A question for hexrod users and Penta Rod builders

[RSalar]

I am modifying an existing six sided rod to a five sided configuration. After bringing up the taper I want to modify I click on "Modify Rod Design" then "Geometry" then I get three options for "Equivalence Method" -- 1) Equal Cross Sectional Areas, 2) Equal Stiffness, and 3) Equal Casting Deflection.

My question is: which one of those three options will result in a rod closest to the action of the six sided version? The taper I am modifying is J Howell's version of the Dickerson 8015 GS.

Thanks

[Tim Anderson]

My method would be to make all three calculations, graph them, and compare the results. My guess is that the variations will be small.

Tim

[Fcs]

Yes the differences will be small. Personally I think equal casting deflection makes a lot of sense, if i had to choose one.
—
Frank Stetzer, Hexrod’s stepfather

[GrayHackleRods]

Always use casting deflection. I did a program at CRR last year where I took 3 rods, one hex, one quad and one penta and converted them (for a total of 9 rods) using casting deflection and they almost matched perfectly in family. Also know that all rods do not necessarily convert well to different geometries. BTW the Dickerson 8015 converts very nicely.

[RSalar]

Thank you all for your answers— I appreciate the help!