Can you guys check my tiller so far?

[Kaspar825]

Hey everyone this is my first bow and first post on tradgang! Im making a 65" mollegabet bow and my goal is 35-40 pounds at 29 inches. I'm long string tillering with 550 cord and I'm at about 8 inches now but the string stretches a lot. I'm not tillering anymore until my b-50 comes in and I can make a string. So first can you check my tiller? Here's a picture
   

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Next is how thin should I go on the levers without them bending? Im at 3/4 of an inch and thinking about going down 1/8 of an inch. Thanks guys!

[WestTexan]

I'd hate to tell you to go anymore...with para cord and the stretch it's going to give you a false tiller. I'd wait till you get a good string and check it before do anything else to it.

[Kaspar825]

That's the plan right now. I should have my string in by next weekend and then I'll be able to post another picture. Thanks for the reply!

Kaspar

[Black Mockingbird]

Wait to reduce your levers until your ready to shoot it in...when ready to start shooting reduce them down to 1/8" thicker than the thinnest point of your working limbs,which will be right before the levers in a properly tillered bow..that will get you in the ballpark to do trial n error from there in reduction..right limb inner limb looks thinner and bending more than it should...left limb the same but not quite as bad...that's a tough design to do for your first attempt...what wood is it? Stave? Board? Dimensions?

[Kaspar825]

It seemed like the recommended bow type when I first started it but now everyone's saying it's harder. I have to read a little more before I start projects. Too late now

14 inch working limb
12 inch lever
2 inch fade
3/4 lever depth
5/16 working limb depth
2 inch wide working limb
3/4 - 1/2 beginning of lever to nock
Here's some dimensions and it's maple board bow. If you need any more tell me. Thanks a lot guys!

Kaspar

[Ice Mike]

It looks as though you may be a little thin already in the working section. What poundage is it pulling right there? Also, are you pulling 20-30 pulls to work the wood after each scraping?

Remember that wood doesn't want to bend, so when you're tillering you aren't just taking off wood to get it to bend without breaking. Every time you scrape you expose a brand new surface and you have to "teach" that new wood how to bend. If you don't teach it properly, or in other words if you don't work the wood between scraping, you will wind up going way too thin.

Also, the 550 will stretch, but only so much. If you're working the wood correctly then you will negate the stretching of the paracord after the first 4 to 5 scrapings.

[Kaspar825]

It's just a little under 35 pounds. And yes I am pulling it back about 35 pounds 15-20 times before another scraping. I'll be sure to do it more next time. Thanks for the advice! How could it be too thin now if the weight is only pulling it back 8 inches?

Kaspar

[Ice Mike]

Oh no man I'm sorry... I didn't mean that it IS  too thin, I was just making the observation that it LOOKED that way from the pic, which is why I asked about the poundage and the wood working between scraping.

I didn't work the wood properly on my first one so I just kept scraping until it got where I thought it was right (around 30 lbs). After the wood actually worked a little bit I was down to around 10 lbs, and shortly thereafter broke! I just wanted to make sure that you weren't going to make the same mistake I did.

[Kaspar825]

Hahaha thanks for the heads up I'll be sure to watch out for it.

I can't wait to be able to start working on it again when I get my string. Until then how do you guys decide whether or not to back a bow? I have 3 run offs on my bow and bought some rawhide in the form of dog bones and I realized they are a couple of inches short. I could overlap them and then file it flat I think but does anyone have experience doing this? Should I just not back it?

Thanks for your help!

[Ice Mike]

If you've got runoff you will probably want to back it.

Also, backing will drastically change the weight and tiller, so if you're going to back it you need to do it before you continue tillering.  I haven't used rawhide before, but I know that others have used it with great success. It's a little heavy and will cost you a bit in cast though.

[Kaspar825]

Ok. I wasn't planning on it but this extra time made me think about it a little more. I'll probably back it then.

Thank you!

[Black Mockingbird]

Originally posted by Ice Mike:
If you've got runoff you will probably want to back it.

Also, backing will drastically change the weight and tiller, so if you're going to back it you need to do it before you continue tillering.  I haven't used rawhide before, but I know that others have used it with great success. It's a little heavy and will cost you a bit in cast though.

Backing with rawhide will NOT change your weight or tiller

[fujimo]

and if you have a non working handle- you can overlap, or butt join the rawhide in the handle- and hide it under the handle.
sinew or glass backings will change draw weight etc.
 but silk, raw hide, drywall tape, etc will add a little to the overall weight , but not effect too much thereafter.
I might not think that you would want to back the non working levers- just the working section.
deer rawhide is the best- nice and thin and light- cow raw hide can be a little thick and heavy- but you can rasp/ sand the flesh side to make it thinner.
 good luck
 cheers
wayne

[Ice Mike]

Originally posted by Black Mockingbird:
 

Originally posted by Ice Mike:
If you've got runoff you will probably want to back it.

Also, backing will drastically change the weight and tiller, so if you're going to back it you need to do it before you continue tillering.  I haven't used rawhide before, but I know that others have used it with great success. It's a little heavy and will cost you a bit in cast though.

Backing with rawhide will NOT change your weight or tiller [/b]

Wow I did not know that. I would have thought that since rawhide is thicker than sinew, and I know from experience that sinew will greatly effect the weight and tiller, that rawhide would have done so as well. Thank you for correcting this.

[Ice Mike]

Originally posted by Black Mockingbird:
 

Originally posted by Ice Mike:
If you've got runoff you will probably want to back it.

Also, backing will drastically change the weight and tiller, so if you're going to back it you need to do it before you continue tillering.  I haven't used rawhide before, but I know that others have used it with great success. It's a little heavy and will cost you a bit in cast though.

Backing with rawhide will NOT change your weight or tiller [/b]

Wow I did not know that. I would have thought that since rawhide is thicker than sinew, and I know from experience that sinew will greatly effect the weight and tiller, that rawhide would have done so as well. Thank you for correcting this.

[mwosborn]

Originally posted by Ice Mike:
 

Originally posted by Black Mockingbird:
 

Originally posted by Ice Mike:
If you've got runoff you will probably want to back it.

Also, backing will drastically change the weight and tiller, so if you're going to back it you need to do it before you continue tillering.  I haven't used rawhide before, but I know that others have used it with great success. It's a little heavy and will cost you a bit in cast though.

Backing with rawhide will NOT change your weight or tiller [/b]

Wow I did not know that. I would have thought that since rawhide is thicker than sinew, and I know from experience that sinew will greatly effect the weight and tiller, that rawhide would have done so as well. Thank you for correcting this. [/b]

Sinew is put down as small "threads"/"strands" or bundles of "threads"/"strands".  You can put down as much as you want and make it "thinner" or "thicker".  Rawhides thickness depends upon the type it is...deer rawhide from a young deer is about like construction paper.  Rawhide from an older deer taken from the back is a bit thicker.  Cow rawhide is considerably thicker.

Deer rawhide added to the working part of the limb adds very little mass to the limb and affects "cast" minimally. (IMO)