Gear alignment when reassembling reels: Does it matter?

[boon]

So there was a discussion recently where the topic of precisely realigning gears in their previous exact position came up.

The question was asked about whether it actually matters; does every tooth on the drive gear eventually meet every tooth on the pinion, or do only some teeth ever mesh, suggesting the reel would develop a wear pattern specific to those teeth, and this would be disrupted if the gears were repositioned, potentially resulting in a noisy or non-smooth geartrain?

I set out to answer this with an excel spreadsheet and lots of numbers, and the answer is, interestingly, sometimes.

For example, in a 5:1 reel, with for argument's sake 10 teeth on the pinion and 50 teeth on the drive, tooth "1" on the pinion will only ever contact the teeth 1, 11, 21, 31, and 41 on the drive gear.
If the ratio is 3.6:1 (10 and 36 teeth) tooth 1 will meet 1, 11, 21, 31, 5, 15, 25, 35, 9, 19, 29, 3, 13, 33, 7, 17, and 27. This is exactly half the teeth on the drive gear (unsure how to mathematically work out this relationship). This means you have a 50% chance of correctly aligning the gear again when you put it back in - if you get it wrong by one tooth, it will forever be on the "alternate" set of teeth that it has previously never meshed with before.

This does fall down for certain ratios, i.e. a completely hypothetical 5.857142:1, caused by a 7:41 relationship (this may be because both 7 and 41 are prime numbers? still not sure). In this instance, every tooth of the pinion will eventually meet every tooth of the drive gear, meaning alignment when reassembling does not matter.


Just some food for thought anyway! Personally (other than the oscillation gear of certain spinners) I don't worry about alignment when reassembling.

[Gfish]

Pretty interesting. So on the last example, yer talkin bout 7 pinion teeth and 41 drive gear teeth.
It do seem like a reel will sometimes perform/feel diffrent upon reassembly. Of course, that could be any number of causes. Why not gear non-realignment?

[alantani]

never worried about this one.  it might explain why some of those calcuttas never felt right afterwards..... 

[bhale1]

whoa....this is way above my level of "reel" knowledge...but, something to think about
Brett

[Reel 224]

To simplify this. When a reel is said to have a 5:1 ratio you have five(5) rotations on the spool to one (1) crank of the crank. I always check the rotations of the spool to crank rotation to see if the ratio is correct.

That will tell you if all the gears are meshing correctly. To simply explain that theory.

Joe

[Cor]

I have thought about this a number of times, but never came up with anything concrete and ignore it.

The Diawa X wave range of reels with the floating SS pinion on brass main gear very quickly become rough (or start to rumble) which I find very bothersome but I've never come up with a solution to this either, other then replacing them.

[exp2000]

So there was a discussion recently where the topic of precisely realigning gears in their previous exact position came up.

The question was asked about whether it actually matters; does every tooth on the drive gear eventually meet every tooth on the pinion, or do only some teeth ever mesh, suggesting the reel would develop a wear pattern specific to those teeth, and this would be disrupted if the gears were repositioned, potentially resulting in a noisy or non-smooth gear train?

It should be noted that this discussion was specific to the hypoid gear sets found in spinning reels.

I have never noticed this problem in conventional reels although I do make a practice of using a Dremel wire brush to scrub clean brass maingear and pinion teeth.
~

[jurelometer]

Hey Boon,   I think you correctly answered your own question! 

Count the teeth.   If the gears are designed correctly, there is no mating pattern.

I'm no expert on this stuff, but one of the basic principles for proper gear design is to use tooth counts that result in a non-whole number gear ratio  to avoid having the same combinations of teeth meshing and creating wear issues. For example,  if a  main gear tooth had a high spot,  it is better if it did not only wear down  only one tooth on the pinion.   Correct design also means that you don't have to worry about matching the original tooth orientation when reassembling for maintenance.    Although a gear set may be advertised as 5:1, in reality it should be something like 4.8181:1 (53 to 11 teeth).  Using prime numbers can help to get a good ratio.  If anybody wants to read up on it this, look up hunting vs. non-hunting gear ratios in your favorite search engine.

But there are often basic mechanical engineering principles  that are ignored in reel design, so I wouldn't be surprised if there are some gear sets out there that are not kosher.   

-J

[Robert Janssen]

^^ Exactly.

[Pro Reel]

I can absolutely without a shadow of a doubt say that Yes, it does matter on spinning reels. I have proved it many times. On spinning reels there is a distinct set of matching wear patterns, get it one tooth off and it's rough after service. Get it back where it was and it's smooth again. I take a spinning reel apart in a way that allows me to use an awl to scratch line up marks on the side of the pinion shaft and the surface on the drive gear. I have purposely put them together not quite lined up and they are not smooth, put them back and they are smooth again. If you let the pinion or drive gear slip apart before scratch line up marks in them, you may just need a new set of gears because at that point it could days of taking it apart and moving the drive gear one tooth over and then putting it back together to try and find the sweet spot again. I know, I've done it.

[Reel 224]

Yes it does mater with all reels. Ask a expert, like Fred.

Joe

[boon]

Hey Boon,   I think you correctly answered your own question! 

Count the teeth.   If the gears are designed correctly, there is no mating pattern.

I'm no expert on this stuff, but one of the basic principles for proper gear design is to use tooth counts that result in a non-whole number gear ratio  to avoid having the same combinations of teeth meshing and creating wear issues. For example,  if a  main gear tooth had a high spot,  it is better if it did not only wear down  only one tooth on the pinion.   Correct design also means that you don't have to worry about matching the original tooth orientation when reassembling for maintenance.    Although a gear set may be advertised as 5:1, in reality it should be something like 4.8181:1 (53 to 11 teeth).  Using prime numbers can help to get a good ratio.  If anybody wants to read up on it this, look up hunting vs. non-hunting gear ratios in your favorite search engine.

But there are often basic mechanical engineering principles  that are ignored in reel design, so I wouldn't be surprised if there are some gear sets out there that are not kosher.   

-J

I knew someone would have the engineering answer to this, complete with the accurate terms that refer to this. Today I learned something! Cheers.