Primitive Archer

https://www.virtualbow.org/

It's an independent program that you download and install. It's really easy to install and quite easy to use, with a fairly shallow and short learning curve.

I have win 11 and get a warning about it "not being commonly downloaded.  Be sure that you trust the link"   It did download something but the file is called "unconfirmed download" and it won't open...

Also, the more whip-tillered the bow is, the more efficient it becomes (the reason here being lower tip mass)

Although the tip area with the steep taper is somewhat lighter, I dont think those FPS are attainable because the max strains in bow 9 are 73% higher than bow 4

• Know exactly what it's meant to look like at full draw before you start. This done by sketching, modelling or emulating another bow. This helps prevent hinges or overshooting the limb's curvature.

Are those the main points or have I missed something vital?

with virtual bow you should be able to see what the bow should look like at any stage of the draw, eliminating the need to compare it to a different bow

So, I've collated some commentary and for future reference the key things to keep in mind when making a D/R bow are:

• The laminations must be pretty accurate to begin with (difficult if using natural bamboo, but we must try what we can, eh?)
• Avoid having uneven reflex. Smooth curves at the start = smooth curves at the end. This would be a manifestation of the above point being gotten right, in addition to having a good form/caul.
• At brace, the limbs should be actually or close to pretty straight
• Avoid putting in too much reflex. Having the tips around even with, or just in front of, the back of the handle helps to avoid nasty problems during tillering
• Go slowly through tillering - this done to avoid putting too much bend somewhere in particular, which can happen very quickly with a bow like this. Consider using a scraper of some sort. The accuracy of the lams to begin with helps reduce the amount of bulk stock removal, making the scraper effective.
• Know exactly what it's meant to look like at full draw before you start. This done by sketching, modelling or emulating another bow. This helps prevent hinges or overshooting the limb's curvature.

Are those the main points or have I missed something vital?

Here are clearly very experienced bowyers (and I already knew that…)! Number 4 is the best!

Here are the results I got from the program. It is clearly shown that the closer the bend is to the handle, the more energy the bow stores. Also, the more whip-tillered the bow is, the more efficient it becomes (the reason here being lower tip mass). Very interestingly, the speed is almost the same, independent of the tiller shape! It would be possible to say that every taper rate from −0.006 to 0.002 is good, so in that sense it does not really matter how you tiller.