Unsure on a few aspects of bow making and couldn't find a good answer

[Nidhoggr]

So I have begun making my first bow and am to the point of thinning the limbs for tillering.  The wood rasp I have is a fairly rinky dink one and wasn't sure what people would reccomend as a good tool for taking large amounts away quickly.

As well: i remember hearing somewhere that decreasing the width reduces the draw weight by double what decreasing the width does.  Is this correct?

[leonwood]

Good that you started! Now for your questions, fast wood removal is mostly done with drawknife, farriers rasp, blockplane, spokeshaves etc... BUT: Once you start tillering the best way is to go slow and use a scraper! Fast removing tools are fine for roughing out a stave or board but tillering requires some finesse and you can mess up quickly if you go to fast.

About your other assumption, that is actually the other way around. Making the limbs thinner will quickly reduce draw weight. Making them narrower wil not reduce the draw weight very fast.

Usually when making a board bow (a flatbow I presume?) you start by reducing the top profile and when that is done you start tillering the bow by removing wood from the belly.

There are som boardbow buildalongs in the howto section on this site but the pics are probably eaten by photobucket.

Hmmm new buildalong anyone?

[Nidhoggr]

Good that you started! Now for your questions, fast wood removal is mostly done with drawknife, farriers rasp, blockplane, spokeshaves etc... BUT: Once you start tillering the best way is to go slow and use a scraper! Fast removing tools are fine for roughing out a stave or board but tillering requires some finesse and you can mess up quickly if you go to fast.

About your other assumption, that is actually the other way around. Making the limbs thinner will quickly reduce draw weight. Making them narrower wil not reduce the draw weight very fast.

Usually when making a board bow (a flatbow I presume?) you start by reducing the top profile and when that is done you start tillering the bow by removing wood from the belly.

There are som boardbow buildalongs in the howto section on this site but the pics are probably eaten by photobucket.

Hmmm new buildalong anyone?

Thank you!  I think i misspoke: I am not QUITE to tillering yet.  I am thinning out the belly as it is currently over an inch thick and not even remotely usable or able to be strung yet.

[Eric Krewson]

I read somewhere that the thickness was 7 times the strength of the width.

[Lehtis]

A rule of thumb I have heard: Take 1/2 from the width and youŽll lose half of the stiffness. Take 1/8 from the thickness and youŽll lose half of the stiffness.

[Del the cat]

Stiffness of a beam is proportional to the cube of the thickness, but only directly proportional to the width.
So if you go 2 x the thickness the stiffness is 2x2x2  that's 8 times stiffer!
If you go 2 x the width it is just 2 times stiffer.
To remove wood, drawknife, spokeshave, rasp.
The edged tools can dig in and follow the grain ripping out too much of the wood has tricky grain or you are cutting against the grain. So if it's tricky, use the rasp.
Del

[Pat B]

Farriers rasp is probably the least expensive tool for quickly reducing wood with control. If you know any horse people have them ask their farrier for one of his throw away rasps or you can buy a new one for less than $20. Tractor Supply or other farm stores, feed and seed stores, etc. will have them.
 When I get to floor tiller stage, a time when I can slightly bend each limb individually to see it's bend, I use primarily a scraper for tillering. Sometimes I will use a finer rasp to make correction but I use a scraper mostly.
 Generally I'm at floor tiller stage when the limbs are from 3/4" to 5/8"  at the fades and maybe slightly thinner just before the tips.

[George Tsoukalas]

There are buildalongs on my site. Jawge

http://traditionalarchery101.com

[dragonman]

ah, the dragon that chews on the roots of mighty Yggdrasil..dont let him gnaw on your bows....Nidhoggr

Dels got the physics right...its 8x   ..just to confirm..

buy yourself a good quality rasp....its worth it

dragonman

[Nidhoggr]

ah, the dragon that chews on the roots of mighty Yggdrasil..dont let him gnaw on your bows....Nidhoggr

Dels got the physics right...its 8x   ..just to confirm..

buy yourself a good quality rasp....its worth it

dragonman

   Yep!  You got it!  I'm a big fan of Norse Mythology and a follower of Asatru.

Thank you everyone for your advice and help!