A Dream Finally Realized...

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

rokitflite

Well-Known Member
Joined
Jan 17, 2009
Messages
5,156
Reaction score
8
Wow… This is a build thread 30 years in the making. Back in the early 80’s when I was a somewhat new model rocket enthusiast, I was looking at a copy of Radio Controlled Modeler. American Hobby Center had an ad for a Mattel single channel radio control unit. My mind thought back to a year or two earlier when I had visited Estes industries in Penrose Colorado for the very first time. I met a wonderful lady named Oakie Six while on my first tour of the company. Oakie had been there since the very early years of the company and above her work station there were a whole bunch of built models from the earliest years of Estes Industries. There was one that caught my eye, a very unique boost glider, I saw it and fell in love. I took a couple of measurements and thought I had all that I needed (I was like 13… I know better now) to make my own clone of this model. The first flights were a disaster to say the least; there was hissing looping and thrashing of the model and screaming, running and ducking from my friends that came to watch the train wreck. Still, I LOVED the look of the model. I had dreams of building a larger version and putting the Mattel remote in it so I could steer it where I wanted it to go. I imagined launching in my driveway, flying it over the neighborhood then landing it back in my driveway… Yeah, right. I never built the thing, but DID gain a bunch of RC knowledge and experience since then.

Flash forward to the present. After building several upscale RC Mach 10s and a flying Jenny, I decided to have another go at my old favorite. Add 30+ years of experience AND much better, smaller RC technology… I think I’m ready to go at it again!

This is gonna be a "Mostly pictures" build thread since I am a slow assed typist! But hey, we all like pictures here right? :)
 
Step 1, a drawing and a trip to my friend's shop for laser cutting. The wood had already been prepared using an epoxy and lightweight silkspan technique that I will describe next.

a 1.jpg

a 2.jpg

a 3.jpg

a 4.jpg

a 5.jpg
 
Wow… This is a build thread 30 years in the making. Back in the early 80’s when I was a somewhat new model rocket enthusiast, I was looking at a copy of Radio Controlled Modeler. American Hobby Center had an ad for a Mattel single channel radio control unit. My mind thought back to a year or two earlier when I had visited Estes industries in Penrose Colorado for the very first time. I met a wonderful lady named Oakie Six while on my first tour of the company. Oakie had been there since the very early years of the company and above her work station there were a whole bunch of built models from the earliest years of Estes Industries. There was one that caught my eye, a very unique boost glider, I saw it and fell in love. I took a couple of measurements and thought I had all that I needed (I was like 13… I know better now) to make my own clone of this model. The first flights were a disaster to say the least; there was hissing looping and thrashing of the model and screaming, running and ducking from my friends that came to watch the train wreck. Still, I LOVED the look of the model. I had dreams of building a larger version and putting the Mattel remote in it so I could steer it where I wanted it to go. I imagined launching in my driveway, flying it over the neighborhood then landing it back in my driveway… Yeah, right. I never built the thing, but DID gain a bunch of RC knowledge and experience since then.

Flash forward to the present. After building several upscale RC Mach 10s and a flying Jenny, I decided to have another go at my old favorite. Add 30+ years of experience AND much better, smaller RC technology… I think I’m ready to go at it again!

This is gonna be a "Mostly pictures" build thread since I am a slow assed typist! But hey, we all like pictures here right? :)

So, I'm dying to know what this thing looks like.

You going to give us a hint, or is it classified?

My guess ......from the first cut on the wood ....

astron_invador.jpg
 
Last edited:
This is how all of the balsa parts were prepared on this model. First, a thin coat of finishing epoxy was applied to the wood. Next a thin piece of silkspan was placed over the wood. A playing card was used to squeegee out excess glue and to press the silkspan firmly against the wood. After that, a piece of waxed paper was squeegeed over top of the silkspan, epoxy and wood making sure no air bubbles remained.

a 6 (800x600).jpg

a 7 (800x600).jpg

a 8 (800x600).jpg

a 9 (800x600).jpg

b 1 (800x600).jpg
 
Not trying to keep you guessing, just being stupid at uploads :). And yes, you are 100% correct :wink:. I am not trying to drag this out over months and months like some build threads end up... Thats just irritating.
 
Not trying to keep you guessing, just being stupid at uploads :). And yes, you are 100% correct :wink:. I am not trying to drag this out over months and months like some build threads end up... Thats just irritating.

That was a unique one..my friend way back then had one....painted it with Model Car metalflake red...he didn't seal the wood so it was pretty funky looking - but it flew.
 
Then a sheet of glass is placed over the prepared balsa and a weight is put on top of it (a 30lb piggy bank in this case). Once cured, the waxed paper is peeled off and the excess silkspan is trimmed away.

b 2 (800x600).jpg

b 3 (800x600).jpg

b 4 (800x600).jpg

b 5 (800x600).jpg

b 6 (800x600).jpg
 
Cool, Scott! :)

I look forward to you finishing and flying this model.
 
Because it was such a large area, I opted to use a Dremel router attachment with a jig I made out of the scrap balsa to round the edges of the wing... Thanks Kevin :)

c 5 (800x600).jpg

c 6 (800x600).jpg

c 7 (800x600).jpg
 
Subscribed! Very interested, I hope you can get some flight video of this.
 
Micro RC electronics from tiny E-park flyers have opened up a whole world of possibilities not dreamed of back when this model first came out.

What RX/TX are you using......only needs elevon control?
 
Micro RC electronics from tiny E-park flyers have opened up a whole world of possibilities not dreamed of back when this model first came out.

What RX/TX are you using......only needs elevon control?

Yes, elevon only, SPMAR6100 receiver DX6I transmitter... The gear is not that micro by today's standards, but WAY cheaper than it was 20 years ago!
 
