Penn Baja Special anti-reverse problem

Started by steelfish, May 03, 2016, 04:37:16 PM

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Robert Janssen

#105
QuoteThe posts are under quite a bit of force (435 lbs by my calculation, but still being debated).....

Sorry for delay; been very busy. Working night shifts, which as is known to some can turn a man's brain to mush.

Nope, not being debated anymore. You were right all along. I was having trouble agreeing with myself over that, and got a little curious as to why. So, I pulled out the gear hobber and built this little gizmo here, in a scale of 1:1. It has a spool disc with a diameter of precisely 3", a ratchet wheel of precisely 0.8" and 65:15 gears thereinbetween, giving a ratio of 4.3:1 and two scales that compare the forces acting upon them.

Which made it abundantly clear how that works in the real-life scenario in the reel. If viewed as a coupled pair of compound gears, it becomes perfectly obvious, since gears are really just round levers. Compound gears are calculated thusly: The inherent ratio of one, times the inherent ratio of the other, equals total ratio. Like in this masterfully composed colorful little diagram.

(values are approximate. Jurelometer got a final ratio of the aforementioned 435 lbs / 27 = roughly 16:1. This one here says 15:1. So what; close enough. By extrapolation this is similar to what I got in the experimental device. Obviously I didn't pull 435 lbs on a 50 lb scale, but the relationship appeared to be similar)

(somewhat interestingly though, I did take the opportunity to mess around some more, and noted that had the ratchet been the same size as the main gear, the force upon it would only have been about 162 lbs. And had it been a smaller baitcasting reel with a one-inch spool, only about 125 lbs.)

So, good thinking by Jurelometer, and brain fart by me.

We now return you to the regularly scheduled thread...

.

Rancanfish

All good stuff.  I find this thread to be one of the more interesting on this site.  I don't care to do calculations, etc.  but appreciate the curious that just have to try.

I don't have a Baja but am keeping my eyes open, because when Tom gets done I'll be upgrading it, lol.
I woke today and suddenly nothing happened.

richard

#107
 Rivverrat...I keep a spring balance on the boat for outrigger clips and drags. I usually measure straight off
the spool having "warmed the drag up" by cranking the handle fast for half a minute on a light drag first.
I find that a bent rod with ceramic or stainless rings will add around 10% to the figure, whilst good rollers
add little or nothing.
I used to fish Tiburon 113,s with a max of 15lb drag and even with extra finger pressure on the spool the yellowtail  and snapper would get
to the rocks. Set the Baja on 25lb and drive away with the rod pulled down flat....job done!
We have an angry fish on one end, a guy  in a boat on the other, and in between a couple of dogs with the surface area of a matchstick.
What could possibly go wrong.... ;D
Its easier to talk about 25lb of drag than to hold on to a fish pulling that figure, for any fight over a few minutes I have to use the gimbal and clip
up to the reel as well.

richard


Hi Jurelometer.
                         Yup my solution I very much an easy first fix for anyone who has not bent their posts yet!
I totally agree that there are much better solutions out there, and I would like to see thicker dogs up against
thicker teeth. With no play or gaps to get the forces out of line.
I had no idea that the forces concerned were so high!!
I hope I,ve got nearer to a 50/50 split with the dogs, but either way they are having an easier time by helping one another!!
I was very careful to file the dog a little at a time ,after marking the excess with a felt tip pen.
With the main gear removed you can twist the shaft and watch the dogs working. I made sure that I held the shaft dead upright
rather than favour one dog over another. I the end, one stroke of a fine file was enough to get both dogs engaging at exactly the same time.
Thank you for putting things in a mathematical perspective sir.

richard


Not sure if I should start another thread but I would really appreciate your comments on:
COULD THE AR GEAR BE MADE ANY LARGER IN DIA.
This would add surface area to an undergear HT 100 for a bit more drag.
There would be more/slightly larger gear teeth for the AR dogs to engage.
The forces between dog and teeth would be less than with a smaller dia AR gear.
  which means less pressure on the posts?
  What is the downside?

steelfish

Richard,  nice idea on a bigger ratchet, more bigger teeth means better contact and less stress on the dogs.

really nice to see more guys participate on this issue.
The Baja Guy

jurelometer

#111
Quote from: Robert Janssen on May 24, 2016, 09:34:44 PM
QuoteThe posts are under quite a bit of force (435 lbs by my calculation, but still being debated).....

Sorry for delay; been very busy. Working night shifts, which as is known to some can turn a man's brain to mush.

Nope, not being debated anymore. You were right all along. I was having trouble agreeing with myself over that, and got a little curious as to why. So, I pulled out the gear hobber and built this little gizmo here, in a scale of 1:1. It has a spool disc with a diameter of precisely 3", a ratchet wheel of precisely 0.8" and 65:15 gears thereinbetween, giving a ratio of 4.3:1 and two scales that compare the forces acting upon them.

