Help fixing tiller on my first FHLB.

[Bryan Adolphe]

Well, I’m definitely confusing myself here. I need a bit of help. Thank you Kenny for all your help on the weekend but I don’t like bothering you with questions all the time I’m sure you get a lot already with amateurs like myself  
I glued on a piece for my riser I think too early anyways, I profiled the limbs. I’ve double checked, and they’re both very close to being similar all the way to the tips I measured tiller at the end of the fades ? and my top limb measures 6 5/16 my bottom limb measures 6 9/16 so if I read that right, I’m a quarter inch negative on the top ? The bow is braced at 8 inches. As you can see in the pictures, my lower limb tip which is on the left now that I glued that riser piece in. It’s about 3/4 of an inch short to be in balanced with the top limb tip. I have block sanded the lower limb on the back a fair bit, but it has not moved yet. I would like to hear your thoughts honest, you won’t hurt my feelings.  Bryan

[Kirkll]

Just keep sanding the glass belly and back.... you'll get there.... But.... pay attention to where the limbs are bending. With your photo upside down, and the hook on your string off center, it makes it tough to see the bend of the limbs.You want those limb tips hitting the same place on your back ground lines to study the limb bend locations.

best way to balance the limbs is putting an 18" stick on the bow that holds it at about half draw, then put it on your bench on some butcher paper and trace out the back of the limbs, then flip the bow over.... That will tell you the story on limb balance right now....

Also..... Tiller measurements, and Tillering a bow is 2 different things.... On glass bows with precise lamination grinding, its typically close to even tiller.... But after balancing the limbs it can easily be a positive or negative tiller measurement...... Ya gotta thump the string and check for vibration... Pull it back an inch or so and drop the string.... Listen to it... feel it.... Shoot it.... You get the feel of a good tiller more than measurements...     .02 cents...    Kirk

[Bryan Adolphe]

Thanks Kirk really appreciate that great info i will carry on 
Also thanks Roy for the picture fix 👍

[Roy from Pa]

Welcome dude..

 

[kennym]

Kirk has good info there.

Did your riser move a little maybe during glue up?

Those bows are a little sensitive to tiller.

[Bryan Adolphe]

Hey Kenny, good question I wish I had a good answer. I think I very much over thought the whole thing at the time of glue up I cranked up the Tom Petty tunes. And that’s what I came up with lol.,at the time I didn’t think it mattered if it was centred but after I think about it. why wouldn’t I centre it? Oh well shes not in the wood burner yet I’ll get her to tonight and shape some kind of a grip out of that tomorrow it’s my back feels like doing it. Thanks guys!

[Kirkll]

Kirk has good info there.

Did your riser move a little maybe during glue up?

Those bows are a little sensitive to tiller.

Hey Kenny.... What is the length of this design, forward taper rate on lams, and how is the vertical stability?

  I played with a design similar to this years ago in a 52-54" length, and it got great performance, but mine had very poor vertical stability. I messed with taper rates and width profile, but still couldn't get what i was looking for. i finally ended up changing the limb shape in the form and added a flat section in the working section.

This is what mine came out like in the end..... This one was a prototype i hunted with for two years before i had it start to come loose at the fades. She's a wall hanger now..... After this one i used longer fades and a power lam to solve that problem. I haven't built one in years. I called it the "Yeti".

Sorry for the hi jack on your thread here....

[Crooked Stic]

Built several of that FHLB of Kennys design thinking it had the .001 superman ( built in powerlam) and was very stable.

[kennym]

Kirk- 16" riser, with a powerlam and tip wedge like Mike says.

[Kirkll]

Cool.... What are the lengths those are built? Is that a shorty?

[kennym]

58/60 but I did build one without the superlam and cut it to 56" and it worked fairly well...

.001 taper only in that one- you know , testing...

[Bryan Adolphe]

Well, of course, this is all new to me, but I’ve been carefully sanding and sanding and sanding using a block with 120 and 150 and that damn limb won’t move yet lol  I’m gonna go back out to the shop now and keep trying. I’m guessing pretty soon it’ll just takeoff on me . This is how we learn.

[Kirkll]

I use a palm sander with 80 grit on mine....      Get er done!   

[Bryan Adolphe]

Hahahaha so what you’re saying is I’m just tickling it!  I used the orbital, but with 150 I Musta rub that thing 100 times back and belly  and it barely moved. 

[Bryan Adolphe]

And that was after block sanding it for sometime, and she wouldn’t move for me lol

[Crooked Stic]

I have used 80 before only on a block being sure not to get it uneven. You might try rounding the corners aggressive on that limb and if it works call it a character flaw.

[kennym]

Be careful with a power sander if it has a rubber pad under the paper.  I'm thinkin it will thin the glass more on edges than limb center.?

[Bryan Adolphe]

Yes, eventually I did try and use the power sander but realized it’s very difficult to keep it flat when the limbs taper to a half inch wide so I did do most of my sanding with a block. I went ahead and finished my limb tips and I’m working on shaping the riser. I will come back to try and do something with the limbs. 👍

[Bryan Adolphe]

This is starting to look not right to me.

So i havnt touched my upper limb but it seems the more i screw with a lower limb its crazy but It looks like it’s changing the shape of the upper limb. i may surrender while it’s still shoots  not bad for my first bow had a ton of fun, learned what I shouldn’t do , and it shoots not bad, considering I’m sure it could be improved by someone that knows what they’re doing . heres a couple pics of the riser before finish sanding.

[Kirkll]

That particular limb shape with all that R&D going on, those limbs are ultra sensitive to balance. I had a buddy send me one years ago to try and get balanced and this is what his did...

The unstrung brace looked very similar to your bow, and it had a fast taper rate.... I did get it balanced out.



There has been a debate about this particular limb design for as long as I  have been building bows. Some guys like em... some guys don't...........Trust me....I'm not bad mouthing the design here.... I just do not care for the floppy limbs. These things can really fling an arrow once you get em dialed in....

Zipper Bows had a design just like this and he sold em like hot cakes!

You are doing great being patient, and did a great job on shaping the riser...    Kirk