Tiller is now off

[kenboonejr]

So while I was going through this Binghams Projects Take Down Recurve build, early in the process I was supposed to figure out which limb was stronger and make that my lower limb.  Instructions also said that if the distance between the string and each end of the riser was off by more than 1/4" to take the stiffer limb and hit with 120 sandpaper and repeat until its within 1/4".  Well when I was at that point, I was right on at a 1/4" difference so I marked the lower limb and moved on.  At this point, I am just down to finish sanding.  I got everything sanded to 320 and felt like I was about ready for the spray but when I strung it up to look at it, I could tell it was off.  From tip to tip everything is lined up, no twist or anything like that.  But the distance between the string and the two ends of the riser is now off by 1/2".  Well I have hit it with 120 grit a few times now and I am definitely removing stuff as it gets really white from the glass being sanded off, but then I string it up again and I still am off by about 1/2".  I have done this about 3 or 4 times now and don't seem to be making any progress.  Do I just need to be a sanding ninja and sand a ton and then go back and check it? 

I know some of you guys said I did not need to sand the limbs with 120 like Bingham's said, but when I was finished with everything but finish sanding I hit 48 pounds at 28".  I called Elmont and talked to him and he said I was right where I should be for a 45# bow.  He said once I round the edges on the limbs and sand the limbs with the 120 that will bring it down to about 45#.  So I guess in his plans, he is expecting someone to use the 120 to bring the weight to where it needs to be as well.  He said a little sanding goes a long way so don't take too much off at a time.

So I am just wondering.  Do I just need to sand that lower limb until the distance closes down to 1/4"?  And should I expect that to be a LOT of sanding?  I am not worried if the weight goes below 45, that is a non issue, but I think the tiller needs to be closer to 1/4".  Right now it is visibly noticeable that it is off.

[JamesV]

I would try rotating the limbs. If the limb pads are off a few thousands it will make a big difference. You could also shim under the limb with some tape to bring the tiller in line.

[Crooked Stic]

Take a measurement at the ends of the wedge fades. May  be better or may be the same.
If your wedge is thick off the riser can't see how that is gonna change much.

[kenboonejr]

I would try rotating the limbs. If the limb pads are off a few thousands it will make a big difference. You could also shim under the limb with some tape to bring the tiller in line.

Yea I can't rotate the limbs because I followed the design too closely.  With the riser design, and me not knowing better, the sight window extends barely into the butt of the limb, so you need to trim some of the corner of the butt of the top limb.  Next time I would not make the sight window so big.

So I were to shim it, which limb would I put the shim under?  I guess it would go under the weaker limb?

[kenboonejr]

Take a measurement at the ends of the wedge fades. May  be better or may be the same.
If your wedge is thick off the riser can't see how that is gonna change much.

Ok i'll check that tomorrow when I get back from fishing!

[kenboonejr]

ok I got my tiller fixed!!!  I talked to Elmont and told him I was sanding the glass and it didn't seem to improve so he told me to round the edges of the strong limb some more.  A few round of that brought things into just under a 1/4" difference now.  And now I am on to finishing.. YEA

[Crooked Stic]

Just did one myself that was off about 3/4 in. At the end of the riser. Has pretty thick wedges. Was a bit less at the wedge fades off. Took quite a bit of sanding on the belly glass. It did change at the riser end but the wedge fade is now a twig over 1/8. So calling it good.

[kenboonejr]

Just did one myself that was off about 3/4 in. At the end of the riser. Has pretty thick wedges. Was a bit less at the wedge fades off. Took quite a bit of sanding on the belly glass. It did change at the riser end but the wedge fade is now a twig over 1/8. So calling it good.

What struck me odd, is that I sanded the back and the belly of the lower limb like 3 times and it did nothing to improve my gap.  Then I went and worked on the rounding of the limbs edges a little more and that made a quick change.  I wasn't expecting that but this is all new to me.  Finally got it worked out though so I am happy!  I will keep that in mind next time to check against the fade as well as the riser.
Thanks!