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A tapered joint like that is actually called a scarf joint. There are jigs that allow you to cut the taper. I always thought a scarfing jig would be a great way to bevel fins also.
Steve Shannon I resorted to hand beveling because the balsa was no longer flat but bent into a tight curve. Are there any jigs that you know of that are specifically made for thin fragile balsa? Did an online search and found only scarfing jigs for much thicker ply and hardwood.
I haven't seen any, but there must be for veneer.
Steve Shannon
Steve Shannon I resorted to hand beveling because the balsa was no longer flat but bent into a tight curve. Are there any jigs that you know of that are specifically made for thin fragile balsa? Did an online search and found only scarfing jigs for much thicker ply and hardwood.
Here is a plan for a scarfing jig that claims it's able to cut scarf joints on thin stock down to 0.4 mm. That's pretty small.
https://www.pilotshop.com/catalog/t...VKKxp-lXKX9Vlr-WIoCRUpWv5Ncz-uxkoYaAocm8P8HAQ
Steve Shannon
I've also built that glider. I never got the booster to separate cleanly. And modern ejection charges really blow the crap out of a small vented model like that.
The ring glider itself glides great if you get the toss correctly. It really locks onto a zero-angle-of-attack path and just goes.
These things appear to be related to the Dyson bladeless fans. The inner leading airfoil makes a low pressure region that draws more air in and 'amplifies' the flow. The fan uses compressed air. The glider uses its forward motion.
Notes on that glider- it does really need the spin to work. And it really like 0 AoA. If it's thrown with a small AoA, it wobbles a bit, then visibly dampens the wobble and locks onto path. If the wobble is too great, it just kind of flops to the ground.
I wish the forum send out a notification when someone tagged you in a post.
It's pretty tight. Like this.
[video=youtube;8ctUkhwE7cw]https://www.youtube.com/watch?v=8ctUkhwE7cw[/video]
I used a rubberband to provide some cushioning.
View attachment 316947
Looks great.
It's about the aerofoil- it's all in the angle of attack
Great! Estimated weight on each of the ring fins?
Wondering if for the more craftsman challenged guys like me I can replace it with a cardboard cutout from a cylindrical box.
The aerodynamics of this blow by me (pun intended), but then a lot of aerodynamics do.
Looking forward to a great flight report!
Yes ammonia or vinegar added to the water helps.
Sounds like a pretty good flight. I think I had to repair a ring fin joint, too.
I painted my red, yellow and black - and promptly lost it a pear tree during the fall color season. Found it again, still resting in the branches, during late winter pruning season.
Congrats on the flight, and thanks for the posts. Would really like to hear about a paper ring version if you build it!
@Rktman Thanks for reposting your photos. I'm in the process of building a RingHawk and found this thread to be very helpful.Seems like all the photo links stopped working when they switched over to the new interface awhile ago. While I no longer have all the photos that once appeared here, I'm posting the ones I have left that might prove helpful to clarify some of the sections.
Here's the result of the butt joints. There's a small amount of bowing but once the fin is attached, it pulls this area back in so it's far less prominent:
View attachment 435083
View attachment 435084
Rings made with 1/64" ply are far faster and easier to accomplish, and the amount of outward bowing is far less:
View attachment 435085
And a shot of the finished model:
View attachment 435086
BTW as of last year she was still flying, and gliding, really well and getting times well over a minute on C6-3's. I've had to repair cracks in the fins and replace the ejectable motor pod, and been meaning to build a new one once this one can't fly anymore...but it just keeps on going. Maybe someday when it gives up the ghost I'll get around to throwing together another. For now though all my time is spent on whittling down my build pile or working on clones or scratch building my own experimental designs.
Glad it helps. Feel free to ask if you have questions or run into problems.@Rktman Thanks for reposting your photos. I'm in the process of building a RingHawk and found this thread to be very helpful.
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