SMALL - Telemetry SMALL - Radio
Thread Tools
Old Jan 28, 2012, 08:43 AM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
Discussion
HK Bela Trike, and Parafoil

Okay, started a new thread here to discuss this kit from hobby king. There is little information avaliable for it, and no formal instructions so I will try to compile all useful information obtained through reading other forums, here in this thread.

I recieved this kit two days ago, and being on a leave from work, was able to spend most of the last two days on it. Assembly of the gondola took aprox. 9hours, and presented no big suprises. I found the gondola portion to be well thought out, and great value for the purchase price.
canada_jim is offline Find More Posts by canada_jim
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 28, 2012, 09:06 AM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
So yesterday morning I began the foil set-up regime, as outined in the hobby king forum here; http://www.hobbyking.com/hobbyking/f....asp?TID=15974

I found that I could not get the kite to pop consistently no matter what I did. I took the thing back inside and started looking it over.

A lot of the packaging creases were evident throughout the foil, not allowing the cells to open evenly. Some tie points had slipped down, thier main strings, and a couple had let go at the kite attachment point. I must also say that the sewing job on this kite leaves alot to be desired, but I somewhat expected that, and hey..........it was $17.00.

I spent hours with the heat gun and steamer, working out the creases in the foil, and was moderately sucessful. I also repaired the failed tie-points to the best of my ability.

At this point I rigged it to the gondola, because it is very difficult, if not impossible to hold the "d" rings in the correct AOA position, and the brake lines in thier respective positions to pop-test.

By the end of the day I think I had it popping pretty consistantly up, but I remain somewhat skeptical of the foil because the sewing does not seem symetrical.
canada_jim is offline Find More Posts by canada_jim
Reply With Quote
Old Jan 28, 2012, 09:30 AM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
I'm reluctant to start hand-launching this machine yet, and I'm wondering if an intermediate test might be performed from a pick-up truck. I'm thinking about setting up in a truck bed, and trying to fly the foil at speed while being held in the truck.

Can some more experienced people comment on this?

Inventing Man, I'm considering this method to test the larger kite also, for the giant scale project. I think it can be controlled for safety this way...............comments?
canada_jim is offline Find More Posts by canada_jim
Reply With Quote
Old Jan 28, 2012, 11:45 AM
inventing_man is offline
Find More Posts by inventing_man
Whats a search engine?
inventing_man's Avatar
Missouri
Joined Jun 2006
886 Posts
Yeah thats the problem with the Bella dog "pop up test" Its not giving you any information about the how the airfoil shape is going to fly . All the pop up test is going to show is if the risers are being pulled equal on the wings way up to the overhead position. As you have seen holding on to the risers and brake lines by hand is kind of hard to say the least . Thats why I used control handles like 4 line power kites use . My HK would pop up just fine too, but once actually flying over head, for a second or 2, it would always peal off sharply to the left with no input from me and no miss adjusted brake line . It WAS due to the airfoil being sewn crooked . I had to REALLY tweek those D rings WAY past the shown adjustment to get it to fly even half way correct . But it still always wants to go ( hunt) to the left side , but not as bad . So Flying it like a power kite its not really noticable , But for working As a paraglider where it needs to be very stationary over the trike , would have ment a constant correction input and a Squirrely flight.
The truck bed Might work, But vehical turbulance and a cross wind component ( road not going straight with the wind direction) especially at slow speed, might also show you indications thats not really happening. So I going to stick by the suggestion of overhead kiting in good straight line winds . This way you can actually Feel what the wing is doing through the risers . Attached to a trike you wont be able to feel the wing . Again I'm going to stick by my guns and say "if it wont kite like a paraglider should, It wont fly like one" I got severaly hammered on the HK forum for this , and why I no longer participate there. Some people just dont get it, but Kiting is a fundamental function of any paraglider. If it wont kite , It wont fly.
I flew the HK foil directly over head for at least 30 mins sucessfuly , BUT with the constant and regular like clock work touch of right brake to keep the left hand hunt at bay , I decided it was going to be too much to try and deal with . I couldnt trim it out with risers, or by adding a touch of constant brake to the right side. I had to always give it a touch of right brake and then let off , to keep it over head. Touching brakes ,Both left and right in a random fashion is normal kiting to keep the wing directly over you. , Fighting a constant turn to one side, all the time , is not . Something is a-miss in this condition and thats what you want to find out before comitting your gear to it.
And even now as a 4 line power kite , Doing a left hand loop is fast , but it takes almost twice as long to do a right loop = bad sewn wing . Not Symmetrical .
Here is a vid of paragliders kiting , Its a whole lot of fun even with little wings. The feed back from the wing , through the lines to your hands coupled with seeing how the wing is reacting, is invalueable information to know, IMHO. .
Paramotor National Kiting Contest Swept By Flat Top Powered Paragliding Team!!! (10 min 33 sec)
inventing_man is offline Find More Posts by inventing_man
Last edited by inventing_man; Jan 28, 2012 at 02:22 PM.
Reply With Quote
Old Feb 01, 2012, 09:12 AM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
So, I'm not one to give up on any model easily. I have spent the good majority of the last two days trying to sort out the Hobbyking parafoil.

