More Tillering advise needed

[bigcountry]

Ok, so I made one of those gizmos that Eric showed me for tillering with the pencil in the middle.  And all I can say, is its awesome. 

I have got my osage bow tillered almost.  I have a hinge about 6" from the tip.  Did this hinge before I put the tool on.  I am going to pike the bow and maybe whip the ends some.   Bow is 42lbs now.  I would like a solid 50lbs.  Besides this hinge, according to the tiller gizmo, both limbs bend evenly and the same except the last 6" to the tip.

This was just some background info for my real question.  Ok, all that aside, getting ready to start another osage.  I don't want to fix problems that could have been prevented in the beginning.  I like the tillering gizmo, but can it be used right after floor tiller?  In other words, after you get a rough floor tiller (which will be the tricky part for me, as I don't have the feel yet), I will brace the bow at like 2-4".  Do I want a perfect even arc braced? 

I am startin to think its best to build a 70" bow at first and tiller it, so I can then take off 2" off each side to make sure I hit my mark.   

[YewArcher]

The best sugestion that I can possibly give is to read the chapter on tillering in the TBB vol. 1. It soundsl like you are missing allot of the basic tillering skills needed to build bows. Thats allot of information that is best covered by Jim Hamm in the book mentioned above. That chapter alone will cover more information then you could get here because it covers questions you could not know to ask.  You really should read this prior to staring your next bow. People who start there are often sucsesfull with there first bow. Its a worth while investment in time and money. That chapter is one of the greates gifts given to us contemporary self bow builders.

I sugest this in a very helpfull way.

SJM

[bigcountry]

The best sugestion that I can possibly give is to read the chapter on tillering in the TBB vol. 1. It soundsl like you are missing allot of the basic tillering skills needed to build bows. Thats allot of information that is best covered by Jim Hamm in the book mentioned above. That chapter alone will cover more information then you could get here because it covers questions you could not know to ask.  You really should read this prior to staring your next bow. People who start there are often sucsesfull with there first bow. Its a worth while investment in time and money. That chapter is one of the greates gifts given to us contemporary self bow builders.

I sugest this in a very helpfull way.

SJM

Yea, I read it.  A few times.  That chapter is what got me in trouble in the first place with the floor tiller, that I had to correct now.  It doesn't cover simple information I am asking.  And if it does, its very long winded at that.  It doesn't show using the block with a pencil in it. 

And if it does can you point me to the page? 

Thanks for the reply.

[Papa Matt]

Big~

  You just need to rough out your bow and leave it 4-8 inches longer that you want it to be when it's finished. Make sure it looks even in width and thickness as you rough it out. Then when you feel like the limbs are beginning to flex, slightly floo tiller your roughed out bow, from just out of the fades, to tips-make sure you have everything bending, then of course do the other limb. T this point, only concern yourself that every inch is bending evenly. Don't worry about pull weight just yet. Next, after floor tillering seems to show you that everything is bending evenly, get a tillering string and string the bow on your tillering gizmo, with a very low brace height. (Just enough to be able to step back from the bow and be able to see the tiller, with the bow in a slight arc. Start out on the first notch, then try second and then third. If it is not even, file or scrape the stiff  spots, and try again. Never file or scrape too much at one time. If it looks even, Take it off this tillering gizmo, and use the tillering string as a temporary bowstring, to pull the bow slightly and get a feel for where the poundage is. File/scrape/sand as necessary, til you get about where you want it to be. If at this point your bow is still a little too long, trim your end, ONE INCH at a time. Continue to file/scrape as necessary.

I hope this helps you. This is how I do it, except I haven't made myself a tillering gizmo yet, but I need to and am going to.

