Help fixing tiller on my first FHLB.

[Kirkll]

One other thing regarding sanding.... I was not kidding about using a random orbital sander to sand my glass with 80 grit then 120 grit.....

BUT..... When you use a power sander on glass with aggressive grit paper, you can screw up a limb REAL quickly trying to shorten your sanding time, and i screwed a few up learning the tricks too.   I use a very stiff backing pad with hook and loop paper, on a very well balanced palm sander.... that ..... and i have about 30 years of experience running these things, and there is a feel to it you learn.

Here is a video explaining this better......     

[Bryan Adolphe]

That’s great info there Kirk thank you very much, This all could stem from inaccuracies when I sanded my lams I will be paying more attention to alternating passes and  flipping end to end ,  doing one at a time and trying to get more consistent  accurate laminations.

[Kirkll]

There are so many ways to bugger up these bows its not funny.... even after you have a 100 of them under your belt, and have done everything the same as the last one....something unexplainable happens leaving you scratching your head....

Good example.... i just laid up a bow that i have literally built hundreds of this same design , and the tiller was off by an inch....    Precession lam grinding was done with veneers belly and back, that i ground myself. I used book matched core lams, &  I double checked the stack thickness too.... I also double checked the limb lengths from riser to tip notch's, and had my limb profile the same.... I use a pattern for that, and spray paint the outline on the limbs.....

There is absolutely no reason at all these limbs should be so different...... But they are....

Saving grace is that i ALWAYS bring these things in 5-7 #'s over my target draw weight so i have room for adjustment. This one came in about 8-9 pounds over on the rough profile. I always leave the limbs an 1/8" wide all the way through the limb on rough profile.  This gives me a bit of room for adjusting alignment , tiller , and draw weight.  On long bow limbs you can often adjust these things a lot more than you think by just reducing width and trapping the belly side...... I've got this one within 3# of my target draw weight now
and haven't even sanded glass yet....... I gotta admit... The stiff limb was a bit wider through the fades than the lighter limb, so that helped with my excessive tiller difference quandary. It's manageable now with sanding and trapping.

Bottom line is some of these go smooth as silk, and others fight you every inch of the way, and leave you scratching your head on why..... But that's what makes you a good bowyer. Learning the tricks to balancing things out, and knowing how far you can take it.  Sometimes you get da lion.... Sometimes da lion get you...     Keep after it bro............ Kirk

[Bryan Adolphe]

That’s real good advice Kirk i will remind myself of that on the next one here because I profiled this one down too close to finish and then found out I needed to do a bunch of limb work, and of course my weight went way down next time I build my profiles they will be oversized. 👍

[Kirkll]

A lot of guys use masking tape over the glass to lay out limb profile, and it's not a bad way to go to get started either , because you can mark a centerline the full length of the limb for a reference point ....

Personally... i just use enough masking tape on the limb butts to lay out my drilling AFTER the limbs come out of the form. I never lay up limbs with tape on them.... It's too hard to get off after cooking that tape to the glass. Sometimes i use a bit of tape on the limb tips for a center line reference and tip notch location, and razor knife it after i clamp the pattern on.

Using a formica pattern works well. I Just clamp it on the limb and use some primer or spray paint..... Bingo!  the finished limb shape is right there.... Easy to sand on the edge sander without having tape curling up too.....   

 https://photos.app.goo.gl/QZ1pQGPLxtgRYJUp6


Here is another little trick that works well on getting your centerline established on recurve limbs if you do not have a machinist table that would work well on that limb design you are building now.  This is another reason you want a wider width on rough profile, so you can adjust the tracking of the limbs.

https://photos.app.goo.gl/S5pZf5LkezQwmpqT6

[Buemaker]

Good info Kirk, but I wonder how much glass dust have you eaten the last 20 years.

[Kirkll]

Probably enough to kill a horse....

[Buggs]

You know they make sanders with built in dust collection  

How much glass are you removing? I don't think I am brave enough to power sand finish side glass

[Kirkll]

You would be surprised how much glass you can remove on a bow less than 50#.
I’ve taken it down to .030 many times on mid 40# bows and they have been shooting for many, many years heavily.

Now you start getting up around 55-60# you want to keep your glass above .035.

60-70# range, or higher it’s best to start out with .050 glass. I’ve built them up to 70# with .040 , but I had minimal glass sanding. I Mostly used trapping and profile adjustment for balancing limbs that heavy with.040.

Now when I get orders for 60-80# bows I just order .050 glass so I have some room to adjust and sand my limbs.    Kirk

[kennym]

My hunting bow for this year has .030 on back and .050 on belly. Working so far...

[Crooked Stic]

That's what ya want Kenny. Most of us heavy bellies holding up pretty good 

[Bryan Adolphe]

Lol I’m going to ask one question at a time so I don’t make it confusing ! I think I figured out what my problem was on this bow (I didn’t really know what I was doing!) anyways, I do need to figure this out, so I don’t make the same mistakes.
#1 My question is when you first get the limbs profiled and a string on it and you put it up on the Tiller tree the riser itself should be level?
#2 when it’s on the tree and it’s at brace The limb tips should be relatively level also ?
#3 when you go to exercise the limbs, do you draw the bow on the tree from the centre of the bow or from where you would normally draw from with your fingers slightly off-center ?

[Buggs]

#1 yes
#2 yes
#3 lots of different methods. I do this;

[Bryan Adolphe]

 Thanks buggs 

[Kelly]

First off I must say that have never built a bow. Have wanted to for decades but have not yet done it. That said, I’ve read lots of threads here about the process plus talked to bowyers.

Couple of questions from my observations here. 1. Shouldn’t the center of the handle be on the tillering tree?  Looks to me like your handle is more on the top limb than the bottom.

2. If the the bottom limb is positive tiller measurement over the upper which you stated in the very first post, shouldn’t one be trying to weaken the upper limb?

This is not a critic just trying to learn for the day when I try building my own.

By the way, I like this design but have not shot one shorter than 60”, I sure would like to tho.

[Kirkll]

I typically balance the limbs out before i shape the riser and use a center point hook up for a single hook, or slighty lower using a fingers block. I try and simulate where the fingers are going to be placed on the string.

Keeping the riser block flat and level, and hooking to center to start out, lets you see the limb balance easier.  I put the deepest part of the grip centered on the bow for an ergonomic grip shape with a thumb ledge.....   

For ASL style risers  (Straight & dished shape grip) A lot of long bow guys heel down pressure on the grip, and the limb balance should be done from the pressure point applied to the riser.

[Bryan Adolphe]

Hey Kelly, all good questions for sure but right now being the first complete bow i built I’m the wrong guy to be asking this was definitely an experimental bow build for me. I’m still trying to get my head around this one, I definitely know what I did wrong the first time around , the centre of the bow is in the deepest part of the grip and then i glued on that riser block  off-center on the belly of the bow before I balance the limbs , then when I first put it on the tree, I did not level the riser ! Big mistake because it showed my limb tips way off at brace. That’s when things went sideways. anyways I learned a lot on this first one there will definitely be more questions to come on the second one but it should run smoother. I am thankful to all the guys on tradgang I couldn’t of done it without your help, all things, considering I’m pretty happy with the bow even with all my screw ups in the end It shoots pretty darn nice even with all my mistakes. I’ll put a couple pictures up of the finished bow in a couple days 
onto the next one. Bryan