have to consider what happens with the static line attached to the drone after deployment.

What you should do is contact your local dropzone (google is your friend) and find out who their rigger is. Face to face with a qualified rigger will give you a lot of answers and information, especially if you take your setup and show him what you have got.

Its tricky trying to do some of this on the internet.

My computer beat me at chess, It was no match for me at kickboxing....

[wolfriverjoe 1,340]

First off, welcome. This sounds like a really cool project.

As was already noted, the slider slows down the opening. It more or less 'chokes off' the canopy, keeping it from opening all at once. While your bear may not feel the effects of a hard opening, your electronics might. Hard openings can also break lines.

Full scale parachutes are sized by square footage. A "190" is 190 square feet. Generally, newer jumpers are advised to choose a canopy that gives one square foot per pound of weight. That is, a jumper who weighs 190 lbs (85kg or so) would be advised to jump a 190 canopy.

One problem with that for your project is that it doesn't scale down very well. Part of that is because smaller canopies have shorter lines, which increase the speed of any maneuver (faster pendulum effect).

On the flip side of that is that the bear wouldn't have the density of a human body. How much do you expect the bear to weigh (with all of the electronics)? One thing to remember is the term "exit weight." The weight of a jumper, for calculating wing loading, is considered to be the entire weight of the jumper and all of his gear. That is, how much the jumper would weigh if he stepped on a scale fully geared up, just before boarding the plane.

If you are dropping from a plane, it would probably be simplest to go with a static line (S/L) setup, as opposed to using a pilot chute. Simply attach a bridle to the top of the canopy (a velcro attachment would be best) and attach that to the plane. As the bear falls away, the S/L pulls the pin, extracts the canopy and then lets go. Sport rigs have the canopy packed into a deployment bag, but for your setup, I'd think you could get away with "free packing" it (no bag).

The suggestion that you go to the closest DZ and talk with the rigger there about this. You could see a real rig, perhaps even a S/L setup. You could also get advice on how to set this up.

Helpful hint: If you go to a DZ to ask for help, take along a case of beer. It's the typical payment for asking questions.

You might also get in touch with John Kallend ("Kallend" on here). He's a long time R/C plane enthusiast.

"There are NO situations which do not call for a French Maid outfit." Lucky McSwervy

"~ya don't GET old by being weak & stupid!" - Airtwardo

[mr2mk1g 10]

Some train of thought comments:

Power kites are typically attached to their flying lines by larkshead knots, generally these are attached to the kite lines at knots so that the larkshead knot does not slide along the line and generally there will be a choice of which knot to use. If you have a 4-line kite (you'll want a 4 line kite, not a 2 line one) all of the lines coming from the canopy should terminate at 1 of 4 lines (plus two further lines at the rear for the brakes).

If the trim is different to parachutes, that is something you'll probably want to fix. Parachutes rely on their trim to inflate and stay inflated when in flight. Screw up the trim and the canopy will not want to stay inflated and may just turn into a streaming mess. This is easily seen with power kites by pulling on the rear line sets hard and collapsing the kite.

A simple method of adjusting the trim would be to simply have the rear lines attached to the suspension lines one or two knots higher than the ones on the front suspension lines. If you don't have a choice of knots, just add some.

As above, you'll also want to work out how heavy you want to make ted. Skydiving parachutes are loaded at about 1lb per square foot of canopy all the way up to well over 2lb/square foot on higher performance parachutes. Kites are measured in square metres (at least over here they are anyway) but some basic maths will help you convert the figures.

The higher the loading, the faster everything happens. A higher wing loading might actually be helpful with a little thing like a bear (it might not want to inflate at loadings of 1lb/square foot but you'll have to try it out. I'd start low and work out what does or doesn't work.

You may have issues with deployment. High aspect wings like power kites (large ratio between it's width side to side vs depth front to back) are easy to spin up. Kites like the one you have are not designed for deployment into an airflow and will not behave well. Skydiving parachutes, even the most extreme versions, have a significantly lower aspect ration than power kites and much less taper to them. Simply put, higher aspect parachutes with more taper are known to have more deployment issues, potentially spinning up - for example reserve parachutes are much squarer as we're looking for reliability over fun factor.

Make sure Ted loads the parachute equally left to right. If not he'll have at best an in built turn and at worst the openings will spin up.

[Airgump 1]

look up "rigger lee" he is on here now and then. he has worked on some interesting "deceleration" projects.

[Canada_Jim 0]

I really appreciate all the awesome advise and knowledge you all have taken the time to share with me.

I have limited time and cannot visit this site as often as I would like, but I vow to keep you posted on my progress.

Attached is a pic of the plane under construction that will carry the teddy bear up, and here is a video clip of the first completed animatronic arm;
https://youtu.be/kQkjtNW7vhw

I am not a skydiver, but a radio controlled modeler seeking information about building a radio controlled skydiver.