How To Design A Form?

[EvilDogBeast]

I did some light searching through the forums and was unable to come up with anything useful so I figured I'd just ask.  I would like to start designing my own forms but am unsure on how to do it.  Is there any one book or series I can get a hold of to find all the different formulas and concepts to design a form from the ground up?  I'm assuming one of the TBB books has it, just not sure which one or if there is another resource that goes well with it.  It would be nice to design something that was my own rather than copying and altering pre-existing plans or tracing and altering the profile of an existing bow.  Any guidance is greatly appreciated!

[Mark R]

Do yourself a solid and go to kennysarchery.com I believe he has a walk through of the process on his website. Designing your own bow is great, but don't try to reinvent the wheel, the best designs have been around a long time and if you experiment enough you'll probly come to the same conclusion many have, unless you have some unknown material no one has used before. Have fun with it and good bowyering to ya.

[EvilDogBeast]

I have been utilizing Kenny quite a bit, he is a huge help.  I'm not trying to come up with anything drastic, just want to design and build Chris' bow instead of rebuilding ______'s bow. 

[monterey]

I have designed three of my own forms and all three were successful but not revolutionary by a long shot.  Two are good but no better than existing designs.  One is, IMO, superior to most similar designs.

But, realize that you can have a great design and produce a mediocre bow by making poor choices in selecting thickness tapers, frontal profile, riser length and a few others to boot.

TBB doesn't address FG bow building but the extensive study of design and performance is very useful.  So, it's a good place to start and really fascinating reading.

[Shredd]

  Hey Chris...  Mark's post rings mostly true...  But I hear Yah...  I like making and designing my own stuff also...  It's the artistic side of you and the side that says it's mine not a knock-off...

   The best advice I can give you is study all your favorite bows out there and then mold them all into your style and what you like...  Even though it will be very close to other bows it will be different...  There are so many small intricacies... Expect 1/4" to 1/2" spring-back when it comes off the form...  Make the bottom half (or main half) of the form a few inches longer and deeper than needed...  That way you can reshape your form if you want to change a design or trash a design...  You can always cut the excess off later on...   Your priority is to get your riser area of the form dead nuts first  and then work off of that... Start off on the shallow side or larger radius's  on your form and work off of the riser area in middle of the form outwards... Then tighten up on your radius's if you have to...  It's always easier to take off the wood than try to put it back on...  Tinkering with power lams is a good thing and it  takes a lot of guess work and fine tuning in the area just outside the fades on your form...  This area is crucial, it is the base of the limb and everything works off of it... 
There are many other things to consider also and you will learn them as you go along...

   Couple more things...  Work off of the flattest most truest side of the form and keep every thing perfectly dead-nuts 90* off that side of the form...  Use your drawn lines as references and eyeball your curves but most importantly run your hands over the curves...  Do it lots of times...  Do it fast and do it slow...  Oh Yeah Baby!!! She likes it that way...     But seriously, It will tell you if something is out...

   Like Monty says,  there is a lot more that goes into it than just the side profile...  Like my buddy Kirk says, it may take you twenty bows to get that design dialed in...  It has taken me about 15 bows to get my design dialed in...  That is if you have the patience and will to make the best possible bow for that given design...  Each bow has it's own special recipe for the best performance...  After you dial in your first one I would think the next one could be dialed in a lot faster being that you have gained previous knowledge from the first bow you dialed in....

   Good Luck...   

[kennym]

Much good advice.

Use a router for the form.

Make your template smooooth curves , bend something around the curves and look it over. I can't always feel a dip or bump but can sure see it when you spray the bow!!

Take a bow or two you love , and see if you can make it more loveable....

Then when you get the bow you like, start tweaking. You don't even have to always change the form, sometimes taper rate, power lams, tip wedges, width, trapping, riser length, etc. will do....

Mainly, have fun with it ,  a hobby or business that pisses you is no good....

[Gundog68]

I did study and measure all bows i get hands on. BW, Tomahawk, Thunderstick, Border to name a few. I put them in a CAD-System and compared the forms. A lot of them are nearly identical. I draw a curve with the cad system in the middle of the top rated models. This data feed to "supertiller" led me to the stack height and other points (fade-out..etc) . The result produced with a CNC Machine...  Kennym´s form is also realy near to that. I did some test with the first 2 bows out of the form , then did a bow building workshop with several club members. The bows are between 184 to 192 fps with 9gpp.

