J/30 Class Association Forums J/30 Forum One Design Class Rules Official Keel Drawing Not To Scale

Just a head's up. The drawing of the keel is not to scale in the "Official Keel Drawing & Offsets" page in the Class Rules and Specs.

The distance between Section I and Section II is drawn smaller than the distance between Section II and Section III despite the equal measurement markings on the drawing. Same with the distances between III & IV and IV & V.



I just happened to notice this while I was overlaying the drawing on top of a picture of my keel and I couldn't get the section stations to line up. Likely not an issue for anyone else.

The easiest way to transfer the liner dimension listed is to create two marked tapes or strings that have the dimensions clearly marked as shown in the leading and trailing edges of the keel template. Locate this with a reference 0 at the keel/hull intersection. Take a sharpie and mark the keel with the locations marked on the tape. Then it is easy to use those marks as a guide to locate each of the template sections. This is how the Compukeel kits do it.

Thanks Bill, I'm all set with templates and measurements. I do like the string idea for the leading edge. Our leading edge needs to be built up enough that it is quite the imaginary line. I'm glad I haven't had as much lead to remove as you did. I think the keel has been faired before but never templated.

I just noticed that the spacing was off in the drawing. Looks like that came straight from J/Boats, so at least it's not our foul. I don't think it will mess anyone up, but good to know that the drawing has irregularities.

Blaine

I actually traced that from a pencil drawing that Rod Johnstone had and digitized it to post on the website years ago. It wasn't done using a CAD program so there was no tolerancing or checking done. It accurately represents exactly how the original drawing was done. I also created the Excel spreadsheets with the offsets as an easier way to get the tabular data. If you use the dimensions listed, you'll be fine.