Estes Condor #0807 Build, Part 1, Parts

Here's the kit in the original bag.

The picture on the face card is dark. Estes might have bumped up the contrast. The model is painted white after all.

All the parts -

The body tube is very tight with almost no seam. Paramount made better tubes back then.

The die-cut balsa was pressed with older, dull blades. The pieces will have to be cut and separated by hand.

Estes Condor #0807 Build Background

 

The Estes Condor was introduced in the 1977 catalog.

I never noticed then, but in this catalog Mini Brutes were now renamed "SUPER" Mini Brutes.

This model was almost a smaller, less detailed Orbital Transport using 13mm mini motors. A parasite glider that detaches at ejection, glides down while the main body recovers under parachute.

This kit was available from 1977 through 1980. The build starts tomorrow . . .

New Estes Arcas Kit Fin Shaping?

On TRF, Solar Yellow posted something directed to me:

"I'm expecting a build. Likely with diamond-profiled fins because that is the cooler way to do it if you have the skillz."

My response:

I'll do a blog build if Estes sends me some kits.
If I'm working for a vendor, I build them as directed by the instructions.
In some extra blog build posts, I would cut out some additional fins and show how the diamond taper can be done.
That depends though - if the kit fins are only 1/16" thick, the diamond taper isn't practical.

Neil W added probably the best solution of all - 

"I was thinking that too."

"I think you could fool the casual observer by shading the bottom half of the fins slightly darker (could be accomplished with a very light grey transparent decal)."

Old Estes Parts, Part 2

Here's that same BT-30 (from a post a few day's back) with a nose cone a fin unit.

   

The plastic fin unit was re-purposed from those used in fireworks. 

The fit over the end of the BT-30 tube is very good.

The fin unit and nose cone are listed in the 1960 Estes catalog. The fins used in the Sky Bird and Dirty Bird designs.

An illustration for both parts is in the second 1961 catalog: CLICK HERE

The nose cone shoulder slips over the body tube edge. This is another fireworks piece.

These plastic parts were phased out as balsa equivalents replaced them. The manufacturer's probably didn't want to associate with any ties to fireworks.

Thanks again to Lonnie Buchanon for lending me these parts.

Estes ARCAS Now Available

The new Estes ARCAS kit is available!

BT-20 based, 14.5" tall with streamer recovery.

Mini engine powered, friction fit retention.

The model is small so the instructions suggest simply rounding the leading edge of the fins. A scale diamond taper is not shown.

The instructions include a mask pattern for the difficult red and white separations. 

The instructions have just been posted on the Estes website: CLICK HERE

Old Estes Parts, Part 1

Lonnie Buchanon let me borrow some old Estes parts he found in a Craig's List buy.

Below is a BT-30 tube.

Mark II wrote in YORF:

https://www.rocketshoppe.com/info/Estes_Body_Tube_List_3.1.pdf

"BT-30 is a recreation of the very first body tubes that the fledgling Estes Industries sold in 1960. Yes, these were the legendary tubes that Gleda Estes hand-rolled from mimeograph stencil backing using a slotted aluminum mandrel. BT-30 was used in most of the early Estes Industries kits, including the Scout, Mark, Space Plane, Sky Hook and Sprite (K-1, -2, -3, -8 and -15). The somewhat loose fit of their 18mm motors in it is what makes the tumble recovery-inducing weight shift easier and more controllable in the Scout and Sprite. Other kits that used it were the TK-4 Hornet Mini Brute, the Scout II and Scout III, the Mark II and a number of MRN plans. There is an extended discussion of this tube in John Brohm's Estes Body Tube/Kit Reference v3.1." CLICK HERE

  

I don't think this is a Gleda Estes rolled tube but a manufactured recreation as mentioned above.

Estes probably had BT-30 tubes made for them when the kit demand got too high to hand roll the tubes.

This one is rolled very tight and clean, I would assume the hand rolled tubes weren't as taut. I can't say for sure as I've never seen a Gleda Estes hand rolled tube in person.

 

This shows the fit of a current engine slid into the BT-30 tube. There is plenty of space for a few tape wraps to get a good friction fit.

The loose fit reminds me of the old Model Missiles instructions that mention you could use rubber bands wrapped around the motor for a friction fit.

Old Letter

I'm cleaning out the garage, getting rid of old things I haven't looked at in years. In a file cabinet, I found this letter from Bob Bruce. I met and hung out with Bob at the 1975 NARAM 17 in Orlando, FL.

Bob always seemed to place in the Estes design contests, some of his ideas were groundbreaking. He started his own rocketry company called California Model Rockets. Back when a model rocket had to weigh under one pound, he sold models named "Woppers". They were big for their time, 4" diameter rockets with foam centering rings and cardstock wrapped bodies.