Which made it abundantly clear how that works in the real-life scenario in the reel. If viewed as a coupled pair of compound gears, it becomes perfectly obvious, since gears are really just round levers. Compound gears are calculated thusly: The inherent ratio of one, times the inherent ratio of the other, equals total ratio. Like in this masterfully composed colorful little diagram.

(values are approximate. Jurelometer got a final ratio of the aforementioned 435 lbs / 27 = roughly 16:1. This one here says 15:1. So what; close enough. By extrapolation this is similar to what I got in the experimental device. Obviously I didn't pull 435 lbs on a 50 lb scale, but the relationship appeared to be similar)

(somewhat interestingly though, I did take the opportunity to mess around some more, and noted that had the ratchet been the same size as the main gear, the force upon it would only have been about 162 lbs. And had it been a smaller baitcasting reel with a one-inch spool, only about 125 lbs.)

[snip]

.

So after working night shifts, you just threw together a complete mechanical model, including hobbing some gears?  That is (expletive deleted) IMPRESSIVE!    Thanks again for helping educate all of us.

I like your description of  "final ratio".  That seems to be the best way to describe it.   And I think it makes it clear that there is something of an upper limit on star drag reel design.   A combination of large spool diameter,  high gear ratio, and high drag settings, ends up creating a lot of force on the drag/anti-reverse system.  The system has to be well designed to avoid failure.  When designing from scratch, making the ratchet as large as possible is  clearly advisable- it just has to stay under the main gear.   A ratchet that is twice the diameter cuts the load in half.

On a side note:the force on the pinion junction can also be calculated.  Simply divide the drag torque by the pinon contact radius. So for the example we have been using,  if the radius of the point of contact at the pinion junction is .25 inches 40.5 /.25 =162 lbs of force on the pinion before the drag slips.  Think of a  car driving about 20-30 MPH with a coil of line tied to a 162 lb object.  Now think about the amount of stress when that line goes taut.  That is  what the pinion is facing when it is trying to  engage at full force...

BTW,  I estimated the ratchet, pinion and full spool radius .  If someone has the exact measurements we can get to a closer calculation.  This would still be a rough estimate, as the parts are not perfectly aligned, friction in the gears,  etc. Thanks to Mr, Janssen, we have some evidence that we are in the right ballpark.

jurelometer

#112
Quote from: richard on May 25, 2016, 01:20:09 PM

Not sure if I should start another thread but I would really appreciate your comments on:
COULD THE AR GEAR BE MADE ANY LARGER IN DIA.
This would add surface area to an undergear HT 100 for a bit more drag.
There would be more/slightly larger gear teeth for the AR dogs to engage.
The forces between dog and teeth would be less than with a smaller dia AR gear.
 which means less pressure on the posts?
 What is the downside?

Yup, as a couple of us have noted,  the most important advantage of a larger ratchet is increasing the leverage at the dog ( thereby decreasing the force).  Twice as big a ratchet means half the force on the dog.  

there are some other important design considerations from what I have read about dog/ratchet systems.  the dog post has to be positioned correctly, so that the the force from the ratchet tooth is at a 90 degree angle from the radius (I.e. tangent to the the circle defined by the contact point).   If the angle is off, it has the same effect as making the ratchet smaller.  Not to mention that this layout ends up creating a risk of  dog binding, wear, designing curved dogs that are not as strong, etc.

So for upgrading this reel, a larger ratchet means relocating the dog posts - maybe doable if any upgrade requires some drilling /reaming on the bridge anyways, but more risk of unforeseen complications (maybe something in the design requires a smaller ratchet- or maybe the post gets moved too close to the side of the bridge?

Regarding the under-gear  washer, there has been quite a bit of debate on this topic.  I am in the camp that this is primarily a thrust washer, whose job is to allow the main gear and ratchet to stay aligned and smoothly move independently.   A drag washer is soft, compressible, and easily torn,  not an ideal thrust washer.  The big advantage over other washer materials is heat tolerance.   Delrin/Acetal makes a better thrust washer, can run indefinitely 180F. You don't want to run it over  about 250F, or its start to get squishy.  Fiber reinforced PTFE (AKA Rulon) is smoother, and has higher heat tolerance, but is not as tough and compression resistant as delrin.  A mechanical thrust bearing ( with balls or rollers)might be the best option, but finding room for it is tough. Many folks  here have been using delrin for awhile,  the reports I have seen are that it's makes for a smoother drag, and I haven't seen any reported failures. If you do a search on this topic, you can decide for yourself.

There are some other things that go into a good ratchet design, but I don't want to keep rambling.  Here is an example of what I think is a pretty good ratchet design (Shimano TLD star) that has a gear shaft/ratchet assembly  similar to the 113HN.  Note that the ratchet is as large as possible.