Joining/gluing up the wing halves (the coffee cup is a VERY important tool), gluing on the rudders and so forth...

d 1 (800x600).jpg

d 2 (800x600).jpg

d 3 (800x600).jpg

d 4 (800x600).jpg

d 6 (800x600).jpg
 
Using some sandpaper set on top of the wing to sand the proper angle into the motor pod standoffs.

d 8 (800x600).jpg

d 9 (800x600).jpg

e 1 (800x600).jpg

e 2 (800x600).jpg
 
I had one of these Estes things about 45 years ago. Was it called Astron Invader or something like that? I could not get it to fly very well. I take it that the Estes kit is your inspiration for this modification. Is this an upscale of sorts? Can you tell us a little bit more about your friend's laser cutter. Are they very expensive? What can of laser does it use?
 
I had one of these Estes things about 45 years ago. Was it called Astron Invader or something like that? I could not get it to fly very well. I take it that the Estes kit is your inspiration for this modification. Is this an upscale of sorts? Can you tell us a little bit more about your friend's laser cutter. Are they very expensive? What can of laser does it use?



https://www.epiloglaser.com/legend_helix.htm
 
Channels routed for the pylons and fiberglass tape epoxied around the wing joint.

e 3 (800x600).jpg

e 4 (800x600).jpg

e 5 (800x600).jpg

e 6 (800x600).jpg
 
Cutting the "floor" for the servos out of 1/64" plywood, marking and gluing them in place.

e 8 (800x600).jpg

e 9 (800x600).jpg

f 1 (800x600).jpg

f 2 (800x600).jpg
 
Now the building of the radio box. I used 1/32 basswood and 1/64 plywood for this. (Sorry, the photos don't always seem to be in order)

f 3 (800x600).jpg

f 4 (800x600).jpg

f 5 (800x600).jpg

f 6 (800x600).jpg

f 7 (800x600).jpg
 
With every RC project I have built, the biggest pain in the butt was figuring out the hatch to access the radio gear. This build was no exception. I finally decided to make it part of the bottom skid.

g 1 (800x600).jpg

g 2 (800x600).jpg

g 3 (800x600).jpg

g 4 (800x600).jpg

g 5 (800x600).jpg
 
Excellent build thread, thanks! Planning to fly this at Battle Park on Saturday?

*sigh* no... I destroyed my ACL Christmas morning so I am kinda confined to my house... Thats how I have time for this build thread...
 
Excellent, Scott, most excellent!!

I've flown so many saucer gliders ala Invaders I've lost count. Biggest I ever did was the 50" disc flown on a J350 back in 1996 or so. Needed *5lbs* of nose mass to transition between boost and glide! Worked pretty well, for such a beast, and I never got the chance to go further (quit TRA due to political BS).

It looks like yours seems right around an 18" span, and should be enough 'meat in the sky' to really enjoy flying. That's about the size of the old D/E ones I used to fly incessantly. Yours being RC.....that will be quite odd and cool though!!

Being that all mine were free flight, I had to have the boost CG pretty much at or near the discs leading edge in order for them to boost well. As far as glide CG - that tended to be somewhere between 25% to nearly 28% aft of disc tip LE, with around 26% being really close. Warpages and such, even if very minor, did affect the overall 'end up' glide CG. Since yours is going to be 'rocket glidered' as an RC ship, where do you plan to locate your boost CG? Are you going to try something like 20% aft at takeoff, knowing you can correct the pitch on the way up (and youre probably gonna need to :y:)? Those elevons certainly look like you can 'barndoor' the nose up even from a 'forwardy' position.

Look forward to seeing this in fruition, especially in video form!! For added enjoyment, please let Kevin handle the RC duties on the first flight, since he's got 'experience' due to that SpaceShip One he did a while back :kill: Give you time to get far enough back to not get impaled on the pitch loop he can't pull out of!
 
Excellent, Scott, most excellent!!

I've flown so many saucer gliders ala Invaders I've lost count. Biggest I ever did was the 50" disc flown on a J350 back in 1996 or so. Needed *5lbs* of nose mass to transition between boost and glide! Worked pretty well, for such a beast, and I never got the chance to go further (quit TRA due to political BS).

It looks like yours seems right around an 18" span, and should be enough 'meat in the sky' to really enjoy flying. That's about the size of the old D/E ones I used to fly incessantly. Yours being RC.....that will be quite odd and cool though!!

Being that all mine were free flight, I had to have the boost CG pretty much at or near the discs leading edge in order for them to boost well. As far as glide CG - that tended to be somewhere between 25% to nearly 28% aft of disc tip LE, with around 26% being really close. Warpages and such, even if very minor, did affect the overall 'end up' glide CG. Since yours is going to be 'rocket glidered' as an RC ship, where do you plan to locate your boost CG? Are you going to try something like 20% aft at takeoff, knowing you can correct the pitch on the way up (and youre probably gonna need to :y:)? Those elevons certainly look like you can 'barndoor' the nose up even from a 'forwardy' position.

Look forward to seeing this in fruition, especially in video form!! For added enjoyment, please let Kevin handle the RC duties on the first flight, since he's got 'experience' due to that SpaceShip One he did a while back :kill: Give you time to get far enough back to not get impaled on the pitch loop he can't pull out of!

I have been flying RC for 25 years, I think I can handle it. Most invaders tend to loop on boost. I have plenty of down elevator available to me ;). I am thinking an E-15 for the first few launches to get it trimmed out. It WILL eject the motor mount on a chute, so I can add weight to the front for boost if needed. Oh, and its about 20" in diameter... Motor section is BT-60.
 
Last edited:
Back
Top