~Matt

[Pat B]

The tiller gizmo can be used any time your limbs are bending to show you where they bend and where not. As the limbs bend more it is more critical that you don't over stress the wood in possible hinge areas. As you bend your limb to use the gizmo try not to hold it too long as this adds extra stress to the limbs.      Pat

[bigcountry]

Papa, the tiller gizmo, I am referring too is a 6" block of wood with a pencil in the middle where you can see if the limbs bend evenly.  I think you set the pencil up to the deepest arc.   I just didn't know if you wanted a even arc braced.  Because most bows appear stiff  from the fade to about 6" up the limb braced, but and even arc at full draw.

Reason I ask this, is there are so many ways people seem to tiller floor tiller.  I hear some guys say they get a bend from the fades to about 10" from the tips first since this is doign most of the work, and this lets them put a string on it.  When they get a string on, then they work towards the tips.

Others I talk to like to remove wood evenly all the way to 6" from the tips and get each limb bending about the same evenly. 

So many ways of doing to get to the same ending.  I messed up on this bow during the floor tiller stage.  I worked one limb evenly and the other I concentrated on the fade to mid limb area too much with my ferriers rasp.

[adb]

I use a walky talkie stick more towards the end, to get the final tiller perfect. I go by eye at floor tiller and with long string. After 1st brace, I start to use the stick. If you're a new bowyer, don't muck with floor tillering too long. It's hard to see if you're getting even bend. Get it up on the tiller tree asap.
Remember... have a solid goal in mind before you start. Try not to get to the end by having to pike, or otherwise modify. Read the chapter on tillering in TBB 1 again.

[bigcountry]

Also guys, I really do appreciate the advise.  I know these seem like elementary questions.  But I came into this totally blind besides reading books on my own.

[adb]

Patience, patience. The greatest virtue of any bowyer.

[tom sawyer]

Like Pat said, yes you can use Erik's tillering tool at brace.  You use it right up to and including brace.  I tend to try and get a smooth bend out to within a few inches of the tips.

I think you are misunderstanding about the way a limb looks at brace vs full draw.  When you are braced with a short string, the relative bend in the limbs is about the same as full draw, just less of a bend.  Where you get a difference is when you are using a long string and tillering board.  The long string doesn't stress the outer limbs as much as a short string because its not squishing the bow together, only pulling it back.

I use something akin to Eric's tillering tool at brace.  I use a credit card (debit will work) and look at the gap underneath.  I think if you had a 3 or 4" tool to go along with the 6", it might show you smaller flat spots.  Then the longer one would give you the "bigger picture".

I've tried tillering from "outside in", then "inside out", really for me the best thing is to get a smooth bend as soon as possible, and then concentrate on removing wood evenly to reduce weight.  I will put a bow on the tiller stick using a moderate amount of pressure to get it bent, and as soon as I see flat spots (using tools or just my eyes) I mark and work on those spots.

The other thing I've learned is, when I look down a limb I check the thickness of the limb and I've gotten to where I can see fairly small changes in the thickness.  A slightly thicker area is sure to be stiffer, so I will often even things up before I even bother to double-check using the tiller stick.  More often than not, this works well.

The one time you won't get a smooth bend at brace, is if your bow limbs are reflexed.  If you are working from 3" of reflex, your limbs will look pretty flat at brace height and only come round at full draw.  Might even still look a bit stiff then, but if things are smooth then you are at least distributing the stress evenly.

Have you read Torges' Hunting the Osage Bow?  Thats the best description of tillering there is.  His method provides a logical framework for progressing.

[Papa Matt]

Big~

 I think the answer to your question is this--you have to have even BEND, but not necessarily an even ARC when just at brace. "Even bend" just means that as you flex the limb, all areas bend evenly. Example, any kind of recurve or reflex, will not have an even arc at brace, or even at full draw for that matter, but all areas must bend an even ammount. What you must have is even BEND. I think that's what's confusing you--even bend V. even arc.  Is there any reflex or recurve at all in your limbs? If so, then your arc may not be completely even, however, if there isn't any reflex or recurve, then yes, the arc should be pretty even, except for stiff tips if you want.

~Matt

[bigcountry]

Thanks guys, good explanations.  I think I understand.