 

Here's the interesting part of the 1976 letter - for all the Star Wars fans:

The original title of Star Wars was "War Star". Bob told me that many of the spaceship detail pieces were plastic parts from AMT car model kits - Muffler pipes, axles and the like.

I understand Bob (Brandy) passed away in 2019.

The Mystery Fin

Last November, my Sister finally brought my comic books from California. When I was going through the books, I came across this fin.

It looks to be 1/32" plywood. It is airfoiled. I think it came off a Streamer Duration model I flew at NARAM 17.

If you are curious, the comics were from the mid to late 1960s. 

The box of comics sold for $700!

Estes Mini Bertha Clone, #TK-3, Part 12, Finished

This was a fun little build. My original 1970s fleet had quite a few Mini-Brutes and this was a favorite.

The double layer decals got me close to the full black color density on the nose cone.

I tried to clean up the "bug" decal. In the original art the lettering was thicker and a bit hard to read.

This one represents the 1970s Estes décor. Many catalog  rockets then were only two colors, one fin and the nosecone the same color.

Estes Mini Bertha Clone, #TK-3, Part 11, Two-Layer Decals

This was one of those home print decals that didn't give a good opaque coverage. With the nose cone in place you can really tell the difference between the two blacks.

On the left is a single layer decal, on the right is a two layer. There is a big difference. Sometimes home print decals don't cover over white paint.

Lay down the first decal and let fully dry overnight.

To apply the second decal - 

Soak the decal, wet the first decal already set on the tube. The surface is wetted down so the second overlay decal can easily slide into position.

As you are positioning the second overlay decal, simply line up the ink lines on the decal underneath. It's easier than it sounds.

I only had to double the two wrap around decals. The two Mini-Brute bugs looked fine.

Here's the shock cord ties.

The nose cone screw eye got the Duncan Uni-Knot.

The Kevlar / Elastic shock cord got interlocking overhand knots.

There was some clear decal overhanging the top of the body tube. When the decal is completely dry, you can shave off the edge with a razor blade.

Use a "sawing" back and forth motion when cutting off the clear overhang.

Apply some clear acrylic Future on the exposed edge so it won't peel back. I don't overall clear coat models, just decal edges like this. 

The tube edge got some Sharpie to blacken up the white paint.

 

Estes Mini Bertha Clone, #TK-3, Part 10, Black Fin & Nose Cone

The single black fin was spray painted black.

The nose cone was painted black separately, off the model.

Note the masking tape doesn't completely cover the shoulder. The edge of the tape is a little below the shoulder lip. The gives you a little paint below the joint. You won't see balsa peeking out if the nose cone isn't completely seated into the body tube.

I drew up some decals based on the old catalog page graphics.

These were home printed on clear decal paper.

PATREON - The Mini Bertha decal PDF is only available to Patreon supporters. Email me at oddlrockets@bellsouth.net and ask for the Mini Bertha PDF.

The fit was good, the decal start and stop overlap was set in line with the launch lug.

The Mini-Brute "bugs" were set on the body tube and both sides of one white fin.

Estes Mini Bertha Clone, #TK-3, Part 7, Gluing On The Fins With No Wobble!

Well, I did it again! This is a missing, out of order post, 

It's an important one, showing how to get rid of standing wobble of four finned models. 

Here's post #7. I'll put them into correct order in a few days.

 

Extend the fin position lines under and onto the centering ring.

I also mark the intersection of the root edge and trailing edge on the fin itself. It gives me another alignment point.

I've scraped the glue lines for the four fins and the launch lug.

After scraping the pencil alignment lines are redrawn.

TIP: Four fin rockets can wobble when standing up on the fin tips. To fix this - 

Glue on three fins. The model might stand up by itself now, but can tip over.

Apply glue onto the root edge of the fourth fin.

Set the root edge on the pencil line.

While the fourth fin glue is still wet - You can slide the fourth fin up or down. 

Set the fin and check by standing the model on a tabletop. 

Pay attention to the last glued, fourth fin position. By making slight up and down movement on the fin down the alignment line you should find the spot where the model will stand on all four fins without wobbling.

Estes Mini Bertha Clone, #TK-3, Part 9, White Paint & Masking

Here's the model after the first white coat.

This is an easy mask, the body is white, the nose cone and one fin are black.

There are always glue fillet ridges.

Here's the same fillet area after sanding.

The single fin is painted black.

This shows the Scotch tape masks.

These are followed with brown masking tape covering the larger areas. A plastic bag covered the upper tube.

Before spraying the black, the edges are soft burnished with a Q-tip.

