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thinwall annular booster fabing (update)
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Author:  argentina-slantsixer [ Tue Oct 25, 2005 5:14 pm ]
Post subject:  thinwall annular booster fabing (update)

Hey guys

check this out:

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Stock piece to start from scratch

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I drill concentrical holes starting with a 5/16 drillbit...

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removing the center piece

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till I reach 1/2" with a drillbit. I keep on enlargening the inner diameter to 0.55" but using a lathe tool (see pic below)
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then...
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I use solid aluminium stock (not delrin, DW... :lol:) to line the centerpiece

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I mark the piece so the passages match

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And finally I have the centerpieces ready to install (I haven't worked on the inner wingfoil profile at this point)

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This is the thinwall, not so restrictive annularm boosters that I have come up with

Now, I haven't installed them yet but I can't wait to evaluate the results.
Inputs? please, don't panic (or, panic: don't)

Author:  VDART [ Tue Oct 25, 2005 5:35 pm ]
Post subject: 

that looks fab!!

curious to hear how it performed!!!!

Author:  emsvitil [ Tue Oct 25, 2005 7:03 pm ]
Post subject:  Looks Good........

I'd clean up the casting mark on the outside of the orginal too.........


Any way to airfoil shape the round leg??????

Teardrop shape should do it. Or make an aluminum tail for it.......... :wink:

Author:  argentina-slantsixer [ Tue Oct 25, 2005 8:32 pm ]
Post subject:  Re: Looks Good........

Quote:
I'd clean up the casting mark on the outside of the orginal too.........
That's next along with keeping the cutting edge and the trailing edge as thin as humanly possible
Quote:
Any way to airfoil shape the round leg??????
Nice! we think alike! I'm looking over epoxying some ^ shaped piece of aluminium (or delrin, my fetish material) along with giving the exterior leg a good filing on the sides to obtain this () shape instead of the regular O
Quote:
Teardrop shape should do it. Or make an aluminum tail for it.......... :wink:
yes. I'm going slow cuz I wanna document all the process so if anyone wants to follow this mad fabrication is clear and graphic. I can go on talking tons of theoretical stuff but one image is worth thousands of words... :wink:

BTW forgive all my mistyping lately, I'm going like hawkins? no. I just changed my KB and I didn´t got one replacement for my "latinamerican" distribution, I'm fighting with this "Spanish-Traditional" unit. Shoot!.

Author:  argentina-slantsixer [ Tue Oct 25, 2005 8:33 pm ]
Post subject: 

Hey ed, that's like passg seat fabrication, not "backseat anymore :lol:

Author:  emsvitil [ Tue Oct 25, 2005 9:51 pm ]
Post subject:  Hobby stores..........

Check out some hobby stores..........

there's tubing that's in the shape of airfoils....

Author:  argentina-slantsixer [ Tue Oct 25, 2005 10:17 pm ]
Post subject: 

there's a good company up there called K&S or K&D engineering from chicago that produces a mouthwtering variety of diffrent tubing, solid stock and shaped pieces of metal (good quality brass, top otch aluminium) for modeling purposes....

Author:  emsvitil [ Tue Oct 25, 2005 10:54 pm ]
Post subject: 

It's K&S

Author:  SlantSixDan [ Wed Oct 26, 2005 9:06 am ]
Post subject: 

Quote:
please, don't panic (or, panic: don't)
Image

Author:  SlantSixDan [ Wed Oct 26, 2005 9:07 am ]
Post subject: 

Quote:
It's K&S
Got a link?

Author:  emsvitil [ Wed Oct 26, 2005 11:23 am ]
Post subject: 

http://www.ksmetals.com/


But I've found better descriptions elsewhere?????????? (which I can't find at the moment :cry: ) (K & S tubing, K & S streamline, towerhobbies,..... might work)

Author:  gearhead [ Wed Oct 26, 2005 5:09 pm ]
Post subject: 

Sorry I haven't been posting...been working way to much and am flying out to CA this weekend, then home to Portland for a few days to solve a major issue there...

However, I need to say something about this project...

You want the outside of the booster to remain straight because you need to create an airfoil that generates lift...or (low pressure) at the top of the hump.

A teardrop shape is known as a symetrical airfoil and does not generate "lift". You will end up with less signal. You will still develop low pressure because the air still has to accelerate accross the wing to meet up on the other side, which will produce a signal at the correct location. On an airplane wing, however, the net is lift on both sides, so that the "lift" is nuetral and produces only stability...this type airfoil is commonly used on model aircraft design for aerobatics, so that the plane behaves similar upright or upside down.

So on your booster, it will produce a stronger signal on the discharge side relative to atmospheric in the float bowl if you stick with a flat bottomed airfoil(outer edge) and maybe only experiment with leading edge transition and airfoil shape.

Although they make tubing, It is designed to be used as skirts and such for landing gear, and probably not much help in your project.

I would use a dremel or die grinder with one of those long tapered sanding rolls and sand your way in from the bottom. On top, use progressively smaller ball stones to initiate the shape, then switch to a small sanding roll that you where out ahead of time on something hard so that it helps form the shape.

When close, switch to Dremel with polishing wheels and course compound to polish and finalize the shape.

This is how I modify and enlarge the boosters on Qjets. Time consuming but good results.

Must go, my business partner just flew into Charlotte and I must go meet up with him...

Later

Gearhead

Author:  emsvitil [ Wed Oct 26, 2005 6:31 pm ]
Post subject: 

The teardrop/airfoil shape wasn't for the booster part, it's for the leg that supports the booster... Getting rid of a round leg and streamlining should help your flow.............


BTW, the original booster looks quite restrictive with that large tube in the middle................

Author:  argentina-slantsixer [ Wed Oct 26, 2005 6:51 pm ]
Post subject: 

Hey Karl and guys

Karl, as Ed stated, the teardrop or double airfoil is for the leg. As far as for inner shaping I did it by hand, on the lathe, with diffrent kids of burring knifes. I don't know if you're familiar with NOGA, a brand from Israel, they make some serious deburring tools for fine mechanics and machinists.

I got some pix while doing it but came up blurry because I was shaping on a revolving chuck with one hand and trying to aim a big FD mavica on the other..... not the best way of getting it done. I'll take some closeups of the inner shape and post it soon. After doing all the shape I mirror polished all the inner airfoil spahe, and I'm deburring the casting marks soon and mirror buffing them on the outside too.

I guess that I'll need leaner jetting, huh?

Author:  emsvitil [ Wed Oct 26, 2005 7:09 pm ]
Post subject: 

Quote:
I guess that I'll need leaner jetting, huh?

I actually have no idea what you'll have to do with the jetting..........


If there's better airflow (less obstruction), you might get more air and need to go richer............


It's trial and error time.............. :twisted:

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