alan tani @ alantani.com fishing reel repair rebuild tutorial Calculating main gear shaft torque from drag settings
Reel Repair by Alan Tani
December 11, 2018, 08:21:39 AM *
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Author Topic: Calculating main gear shaft torque from drag settings  (Read 19037 times)
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jurelometer
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« Reply #30 on: June 08, 2015, 09:45:22 AM »

Dave, being in construction for over 40 years and building things by hand, I tend to lean towards actual tests instead of formulas, sorry, its just the way I am, so be patient with me Grin, I do enjoy all that you've been showing us.

On the dogs, giving  the right amount of force and causing some flex with the dogs or ratchet, do you believe the two dogs would share the load? I believe there would definitely be some flexing and I also believe at some point the load would be shared.
When that does happen, I couldn't tell you, I'm not that smart, but I do believe it would also be related to the material used and not just the amount of force applied.

Your statement makes sense to me, about never being able to having true synchronized dogs, but under the right conditions while using the tool, it could be.

Not related and pulling away from this, do you believe double dogs is a better choice than just one dog in fishing reels? and the you also agree that trying to get them synchronized is a better choice than alternating?

Sal

Hi Sal

First, you are being way too modest.  Second,  Somehow folks have me confused with a mechanical engineer.  I just play one on the Internet Wink   

The engineering part of this does not replace the testing.  The best result  is when everything is combined in the right amounts, which is what I hope  we are  doing here.  But whoever is doing the work gets to pick the methods.   

Some imes you need to rely more on engineering and science - it wouldn't be advisable to use trial and error to build railroad bridges.

Sometimes you need more live testing:  I have been working on a swimbait  for over two years now.   There was no chance that I had the brainpower to figure any of this out with hydrodynamics  Smiley. So this problem was pretty much solved with trial and error, and very little engineering.

Regarding materials- Agree that the materials will affect the outcome. Different flex, stiffness, impact resistance, etc.  If we made the dogs out of rubber, we would get very good load sharing, but also busted knuckles Smiley.  Another example- Replacing plastic sideplates with aluminum might change which part of the system flexes or fails.

Regarding asynchronous vs sync double dogs  vs  single dogs.

1.   if you gave me a modded jigmaster:

for big yellowtail in the kelp beds -   the further I can button down the drag the better.  My chances are better with sync.

for pulling big snappers out of mangroves-  this is short line- u-turn bites.  Async saves me a couple inches on the u-turn.

 Fishing enjoyment- I marginally prefer  less back play ( not enough to go to one way bearings) but this is a personal preference.

2.  Designing a reel from scratch for me -  I would use a large ratchet with async dogs.  The engineering shows that it should be possible  to properly design dog systems that can handle the load beyond what the gears can take.  Having a redundant dog seems unnecessary. If you make the ratchet big enough, you can probably get away with a single dog with minimal back play in a well designed system. 

3. Designing a reel to be popular - One way bearing unless the load is too large.


Correct me if I am wrong, but I think your goal for multi-dog   is primarily increasing the strength of these classic reels.  Decreasing backplay is less important.  Exactly how much flex or failure occurs before load sharing kicks in will affect the ultimate strength, but I believe that  sync dogs will probably have the best chance to meet your goals irregardless.  But you already knew this:). 

Jurelometer does trial and error on swimbait design (this is not even half of them-eek)

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mhc
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« Reply #31 on: October 09, 2016, 03:04:19 AM »

12 months later, I finally got around to testing another set of dogs - this time with a gear in place as Sal had suggested.
I had added an extra 2 dogs and a Cortez Conversions 98-155 9 tooth sleeve to a jigmaster bridge and was concerned the smaller diameter of the ratchet would put extra load on the dogs and the smaller teeth would apply that load to smaller area at the tip of the dog. (I used the 155 sleeve because the smaller ratchet gave enough room to add the dogs)
The bridge;


Using Dave's spreadsheets and assuming a spool diameter of 1.8", drag of 30 lb and gear ratio of 4:1, I got a torque of 108 lb/in.
Instead of the crescent wrench used last time, I screwed an old handle to a flat piece of iron bar with a hole to attach the spring scales 10" from the centre of the sleeve;



With a 10" lever, the force required at the spring scale is 10.8 lb (108/10). I started at 13 lb equivalent (~4.7 lb on the scale) and checked the dogs, posts and sleeve. There was a slight dimple on the face of the second dog where the point of the tooth contacts. I then applied 20 lb drag equivalent (~7.2 lb on the scale) and checked it all again and couldn't see any change.
Finally I took it up to around 30 lb drag equivalent (10.8 lb on the scale). This time the faces of the 2nd and 3rd dogs were noticeably indented by the ratchet teeth the original dog slightly marked. They still worked fine and I'm sure if they had been shaped to match the angle of the teeth there would have been marked less. The posts stood up to the load - I couldn't see any deformation and Tom's ratchet was unmarked as I expected.
After 13 lb equiv' showing slight mark in the tip of dog 2;


After 30 lb eqiv' showing more obvious marks in dogs 2 & 3;


The dogs;


The posts and sleeve;


Recalculating this test and changing the gear ratio to 4.8:1 the calculated drag equivalent is around 25 lbs - which is more than enough for 50 lb line.
This test has given me confidence Tom's 98-155 sleeve will work in a jigmaster with three alternating dogs and DIY dog posts. Thanks again Dave for coming up with the concept. 

Mike
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Alto Mare
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« Reply #32 on: October 09, 2016, 04:12:49 AM »

Great job Mike, I always enjoy homemade gadgets.
Now, are you saying that you've calculated the distance on that steel bar from the handle?

 
If I had to figure that one out on a calculator, it would make my head spin.

I could get it done though, but it would require lots of manual labor, as drilling holes every 1" or so, set a bolt in the center and a heavy spring on the right, with a witness mark.

Thanks for all your hard work Mike, it's very much appreciated.

Sal
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mhc
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« Reply #33 on: October 09, 2016, 04:49:14 AM »

Thanks Sal. The 10" measurement is from the centre of the gear sleeve to where the scale is attached, the steel bar and handle are rigid - there is a screw from the underside where the handle nut lock screw goes;



I thought of multiple hole locations but it's easier to calculate the torque with a 10" lever.

Mike
PS, I hadn't noticed that 'alantani.com' logo on my wrench before - must be the camera angle.  Cheesy
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Alto Mare
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« Reply #34 on: October 09, 2016, 04:59:38 AM »

haha...I softly placed that in to see if you would notice, tried to go lighter but couldn't Grin.

Thanks again Mike, great job on the dog posts as well...good stuff!
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gstours
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« Reply #35 on: May 12, 2018, 07:52:02 PM »

Thanks folks.   But I can’t see the photo f bucket pictures ..?? Huh?
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handi2
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« Reply #36 on: May 13, 2018, 07:31:16 AM »

Too much unneeded information. Its just a fishing reel...
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Gfish
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« Reply #37 on: May 13, 2018, 09:29:37 AM »

Pretty interesting read.
 Wouldn't it be great if those manufacturers of quality tackle, with the resources, would engineer reels at certain load bearing capacities without having to "overbuild" systems(too much weight & cost---but who does that these days?)or cheapen parts to save money( pressure bearing metal parts, to composite plastics).
 Probably too much to expect, but shouldn't, for example, a pinion bearing on a lever drag reel last at least almost as long as the the rest of the reel?
« Last Edit: May 13, 2018, 09:37:04 AM by Gfish » Logged

Fishing tackle is an art form and all fish caught on the right tackle are"Gfish"!
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