I started by pop testing and altering brake tension, to trim out the foil, but could get nothing to happen consistantly. While doing this I observed that the all important underside of the canopy was bunched up in some areas, no consistant shape was visible.

I believe that a wing is a wing, and some basics apply to even these flexable wings. I went back in the house, and started looking , through one of the larger cells. What I was looking for at this time was an indication of the inside the foil, for the cause of the uneven bunching.

Inside the cells, the the bottoms had the lower portion of the ribs folded and de-formed. This was because the bridal length, was not correct to hold the airfoil (rib) shape.....do you know what I mean?

So I unfolded an internal rib inside a cell, put the steamer to it, and observed the airfoil used to construct this wing, it is a semi-symetrical airfoil. The "A" lines attach below the leading edge, at the bottom of the ram air opening. The "B" lines attach at the low point of the elipse, the "C" lines attach closest to the mean air chord, of the airfoil I believe, and the "D" lines are even higher up the rearward portion of the chord line. Obviously the brake bridals are trailing edge attached.

That being said, neither bridal line configuration; the pre-set from manufacturer, or the hobbyking forum recomended D-ring spacing configuration, come close to rigging the shape of the airfoil of this wing. Am I being clear, you guy's still following me? Have a look at most of the failure to launch video's and compare them to the full scale video of the last post. See how the full scale wing underside looks so smooth and evenly inflated. Compared to the fail video's, this same zone of the wing is bunched and un-even, this is a big problem.It's like bashing the underside of the wing of your Cessna 172 with a sledge hammer, prior to flight. You may get it up, but your gonna be in for one hell of a ride...........and nothing is going to be consistant.

After scrutinizing this I attempted to alter the rigging of my bridal D-rings to facilitate correct wing inflation. With a decent wind blowing yesterday I spent the afternoon tweeking the zip tie stantioning, slowly obtaining better inflation. Once the wing was inflating correctly the increase in lift, was dramatic. In 30km wind the gondola became hard to hold onto, if this thing ever flies, it's gonna pack a load thats for sure.

Yes I have acheived great inflation now with revised d-line spacing, but it's never that easy. I now get great pop but the wing is very resistant to coming straight up, it hangs back, or peels off to one side or the other in a very strong way. I am assuming that my AOA is too positive right now, based on these characteristics.

The issue with this now is that the d-rings will not facilitate any more adjustment of AOA to the negative, or more specifically toward zero. I believe now that completely re-stringing this wing is the only remedy.

So, during my enitial research of this machine, I followed a link from what I think was the hobbyking forum to maybe a Romanian forum, Popado, was that you?...................anyway in a different language, the thread was regarding re-stringing this wing. I captured two jpegs from that thread, a measurement schematic, and a tie-off diagram. I will post them here below, hopefully the author of them does not mind. Please contact me if that is not the case.

Anyway you can see that the measurements (assuming millemeters here), atleast are consistant with the shape of the airfoil we determined as being semi-symetrical. I believe that these measurements are calculated correctly. If anyone else has used them please chime in here, and let us know your experience. Also Popado, can you comment on your experience and these measurements please?

So that is my next order of bussiness is to re-string this entire wing...based on these measurement schematics. I bought some nylon string yesterday, but it is heavier than the stock stuff. I think I will try to use it, because thats what I have on hand, and the photo's in the tieing diagram attached seem to show heavier string, maybe someone could comment on that also........................

I'll keep everyone posted on my progress, because I'm sure that there are more people wanting to fly this wing...............
canada_jim is offline Find More Posts by canada_jim
Last edited by canada_jim; Feb 01, 2012 at 09:45 AM.
Reply With Quote
Old Feb 01, 2012, 04:55 PM
inventing_man is offline
Find More Posts by inventing_man
Whats a search engine?
inventing_man's Avatar
Missouri
Joined Jun 2006
886 Posts
Use braided fishing line , like Spider wire in the 10 pound test range . Does not stretch ,more like real paraglider lines made of spectra . Thicker lines increase drag . Thinner Improve flight .
inventing_man is offline Find More Posts by inventing_man
Reply With Quote
Old Feb 02, 2012, 07:48 AM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
Inventing man, thanks................I ended up at Popad's site yesterday to see what he has done. I saw the line he was using and went to town and got some for this project.

