Some observations on overloading jigmaster gears

[jurelometer]

I have been learning a bit about how to design gears, and this got me interested in the ongoing efforts here to beef up the Jigmaster.   I took apart a 500 and a 505 to examine how the gear system behaves.  It seems that the basic design for nearly all star drag reels  is not very gear-friendly.   It also seems there are some things that could be done with some aftermarket work, but there are limits.  BTW,  this is more of a semi-theoretical design discussion of the stock reels, and not a critique of the the Jigmaster upgrades out there that are built to address actual real world failures and to add features that owners value.    Note that some of the issues I discuss could be minor relative to others.  It is difficult to weight the importance of each issue without some measurement and trials.

The big picture is that parallel gears need to be kept in parallel and not subject to sudden loads. This usually means minimal play on well supported shafts, and possibly techniques to soften the blow of a sudden load.   So what do we see in star drag reels, and in particular the Jigmasters?

In no particular order:

1. Reversal under load - this is something the designer is supposed to avoid whenever possible.    the dog is at the far end of the gear train from the spool, so when the load switches back and forth from reeling to drag, the pressure on the gears reverses.   The more slop in the gears the more violent the banging.  I don't think there is much that can be done about dog placement in a star drag system.  The best you can do is remove slop in the system.

2.   Pinion gear play on the shaft.   The spool shaft is supported on both sides of the pinon gear- so far so good.   But there has to be significant clearance to allow the pinion to not rub on the shaft during freespool/casting.  Additionally the pinion  slot needs some clearance to slide easily on/off the flat sided part of the shaft.   There is significant wobble on the stock pinions for both my 500 and 505, especially toward the flat sides of the shaft.  A design that had the spool rote independently of the shaft would provide better design options, but this is probably not an aftermarket opportunity.  BTW- those of you that worry about dog play should check out how much rotational play the pinion/shaft junction is allowing.

3.   Bridge shaft/sleeve flex.    I was shocked when I saw how far I could easily flex the bridge  shaft/sleeve.    A longer handle arm makes this more likely.   By eyeball it was looking like 8-10 degrees without much effort.    This is because the shaft is supported only on one side and a lever (handle arm) is attached to the other.

4.  Bridge shaft/ sleeve/ main gear play.      The bridge sleeve has to rotate of the shaft without the benefit of a bushing.  This requires a loose fit.   The main gear has to rotate on the bridge sleeve.  The original brass/bronze gears have a bushing, but the various stainless versions out there do not.  So there are basically two nested main gear shafts on the bridge, each introducing some necessary amount of play.

5.  Main gear wobble.   The main gear is held against the bottom of the gear sleeve at the dog gear by the pressure of the drag system.    But the main gear has to rotate on the bridge sleeve.  This is why there is a thrust washer under the main gear.    If the shaft is experiencing angular pressure, the force on this thrust washer will be unevenly distributed.   This means that the thrust washer must be be tough and compression resistant.

6.  Helical cut gears  - edge loading and "ramping".    Under ideal conditions, helical gears are considered stronger the straight cut crown gears, as the diagonal tooth means more surface area for a given width of gear, and more teeth are engaged at a time.  However helical gears have some specific issues.  The one most commonly discussed is thrust, which basically means that some of the radial load is transferred to axial load by virtue of the teeth being angled. If the shafts stay parallel the load is transferred axially (up the shaft).  A bigger issue for reels is edge loading, which can occur with helical gears when the radial to axial load conversion drives parallel gears off axis.

So putting it all together:    Suppose you have the drag set high, and the  spool is under load from a fish or snag.  Now you start to wind against the load and  possibly on the upstroke accidentally pull the bridge sleeve and shaft off axis, so that the bottom (bridge facing) side of   main gear facing the pinon  is starting to tip toward the bearing cup.  Now as you wind, the angle of the helical cut provides a ramp up the pinion that causes  some of the rotational load on the main gear to transfer to an axial load driving the main gear up the pinion, further off parallel axis.    Now suppose that the the thrust washer under the main gear is a drag washer that can be torn and or compressed on the downhill side- more tilt.   Now the bottom of main gear is riding far up the pinion.  The load is concentrated on the corner of one tooth of the main gear, and the side edge of one tooth of the pinon.   SHRED!   You end up with something that looks like what Erik posted:

http://alantani.com/index.php?topic=8592.msg88782#msg88782


Is what shredded gears normally look like, or whether  there are other  common flavors as well?


