Estes Skydancer

[Doug Holverson]

I've been on and off building an Estes Skydancer, which was an old Estes RCBG design from the Moon Landing days. It's been an on and off bottom priority bucket list side project. It's probably over my head enough to get me into trouble.



This is in my little retro corner of Mom's house. My late Dad built the bench almost 50 years ago. The late John Carroll gave me copies of the Skydancer blueprints that he picked up back when he worked at Estes. That's a homemade fuselage jig. That's mostly my art back there replacing some long gone MAD Super Special mini-posters. Although there's a printout of the Centuri Model Rocket Headquarters poster up in the corner for really nostalgic kicks.

Anybody know what airfoil was used in the original? I thought it was the ubiquitous Clark-Y modified to 10% thickness, but it seems to be a much flatter foil. I'm also wondering since I'm going to save a lot of weight by using micro mini electronics instead of the boat-anchor Kraft originals, that if I could splurge some of those weight budget savings on using 1/16" balsa in the ribs and skins to make less frightfully frail wings?

 

[Doug Holverson]

Update: I'm trying to piece together what the circa '70 electronics would weigh. The two Kraft servos would weigh 2.4 ounces, plus the Kraft KPR-3B receiver would weigh in at 1.6 ounces. That's four ounces without battery. I haven't been able to knock loose what a 225mAh nicad from then would weigh, but I'm guessing about 2.5 ounces. So you have a 10-11 ounce glider with 6.5 ounces of electronics.

Two 9 gram servos would be 18 grams, an OrangeRx would be 10 grams, and a 220mAh lipo would be 6 grams for a total of 34 grams. As opposed to ~180 grams for the old stuff.

 

[Crawf56]

Yeah, advances in batteries have definitely been kind to the rocket glider world.

 

[Ez2cDave]

The late John Carroll gave me copies of the Skydancer blueprints that he picked up back when he worked at Estes.

Any chance of you posting scanned, PDF copies of those ?

Dave F.

 

[burkefj]

The article by Larry Renger says 6.5 oz flight weight for electronics and a total weight of 12.25 oz but says with his larger wing he dropped 3/4 ounces from the airframe so maybe a bit less.

Skydancer Rocket Boost R/C Glider Article and Plans, March 1971 American Aircraft Modeler

Estes does not sell the D-13 engine line anymore, but it does sell a D-12.

www.airplanesandrockets.com

 

[shockie]

I would use some thin carbon fiber strips for wing reinforcement.

You could use 1/32" balsa skins with 0.6 oz fiberglass or 0.2 or 0.5 oz carbon fiber tissue (aka mat or veil).

A little more work but it will make the glider much stronger and lighter.

Heck if you know the airfoil, you could get a custom cut foam wing.

Larry Renger lives in CA and if you Google search on his name. I'm sure you'll find his email address.

 

[Ez2cDave]

Larry Renger lives in CA and if you Google search on his name. I'm sure you'll find his email address.

I wouldn't waste any time, as Larry Renger is probably in his 80's, by now.

Try "Rancho Santa Margarita, CA" in your search for him.

I PM'd you with the last email address I have for him.

Dave F.

 

[Doug Holverson]

Any chance of you posting scanned, PDF copies of those ?

Dave F.

I scanned it as a tiff years ago. It was posted on a Gassaway page about RCRG history that I was looking at earlier today, but can't find now.

 

[shockie]

Early R/C

Larry was born in 1942 so he'd be 80 this year. He may have passed away by now.

15 years ago, or so, Larry gave me a lot of pictures of his early boost glider work.

Maybe one if these days if I feel like it , I'll publish it for all to see.
On the other hand i.may just take it to the grave with me.

 

[trialsguy]

… and where would you be planning to be buried? ;o).

 

[Doug Holverson]

Tell me more about applying carbon tissue to a Skydancer. I'm an absolute noobie at that stuff.

 

[Initiator001]

I spoke with Larry at NARAM-60 in Colorado.

He'd be in his early 80s by now.

 

[shockie]

I spoke with Larry at NARAM-60 in Colorado.

He'd be in his early 80s by now.

I added wrong. He would be 80 this year. 1942 to 2022. My bad

 

[shockie]

Tell me more about applying carbon tissue to a Skydancer. I'm an absolute noobie at that stuff.

Doug. Pretty simple really. Stir up a batch if laminating epoxy resin which is thin like water, cut a piece of the cf tissue to size, apply a light coat of the epoxy resin to the wood surface,lay the cf tissue in place,use a teflon roller andgloved fingers to squeeze the resin into the cf tissue. Apply some additional resin as needed so you don't have any dry spots. Wrap the wing in wax paper. Then use tape to apply some pressure against the sandwich.
Tape it down to a flat surface so it won't warp.