Some years ago i did a revers. I made a bow form with the wanted full-drawn bow form. Then i bend this back to get the original. This works a little, but you can put a lot in a bow stack (powerlams,tipwedges) to randomize your results ;-)

[EvilDogBeast]

Ok I think I understand.  Basically the shape of most bows is pretty much "the shape", and even if I was to math out my own I would most likely end up drawing something pretty close to all the others?

[Forwardhandle]

I learned a lot about bow design making natural material bows & reading bow design books and had enough failures that I don't mind taking some body else design that has done the R&D for me and making mods to it , If you study bows long enough it seems most bow designs have been done at some point in history any way , but the caveat being different materials and execution of the design , But I would like to try some time making a reflexed ASL bow of my own down the line !

[TradBowyer]

first thing I would suggest is decide what you want to do. Meaning are you just wanting to build a bow to say you built your own from design to finish? or are you trying to do something more revolutionary? If you are wanting to do something more revolutionary, you will more than likely be building several forms till you get what you are really after. If you are just wanting to build a bow, then there is nothing wrong with getting plans already out there and using those. THe guess work has all been taking out for you. If you build a new design yourself, plan on building 3 bows off of it before you can get your thickness charts to where you know where your thicknesses are going to be for a given poundage you want. Its going to cost you in the neighborhood of $100 min for a bows worth of materials not counting the materials to build your form, bow oven, etc...if you build 3 bows you will have quite a few franklins invested already. If you use a pattern that is already out there, as long as you build the form accurately, you should hit your bow on the first shot. And as already stated, there isn't a bow design out there that hasn't been tried already so you won't be coming up with anything new. Most of what guys are doing today is playing with taper rates to get their limbs bending differently but for the most part, the bows shapes are pretty much similar with a few exceptions.

[Shredd]

Ok I think I understand.  Basically the shape of most bows is pretty much "the shape", and even if I was to math out my own I would most likely end up drawing something pretty close to all the others?

   It will look the same or similar but it could be drastically different in the 'eye' of measurement and performance...  Thousandths of an inch can separate a good shooting bow from a dog...  Your eye cannot tell the difference between a 28" radius and a 30" radius in a small section of limb...  But the bow can tell...  That is why you could have two bows that look the same and one shoot 185 fps and the other shoots 170 fps...

    Here is another tip... When drawing out your design write down all measurements on the drawing and where they start and end along your drawn line... If you decide to change your design, go in small increments... Small can make a big difference... Don't go by your eye... Go by the measurements...  For example... If you used a french curve, go back to it's original position and slide it over a small amount like a 1/2" or an 1" depending on the curve You may only go a 1/4"... If you used a 28" radius go to a 29" or 30" or visa versa...  It won't look like much of a change but the bow can tell and it can make big changes when it strung or drawn... Then use your eye at the end to make sure all the curves are blended well...

   If you want to take the headache out of drawing out a bow I suggest you take a day or two a make a bunch of radius's 24" long out of some melamine and a couple of curves out of some lexan... You can also find some nice long curves in a fabric shop...  Screww the compass thing... It is a pain in the ass and hard to get accurate...  Trust me it will be worth it....

[C. Johnson]

I built bows off of Bingham's designs for a long time.  They're tried and true and I was never disappointed.  Eventually, I wanted to come up with my own designs.  I knew better than to try to reinvent the wheel, so, I took elements of design from various other bows and kinda mashed them together.

There's a long learning curve and a lot of time and money invested, but this can be lessened by careful planning.

I do a few things differently than a lot of other guys, but the principals are still the same.

[monterey]

If you don't have a cad program, here is a free one  http://www.cadstd.com/ 

You can also pay for an upgrade but I used the freebie for a long time without any need for the upgrade features.

[monterey]

Craig, you are not that far away from me and I'd love to spend some time in your shop someday.

[C. Johnson]

Craig, you are not that far away from me and I'd love to spend some time in your shop someday.

I would be honored.

What part of Colorado are you in?

[monterey]

Arvada

[C. Johnson]

Arvada

I used to live off of 84'th and Sheridan back in the 90's

[monterey]

Four people shot and one killed corner of 80 & Sheridan yesterday.  Good place to be from.

[Mark R]

All great advice, it takes time, patience and work,not to mention $ in material, don't waste it on unproven designs and techniques. You want a bow that shoots well, use quality material the cost  is minimal.  I have 5 different designs and have been tweking only 2 designs to my liking in the past 2 years, all have been good solid shooters, come to find out there very similar to others that have been around a long time, and I just do this for fun out of my garage when I have time. Always things you can do to take a proven design and make it you own,after all you made it, at first( kiss). Good form good bow bad form bad bow.

[kennym]

"Good form good bow bad form bad bow."

This is a really good piece of advice!!