Big Daddy Baron

I'm building a sort-of-upscale of the Mega Baron. I've had some excellent flights with my 20" R/C conversion. This one is 50" wingspan and has a 29mm mount.

The wings are from a [foam sport-scale model of Albatros D.III] My original plan is to buy two horizontal stabilizers from the same model to use as vertical fins, but they are out of stock. A builder on RCGroups has photos of the parts as they come from the factory: [top], [bottom].

The booster section is a Big Daddy/Leviathan nosecone and BT.

I'm still working out the dimensions and materials for vertical stabilizers and canards. Foam board strips in the photos are only mockups. The real things have to carry the entire thrust of the motor against drag of the wings. I want to mount them TTW through Estes' 1/8" slots. One idea is to use 1/8" plywood through the slots, 3/8" balsa for canards, and cut 1/8" slot, perhaps an inch wide, into the mating edge on canard.

Ari.

A great concept! :wink:

This is going to be impressive!


Richard

Love the foamy wings! In my best Hogan's Heros German accent I say "Very Interesting!"

I've made little progress on the upslace, but last Saturday I flew the 20" Baron as a 3-stage CHAD D12-0 to D12-0 to D11P.

[video=youtube_share;Rfw21Y9_fak]https://youtu.be/Rfw21Y9_fak[/video]
https://youtu.be/Rfw21Y9_fak

This is the first time I've filled out all 3 motor-by-stage boxes on a flight card. I neglected to take a photo of the 8.25", 3-motor stick taped together with clear tape. You can sort of see it in the takeoff photo.

TIL: looking at the photos of ejection sequence, I learn something new about CHAD staging. I thought the burnout gases of a lower stage burn through the CHAD tape. Tuns out it is the the exhaust of upper stage that melts the tape. For about a third of a second the upper stage exhausts through two nozzles: its own, and the lower stage's, which is still attached. Then tape melts and lower stage falls off. For BP enburners, where most of the thrust is in the initial spike, I wonder how much impulse I'm giving up by forcing the exhaust through two nozzles initially.

The liftoff with 3 motors' weight is very slow, and by the end of first stage's burn, I'm getting nervous about running out of airspeed. I push the nose over just as the second stage lights, and most of that burn is in a very shallow climb. Third stage ignition is uneventful.

I'm thinking for the next flight I might tape 2 extra A10-PTs to the first stage, to give it that little extra boost off the pad.

Or I might fly it on a single CTI F30 (3G 24mm).

Video courtesy of Nolan Leake; photos courtesy of Sam Fineberg.

Ari.

Doesn't look to me as if power off the pad was a problem; it was after second-stage ignition when things started going funny.

JStarStar said:

Doesn't look to me as if power off the pad was a problem; it was after second-stage ignition when things started going funny.

Click to expand...

Define "funny."

Power off the pas was OK. BP motors have a thrust spike at the start. Then thrust flattens out.

I remember thinking the glider was running out of speed towards first stage burnout, so I did what I do when my speed gets low: I pushed the nose over. Just then second stage lit. This reduced the mass and initial thrust spike pushed the speed back up. The glider was by then climbing at a very shallow angle.

Ari.

Funny as it changed direction at each staging event. But a neat flight nonetheless.

kj

kjohnson said:

Funny as it changed direction at each staging event. But a neat flight nonetheless.

kj

Click to expand...

It is a great benefit of radio control that you can control it.

Ari.

What is your rtf weight less motors?

20" version weighs 197g without motors.

Ari.