Friday, March 27, 2026

Estes Mini Arcas, #2441, Part 4, Tail Cone Fix - Gotcha!



After forming too many shrouds printed from the scanned kit tail cone,
I thought I'd try the provided kit shroud.
GOTCHA: The kit shroud fit like my scanned cardstock ones did - 
It fits the BT-5 but was small on the BT-20 top end.






So - off to payloadbay.com and their transitions tool.


Four more were printed and cut out.

Notice the picture on the left - 
You can see some very subtle raised areas. With 400 grit, sand and round them down. This removes the high spots and makes a better fit at the base of the BT-20.






Four cardstock tail cones were formed with a clean dowel in the heel of my left hand. Check the last post picture.

Thursday, March 26, 2026

Estes Mini Arcas, #2441, Part 3, Tail Cone Problems



Cut the flat sides with a ruler and sharp knife. 
Cut the curves with scissors.




I make a smooth curve by rolling a dowel in an arc pressed against the soft heel of your hand. 

It take very little glue to join the ends.
With the printed edge lines lined up, I held the shroud closed using smooth faced tweezers.
 
Here's where I ran into problems.
The bottom fits the BT-5, but the wider end doesn't match the diameter of the BT-20!

I made another tail cone with a slightly wider top. 
It was still too small!


These two shown above aren't the kit supplied tail cone. The kit shroud was scanned and some extras were printed up on 110 lb. stock. There doesn't seem to be any difference in size between the kit shroud and what I printed. I was saving the kit tail cone for a final try. It's a bit thicker and has a smooth side.

Wednesday, March 25, 2026

Estes Shark #1111, Build, Follow-up

Well, yesterday's post (shown below) ended up being posted on the wrong date, last week! Don't know how that happened. You can specify what days you want things to be posted. I must have hit "Set Date and Time" button and not the "Automatic" publish button.    

I got my BNC-50AR balsa nose cone from erockets.biz
The upper pic was the Alpha style "placeholder".
The lower picture shows the new, bare balsa cone.





How the rocket looked before:

Here's the build with the correct shape, original nose cone.
Sometimes a little change makes a much better design.

Monday, March 23, 2026

Estes Mini Arcas, #2441, Part 2, Tail Cone

Any rocket kit that has a tail cone only includes one cardstock shroud. If you've ever formed a cardstock shroud, you know the fit might be iffy. 

I won't be taking any chances with a single shroud.
I drew a 1" reference line above the printed kit shroud. The tail cone was scanned, the 1"reference span was double checked in Corel Draw. The shrouds were printed on 110 lb. cardstock.

Will I really need eight tail cones? No.
But, I can make a few and use the best fitting shroud.

Sunday, March 22, 2026

Estes Mini Arcas, #2441, Part 1, Parts



Here's a newer one from Estes.
A larger BT-55 Arcas kit was produced by Estes from 1972-1973.

This "mini" motor version is BT-20 based with streamer recovery.


Parts are of good quality.
The streamer is 2" x 24" chrome Mylar.


To see the instructions: CLICK HERE

The balsa sheet is 1/16" thick.
The small laser cut pieces are the fin supports. They are tiny!

Only one cardstock shroud is supplied. 
More on that later - 

Saturday, March 21, 2026

What Does This Have To Do With Rocketry?



It doesn't have much to do with rockets!

Still, a fascinating look at a pedal car restoration.
You think some rocket repairs are complicated?

Worth a watch - CLICK HERE

Tuesday, March 17, 2026

I'm Camping!



Sorry, no posts for the next three days - 
I'll be camping (with Dakota) at the Lake Manatee State Park in Bradenton, FL.

Posts should be back to normal this Saturday . . .