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  #1  
Old 08-29-2020, 08:30 PM
dholvrsn dholvrsn is offline
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Default "perigee" glider hooks

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Old 08-29-2020, 10:26 PM
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Ez2cDave Ez2cDave is offline
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Originally Posted by dholvrsn


Nice Xerclod !

Dave F.
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  #3  
Old 10-04-2020, 05:40 PM
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FWIW - I invented the Apogee Universal Pod Hook, around 1993 when Ed LaCroix owned it, for the Maxima Boost Glider kits.

I recalled at NARAM in 1992, when an A Div flier had a Shecter glider kit, using telescoping brass tubing for hooks, which jammed both flights and Red Baroned (pod stayed on). I wanted to come up with some hook design for the Apogee kit that would not need any assembly, that would work consistently. So consistently, that any glider could use any pod.

I originally had a twin hook design that had two totally different hook pairs. One had two hooks sticking out, and one had two slots. It worked, but it occurred to me later to make them universal, just one master part with both a hook and a slot.
And I designed them so it was practical to cast them using RTV molds and fast-curing casting resin.

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Old 10-04-2020, 10:37 PM
Green Dragon Green Dragon is offline
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Quote:
Originally Posted by georgegassaway
FWIW - I invented the Apogee Universal Pod Hook, around 1993 when Ed LaCroix owned it, for the Maxima Boost Glider kits.

I recalled at NARAM in 1992, when an A Div flier had a Shecter glider kit, using telescoping brass tubing for hooks, which jammed both flights and Red Baroned (pod stayed on). I wanted to come up with some hook design for the Apogee kit that would not need any assembly, that would work consistently. So consistently, that any glider could use any pod.

I originally had a twin hook design that had two totally different hook pairs. One had two hooks sticking out, and one had two slots. It worked, but it occurred to me later to make them universal, just one master part with both a hook and a slot.
And I designed them so it was practical to cast them using RTV molds and fast-curing casting resin.




Interesting tidbit that you designed those - and a great design.

I still have a few sets of those in the box, and some one gliders - the unused ones have warped horribly, ones glued to pods ( not sure I have any B/Gs with them anymore, seem ok when glued fast.

Although I'm a dedicated 'power freak' ( now maybe mid-power freak, lol ), and sport flyer.. sad the competition has mostly died off, lots of good times and memories and learned lots.
Would do a lot of fliers good to compete,vs " rush right tot he largest fiberglass beast we can " .
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Old 10-05-2020, 08:25 PM
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Quote:
Originally Posted by Green Dragon
Would do a lot of fliers good to compete,vs " rush right tot he largest fiberglass beast we can " .


Agreed . . . Competition is much more challenging than Sport Flying, whether LPR, MPR, or HPR !

I'm glad that George posted his B/G hooks . . . I actually thought that he had invented them in the late 1980's, rather than the early 1990's. 27 years and nothing better has been invented.

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  #6  
Old 10-06-2020, 01:40 AM
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georgegassaway georgegassaway is offline
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Quote:
Originally Posted by Ez2cDave
I'm glad that George posted his B/G hooks . . . I actually thought that he had invented them in the late 1980's, rather than the early 1990's. 27 years and nothing better has been invented.

Well, actually, something better has been invented. One drawback to the Apogee universal hook, and true of any "Xerclod" glider hook, is that the glider can pry off due to wind, usually on the pad.

When I started flying 2-channel R/C B/G's in summer 1980, I used very long pop-pods, and the pods sometime pried off during boost when I made an elecator correction. I came up with what I called "L" hooks, a pair of interlocking hooks that could not pry off, at all. The hook had to move backawards aobut 1/4" or so to become detached. But those were made out of plywood, a bit of a hassle ot build, and some other issues, so I only did those for some early 1980's R/C B/G's. before I moved on to R/C R/G's. The drawings below do not show the 1980 plywood design, but the 1990's and onwards cast version.




But once I got into casting parts for scale models like Little Joe-II, I looked at casting other kinds of parts. The Apogee universal hook was the first cast hook I did. And it worked pretty well. But had the same sort of prying issue.

And in 1996, I was working up some B pwoered gliders for the world championships, to use 10mm B2 motors. I wanted to do a hook design that was lighter, smaller, and would not pry off. So I dusted off the 1980 "L Hook" idea, and made some prototypes. They worked well, and I shared them with US team members who wanted ot use them. Thru the years, I've sold them on and off. Currnetly not for sale, as the RTV molds are torn (only last a few dozen castings).

