Tillering?

[Pretzelcoatl]

I would like to know what is the best way to tiller. Iv'e been watching a few self bow making videos by Billy Berger and he didn't un-string the bow during the tillering process. but he did flex it a bit. Iv'e been tillering my bows with a tillering tree and removing the string every time i have to scrape wood off. does it make a difference? Let me know how you do it and what way is the best. Thanks in advance!

[Dauntless]

I think everyone tillers differently. The goal is not to overstress the wood which leads to higher than usual set.

I'm a bit of a cowbow tillering guy. Work the wood till it looks good fully braced (drawknife, file and a little bit of cabinet scraping for no tool marks). Then it's drawing the bow in front of a mirror to see the limbs bending. Tillering is then done with a cabinet scraper. When she looks good at full draw I sand down to about 200 grit.  Then it's shooting in, touch ups if I can see them and finish.

[George Tsoukalas]

There are buildalongs on my site. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/

[DarkSoul]

If you leave the bow strung, you cannot remove wood from the last 10" of the limbs, because the tool will damage the string.

[Jude]

By the time I get to the short string, the outer thirds of the limbs are at their finished dimensions, since they don't bend anyway, so I just leave the string on.  I mark the flat spots, scrape them down a bit, draw the bow 20 times to work in the changes, then recheck, keeping the bow strung the whole time.  When the curve is corrected, the draw weight will have been reduced and it's time to move up to the next measurement at the target weight. You should be able to remove wood evenly at this point, as you bring the draw length up, but make sure you continually check for hinges and flats and exercise  the bow each time you remove wood.  I never pull past the target weight until I get to the last few inches.  Then I shoot for 5# over the target weight at the target draw length, to allow for finish sanding and shooting in.  I also like to tiller it out 2" past the target length for safety.  Pardon my long-windedness, but I hope this helps.

Julian

[PAHunter]

I don't know the best but here is what I do.  I use the stringer with leather ups on the end until it's tilleres to about 18 inches or so.  Then I string it up and use the tiller tree.  I typically unstring it to make adjustments but may not depending on where needs adjusted.  At first I rasp, then scrape, and last sand.  I try to never leave it braced beyond 18 inches to reduce set, never bend beyond a visible issue, and to never draw beyond my intended draw weight.  Hope that helps!

[k-hat]

I've done both and both work fine. . . provided you're careful and patient with wood removal, exercise the limbs, and all the other stuff good tillering involves   That would bite to accidentally sever that string while it was braced tho

Also, i've found it helpful  to shoot 10-20 arrows through at the tillered draw length (once you start going beyond brace) with each wood removal.  Helps the wood accept the changes you've made (imho, better than exercising), and the bow will be pretty much shot in by the time you get to full draw.  I've had fewer post-tiller surprises this way, but maybe it's just me

[Eric Krewson]

Say what! Can't remove wood from the last 10" of bow limb with the bow strung?

I guess this is true if you have about a 1" brace height,  at normal brace you can scrape right up to the tips if you want to, that is if you use a sensible sized scraper and not something like a machete. You do have to tilt your scraper almost parallel to the limb and let the scrapers "hook" do the work.

I tiller and scrape with the bow strung. I want to see immediately if my scraping cause the string to wander off the center of the handle

Sorry to be so abrupt Dark Soul but bad information is picked up by people who are just starting out and turned into fact in their minds whether the info is correct or not. 

[artcher1]

Yep, leave it strung and finish tillering out. Exercise by hand and not the tree. Gotta man up at some point , LOL!

[Jude]

I still leave it on my tillering stick to exercise it so I don't draw past the last length I checked at.

[Badger]

  Eric, I used your gadget on a bow a few days ago, a 70" maple straight self bow pyramid. It was slow going but the bow came out with a perfect tiller, I leave the last 8" stiff anyway so no issue for me. I was trying to think of a way I could appy that same tool to an elytical tillered bow with paralell limbs. I found if I use a soft tipped felt pen I can go by the width of the line, It should get thinner as I move away from the handle. This works pretty good as long as I tiller the inner limb forst and then work outward in about 8" increments. It really wasn't all that slow actually took me a couple of hours to get it tillered out.

[Jude]

Eric, I vaguely remember the tool Badger is talking about.  Do you have a link to that post so I can refresh my memory?

[Pat B]

Jude, look at the top of the "How To" page. Eric's Gizmo is stickied there.

[Jude]

Thanks Pat.  I never built the gizmo, but I think its what planted the idea in my head to use a short block of wood to help eyeball the curve.  My tillering got much better after I started doing that.  I'll definitely need to make one of those when I get home.

[DarkSoul]

Say what! Can't remove wood from the last 10" of bow limb with the bow strung?

I guess this is true if you have about a 1" brace height,  at normal brace you can scrape right up to the tips if you want to, that is if you use a sensible sized scraper and not something like a machete. You do have to tilt your scraper almost parallel to the limb and let the scrapers "hook" do the work.

I tiller and scrape with the bow strung. I want to see immediately if my scraping cause the string to wander off the center of the handle

Sorry to be so abrupt Dark Soul but bad information is picked up by people who are just starting out and turned into fact in their minds whether the info is correct or not. 

I've seen a few beginners destroy their strings by leaving the bow strung while handling a scraper. We are more experienced, we know what can go wrong. But it's SO darn easy to make a slip with your scraper, and then the other edge scratches the string. It may damage only a few threads of B50, if that happens three times...you suddenly lost half the tensile strenght of the string.
Of course it depends on the tool as well. With a file you can go closer to the tips. But a scraper or spokeshave I would not use closer than ten inches from the tips.

It's not about "bad information", but a discussion. You don't need to agree with me. Myself, I do sometimes tiller while leaving the bow strung. But I've noticed that leaves me handicapped when trying to create uniformity in the limbs. I'm having difficulty in blending the tiller, and my scrapes, all the way to the tips. I therefore only use this method for tillering midlimb and handle fades. I do most of my tillering when the bow is UNstrung. A lot easier, and I can reach every bit on the limbs flawlessly, without having to worry about damaging the string. It's not hard to string and unstring a bow mutiple times.