Gun shy

[bownarra]

Its looking good so far.
I'd leave it braced for an hour or so and mark where the set is compared to rested unbraced. That will tell you with unfailing certainty

[DC]

I got it out to 40#@28" and it's looking OK. I had a moment when I thought it had gone west but it seems to have worked out. When I was at about 20" or so I checked it against my tracing and it had taken a bit of set. A few scrapes ago it was fine. The strange thing was that it had taken about 1 1/2" of set in the same spot (mid limb) on both limbs. I avoided that spot and continued. When I finished it only has about an inch of set. I didn't know set could be reduced once it happened.  The recurves are a bit aggressive(90°) and don't lift off. They are also too long so I have to cut the dead wood off the ends. This will cost me all my reflex. I'll chrono it this morning after the tipectomy. 

[bradsmith2010]

before you cut it off,, do you think you could draw it further,,
so the tips can lift off,, it gonna shoot hard,, if it dont blow,,

[DC]

It's already got some set. Pulling it further will just make it worse I think. That plus my shooting machine will only go to 28". Since my goal is as close to 200fps as I can get with a 40#@28" I don't think there is any point.
Anyway here's a pic of the final tiller. I'm pretty pleased with it. I chronoed it and got a disappointing 180 fps. I think the lack of reflex and no heat treating this time killed the speed. I'm starting to run out of Yew so I'd better get my act together. I've got one piece of primo Yew that I'm saving for when I've figured my design a bit better.
I'll try again

[bradsmith2010]

do you think the bow might be a bit long,, even with taking some set,,I am just thinking out loud,, and may be off about this, ,but if you drew it to 29,, it would tell you about the design,, if the bow is slightly overbuilt,, it would not take much more set and probably shoot harder than 180,,, if you are right on about the design, then pulling it to 29 would  be a wash,,  and no point as you suggested,,

[Woodely]

I pull 28"  when all is said and done I like to pull past that like 29" or so.  If she blows she blows up,  but a good solid bow should be able to be pulled an inch past the desired draw length.   Don't coddle it work it..!!  ...........pull it like your life depends on it.

[DC]

Like I said, the machine only goes to 28. I can't draw 28 and even if I could I couldn't get consistent results with the chrono. I decided I would try something and I heated the bow to pull some more reflex into it. It went really nicely, just heated the belly until it started to move and cranked it down to the caul. No sign of the epoxy separating. I got both limbs done and then had company drop in so I have to wait until tomorrow to see if it will pull out or not. I'm half expecting it to pull out  

[DC]

I couldn't wait and it all pulled out. I may try heating the back and see if I can get the epoxy to let go. Then re glue it with more reflex.

[Badger]

   The bow looks really good, if it is starting to take some set the added reflex will only make that worse. I would go a tad wider on the next one and look closely to see if you can get any inner limb wood bending more. You get a lot of inches of draw from the inner wood and it really helps to fight set if you can get the max out of it. But it can also backfire if you go to far because inner limb set is very bad.

[DC]

I tried scraping the inners and it just seemed to want to take set. I finally made the fades a little shorter and got a bit more working limb. It was an eighth of an inch wider but I trimmed that off because I thought the limbs were getting a bit thin. The original plan was wider and thinner but that went away somewhere in the build. I'm kind of limited in the width by the diameter of the bamboo. I can use the fat end of the log but the nodes are only 6" apart. I just measured and this one is 1 1/4" wide. The limiting factor on the next one is the width of the yew(if I use this piece) but I might get 1 1/2" wide.
I'm also thinking about making it longer. It's 66" or less on the last couple of bows before bending the recurves. Is there much to be gained by adding an inch? Two inches? When does mass raise its ugly head?

[Badger]

  66" to 68" seem to be the best number

[bjrogg]

Maybe not as much recurves angle. Let them come off so it thinks it's a longer bow. Might help with the set?
Bjrogg

[DC]

I just stripped off the bamboo on one limb. Used the heat gun and carefully pushed a long wedge under it while heating. Once I got it started it just peeled off. took 15 min to half hour. I lose track of time . I can heat treat the belly this time. It's only about 1/4" thick so I should be able to get a good heat treat. I'm going to reduce the recurve angle then. I think it will just take a light sanding to prep it for re gluing. I'm going to go for just a touch more reflex than my best bow.

[SLIMBOB]

Watching with interest.  I'm not qualifies to give any kind of advice on these lam bows, but I think it looks pretty darn good from my perch.

[bradsmith2010]

Sounds like a great plan