Recurve Limb Bolts

Hilltop

New member
I am trying to obtain more details about riser limb bolts regarding an industry standard of size of which after much searching I am unable to find.

I occasionally have the situation of tight fitting limbs which is often cured by opening up the limb dovetail by a little sanding. However, the problem is not always due to the limb tolerance. I have discovered lately that the problem is due to the thickness of the limb bolt itself. After a recent purchase I found one of the limbs to be excessively tight and after checking I found that one of the limb bolts was 0.2mm thicker than the other. Now you may say that 0.2mm is not much but in manufacturing terms this is a lot. The retailer is going to replace this bolt by the way.

After checking quite a few limb bolts I have found that most are made with a diameter of 9.4mm and I would appreciate some feedback on this topic.

I did a search to find out about the industry standard on this without any success. I have dug out various patents on ILF fittings and while they all give highly detailed descriptions and drawings no specific sizes are given.

So, does anyone have an answer to this.
 


Rik

Supporter
Supporter
You're not going to like this answer...
There is no standard. None. ILF is a fiction.

It all stems from when Hoyt invented the fitting and didn't protect it from copying. Other manufacturers copied it and made their own versions. They, more or less, work together (some more, some less) but it's quite possible to find combinations which can't be made to work.
 


Hilltop

New member
Thanks for your reply.

I would still like to find out as to the machining specs for these limb bolts. When manufacturers make these they must have a machining specification and that is what I am trying to find out.

I have written to Hoyt and Win Archery but so far had no reply.

I contacted Border Bows with them being a reputable bower for their input but just got a nasty reply saying that if it wasn't anything related to their bows specifically they weren't interested.
 


Timid Toad

Moderator
Staff member
Supporter
Fonz Awardee
Ironman
And remember, whatever the sizes are meant to be, there is a certain amount of tolerance, which varies between manufacturer, and machine tools wear, creating variation too. This is why Border can supply different sized fittings for you. They found there is often a problem of too much slop or too much interference. If I could put a pic up I have one of a beautiful set of 0.05mm increment ilf dovetails from the Border FB page.
 


Timid Toad

Moderator
Staff member
Supporter
Fonz Awardee
Ironman
Not the one I had in mind but it does the job, thanks :)
 


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