[CLONE] Estes Marauder #1922 - fin questions

[bradycros]

Connect the dots with a straight edge.

Wa - La. A scale Marauder fin from a picture.


Expand the photo to get a better look at the lines and measurements.

 

[bradycros]

The original computer.

One end prints, the other end deletes.

 

[K'Tesh]

I came back to this again as I was working on my .ork files, and I pulled up the plans from rocketshoppe (and the fin templates). I futz around with them again. I mean, they do look really slick and convincing... Then after modifying my .ork file, I decided to recheck the fin shape, and re-discovered this thread, and realized that I messed up my perfectly good .ork file, thanks to that link.

FOR THE RECORD: The fin pattern found at https://plans.rocketshoppe.com/estes/est1922/est1922.htm is WRONG! If you cut your fins following the image est1921a.tif, you will not have an accurate clone.

I've modified it some to help clarify things...

Estes #1922 Marauder Parts List and Full-size Fin Patterns (Corrected Some)


You can also download the complete plans from Estes website. (Rocketshoppe's plans are incomplete due to someone cutting out the fin marking guide).

 

[K'Tesh]

Just traded PM's with Craig McGraw (CPMcgraw) (the guy who did the fin template in the plans.rocketshoppe.com file).


He pointed out that the Marauder's fins are the same as the Estes Cyclone 1907 kit. He tossed in a link to the fin template (fins still in the extra balsa). I checked the scans of the instructions (Cyclone (1907), Marauder (1922)) and confirmed that they do have the same part number. So, when I get home, I'll be running the numbers and updating my .ork file accordingly.

Again, according to the instructions, the Marauder's LL standoffs are 1/4" high, 7/8" at the root, and 5/8" at the tip (and cut from the scraps of the die-cut balsa sheet). The Cyclone doesn't have/need standoffs.


Thanks for the additional info Craig!

 

[K'Tesh]

Ok... Based on the image of the Cyclone (1907)'s fins (Estes PN 32607), I've found that the root edge is 1 3/8" long, and that the fin span is longest directly over the rear of the root edge. The measurements I took were from the image of the balsa and not the drawing next to it. The drawing DIDN'T bear out the relationship observed from the balsa right next to it.


Estes Cyclone (1907) & Marauder (1922) Fin Pattern 90°



Estes Cyclone (1907) & Marauder (1922) Fin Pattern



My points plot out as:

X/Y
0/0
1.375" / 3.0625"
2.5" / 2.531"
1.375" / 0

View attachment Estes Marauder (1922) (Accurate Fins) UPDATED.ork

 

[K'Tesh]

Let's put this to bed once and for all...

I finally got a Marauder, opened it up, and scanned it for JimZ's site.

Here's what I found.... A new variation of the instructions (mine had the (ANNOYING) white "Marauder-back-of-the-bag" back side)...

https://www.spacemodeling.org/jimz/est1922.htm