I am now re-stringing the foil using his measurements and will convert to weight shift control as he has done.

What atributes do you lose when you go with weight shift instead of brake bridal beside the flare? It seems to me to be the better system in a lot of ways..........and flight speeds are managable without the ability to flare....no?

Anyway, I should get it completed today....................I'll keep you posted.
canada_jim is offline Find More Posts by canada_jim
Reply With Quote
Old Feb 02, 2012, 04:29 PM
inventing_man is offline
Find More Posts by inventing_man
Whats a search engine?
inventing_man's Avatar
Missouri
Joined Jun 2006
886 Posts
Weight shift is a lot more stable and predictable way to turn these small wings .
Its really the only way " IMHO" when your dealing with small wings like these.
Brakes for turning have a very rapid response , and could stall the wing, quickly into a spiral dive , if pulled to much when turning or going slower than cruse speed . I suspect some pilots are running into this and why they are having trouble learning to fly, besides the HK wing problems you noticed .
Do go with the weight shift starting off . You can always hook up the brakes after you master it . Flair wont be needed , when you cut power its going to slow down plenty real quick.
inventing_man is offline Find More Posts by inventing_man
Last edited by inventing_man; Feb 02, 2012 at 05:11 PM.
Reply With Quote
Old Feb 02, 2012, 06:48 PM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
Yes Inventing Man I agree............................

See where I'm going with this today.....................................Anyone?
canada_jim is offline Find More Posts by canada_jim
Reply With Quote
Old Feb 02, 2012, 07:42 PM
inventing_man is offline
Find More Posts by inventing_man
Whats a search engine?
inventing_man's Avatar
Missouri
Joined Jun 2006
886 Posts
A Assist ?
inventing_man is offline Find More Posts by inventing_man
Last edited by inventing_man; Feb 02, 2012 at 07:52 PM.
Reply With Quote
Old Feb 02, 2012, 08:52 PM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
Yessss.......sir. ....................."A" Assist.............
canada_jim is offline Find More Posts by canada_jim
Reply With Quote
Old Feb 02, 2012, 10:07 PM
inventing_man is offline
Find More Posts by inventing_man
Whats a search engine?
inventing_man's Avatar
Missouri
Joined Jun 2006
886 Posts
Should do the trick nicely. Tension the brake lines to just maintain the trailing edge , with no fabric deflection for a weight shift set up .
If the trike wants to turn , slightly , due to prop torque, trim the brake on the other side, just ever so slightly, to counter it .
inventing_man is offline Find More Posts by inventing_man
Last edited by inventing_man; Feb 02, 2012 at 10:15 PM.
Reply With Quote
Old Feb 02, 2012, 11:47 PM
nadine is offline
Find More Posts by nadine
vtol fan
nadine's Avatar
Joined Jul 2009
627 Posts
Quote:
Originally Posted by canada_jim View Post
Yessss.......sir. ....................."A" Assist.............
Hi!....I am i friend of popado and tonight i will tell him that you need his assistance,if him not seen your topic!
Anyway popado haves a drawing with the new lenghts of bridles for one RTF parachute like yours ,from HK,but you need to make another bridles !..Regards
nadine is offline Find More Posts by nadine
Reply With Quote
Old Feb 03, 2012, 08:01 AM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
Hi Nadine, I am using Popad's new bridal schematic to re-string the HK foil, right now. He has graciously emailed me the drawings and related info, thanks. I follow a link from his re-string blod here, to his site which has alot of the information avaliable, if anyone needs it.

I'll keep you all posted on my progress...............cheers.
canada_jim is offline Find More Posts by canada_jim
Reply With Quote
Old Feb 03, 2012, 10:34 AM
canada_jim is offline
Find More Posts by canada_jim
Registered User
canada_jim's Avatar
Lake Country.British Columbia,Canada
Joined Feb 2004
111 Posts
Okay, re-string is complete using Popado's diagram. I did not use knot's to landmark the measurements, instead I used a black felt to make marks. I also did not bind with zip-ties as he did, rather I went with thread tie's much like tieing a fishing fly, the when done I put shrink tube over it all to prevent fraying...........

See pics attached for clarity.......................................
canada_jim is offline Find More Posts by canada_jim
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold HK parafoil Wave Glider Aircraft - Sailplanes (FS/W) 5 Oct 13, 2011 08:03 AM
Discussion Hobby King 2.15M Parafoil and Trike Bigplumbs RC Kites 3 Jun 06, 2011 05:08 PM