Mini Bertha Fin Dimensions

[DWonders]

Hi all. I'm planning to clone the Estes Mini Bertha and pulled the instructions from JimZ's rocket plans but when I printed out the pattern for the fins/shock cord mount/fin wrap, it filled the entire sheet of paper. The fins are the size of the Big Bertha. And since I don't know what the original size is, I don't know how much to reduce the image to. Does anyone have a Mini Bertha that they can measure the fin dimensions for me? Also, does anyone know if anyone is printing aftermarket water-slide decals for the Mini other than Tango Papa? He's wanting $12 per sheet plus $9 in shipping. A tad too steep for my budget.
Thanks in advance.
Don

 

[BEC]

I cloned the Mini-Bertha recently using laser-cut fins from Semroc. Let me go measure the root edge, and you can scale the patterns from JimZ from that.....


OK - root chord is 1 5/8 inches.

 

[kuririn]

Prior to printing check your pop-up window and make sure your printer settings are not on "fill to page" or "fit to page" or similar, depending on your printer. Should be on something like "normal" or "actual" or "100 %". Cross check: cut out the fin guide and see if it fits a BT-20 tube exactly. Many scans include an inch scale, this one does not.
For decals, the scanned decal is really yellowed. If you don't want to buy from Tango Papa or Stickershock then you need to clean up the background with a graphics program, then use the cleaned up decal scan to home print on decal paper. Good skill to learn, many instructions on this forum and from the manufacturers on how to print on decal paper.
Good luck!

 

[DWonders]

Thanks Bernard. This will be very helpful.

OK - root chord is 1 5/8 inches.View attachment 415025

 

[BEC]

You’re welcome.