First bow build progress

[MikeWinVA]

This is my first bow build.

It is an attempt at a longbow/flatbow.  The first one failed during tillering.  I pushed to far too fast.

I am using red oak with straight grain and have backed the bow with 10 oz canvas and Titebond III.  The bow handle is quilted maple and glued to the bow with Titebond.  The handle is not shaped yet.  I have nearly completed the tiller.  So if one of you that have done this before could look below and let me know if you see any glaring problems I would be appreciative.  

I cut the profile out with a band saw about 1/8 from the intended lines and took it to the lines with a block plane and card scrapers.  I put some scrap Ipe on the tips as overlays.  

I then used a pencil poking about 1/16th" through a 1x3 block to mark the flat areas. I used a combination of files and card scrapers to take out the flat areas. I exercised the bow about 40 times between scrapings. The tiller is less than 1/8" difference at 12" and 17" from the nocks.

I haven't fully braced it yet, as I am waiting for some B-50 to arrive to make a bow string.  The string in the pictures is a nylon one that I made Flemish twist from 50 lb surveyor's line.  It has an awful amount of stretch.  I estimate that the weight will be about 45lbs at 28".  It is 38 lbs now and the brace height is about 3".

     

     

[takefive]

Your tiller looks good to me.  A 6" wood block is a good length to use to check for strong and weak spots.  Once you get it braced with the B50 string, you'll get a better idea of where you still need to scrape.  Keep that nice even arc and you'll be fine.

[Roy from Pa]

Welcome, Mike.. Tiller doesn't look too bad. Here is a link for a neat tool you can make yourself and it helps with tillering.
 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=2;t=000075

[Pat B]

Both limbs look a bit stiff right out of the fades. Other than that is looks fine. How long is the string you are using now? If it is too long it will give you a false reading. I'd wait until you get the right string to continue.

[Bowjunkie]

I agree with everything Pat said. Get a shorter string on it now. I think you'll find the inner limbs even stiffer than they appear now.

Actually the left inner limb looks stiff, the right doesn't look too bad.... right now.

[fujimo]

i always add this when i see a tillering stick being used- so i will stay true to form   :D .
at the lower draw lengths its not as critical, but i try and refrain from using a tillering stick- wooden bows just dont like to be drawn to a long draw, and being under tension/compression forces for extended periods of time- (more than a few seconds really- kinda like the duration a bow would be at full draw whilst shooting- maybe a bit longer!))- they will take excessive set, and possibly even break!
it is best to use a tillering tree- check out Roys and Bowjunkies- and build something like that!
putting them under load, and then studying them from all angles, and taking photos etc, is just to much load for too long- IMHO   :D
glass bows on the other hand, are a whole different kettle of fish!

[MikeWinVA]

The string I am using now is actually 3 inches shorter than the bow, nock to nock. It is real stretchy nylon.

The problem is that I can't find any bow strings locally that are more than 66" long. The bow is 72" long.  So I just ordered some B50 and a serving jig from a local shop.

I have been making strings out of nylon surveyors cord Flemish twist.  4 cords at about 200lbs test rated total.  It is amazing how much stretch nylon has.  It was the only cord I could find locally that I could get to work.  I tried jute, sisal, cotton butchers string and polyester upholsters thread.  They were either too weak or too slick to work.  

All the sporting goods stores nearby only seem to carry dyneema or spectra braided line.  Nobody had Dacron braided line for saltwater fishing. The only advantage or upside to all this experimentation is now I can make a Flemish twist string in about 15 minutes.

The B50 will be in next week.  I will put the bow aside until I get the correct string on it.

I searched the site for about 30 minutes and could not find pictures of Bowjunkie's tillering tree. Is there a link available for it?

I made the tool Roy linked to above, but I made it about 3.5" inches long instead of 6".  My thoughts were it would give me a more accurate tiller because it was a 3.5 inch curve sample.  I will make a 6" one and give it a comparison try (steal one of my daughters colored pencils).

Thanks all for the help.  Bow building has turned into a good stress reliever.

[Eric Krewson]

Use the 6" gizmo, I thought the same about a shorter one years ago but found out it didn't work at all. With the adjustable pencil you can get own to some very fine adjustments with the 6" tool.

[Pat B]

If you make bows you should be able to make strings. It is a simple process and most folks wonder why they didn't learn sooner after they have done one. I use a bowyers knot on the bottom limb so string length is rarely a problem.

[fujimo]

check Roy's posts he has the same configuration of tillering tree as bowjunkies- in fact i think Roybert taught ol' bow junkie everything he knows            ahem!!!

[Roy from Pa]

Ya I did...  

[John Scifres]

Left limb, scrape 20 times inner third.  Right limb, scrape 10 times middle third.

[MikeWinVA]

My B-50 showed up yesterday.  Having a non-stretchy string made a world of difference.

I changed to a 6' gizmo stick think I have the tiller nailed now.  The tips are within 1/8" at 25" draw and the space under the gizmo stick is almost the same from 4" inside the nocks to the fades.  Its close enough where the stick leaves a faint pencil mark all the way down both limbs.  

I just need to take the limb weight down a little more and I should be about 7 or 8 lbs over my desired draw weight.

Is it a good idea to bone or burnish the belly and sides once the final sanding is done?  I already backed the bow with heavy canvas and TB 3.