Estes Mini Bertha Clone, #TK-3, Part 8, Prep For Paint

Here's an old school idea:

TIP: On a four fin model, look across the trailing edges to check the fin alignment. 

While they didn't wobble,

The trailing edge tips weren't perfectly flat. It took very little 400 grit sanding to square them up.

If I had sanded through into the raw balsa, sometimes you can rub some wood glue into the small trailing edge to reseal it. Keep the glue only on the trailing edge.

You can only use this glue seal on small areas like the tip of this fin. Follow with some light sanding.

 

The model is ready for white paint.

Look close to see the masking tape pieces out the back of the engine mount tube, sticky side out. This keeps the paint out. A dowel was slipped in for a painting wand.

To get full paint coverage, the nose cone is pulled out about 1/16". This puts paint over the shoulder lip so you won't see a white line if the nose cone isn't fully seated in the tube.

Estes Mini Bertha Clone, #TK-3, Part 6, Cutting Out The Fins

I had to search to find some 1/16" thick balsa. 1/16" thick balsa is rarely used in rocket kits anymore. You can still see the SIG logo in purple ink on one fin.

Cutting them out by hand makes some small inconsistencies. On the left the four fins are squared up. 

On the right side, the fins have been stacked and the sides sanded even. 

Current laser cut fins are uniform, you don't need to gang sand them. But, you should still sand off the black ash on the fin edges.

Here's another view next to the fin pattern from Jim Z's.

The fins got one coat of CWF and sanding.

Gray filler/primer followed.

On the right side of the picture the fin was sanded with 400 grit. I tend to sand most of the filler/primer off leaving some in any remaining balsa grain.

The printed fin marking guide didn't quite match up after rolling around the tube.

I went to payloadbay.com and printed out one of their fin marking guides: CLICK HERE

Estes Mini Bertha Clone, #TK-3, Part 5, Odds & Ends

Before marking and gluing on the fins - 

I fill the gap between the outside of the centering ring and the edge of the tube.

Apply some CWF around the outside of the joint. Let dry and sand. You can sand and work around the engine hook with a sanding block.

The upper inside edge gets a wipe of CA glue. 

After drying, the glue gets a light sanding with 400 grit wrapped around a finger or dowel.

The nose cone weight is attached to the nose cone.

NEWBIES: Don't just blindly start the hole with the screw eye. If you are off center, that washer might come in contact with the inside walls of the body tube.

Mark the center with a pencil point. Screw the screw eye in first, going in about 3/4 of the threads. Remove the screw eye and squirt some glue in the hole. You know the drill.

Place the washer weight on the screw eye and reinsert the screw eye, this time screwed all the way in. 

Estes Mini Bertha Clone, #TK-3, Part 4, Slightly Longer Engine Mount?

An engine block wasn't included in the original kit.

I added one, glued in so it's flush with the upper centering ring and body tube edge.

Here's why that engine hook was designed to hang 1/2" beyond the bottom of the mount!

There isn't much clearance and flex between the BT-5 and BT-20 tubes. The low bend of the engine hook scrapes along the outside of of an engine casing when slid into the mount.

It's not impossible to get the engine in the mount, you'll just have some friction when being slid into place.

I pressed the mount into place with the flat face of my sanding block. The Kevlar was fed out the back and layed to the side while pressing the mount into the tube.

The mount is certainly useable with the shorter overhang hook. 

TIP: This is a BMS 1 3/4" engine hook. The cut off ends were a little rough. I smoothed out the edges with a few passes of a small, flat diamond file. The engine slides in easier now.

With the Bertha's fin trailing edges in the way it takes a moment to work an mini engine into the mount.

I'm sticking with the modification I made.

Estes Mini Bertha Clone, #TK-3, Part 3, Slightly Longer Engine Mount?

Here's a second dry fit engine mount using a 1/4" longer BT-5 engine mount tube.

With the BT-5 tube now at 1 3/4" long you end up with the engine hook extension only 1/4" out the back.

NEWBIES: I don't recommend using tri-fold shock cord mounts in smaller BT-5 and BT-20 diameter tubes. The bulky triple fold paper and double fold of rubber can block a chute or streamer ejection.

I substituted a Kevlar line.

The Kevlar line knot loop goes under the upper bend of the engine hook, Semroc style.

Like in previous builds,

The flat face of the exposed lower centering ring will be seen, rough layer wraps and all.

Rub in some white or wood glue and let dry. Sand with 400 grit. On the finished model that flat ring face will be sealed, smooth and shiny.

To hold the split ring closed while the glue dries - 

Slide the lower ring dry into the open end of the BT-20. 

Here you also see the cardstock hook retaining wrap between the two centering rings.