What might be done to improve the gear situation if we want to go further than where we are now?  Stronger gear material, especially the pinion is the easiest step -looks like this is in plan.   Larger teeth would help, but as others have pointed out, there is not much room for this without decreasing the gear ratio.  Straight cut (crown) gears seems to be worth pursuing.    Another easy fix is choosing the least compressible material for the thrust washer (probably not carbon fiber).   Getting the pinion fit to be as tight as possible when engaged (maybe it already is?) .

Now getting into the trickier territory,  there might be some clever things to do to keep the main gear on a parallel axis to the spool shaft.   First by providing support at the  far end of the bridge shaft/sleeve- it looks like the Black Pearl kit is doing something along this line with the new spacer), next by using some sort of bushings to tighten up the play between the shaft and sleeve, and sleeve and main gear, or even making the shaft and sleeve slightly larger diameter.  There is some, but not much room to work with here.

If the new gear/bridge kits are capable of supporting extended periods of heavy load without the above modifications, it might be worthwhile to keep track of the wear on the shaft/sleeve and sleeve/main gear.  As these are now all stainless instead of brass it is possible the the angular load will cause wear here that used to be absorbed by gear failure and brass components.

Suppose it were possible to eliminate gear shredding.  Where would the next point of failure be?   My guess would either be at the pinion shaft joint, or the shaft itself bending.

I am curious how all of this lines up with what this community of experts has seen out in the real world.

[VW]

Suppose it were possible to eliminate gear shredding.  Where would the next point of failure be?   My guess would either be at the pinion shaft joint, or the shaft itself bending.

I think a good candidate would be spool body and spindle separation.  It already happens occasionally.

I have wondered about the issues you discuss.  Thought a lot about how to add support to the outboard end of the sleeve.
 Was surprised at the amount of bridge flex you described.  Maybe something could be done about that.  A couple of more mounting screws?  I understand those who are interested in experimenting with "how far can the design be pushed".  Spent enough money, effort and time in hot rodding and racing in the past ('60's teenager, '70's single adult).

I am using the stronger sleeves and gears, and better drag materials, not to "push the limits" but hoping none of those problems occur and everything stays together longer.            

[floating doc]

Excellent analysis of the dynamics of the star drag internals. I too can see a correlation with building hotrods.

[Tightlines667]

This seems like a well thought out insightful post...

Thank you for sharing.

I'm no expert but a couple of things immediately comes to mind regarding observable wear and tear on the drive-train related reel parts.

First.... I often notice heavily fished senators showing significant wobble/play with losened gear sleeve stud to bridge connections.  

Second... the gear sleeve to stud connection be ones loose (where there is considerable play between it's base and the bridge.

Third... excessive play develops between the main gear to gear sleeve connection, sometimes excessive gear is apparent, other times the ring that has been pressed inside the main gear has migrated laterally (usually towards the top of the main gear.

Replacement of the gear set, gear sleeve, and bridge assembly would remedy the issues... But many times wear is not excessive in all parts/connections.  Sometimes I tighten up the gear sleeve to bridge connection by shimming under the gear sleeve, and sometimes the main gear ring can be pressed back into place, which temporarily tightens everything back up.  I have been wondering though if this is in essence leaving the reel probe to develop the same issues again albeit much more quickly.  Also, I've noticed the 'stepped' nature of the inner gear sleeve to shaft connection and shimming reduces the total surface area of contact between these components available to resist torsional forces, and it extends the length of the gear sleeve slightly which increases the forces by increasing the lever.  It just seems like a bushing between the gear sleeve and shaft at the base, and one on the inside of the main gear might help here.  As for the wobbly bridge to gear sleeve stud connection, I always windered why this was connected this way..seems like there should be a more solid alternative available then the preened and welded? end of the stud...maybe a integral collar or something to dissipate these forces.  