Then let it cure, remove hold down tape,and pressure tape and wax. And. You'll have a real smooth surfaced balsa cf covered wing.

I've used wax paper,teflon film and mylar film and I've also used Dunston shrink pressure tape in an oven, if you want to get fancy and spin money.

You can buy thin strips of unidirectional cf that can be applied to the wing soars.

Both ACP and CST among others have cf tissue, kevlar and fiberglass tissue.


It soaks up resin, hence you have to squeeze it down,apply pressure to remove excess resin abd weight.

It will squeeze out if the ends. Just use a paper towel to sop it up.

The BTC vacuum bag their wings and now create 2 piece bladder molds costing thousands to make their lightweight high strength wings.

 

[tab28682]

I have a ton of great memories from flying the Skydancer. It was a wonderful flyer.

I still have my old Skydancer in the garage. Parts of it are in different places out there.

The plan is available and downloadable on the excellent Outerzone web site. A great resource for hard to find model aircraft plans.

Oz : Skydancer plan - free download

outerzone.co.uk

I never really thought of it as the Estes Skydancer, even though it was an Estes R&D project. I always called it the Renger Skydancer.

There is a picture of my slightly modified Skydancer on boost in Model Rocketry in the coverage of the Dallas NARAM in 1990.

Here is a picture of it taken at ignition by the local newspaper at the great SMALL event in Little Rock that I often mention in this forum. The LCO is my good friend Randy Rogers that I still fly RC with to this day. Behind him is a much younger me...... This pic is dated June 4, 1990. Hard to beleive that was 32 years ago this month, a little more than half my life ago. Wow. If I recall correctly, the Skydancer first flew in 1979 or 1980. It actually won the Best Boost Glider award at tge old Dallas Model show in 1980 making the model now over 40 years old. I ought to get it out and take it to Fall SMALL in Oct and make a 32nd anniversary flight.

My two Skydancer mods were a change to strip ailerons instead of the "barn door" style ailerons in the outer wing panels and a change to the shape of the twin fins to make them have a "swoopier" and more exciting shape than the stock fins. These changes are discernable in the launch picture. My Skydancer was covered with Monokote.

All but 1-2 of the well more than 100 flights on the Skydancer were CHAD staged D12-0 to D12-3 motors. If at NAR event, I would have a streamer on the booster motor for safer recovery. It was easy to get 2-3 minutes of duration on the staged D12s. Somec RC RG guys dont like RG boost gliders as you do have to chase the pod, but this never bothered me.

My radio gear was lighter than Larry's, with a micro Royal 4 channel 72mhz RX and two kit built Ace RC micro servos, with a 250mAH nicad RX pack. The RX was tuned to my trusty EK Logictrol 7 channel Championship transmitter.

Forgive me for the slight thread hijack. I loved and still love this model and though some of you would enjoy some Skydancer stories.

Doug, I hope you enjoy the Skydancer as much as I did.

 

[TheAviator]

I've been on and off building an Estes Skydancer, which was an old Estes RCBG design from the Moon Landing days. It's been an on and off bottom priority bucket list side project. It's probably over my head enough to get me into trouble.


This is in my little retro corner of Mom's house. My late Dad built the bench almost 50 years ago. The late John Carroll gave me copies of the Skydancer blueprints that he picked up back when he worked at Estes. That's a homemade fuselage jig. That's mostly my art back there replacing some long gone MAD Super Special mini-posters. Although there's a printout of the Centuri Model Rocket Headquarters poster up in the corner for really nostalgic kicks.

Anybody know what airfoil was used in the original? I thought it was the ubiquitous Clark-Y modified to 10% thickness, but it seems to be a much flatter foil. I'm also wondering since I'm going to save a lot of weight by using micro mini electronics instead of the boat-anchor Kraft originals, that if I could splurge some of those weight budget savings on using 1/16" balsa in the ribs and skins to make less frightfully frail wings?

I would even use 3/32" or 1/8" balsa for the ribs, of properly chosen density, 7-9 pounds per cubic foot (pcf). While 1/32" will suffice for flight loads, the thicker balsa will be better for ground handling. 1/8"x1/4" or 1/4" square stock for the aileron and tail ribs would be a good choice, but it would be good to make sure it's good 5-7 pcf balsa.

A 10% Clark-Y would work, or a Drela AG35 would also be a good choice. This isn't going to be a super high performance glider, but I think you could definitely thermal with it. All you really need to do is make sure the wing is thick enough for the servo and that the cutout in the fuselage matches. Based on the drawing, the airfoil isn't really critical and the tail is more than large enough to counter any pitching moments induced by a change in airfoil.

