Lakeroadster's Rocket Shop

(BAR-31) Anduril Roadrunner

Here's a semi scale flying model rocket of an actual twin-turbojet VTOL Autonomous Air Vehicle.

2024-04-20

I created an OpenRocket simulation to determine the air worthiness of this model. I'm planning on using two D12 black powder motors.

2024-04-23 Nose Cone

Nose Cone Started with a 4 x 4 piece of scrap cedar. I lagged it to the headstock and turned the piece to 1-3/4" dia. and then bored a 0.90" dia hole x 5" deep. Then turned the shoulder for a C-55 and turned the taper.

2024-04-24 Motor Mount - Day 01

Two 24mm motors feeding into a BT-5 ejection tube.... so I needed some way to neck the ejection charges down. I took a piece of 3/4" plywood and made a header. I used plywood to avoid the wood splintering when the ejection charge fires.

Plan is to glue the two body tubes to the header, and to themselves, and then use some wood glue on the inside surfaces as fire proofing.

2024-04-25 Motor Mount - Day 02

Glued the 24mm tubes to the header, and started building fillets. Also started fireproofing the header internal parts with wood glue.

2024-04-26 Wings and Motor Mount Day 03

I cut the wings from 1/4" plywood and the Vert. Stabilizers from 1/8" Basswood.

(BAR-29) Gary Larsen's "Farside" Rocket

2024-04-23 Final Swing Tests

Swing Test - Nose Cone Canted Inward - Gary Larsen "Rocket Scientist" Rocket (youtube.com)

Swing Test - Nose Cone Canted Upward - Gary Larsen "Rocket Scientist" Rocket (youtube.com)

Swing Test - Nose Cone Canted Downward - Gary Larsen "Rocket Scientist" Rocket (youtube.com)

2024-04-22 Metallic Silver and Photo Shoot

2024-04-12 Blue and Red Paint

2024-04-09 CWF and Primer

2024-03-30 Rear Ring and Gluing The Cone

I made a couple openings in the cone to inject some wood glue into the upper section, and then let it set over night.

I trimmed the lower cone and then made a plywood ring to glue onto the rear cone centering ring. I'll glue this to the cone bottom to keep it from getting crunched.

2024-03-24 Fabricating The Lower Cone

I gave up on trying to locate some suitable cardstock, and used the cardboard from a Strawberry Frosted Mini Wheats box. Came out really nice.

2024-03-21 Preliminary Swing Tests

I did a number of preliminary swing tests. The rocket appears stable. The canted nose doesn't appear to push the rocket askew.

It gives me confidence to give this a powered flight.

Preliminary Swing Test - Nose Cone Canted Inward - Gary Larsen "Rocket Scientist" Rocket (youtube.com)

Preliminary Swing Test - Nose Cone Canted Outward - Gary Larsen "Rocket Scientist" Rocket (youtube.com)

(15) Preliminary Swing Test - Nose Cone Canted Upward - Gary Larsen "Rocket Scientist" Rocket - YouTube

Preliminary Swing Test - Nose Cone Canted Downward - Gary Larsen "Rocket Scientist" Rocket (youtube.com)

2024-03-20 Nose Cone Repair

The day after I turned the nose cone I noticed the crack was opening up... like considerably. I used a band clamp and clamped the bottom for 24 hours, periodically checking and re-tightening to close up the crack.

Then I applied wood glue and clamped it again. I'm pretty sure it's back to where it was when I initially turned the piece.

2024-03-18 Nose Cone

I turned the nose cone from a piece of pinyon pine we cut down on our property about 7 years ago. It has some worm holes which adds character. I may end up filling them with wood putty... we'll see.

2024-03-17 Launch Lug

2024-03-13 Upper Body Tube

I placed a glue fillet on the hub and let that dry a bit. Then, slathered some Gorilla Wood Glue on the O.D. of the hub and then slid the upper tube in place... secured with a thumbtack.

Then I injected some more wood glue into the access opening I punched into the tube and spent the next couple hours slowly rotating the rocket to coat the inside of the joint. There's really almost no loading on this joint due to the internal dowel.

2024-03-12 Upper Body Segments

Kind of hard to see, but I used Gorilla Wood Glue to coat the inside of the intermediate upper body tube to Lower body tube joint.

I then cut some masking tape down to 3/16" wide and wrapped it around the 1" dowel. This allows the hub to sit on the tape. I applied some Gorilla Wood Glue into the bore of the hub, and then inverted it onto the dowel. The tape keeps the glue from running down the dowel, yet while the glue was still "fresh" I could rotated it to get optimal fit of the upper body tube.

The upper body tube is removable at this point so I can get a good glue joint of the hub to the dowel.

2024-03-11 Nose Cone Hub

I turned the nose cone hub from a scrap piece of a Southern Yellow Pine 4 x 4. Then cut the 22-1/2 degree angle with my chop saw, and drilled the 1" dia. hole.

I mocked up the upper tubes and the cone hub to check the fit.

2024-03-10 Internal Nose Cone Support / Recovery Anchor

This little gizmo attaches the nose cone to the lower body... and has an eyebolt to anchor the recovery gear.

2024-03-09 Lower Cone Development

I searched high and low on the ole internet for a development of an offset eccentric cone..... not a concentric cone.... not an eccentric cone.... an offset eccentric cone. I never found one?

So I decided to make my own. Using some paper I fit each piece to the rocket, cutting out for the fins. Then I removed the template and copied it onto a piece of 11 x 17 paper.

Now to find some suitable cardstock or poster board to make the cone from.

2024-03-08 Fin Can Day 02

Applied glue fillets to the fin can.

2024-03-07 Fin Can Day 01

I got all the fin can parts glued together with an initial fillet of Gorilla Wood Glue. I ended up sanding the o.d. of the C-80 coupler in the area where the lower BT-80 goes in order to get a sliding fit. I then use Elmer's Glue All to secure it in place.

I'll add glue fillets now.

2024-03-05 Rings, Tubes and Fins

I cut the tubes and made the plywood rings and fins

2024-03-03

This one is slated to be a scaled model of Gary Larsen's Farside rocket.

I used the actual Farside comic and set about to draw a scale model of the iconic rocket.

Armed with these dimensions I picked a body tube size, BT-80H, and then scaled all the dimensions based on that body tube. I fired up the CAD station and created a Model.

I then built an OpenRocket simulation using a straight line version but with the actual diameter and lengths from the CAD model. I wanted to know what size motor might be needed.

Looks like a flyer. So I knocked out a CAD drawing showing the configuration of the fuselage.
It's a rear eject spool design with a 29mm motor mount. None of that is shown in the CAD model / drawings.