Then again the reel manufactures must have thought these things through and are aware of the weaknesses that exist in their drive train components right?

Just a few thoughts on issues I've noticed.

[BMITCH]

As for the wobbly bridge to gear sleeve stud connection, I always windered why this was connected this way..seems like there should be a more solid alternative available then the preened and welded? end of the stud...maybe a integral collar or something to dissipate these forces.

I'm not sue why they did this. Could be a cost factor...I dunno. I was just tinkering with the same issue and maybe drilled and tapped with a low profile headed screw would be a good option. The screw head being a large diameter to spread the load. Just a thought.

[jurelometer]

As for the wobbly bridge to gear sleeve stud connection, I always windered why this was connected this way..seems like there should be a more solid alternative available then the preened and welded? end of the stud...maybe a integral collar or something to dissipate these forces.

I'm not sue why they did this. Could be a cost factor...I dunno. I was just tinkering with the same issue and maybe drilled and tapped with a low profile headed screw would be a good option. The screw head being a large diameter to spread the load. Just a thought.

Thanks!


The post is not detaching at all on my bridges, although  it is flexing a little - not sure if this is the connection to the post or the bridge and/or post flexing. Most of the play seems to be due to the looseness between the post and gear sleeve, which I suspect is necessary, as long as there is a bushing-free post/sleeve design.   Supporting an axle from one side is always tricky.  Not sure how far we could get by making it stiffer on the bridge side.

This seems like a well thought out insightful post...

Thank you for sharing.

I'm no expert but a couple of things immediately comes to mind regarding observable wear and tear on the drive-train related reel parts.

First.... I often notice heavily fished senators showing significant wobble/play with losened gear sleeve stud to bridge connections.  

Second... the gear sleeve to stud connection be ones loose (where there is considerable play between it's base and the bridge.

This is where most of the slop is coming from on the two bridges I looked at-  not only is there lift, there is also wobble.

Third... excessive play develops between the main gear to gear sleeve connection, sometimes excessive gear is apparent, other times the ring that has been pressed inside the main gear has migrated laterally (usually towards the top of the main gear.

Replacement of the gear set, gear sleeve, and bridge assembly would remedy the issues... But many times wear is not excessive in all parts/connections.  Sometimes I tighten up the gear sleeve to bridge connection by shimming under the gear sleeve, and sometimes the main gear ring can be pressed back into place, which temporarily tightens everything back up.  I have been wondering though if this is in essence leaving the reel probe to develop the same issues again albeit much more quickly.  Also, I've noticed the 'stepped' nature of the inner gear sleeve to shaft connection and shimming reduces the total surface area of contact between these components available to resist torsional forces, and it extends the length of the gear sleeve slightly which increases the forces by increasing the lever.  It just seems like a bushing between the gear sleeve and shaft at the base, and one on the inside of the main gear might help here.  As for the wobbly bridge to gear sleeve stud connection, I always windered why this was connected this way..seems like there should be a more solid alternative available then the preened and welded? end of the stud...maybe a integral collar or something to dissipate these forces.  

Then again the reel manufactures must have thought these things through and are aware of the weaknesses that exist in their drive train components right?

Just a few thoughts on issues I've noticed.

Thanks- this makes sense.


The original designs were for reels that had different requirements (driven by larger diameter line of lower breaking strength), and different manufacturing capabilities/costs.    Many of the original Penn star drag parts could be die cut out of brass.  Brass is an easy metal to form -whether forging, casting or cutting, and the tooling will last a long time since it is forming/cutting a soft metal. My guess is the post/sleeve design worked wel with brass, and limited the amount of bushings required, and was strong enough for the original use. If you go back further to the pre-drag penns  AKA knucke-busters,  I think there is some of the source of this design, with the slide out handle shaft for free spool.   As the anti-reverese/drag reels were modified over time, in this case introducing higher gear ratios with smaller teeth, the weakness in this part of the design started creeping toward being an issue.   High strength/low diameter  mono, and then spectra,finally finished the deal.

Looking at the newer star drag designs (Penn, Okuma, Shimano),  there is no bridge sleeve, just a single axle that rotates on the inside plate or bridge.   The pinion to spool shaft design has not changed though, supporting an assertion that pinion slop is not too much of a problem.

