Rotating Vee Bar

albatross

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Hello. I hope someone can help me with a new problem on my recurve. I recently changed my longrod from straight to an adaptor with an 8deg slope. The reason was that the end of the longrod, when straight, was obscuring my sight ring. I don't want to move my sight any furhter out from the riser or shorten my fiberbow S3 longrod. Now I am finding that the Vee bar is continually working loose and rotating out of square with the riser. I have tried a plastic washer, a leather washer, a flat steel washer and today even a shakeproof 'star' washer. All without curing the problem. Has anyone had a similar experience and if so how did you cure it? It is something to do with the sloping longrod I feel. Perhaps it reacts differently when not 'straight'?
 

geoffretired

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I have an idea for a washer that is a cross shape. Two legs of the cross bent back onto the sides of the riser and two bend forwards over the horizontal portion of the V bar mount. Similar idea to tab washers for car wheel bearings.
 

Stretch

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It would appear that the angled adaptor is introducing extra vibration. More often than not this will be a combination of parts that causes the problem (although it can just be the added in part)

So either…
  1. Do it up tighter (my personal favourite)
  2. Find a longer bolt to go through the angled mount
  3. Modify your damping to somehow counter the vibration.
  4. Try a different brand of angle mount
  5. Try a different brand V-bar
A washer between the v-bar and the bow never seems to help.

Stretch
 

albatross

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I have an idea for a washer that is a cross shape. Two legs of the cross bent back onto the sides of the riser and two bend forwards over the horizontal portion of the V bar mount. Similar idea to tab washers for car wheel bearings.
Good idea Geoff. I'll give it some thought.
 

albatross

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It would appear that the angled adaptor is introducing extra vibration. More often than not this will be a combination of parts that causes the problem (although it can just be the added in part)

So either…
  1. Do it up tighter (my personal favourite)
  2. Find a longer bolt to go through the angled mount
  3. Modify your damping to somehow counter the vibration.
  4. Try a different brand of angle mount
  5. Try a different brand V-bar
A washer between the v-bar and the bow never seems to help.

Stretch
Thanks for the reply Stretch. If I do it up tighter I will need a length of scaffold tube on my allen key to undo it! I am thinking along the lines of Geoff's idea.
 

albatross

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Solution designed. It involves a hexagonal boss (the sort that bow slings are attached by). A cheap box spanner to fit the boss a drill and some araldite. If it is successful I will post a pics here.

Well it looks as though it will work. I have attached 3 pics before I paint it.
 

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tabashir

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I'm a bit slow responding here! Looks like a fun project, nicely done. For anyone finding this thread in future though, I'd add that a small wrap of PTFE tape around a thread can work wonders for preventing things working loose.
 

albatross

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I shall be trying my 'invention' out tomorrow morning. If it still does not work I have another idea to consider (not the PTFE tape). But thanks for the reply.
 

albatross

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Well today I tried my new idea out. It worked! Unfortunately the problem has now transferred to the 8deg quick release in front of the vee bar, which kept coming loose (rotating slightly) and put longrod out of alignment. I fitted a 'star washer' between the two and REALLY tightened the retaining bolt, but it still came loose. There is insufficient room in the quick release unit to fit any washer directly under the head of the bolt. I have two choices. Make the quick release unit a solid unit combined with the vee block, drill and araldite come to mind, but there is not a lot of meat in the quick release unit. Or go back to the straight longrod fitting. Incidentally there is no indication of excessive vibration when I shoot the bow!
 

geoffretired

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I could machine the equivalent of the washer I mentioned in an earlier post. That could be a solid fit around the riser and also have the horizontal part of the V block trapped so not able to rotate. Tight fitting is then not really required to prevent rotation; just enough to stop everything coming loose
 

albatross

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Hi Geoff. The vee bar rotating has been solved by using the cut down box spanner. The current problem, which I have solved this evening, was the quick release 8deg fitting vibrating loose. I have filed a 'flat' section on each side of the circular quick release and will fit a small section of steel into each when I assemple it using a nut and bolt to hold it tight and square. I will then fill it with araldite as I did previously. If that does not cure it it will go in the bin!
 

Corax67

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My angled v-bar loosens itself too where my flat one doesn’t - I tighten it more, rely on thick rubber washers and check regularly during a session.
 

albatross

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My angled v-bar loosens itself too where my flat one doesn’t - I tighten it more, rely on thick rubber washers and check regularly during a session.
I tried all of those ideas without success. Now it is rock solid all day. But if anything happens to the plastic S3 fiberbow vee bar I will have to destroy it to take it apart!
 
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