Personally, I would also use solid sheet or trailing edge stock instead of the 1/32" sheeting on the trailing edge.

Also, like George Gassaway said, I would permanently retain the motor pod and fly it as an RG instead of a BG.

 

[burkefj]

I was going to suggest the same thing and retain the pod and that would help with the balance with a lighter equipment as well.

Also, like George Gassaway said, I would permanently retain the motor pod and fly it as an RG instead of a BG.

 

[ChrisFlanigan]

I have a ton of great memories from flying the Skydancer. It was a wonderful flyer.

I still have my old Skydancer in the garage. Parts of it are in different places out there.

The plan is available and downloadable on the excellent Outerzone web site. A great resource for hard to find model aircraft plans.

Oz : Skydancer plan - free download

outerzone.co.uk

I never really thought of it as the Estes Skydancer, even though it was an Estes R&D project. I always called it the Renger Skydancer.

There is a picture of my slightly modified Skydancer on boost in Model Rocketry in the coverage of the Dallas NARAM in 1990.

Here is a picture of it taken at ignition by the local newspaper at the great SMALL event in Little Rock that I often mention in this forum. The LCO is my good friend Randy Rogers that I still fly RC with to this day. Behind him is a much younger me...... This pic is dated June 4, 1990. Hard to beleive that was 32 years ago this month, a little more than half my life ago. Wow. If I recall correctly, the Skydancer first flew in 1979 or 1980. It actually won the Best Boost Glider award at tge old Dallas Model show in 1980 making the model now over 40 years old. I ought to get it out and take it to Fall SMALL in Oct and make a 32nd anniversary flight.

My two Skydancer mods were a change to strip ailerons instead of the "barn door" style ailerons in the outer wing panels and a change to the shape of the twin fins to make them have a "swoopier" and more exciting shape than the stock fins. These changes are discernable in the launch picture. My Skydancer was covered with Monokote.

All but 1-2 of the well more than 100 flights on the Skydancer were CHAD staged D12-0 to D12-3 motors. If at NAR event, I would have a streamer on the booster motor for safer recovery. It was easy to get 2-3 minutes of duration on the staged D12s. Somec RC RG guys dont like RG boost gliders as you do have to chase the pod, but this never bothered me.

My radio gear was lighter than Larry's, with a micro Royal 4 channel 72mhz RX and two kit built Ace RC micro servos, with a 250mAH nicad RX pack. The RX was tuned to my trusty EK Logictrol 7 channel Championship transmitter.

Forgive me for the slight thread hijack. I loved and still love this model and though some of you would enjoy some Skydancer stories.

Doug, I hope you enjoy the Skydancer as much as I did.

Just curious - how did you do the hinges for the ailerons and elevator? The Skydancer drawing doesn’t say anything on this item.

 

[Doug Holverson]

An update on this. The inside doubler on the right broke leaving a kink instead of a smoother curve like on the left. What to do now?



I did make good progress on the wings.

 

[neil_w]

This is in my little retro corner of Mom's house.

I’m digging the orange ball radio, haven’t seen one of those in… well, forever. We had a blue one.

 

[Doug Holverson]

Update of sorts. The kink has been fixed. The project moved down to my house in Omaha.

Here's the mostly finished fuselage with 3D printed translucent canopy.



Here are the wings sanded and shaped. They're now being flattened back out after developing a slight curl during the sheeting.

 

[Doug Holverson]

I'm almost far enough to mount servos or Golden Rods in the wings. Any advice from those who been there?

 

[Rob Campbell]

I'm almost far enough to mount servos or Golden Rods in the wings. Any advice from those who been there?

Don't use golden rods. The yellow pushrods change length with temperature and humidity. I recommend going with two small (9 gram) servos for ailerons. You can either connect them on a Y harness or plug each into a separate channel and mix the channels with the transmitter.

 

[Doug Holverson]

At least one bad idea is shot down, and it's not even noon yet.

 

[Doug Holverson]

I found some ARC servos in the parts stash. Are they good enough for the Skydancer or off-brand junk?

 

[Doug Holverson]

Here is an update.

The wings getting epoxied together.


And a test fitting just to see how it would look.



What's everybody's favorite way to attach the wings to the fuselage?

 

[Doug Holverson]

What does anybody think about using Spektrum A2020 servos for the ailerons?

 

[TheAviator]

What does anybody think about using Spektrum A2020 servos for the ailerons?

Should be adequate, but those are 1S only servos. What is your plan for power and the elevator?

 

[burkefj]

I've been happy with the hitec 35055 metal gear digital servos running on 1s should be plenty for anything this size.

 

[Doug Holverson]

I'm thinking about a Futaba S3108M from the stash for the elevators and a repurposed 200maH drone lipo for the battery.