Torque Twist

[Graeme H]

That one is part of a few videos I shot today. Here's a longer version (maybe including that cast?)

[Merlin]

Thanks for these very interesting videos Graeme. The rod is slightly unstable, which is rather normal for a glass rod. It must be on the low side of speed by comparison to a graphite one. The rod can vibrate on his first and second modes (clamped free), and this is emphasized by PB.

I wonder if you get a bonus with PB: how does it feel? Do you get more speed? A smaller loop? Or is it all in the same ballpark?

Merlin

[Graeme H]

Hi Merlin,

I shot these videos to put them into Tracker. A friend and I wanted to know if there was any measurable rod tip speed difference in casts with a pullback and I thought the 'glass rod would be the most likely candidate to display that.

With only two samples measured (one with and one without pullback), there are no firm conclusions to be drawn. The peak acceleration was significantly higher in the PB version over a few frames but the X component of it was not appreciably higher than the non-PB version.

Peak Acceleration. Top graph = Acceleration amplitude, bottom graph = Velocity amplitude.

That peak acceleration is perpendicular to the rod axis, and since the rod is angled at about 30˚above horizontal when it's occurring, I don't think it had the desired effect. The tip was moving down more than forward.

That's not to say it couldn't be adding line speed with a stiffer rod. The 'glass rod requires a wide casting arc so the rod is close to horizontal when PB is applied. A stiffer rod requires a narrower casting arc for the same cast, so PB might be adding a little bit of extra oomph in the direction of the cast with a stiffer rod for the same distance.

What the pullback DID do with the glass rod was put horrendous waves into the rod leg! I was unable to control that upward tip counter flex on the forward cast (CF2). That's more to do with me than the rod, I think, since I'm able to control it on the back cast. Overall, I did not get a better cast using PB on this rod. The more relaxed stroke was as good without the nasty side effects.

I did shoot some footage in the same session with my HT6 Instructor rod using the same line shown here. I'll see what has come out of that (Computer is not playing nicely at the moment).

Cheers,
Graeme

[Paul Arden]

Hi guys, just off the lake. I had a realisation this morning, Daniel, of another reason why TT feels and behaves like PB... when I twist the rod butt around the thumb the rod butt pulls backwards/upwards. In other words I’m physically pulling the rod butt backwards when I twist the hand.

I have some video to edit which hopefully I can have done by tomorrow some time. I haven’t gone through it yet!

Cheers, Paul

[Paul Arden]

Very interesting post Graeme. It’s funny I remember the video I shot in Australia having huge CF. But I noticed the one recently had very little. I’ve always thought it helped straighten the tip path as the rod unloads.

Right must have a shower and then I’ll have a look through today’s videos.

Cheers, Paul

[Graeme H]

Not trying to beat you to the punch Paul, but here's the video I mentioned above, using the HT6 instead of the 'glass rod. This one also has two casts with torque thrust, both of which show something very different to pullback happening.



Cheers,
Graeme

[Paul Arden]

Very interesting. Maybe the difference is the amount of pull-back? My videos don’t show anything like this, so please keep punching

Mine is much more presentation oriented as in placing the fly first, and how to do it.

I do still (currently) regard pull-back as being the primary cause here. Mind you I realise I now need to compare thumb behind the rod, twisting the butt up through 90 degrees (what I’m currently doing) to thumb at side (V-grip) twisting to thumb on top, which doesn’t pull the grip back, but instead pushes it forward. I wish I had thought about this earlier when I was on the lake!

Cheers, Paul

[Merlin]

Good points Graeme, I agree with your analysis. For sure it would be ideal to force the unloading in the direction of the cast, which might not be that easy. I looked at the video with the HT6 and there is still some PB as you twist the rod handle.

TTe.JPG (35.45 KiB) Viewed 3731 times

Nice loop indeed.
My attempts to significantly increase line speed by varying parameters in my model remain unsuccessful given the small variations. I am looking after trends, but nothing seems to provide a noticeable speed increase.

Merlin

[Paul Arden]

Torque Twist for placing the fly first!

[Bianchetti Ivan]

I'm sorry I translated with google, I hope not to offend anyone, I used this way of turning my wrist and elbow very often, but I ended up using it when I need a shot, to bring the loop to the side or when on the bank left I want to cross the leader to launch on the right bank, as it almost always produces a deviation of the barrel, this wanted error, is convenient for some types of launches. but simply faster).