On the jigmaster, there is plenty of room to support the shaft at the other end with a bearing and a shim.  This would require a modified bridge, and and a new axle to replace the gear sleeve post combo.   

I'm kind of tempted to give this a whirl....

[floating doc]

"I'm kind of tempted to give this a whirl..."

Go for it!  You'll get plenty of interest and support here.

[Ron Jones]

I've often thought that we needed a solid sleeve that seated into a bearing on the bridge. I think that a bushing or bearing in the plate to better support the end of the sleeve would help also. Of course, after a while you no longer have a Jigmaster, you have a new reel with a jigmaster spool and left plate.
Ron

[Alto Mare]

jurelometer, thank you for the analysis on how the jigmaster 500 is built.
Since we are talking about the stock jigmaster 500, I do have a question for you.
Have you ever fished the jigmaster 500? If so, have you ever had any issues as mentioned above with gears shredding and bridge post working itself loose on the bridge plate, while that reel was fished within its limits? I believe the max on that reel is 14lb.

Sal

[jurelometer]

jurelometer, thank you for the analysis on how the jigmaster 500 is built.
Since we are talking about the stock jigmaster 500, I do have a question for you.
Have you ever fished the jigmaster 500? If so, have you ever had any issues as mentioned above with gears shredding and bridge post working itself loose on the bridge plate, while that reel was fished within its limits? I believe the max on that reel is 14lb.

Sal

Hi Sal,

I have a boxful of classic Penns  that I fished in the salt pretty regularly for several decades  with very little maintenance.  Lots of time in the rod holder getting sprayed.   They got sloppier and stickier and collected some surface corrosion, but the only consistent area of failure was the occasional spool expanding, especially when trolling with steel spools.   These were mostly fished within the generally accepted limits ( drag max at %30 of highest listed line rating).  I have not seen anything  from Penn on limits- just capacity.

On the jigmasters -  i have three.   two are lightly used stock 500s with no signs of wear, but with the mentioned play in the handle shaft.  My pride and joy was (is)  a 505 with green accurate plates and a silver frame - no clicker.  Always admired when I took it out for a spin.  Quite the looker.   Dragged  this reel all over the planet, and used it for trolling, popping, deep jigging, you name it.   I am sure this reel has caught well over a thousand fish, some of them pretty hefty  bluewater and reef species.  Well greased everywhere, but otherwise  not  maintained other than a rinse and a wipe down.   Blew out an AL spool once. Also manage to shred the gear sleeve last year when pulling up a 40 lb yellowtail along with 80 lbs of kelp.  This was with 20lbs of drag checked with a scale, stock three washer Ht100 dry stack.  The reel did not fail catastrophically,  the handle just got looser.  The gears show some wear.  The HT-100 Drag is perfect. 

So I am definitely a fan.


I agree with the hot rodding  analogy that other posters have made.   The introduction of carbon drag washers (by Penn) has allowed the reel to be fished above its original design limits.  Gel-spun (spectra) line has opened the door to new styles of fishing using high drag settings, that make high settings more common.

On one hand it is not fair to criticize a reel when driven well  beyond  its design limits.  On the other hand this is a good way to judge a design as well.  The jigmaster actually does pretty well in this regard, compared to some reels with newer technology that will bind up and trash a bearing simply by setting the drag beyond a suggested limit and flipping the lever.

From a design perspective, I am tossing out a theory that crown gears, and a solid axle supported at both ends are a possible aftermarket enhancement that would up the limits of this reel.  It requires updating several parts at once, and may not work at all, or may not  add much over the tried and true aftermarket parts available now or coming out soon, some of which are not available for a 505.

I am hoping to get "old greenie" up to the capabilities needed to get it back into my rotation, as I really enjoyed fishing that reel.

[Alto Mare]

Jurelometer, I'm glad you're still fishing those penns. Green looks nice on reels, is that 505 a narrow?

[jurelometer]

Jurelometer, I'm glad you're still fishing those penns. Green looks nice on reels, is that 505 a narrow?

It is  a wide body  505 size frame and spool.