Also, I did an R&D report for my team , about the L Hooks and Spooler Pop-Pods, which combined solve all sorts of problems with pop-pods for B/G's. Here's a link on my website aobut the R&D report, various photos and drawings, and a link to a PDF of the actual report: http://georgesrockets.com/GRP/RandD/Spooler.htm

Some photos:
Pod portion at top, without one of the side halves (I cast three parts, a left and right half for the pod, and the glider hook itself)


Photo of several in various stages:


Being used with an actual glider and pod.


A flock of B/G's of various sizes, with spooler pods using L Hooks. The pod at top was a BT-55 Spooler Pod with a very large cast L Hook set, for staged D12 power on a "trainer" R/C B/G. Except for the BT-55 pod, all the pods in that photo that had hooks, would fit any of the gliders in any combination due to the same hook design cast from the same master parts set.
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  #7  
Old 10-06-2020, 09:16 AM
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Quote:
Originally Posted by Ez2cDave
Agreed . . . Competition is much more challenging than Sport Flying, whether LPR, MPR, or HPR !
Some of us sport fliers have to do spot landings for every launch or else we come home empty handed, so I disagree.
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  #8  
Old 10-07-2020, 08:43 PM
fulldec fulldec is offline
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Quote:
Originally Posted by georgegassaway
FWIW - I invented the Apogee Universal Pod Hook, around 1993 when Ed LaCroix owned it, for the Maxima Boost Glider kits.

I recalled at NARAM in 1992, when an A Div flier had a Shecter glider kit, using telescoping brass tubing for hooks, which jammed both flights and Red Baroned (pod stayed on). I wanted to come up with some hook design for the Apogee kit that would not need any assembly, that would work consistently. So consistently, that any glider could use any pod.

I originally had a twin hook design that had two totally different hook pairs. One had two hooks sticking out, and one had two slots. It worked, but it occurred to me later to make them universal, just one master part with both a hook and a slot.
And I designed them so it was practical to cast them using RTV molds and fast-curing casting resin.



I flew the telescoping brass tubing hooks for many years, I still have a few, and still fly them once in a while. They are very lightweight. I never had a single Red Baron, never. I have always been amazed that it has worked every time! They look like they should hang up. They are particularly good at holding the pod and glider together on the pad on a windy day.

I am not saying they are better than than other systems, like George's L hooks, just testifying that I've had great "luck" with them.

Don
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  #9  
Old 10-08-2020, 01:49 PM
ManofSteele ManofSteele is offline
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The (now discontinued) NCR North Hawk RC BG used a 3D printed pod hook that was an evolution of George's L hook design. Strength was not an issue. I could probably put the hooks up for sale on the NCR website if there is interest.

Matt
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  #10  
Old 10-08-2020, 04:19 PM
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georgegassaway georgegassaway is offline
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Quote:
Originally Posted by fulldec
I flew the telescoping brass tubing hooks for many years, I still have a few, and still fly them once in a while. They are very lightweight. I never had a single Red Baron, never. I have always been amazed that it has worked every time! They look like they should hang up. They are particularly good at holding the pod and glider together on the pad on a windy day.

It's great that it worked for you. The model I saw, the brass tubing ends were raw, with burrs. I do not know if the kit came with the tubing pre-cut already (so they came with burrs), or had longer pieces that required the builder to cut them, creating the burrs.

In any case, as a kit, it required a lot more special and unique work by the builder to get it to work smoothly, than I think a good kit should require. I mean, how many model rocket kits require a small flat file, also skinny enough to be able to de-burr the inside of the small diameter brass tubing? Most would not have needle files like that. As though building a contest-type glider is not enough of a new or special thing to learn to do without also learning metal-working needing special tools.

As Ed LaCroix and I discussed the glider kits I'd be desiging for Apogee (the Maxima gliders), one of the criteria was a very reliable nad consistent method of attaching the pop-pod, that did not require any special or finicky work by the builder. And so the cast universal hooks were created, where the "hardest" parts of the assembly process were orinting them in the correct direction, and gluing them on with thick CA (in other words, really easy, with zero work on the hook/slot interface).

I'm hoping to get my 3D printer working properly in the next week or so. When I get it working, i'm hoping that the 3D version of the "L-Hook" glider hook prototypes can be mass produced well enough, and if so I'll be selling them.

BTW - none of the above is meant to slam the use of square brass tubing for glider hooks. Some people used them for other pods in the 1970's, worked well for some, and not quite so well for a few others. But the builders were mostly experts (building from plans, often with more scratch-building experience than kit-builders).

There are some methods I use in fabricating some parts for myself, that are not suited for a beginner or typical kit builder to get invovled with.

To pose a theoretical example, if I say to do "X", get out your Dremel tool and use a cut-off wheel. Which does no good for those who do not have that tool, as well as risky to suggest to anyone who may never have used a cut-off wheel before, for their first time to be in fabricating "X".
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Last edited by georgegassaway : 10-08-2020 at 04:38 PM.
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