Tiller check please

PLEASE HELP TO FUND ARCHERY INTERCHANGE

Steve Rough

New member
Bow currently at 60#.
Looks to me like the bottom limb is weaker. (Top of bow is on left of pic)
Can you give your advise on where it needs scraping to tiller it please.
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Del the Cat

Well-known member
It's looking better but it needs the unstrung pic to show where the actual movement is.
Drawing a circle on a limb shows the set, or weak point at the fade into the grip and the lack of movement in the mid/outer portion of the working limb.
Have a play in MS paint drawing circles/ellipses it will help you see the stiff and weak areas
Del Tiller.jpg
 

Del the Cat

Well-known member
Here's another interpretation in red where I've tried to make the curve enter the lever at the correct angle. It again shows too much bend near the grip, but the rest looks better.
A higher resolution picture would allow better fit of curves and better analysis.
Hopefully this gives some ideas.
You can also ask yourself... If pulled to destruction where do you think it would fail... my bet is on the fade.
It's sort of self regulating, a little off the mid to outer, will make that bend more and make the fade area slightly stiffer in comparison, taking some load of it... so small changes can make big improvements.
Slow and steady wins the day...
A little and often...
(Other platitudes are also available ;) )
Join the Primitive Archer forum and post a better resolution pic asking for a tiller check.
You'll get good honest advice from people who have made Mollegabet bows.
I reckon you are 99% there, it's just subtlety and getting your eye in now. It's easy to become "tiller blind", which is why the tiller check posts are V common.
Del
 

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Steve Rough

New member
Thanks mate. Really helpful. Although my compter is playing up at the moment. I've added some more pics of it after I tillered it some more. Hope this helps. It's currently 42#. I'm going to heat treat it too. Can I use use a blow torch as I don't have a heat gun. I know there is more chance of me burning it but if I'm carefully do you think it will work as well?

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Steve Rough

New member
Wow. I thought it looked really well tillered until I just looked at the photos. Now I looks like the bottom limb is bending more than the top.
 

Del the Cat

Well-known member
Ah, that's the perils of learning, and "getting your eye in" the better we get the more critical we become. Most people would be very well pleased with that :)
To make any shootable bow is an achievement.
If you look at my blog, I've just re-worked a bow I did in 2010... the tiller was very even but horrible! We don't notice how we are improving until we look back, that's one reason I do the blog.
Bowyer's Diary: Thunderbolts and Lightning
Don't try and heat treat with a blow torch, I think it's a recipe for disaster. Easy enough to scorch it with a hot air gun I'm sure it will just catch fire with a blow torch.
I'd save heat treating for another bow, you have to know when to quit... funnilly enough I say that on the blog!
Lookin' good
Del
PS. Cheapo hot air gun from Wickes is fine. There is tons of stuff on my blog about heat treating.
 

Steve Rough

New member
Hi.
I shot about 50 arrows last night as I wanted to see how it felt. As I was putting it away I noticed some think cracks on the limbs near the handles on both limbs there very small and am hoping only on the surface. This helps as it points out my errors for the next build. Is the bow salvageable? I know I'll loose alot of power as it's at 42# now. uploadfromtaptalk1431002542444.jpg uploadfromtaptalk1431002565241.jpg
 

Del the Cat

Well-known member
They are the dreaded chrysals.:(
I hate them with a passion usually reserved for Bill Gates and Telecoms companies.
They go surprisingly deep, often 4mm or more. Heat treating will help stiffen that area but the only real cure is rasp 'em out, glue on a long gently curved patch and get the tiller spot on. Basically that area was overstrained early on in the tillering and it's resulted in compression fractures where the wood buckles up. You can probably feel 'em with your fingernail.
They are not fatal, but will make the bow feel "puddingy"
As I often say... making a bow is easy... making a good bow is hard.
Just ignore it and enjoy the bow, or use it to experiment on... or do a bit of each.
Del
 

Steve Rough

New member
Cheers Del. That makes sense as I rushed the first part of the tillering. And I think I have pulled it to 28" too early on in the tillering stage. I love making bows. You learn so much just by diving in and having a go. Third time lucky I say. I'll tiller it a bit more and leave them in. And ill practice finishing the bow with leather dye and use it to practice heat treating. I'll have a go at recurving the tips too.
 
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