Setting Up Hex 8's

Last week, I received my Hex8 -H limbs from Mellerstain, and shot them for the first time on Saturday.
Putting them into my 25" Tempest riser, and leaving the tiller settings the same as the Hex 7.2-H's that I usually shoot, and using a brace height of 7.25".
I found that I was getting fletch contact on the shelf, in the form of a thin white line,from the top of the fletch, initially at the front of the shelf, and then, when I dropped the bracing height, at the rear.
The measurement from the centre of the button to the top of the shelf is greater than the measurement from the centre of the arrow tube to the top of the fletch, so it would appear that the arrow is dropping after the nock leaves the string.
Tiller measures "Zero, i.e same top/bottom.

I've posed the questions to Sid, but the annual shutdown's just started for the next two weeks.

Does anyone have any thoughts on optimum set up re.tiller to get the best out of the Hex8's please? The centre shot's fine.
I'd also be interested to know the bracing height recommendations for the Hex 8 limbs.

I know that Sid has set up "Hex" groups and "Tempest" groups on Facebook, and that some may exchange information there, but I don't do Facebook or Instagram, so the experiences of other owners would be most interesting and greatly appreciated.

Andrew
 

Timid Toad

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I can offer only a little advice. I too have a Tempest. Try a little tiller - 1-2mm. I know the 8s like a low np, and that's not a concern when shot off the shelf, but needs to be considered when using a rest and button. What is your np set at (and tell me how you measure it, so I can compare like with like - there's so many ways!)
 
Thank you Ms Timid,

You're right, I'm using the bow for target shooting standard rounds, not field shooting.
So, it's rest & button on this bow.
I will try a little positive tiller, the configuration of Hex profile drives me crazy in trying to anticipate the changes in limb action, due to the radical curves, when changing tiller.
CV-H's are much simpler.
My NP is currently set at about 4.5mm when measured from the bottom of the nock to the rest wire, and that's giving fletching contact at the back of the shelf, i.e. towards the shooter.
It was initially set at around 6.5mm, and gave contact at the front, i.e towards the target.
I measure with the bow horizontal, to try to avoid limb sag.

An easy answer would be to go for a mid range figure, say, 5.5mm, to hope that this clears, but, as I previously mentioned, there's plenty of clearance in the measurement of button - shelf and arrow centre - top of fletch, so it makes me suspect that the limb action from the bottom limb is pulling harder than the top, and may be exerting a slight downward force on release.

The adjustment to move to positive tiller at the top limb pocket asks for the bottom limb bolt to be wound in a modicum, but this would seem like it strengthens the bottom limb, and may exacerbate the problem?

I re-fletched on Sunday, moving from X-Vanes to Air's, which reduces the fletch height by around 2mm, which may help, but, as I say, the static measurement shows that the X-Vanes should have cleared.

If only Border produced an owners manual, when we could all learn from the Sid's design criteria and intentions. John Kelly mentioned last year, that he was producing one, awaiting "sign off" from Sid, and that could be a real help for us mere mortals, excited to follow the "Hex Trail", but anxious to realise the true potential.

Until such a guide is published, as ever, I appreciate your informed input, and welcome any thoughts.
The Sid's should write the "Border Book"!

Andrew
 

Timid Toad

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If you are measuring from the underside of the upper np to the rest, that's ever so low - mine is around 8-9mm.
Get someone to film you shooting your bow. Look for both limbs rolling over equally and post shot a nice close without flap.
 
Thanks Timid,

No, the 4.5mm NP is from the rest wire to the bottom of the nock, so it's not that low. But, ta-da!
Tonight, I wound everything around again, and reset the tiller, using your recommendation of 2mm positive, and, lo and behold, excellent arrow flight (save a little tail left, so it's button work next)
You are right, the 8's like a low NP.

Andrew
 
Just an update on the tuning and tiller settings for the Hex 8's.
I've been working to some hints that Sid passed on to me, and I've got the limbs pretty much as I want them now, and shooting well.
The fletch contact's gone, and the arrows are coming out nicely, may yet even move to one grade stiffer spine.

But, it's the tiller that's been the real headache, and getting the limbs to load evenly.
So, I've found that using the Rick McKinney Static Tiller method to indicate which direction I should be travelling in has been rather different with the Hex 8's.
I shoot target, a Border Tempest Riser with a full stabiliser set up, long rod, V-bar and twin side rods, and have always been able to gauge the relative strengths of the limbs by watching the reaction of the long rod tip whilst drawing the bow.
Stronger top limb, and McKinney says that the sight ring rises as the draw gets further back, opposite reaction for stronger bottom limb, and adjust until the sight stays pretty level throughout the draw.
These effects are somewhat amplified by the fitment of a long rod due to the length.

On my Hex 6's and 7's, this indication seemed linear, i.e. if the top limb was strong, the tip of the long rod kept rising until full draw, and I could make the adjustments to tiller to keep the long rod level as the draw progressed.
But, on the Hex 8's, very different.
The draw showed the long rod tip move upwards whilst drawing, but then, at about, say three inches away from full draw, the upwards motion ceased, as the limbs went "over a peak", and then the long rod tip came down again quite dramatically to a level approximately at the level starting position at full draw. When locked down at this tiller setting, the bow shoots as I would want it to, and the arrows come out straight.
All the Hex 8 talk mentions "let-off", or a feeling of draw weight reducing in the last couple of inches, so I can only assume that it's the limb action that's giving this effect. It's weird, the feeling of the bow "settling down" again, after rolling over a peak.

Most of the Hex 8 video I've seen, such as Joe Paranee's excellent reviews, are usually whilst the archer is using a Covert Hunter or Black Douglas riser, without the stabilisers, I haven't seen any video's with the Tempest riser (or any other riser with a full target stabilisation package), so maybe this is just something I'm noticing on my own set up.
My imagination then sees the movement of the limbs after release going back over the peak as the string moves forwards but, of course, the pressure on the bowhand is relaxing as the shot progresses, and the looser bow may sort itself out.

Just throwing this one out there as an observation on the mysterious art of Hex tuning. It doesn't happen on my Hex 6's or Hex 7's.
 

Timid Toad

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What you need to look for is how the arrows group at distance. While the unusual feel of the bow may take some getting used to for the archer (just relax and go with it - it'll become normal, imagine when compounds first came on the market!) there's no vertical nock travel. I'll bet you have a low nocking point, and as long as you are getting the groups you want at distance, go with the flow.
Incidentally, what spine did you end up with?
 
Spot on with the NP Ms Toad, it's lower than with any of my other Hex's.
One day I'll get around to making a video recording of the bow action on release, and slow it down to see what mysteries it reveals.
The 8's are medium Hex 8 Hyperflex, at 38#

My Hex 7's are also 38# medium.
I shoot Easton FMJ Match 530 with the 7's.
The 8's like a 490 FMJ Match.

Andrew
 
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