Hello Shaping Hive,
I am about to shape a 7’6" egg out of this Millennium Foam blank. It has no center stringer but has 2 stringers in a wedge pattern (narrow at the bottom and wide at the nose). Photo attached below.
My question, what is the best way to go about laying out a template and measuring various things without the center stringer as a guide. I use the center stringer so much during the shaping process. Any tips or tricks would help. Thank you all. And I hope all of the California folks on here are doing ok and are bouncing back well after the fires. 
Hi @Tim2
I had one similar where there was a big ‘nothing’ where the stringer might have been. I used a cardboard template with a tick mark for center. Then I embedded a piece of colored paper so I could find it again without the templates. Lesson learned was not to use Superglue for EPS foam, use Elmer’s or Arleen’s Tacky…
For your situation, you just need to split the difference on the wide end:
If you strike the red arcs, the centerline will go through both red intersections on the way to the tail. You could also do this with plain old measuring, 1/2 the distance between the stringers would be center.
'Love to see it when you’re done. -J
PS the red arcs need to be the same radius or the method does not work.
As Jrandy mentioned, half the distance between the stringers, at any point along the length, is the center.
For early shaping, you can add a piece of wide masking tape, centered down the length of the surface between the stringers. Make center marks on the tape and draw a line through the marks on the tape. Easy to remove the tape a little later.
I use a narrow piece of masking tape to split a wide piece of FG cloth into 2 equal halves (but I don’t remove the tape, to keep the cloth from fraying).
Thank you for responding, stoneburner. I have already marked the center of the stringers at the wide end. The tape idea is good. So I’ll use that center mark lay the tape use that for my template to draw the outline, then pull the tape plane and sand as usual. I guess to check symmetry and my widths at nose and tail and as the shaping goes on I’ll keep adding the tape line down the center. Adding a center tick mark on end the nose on the would help too.
Jrandy, thank you for this reply. I dig that diagram of my blank you made up. Sweet! I had already gotten the center of the blank by using the center of the stringers. I was hoping someone had some good tricks so I didn’t have to keep drawing a center line or taping one out. I guess I’ll print a full template on AkuShaper and use that when I draw the outline out. I usually use spin templates. I rely heavily on the center stringer throughout my shaping process to check widths and thicknesses at various points up the stringer. I’ll be using a center tick mark at the nose and tail to quickly lay down a piece of tape to make a temp center line. I’ll definitely post pics of the process in this thread as it goes.
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Hi Tim,
You could use a builders laser plumb line to shoot a line on the blank down the centre. As long as you keep the blank in the same spot or reshoot it everytime you need to check something.
https://www.homedepot.com/p/Bosch-50-ft-Dual-Power-Battery-Red-Beam-Self-Leveling-Cross-Line-Laser-Level-GLL50-20/327671498
Railwaysurfer,
Yes! Genius. This is a great idea. I guess I can set it up on a tripod. Thank you!
No problem, glad to be of assistance. I had thought through the same process using EPS with no stringer. Even if you had a shelf at the end of your shaping area would work.
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You can “cut” stringer line with a razor blade instead of mark it with a pen, calculate depth with blank and final shape thickness so it stay visible while you shape. Fill with resin when lam.
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Shapers Square aka “$40 piece of plastic”. Instead of tape or pencil at center, make a cut or awl scratch at center. Draw and cut out your template and shape from there. You will have to check for symmetry from time to time during shaping.
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