Tiller Help

[Bayou Ben]

This is the one I posted on DC's design thread.  Tillered it to 20" on the long string with almost no set.  Here it is at low brace of only a couple inches.  I'm just about to the point where I'm going to need to reduce weight and I keep going back and forth on where it needs to bend more.  The shape is something different for me with all that deflex mid limb.  Any tips besides good luck lol?

[simk]

Hi Ben

Depends on how your fd-profile should end finally. Latest r/d's from Upstatebowyer here on pa kept visible reflex until full draw, what learned me a lot. I'd maybe weaken the whole limbs but be a bit more careful midlimb, where the deflex comes to reflex. I'm actually doin a similar (but selfbow) project and am afraid of too much bend in this area. My last two r/d bows failed midlimb. Sure it's risk-free to first get the bend from the deflexed area. 

Good luck

 

[DC]

I'm thinking that the trouble with R/D tillering is that they all start out with a different side profile so they are all going to end up with a different FD profile. We know that in a straight wiggley character bow the end result is a reflection of all the lumps and bumps of the stave. R/D is the same, it just has two big dips(or three, in my case, counting the one looking at it). I do think that if the curves are fairly even like this one that at some point both limbs should be straight or close to it. Hopefully at the same point . Yours is coming up on that point now and looks good to me. I would just evenly reduce weight til you are there.

[Bayou Ben]

Thanks for the thoughts.  I was either leaning towards reducing weight evenly through the limb or leaving the r/d transition alone and focusing on the inners and finally outers if they were not bending enough when tillered out further.  So you have both touched on my initial thoughts.  That mid limb transition area makes me nervous.  If I could redo the glue up I would have spread that out more.   

[Stick Bender]

Ben I dont know if this pic will help but  I have more deflex/reflex in mine but thats what I was talking about angular braced profile , its a strange profile to get used to and in my FH bows they dont go to full arc tell late in the draw different material but same concept I would think yours looks good maybe remove even tell you can see how it looks stretched out a bit more just my two cents ,how does the early draw weight feel ?  Im probably 16-17 in. in the pic with 7 in. brace your kidnda in pioneer teritory yours is the only boo backed one I have seen so I dont have much to offer other then comparing !

[Bayou Ben]

I would say that looks pretty similar Ritchie.  Hopefully like you say I'll get a better view as I progress. 
 
It does have really high string tension right now, but that's pretty easy to do, it's keeping it that's the challenge!

[Stick Bender]

Ben so far it looks like your guess on the taper rate was spot on for wood & boo I will post these for comparison but this bow is 64 in. and reflex is 3 in front of the handle , what was your reflex on your bow ? like said I dont know if these will help but should give you a ruff guess on profile , but one lesson learned for me is this design puts a lot of presure on the inner limbs ,I think that was a good move on your part with the exstended riser I would think any material removed from the inners is probably going to have a greater effect compared to other designs all speculation on my part !

[Bayou Ben]

This one is 62"ntn, and it had 2" reflex from the back the handle.  That spot where the riser starts will see a lot of pressure.  The last bow I tried like this delaminated at that spot. 

Got a little more done last night. 
In this picture I'm at 20" and a little less than 3" brace.  The limbs are pretty straight at this point like DC was talking about.  I'm guessing I'll be able to see how the inner deflexed area is responding from here out.  I'll take it to full brace next tiller session. 
 

[simk]

Ben, that looks great. Still I can understand your concerns about the begin of the limbs after the fadeout - especially on the right side - be careful there and good luck. But I'm just a blody beginner...looking forward seeing a great bow. Cheers

[BowEd]

Ben...Some time ago I tillered a D/R maple backed red cedar with reflex too close to the fades.Very touchy to tiller out.I would'nt take too much out of the mid limbs to lose it's spunk there but some will need to be I'm sure.A combo of inner and mid limb removal with lots of checking of tiller on the tree which I'm sure you are aware of.

[DC]

I've noticed a few times that laminated bows will give suddenly. I had one go while I was watching it. Had it pulled to about 20" and was holding it steady and it just hinged a bit.  Just enough to ruin the tiller. I have no idea what gave but there was no hinge and then boink, there it was. PD suggested lots of exercising while tillering. Seems to help.

[Bayou Ben]

I took my time, but I finally got it tillered out today.  Didn't take much set, maybe an inch.  It shoots real nice so far.  Time for lipstick.

[Stick Bender]

Looks great how does it feel drawing ? I bet smooth , looks like it held its profile ,congrats on a great design !!

[Bayou Ben]

Thanks.  Yeah it's real smooth with the deflex, feels really balanced, and dead in the hand.  And I'm not going to get too excited until I finish sanding and shoot it more, but it seems like one of my fastest. 

[Badger]

   I bet that bow is fast, right on the edge. Glad you took your time on it. That is what it takes with those angles. Good Job. If you ever get a good test, chrono or distance I would like to hear the results. What did the final weight come out at. I usually end up around 40# on those even when I am aiming for 50#.