Worm gear drive train

Started by basto, April 05, 2018, 07:20:39 AM

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basto

Didn`t quite know where to post this, but I have always wondered why the few most expensive and strongest spinners available do not use this system.
Daiwa used it once, but I do not know of a Shimano with it or an Okuma.
I have read where many very respected and qualified people have said it is the strongest drivetrain for a spin reel, so why has it been abandoned now? or has it not?
regards
Basto
DAM Quick 3001      SHIMANO Spedmaster 3   Jigging Master PE5n

Gfish

#1
Probably a $ thing. I have 2 vintage reels with these drive trains, a Zebco(Abu) Cardinal 4, circa 1970, ana early 50's DAM Quick 250. I recall Allen Hawk goin into some detail about it, but don't have the reference.
Fishing tackle is an art form and all fish caught on the right tackle are"Gfish"!

Midway Tommy

Alloys today hold up a little better, therefore lasting longer, than the old pot metal gears of yesteryear, but it still boils down to cost and profitability.
Love those open face spinning reels! (Especially ABU & ABU/Zebco Cardinals)

Tommy D (ORCA), NE



Favorite Activity? ............... In our boat fishing
RELAXING w/ MY BEST FRIEND (My wife Bonnie)

richard

I read somewhere that it was not so efficient in transferring torque .

basto

Hi Richard
I assume that would depend on the gear ratio.
Greg
DAM Quick 3001      SHIMANO Spedmaster 3   Jigging Master PE5n

richard

Hi Basto.  Well the higher the gear ratio ,the harder it is to turn the handle ,yes true(also handle length is important of coarse).But im talking similar gear ratios ,say 5/1 in each case. On my treasured Cardinals i find it a little more difficult to wind down to a fish with the rod bent under pressure than say with helical cut "modern" reels . Straight cut gears are used to minimise friction ,whilst helical cut is smoother and quieter but with more friction, and next would be worm .Minimal friction but noisy verses a little more friction but smoother and quieter as you go from one extreme to another.Another reason MAY be thats its easier / cheaper to change handle from one side to another with "modern " gears where the main shaft goes straight through the reel body and the handle can be easily swopped round.The superspinners go to a lot of trouble to have the pinion gear as near as possible to the centre line of the main gear for mechanical efficiency. Bittom line, worm gear has more of a "scraping" motion as the teeth mesh, which creates friction.In fishing reels i think the difference is marginal ,especially in the smaller sizes. My take on the subject ,dont mean to sound like a know all.🐟

basto

Thanks for your thoughts Richard. All information is welcome and interesting. I am learning all the time.
I have 3 worm drive spinners and they are all ambidextrous. 2 DAMS and a Cardinal 5 green line (Japan)

Just to digress for a moment, I just bought an old Daiwa Whyte Hall spinner and can`t believe how deformed the main gear and spool shaft are.
It is not worm drive. The rest of the reel must have been too strong for these parts. Funny part is it came with 4lb mono on it.
cheers
Greg
DAM Quick 3001      SHIMANO Spedmaster 3   Jigging Master PE5n

jurelometer

#7
Not an expert either, but have been messing around with gear design at a hobby level for a little while now.

Short answer-

I think Richard is right,  in that at the relatively low gear ratios involved (3:1 to 7:1) ,  a quality design and manufacturing process  would allow any of the three spinning reel gear systems to work pretty efficiently.  However,  the choice does affects the external shape of the reel  with both aesthetic and ergonomic ramifications, with worm designs being the most challenged for spinning reels.  My guess is that it would be more expensive to achieve a high efficiency worm drive system as well, but I am speculating here.


Long answer -

I think Richard mostly hit it on the head, but a couple clarifications.  

There are gear systems that are on the same axis (used in conventional reels),  and systems  that change the axis (used in spinning reels).

Both systems can utilize either straight or curved-path teeth.

Most common choices for "same axis" gears are spur or crown (spur gears with sides of tooth rounded),  and helical  (curved tooth path).

For "change axis" gears  the common  choices are worm, bevel, and hypoid.  With a worm system,  the main gear has to be entirely above the worm,  so once we get into modern spinning reel gear ratios of 5:1 and above,  it will affect the shape and design of the reels (higher gear ratio->larger main gear diameter),  especially to support the higher loads of super lines (higher load-> larger teeth -> larger diameter)  But it is very simple to design a worm drive system where both shafts are supported on both sides.  Very useful for high torque situations like worm drive power saws.

With bevel gears,  the axis of both gears is on the same plane,  a much easier system to  design a spinning reel around.   Hypoid gears are sort of in between.   They look like a bevel setup, but the shafts are not quite on the same plane.  While not as efficient as bevel gears,  it can be useful if  the design needs the shafts to be close, but not  exactly lined up.

  I think (not sure) that a hypoid gear system needs a curved tooth path, but with bevel the tooth path can be straight or curved.

The efficiency of worm vs bevel vs hypoid gets more pronounced at very high gear ratios, above what we see on reels.

As with everything else in mechanical design,  there is no free lunch.  The bigger the tooth size, the stronger, the gear, but you loose efficiency.   Softer materials can be more efficient, but are not as durable.  It is not that expensive  to build a smooth gear system if you don't care about durability.

Curved teeth are a slightly different story:  they  engage gradually and can have more than one tooth engaged at a time,  increasing smoothness, but the curves work like screw threads,  converting some of the radial force to axial (lateral) force.  While this force pulling gears apart is generally a problem,  it can be useful as well.   Most lever drag conventionals use spur gears,  but star drags use helical gears in part to take advantage of the axial force.  With a helical system,  the axial force helps hold the pinion against the spool shaft.

Final thought:  If I was working in the marketing department at a spinning reel company,  "Hypoid Drive System" gets my vote over  bland sounding "bevel"  and who wants a reel that has "worms".   Just sayin'... :)

-J

basto

Very interesting read Jurelometer. Much to chew on there.
Greg
DAM Quick 3001      SHIMANO Spedmaster 3   Jigging Master PE5n