I need a lil advice please (Pic added)

[PZee]

Firstly, I would like to thank everyone that contributes to this site. I have learned a wealth of information already.

I started a Bamboo Backed Bulletwood with 1" deflex and 4" reflex. It held 3 1/2" reflex off the form. Its 61" ntn (meant to be 62, but I got a bit carried away sanding the bamboo backing for the tip overlays). Its 1 1/4" at the fades, straight taper to 1/2" at the tips. I thinned the Bamboo to 1/8" tapering to 1/16" at the tips. The Bulletwood is 1/2 thick tapering to a 1/4". I took these dimensions from what I could gather on here and Sam Harper's website. The problem I have is, when I got to the tiller tree tonight, the long string on, it hardly moved at all, maybe a total of 1". I have read that if you need to scrape the belly to reduce weight, it adds to the reflex, is this true? Also, what do I do next? Do I scrape the belly to get to my desired weight (50#@28"), I haven't yet trapped the belly, will trapping help? Basically I don't know what to do next...

Thanks

Pete

[Osagetree]

In my opinion it will not add reflex!

If you trap the limbs you should see more limb movement. Try to get it floor tillered a bit before going to the tree.

Remember not to draw it any more than your desired draw weight to avoid loosing the relex you have!

[Jim Dahlberg]

I recently built a bamboo backed ironwood bow that did take on a bit more reflex as I scraped the belly.  Nothing severe and was glad to have it.
To answer your question, you must scrape the belly and start taking off wood to make the bow bend.  With bamboo backed bows you want to take your time removing wood.  They "come around" fast.  Scrape shavings off the belly full length of the limbs.  Scrape the same number of times from both limbs to start with.  As OT said, try to push the limbs while holding a tip on the floor (carpeted or padded!) into the position of being strung.  Once it feels like the bow could be strung, even at very low brace height, get it strung up.  I have found that bamboo backed bows are extremely responsive to minute tillering scrapes after getting them to brace height strung.  As Osagetree also said, never draw the bow past your desired weight at ANY length in the building process.  If it's 50# at 2" that's all the farther you draw it until you remove more shavings from the belly and recheck tiller.  Exercise the bow to the 50# every time you remove wood.  Tiller and weight can change just from exercising.  I pull to weight 100 times every time I remove wood to assure that something hasn't changed in tiller that needs to be fixed before moving on to trying to attain desired weight.
Hope this helps.  Good luck.  Sounds like you've got a fine bow in progress!

[PZee]

Hi OT and Jim,

Thank you very much for your replies. They are greatly appreciated. I will take this all on board and get started, hopefully after some hard work, I'll be able to post my bow on the sight for you to take a look at.

Pete

[Stiks-n-Strings]

Looking forward to some pics. Some good advice right here.

[Apex Predator]

That's an awful lot of reflex!

[Loren Holland]

PZ,
What these guys said is so absolutely right.

You will gain a little deflex not reflex, as you tiller (IMO this reflex is actually set that you would see regardless). If you tiller slow, exercise, and don't overstrain, then it won't be too much, although like Apex said it wouldn't hurt to deflex that a bit "That's an awful lot of reflex!"

Jim hit it on the head, Go Slow...I screwed one up last night because of that.  I ruined a Boo/Ipe, by taking a bit too much off a fade.  It hinged on the upper limb fade and the stress made the boo delaminate.  All this was due (to my ADD, aka, lack of patience) to how fast a boo/ipe or in your case boo/bulletwood will come around.

This Hobby/job/endeavor will keep you humble, I was on my first real streak of successful bows, where I could reliably predict what the results would be for weight, etc.  Then last night grounded my aspirations...Go Slow.

[PZee]

Thanks very much Loren.

Apex, why do you think this is 'an awful lot of reflex'? I've measured the reflex, by placing the bow on the floor, belly down, and the measuring to the tips. The deflex is measured the same way from the highest point of the handle to the floor, is this correct?

Thanks

Pete

[PZee]

I must say, this is very addictive. I had to force myself to not pick up the bow and work on it last night, and spend some time with my family. My boy is 2yrs and even though he loves using some of the tools I allow him to on scrap pieces of wood (and occasionally my bow), still all he wants to do is play! I might look at it tonight again... I'll also try and post some pics when I get home.

[PZee]

This is the bow, just off the form and tidied up a bit. The powerlam and handle is made of oak and walnut and the tips are walnut and massaranduba.

Thanks

Pete

   

(Terry, sorry if the pic is too large, I did try to resize it. Just let me know and I'll amend it.)

[Apex Predator]

Looking good,and doesn't look but a little radical.     More reflex causes tillering difficulties, but I think that one is workable.

[PZee]

Thanks AP. Hopefully I'll get this one tillered this w'end. I trapped the belly tonight, just need to sand it all smooth tomorrow.

[PZee]

Okay,

I have 5" of movement to 53# on the long string. At what point do I switch to the short string?

Thanks

Pete

[Jim Dahlberg]

Pete:
How long is the long string?  Are we talking 5" of movement at the bottom of the long string?  Again, if you can get it strung even with a couple of inches between the handle and the string WITHOUT going over your desired weight, get it strung.  If the 53# is just in the 5" of movement at the bottom of the long string you need to continue removing shavings from the entire length of each limb belly evenly.  I know this sounds redundant but it's the way to make the bow.  Have you searched the threads on how to make a long string with only one loop so you can tie a bowyer's knot on the bottom limb?  That is how to get a low brace height and start to see how the limbs are tillered.
Your initial picture looks great of the bow after glue up.  Take your time so it stays looking like it is when unstrung.
Jim

[Jim Dahlberg]

Also, don't form the handle until you get the bow strung to a low brace height.  The handle is the last part of the project.

[Diamondback59]

pzee id do as eric says  i sent yoy a pm brock

[PZee]

Hi Brock, PM returned.

Thanks everyone for your replies!

Unfortunately I got a bit over zealous and the bow formed a bad hinge in the right limb. So it's back to the drawing board for now. I will keep this one though and see if I can make a lighter bow at a leter stage.

Pete