And I agree with Steelfish.  Getting many voices, opinions, experiences has made this a very interesting discussion!

-J

richard


Thanks for the explanation Jurelometer....I can see your point about positioning the posts to create the best angle
for the dogs to meet the teeth....and straight dogs..
My speedmaster has a similar large ratchet gear to the one you showed....the forces must be reasonable for the dog to run on
a "graphite" shaft rather than a bridge screw.
I wonder if "small ratchet syndrome" is something you get when you try to use one of the four bridge screws as a pivot for the AR gear?
The screw is a little closer (to the gear centre) than you really want ,especially if were aiming for straight dogs at the correct angle.
So to keep the best dog angles ,whilst using a convenient pivot point for the dog , they made the ratchet gear smaller in dia than it should be in a perfect world.
   
Re the undergear washer ,yeah a bigger version of the present PENN washer would be fine by me..they are foolproof........
If we replaced this washer with a bearing.......would we end up with something like Avet side thrust ?
    Thanks again for all the info gentlemen


Tightlines667

Great thread.  I am enjoying the reading, learning, and member participation here.

I think these force calculations/equations could be extended by a few more variables to give estimates of the cranking  'power' advantage a given reel design has.  For example, we intuitively know that ttpically, a reel with larger gears (and a lower gear ratio), spools, and a handle arm will translate to a greater mechanical advantage (force in vs. force out).  But actually having a ready-made equation to plug specific variables in for a given model and getting a number out, would be greatly advantageous for comparing designs.  I apologize for straying from the intended topic of this thread.  This idea, may be better served in a new thread.
Hope springs eternal
for the consumate fishermen.

jurelometer

Quote from: Tightlines666 on May 26, 2016, 07:20:31 PM
Great thread.  I am enjoying the reading, learning, and member participation here.

I think these force calculations/equations could be extended by a few more variables to give estimates of the cranking  'power' advantage a given reel design has.  For example, we intuitively know that ttpically, a reel with larger gears (and a lower gear ratio), spools, and a handle arm will translate to a greater mechanical advantage (force in vs. force out).  But actually having a ready-made equation to plug specific variables in for a given model and getting a number out, would be greatly advantageous for comparing designs.  I apologize for straying from the intended topic of this thread.  This idea, may be better served in a new thread.

Good idea!

I think the formula is the same as the force on the dog formula described in this thread.  Just replace the ratchet radius with the handle length from center of gear shaft to center of knob.

If  you replace max drag with 1, then you will have a ratio for how much force on the  knob to get 1 lb of cranking force on the reel.

There is a formula on a document that you can download.   It is .doc and .xls format, so if you have a computer  with MS Office or LibreOffice(Free!),  you can just download and plug in the numbers.  As mentioned before in the thread, you an find it here:
http://alantani.com/index.php?topic=14241.0   (also note all the ribbing I took for doing some science  ;D )

Let me know if it works for you or if there are any questions.


   For this reel at 27 lbs drag and a spool filled to 3 inches (assuming it could hold that much): We were at ~ 174 pound-in of torque.  Divide that  by handle span.  Let's  say   3 inch:  174/3  = 58 lbs of force, meaning the force you apply at the knob  is roughly double the force pulling the line onto the reel. 

Let's try a longer handle- at   5inch span:  174/5 = 34.8 lbs of force,  a big difference, getting close to 1:1.

As with the dog,  if the force is not perfectly  aligned ( tangent) with the cranking circle,  it effectively shortens the crank length.  This is where the ergonomic handles come in to play.   You probably get another  5-10% more cranking efficiency  over the little plastic torpedo knobs by virtue of being able to apply the power correctly.  Not to mention the ability to apply more power with a larger grip.


This also illustrates  the value of a two speed when drags get up above 20 lbs.   if you cut the gear ratio in half, it doubles your cranking force.

And I guess we (Ok, mostly me :))   are getting off topic here.  It would be nice if we has a sub-forum for reel science/design/engineering to collect these type of discussions(hint, hint...)

Rivverrat

jurelometer, I hope you keep this up. Your math showing the forces that reels can experience very clearly shows why these under 30 oz.  20 something oz. reels must be designed right if they are expected to have any reasonable working lifespan. It gives me a much better appreciation of say a 12 or 16 VSX. While also solidifying my need for one or two...errr three of them....Jeff

steelfish

Tom, you got a PM

btw, any update on this problem?

The Baja Guy

Cortez_Conversions

Quote from: steelfish on June 18, 2016, 12:59:57 AM
Tom, you got a PM

btw, any update on this problem?



I did get you PM alex.
I have made some improvements, but nothing really news worthy yet.

Tom
Visit: cortezconversions.com
Forget about all the reasons why something may not work. You only need to find one good reason why it will.-Sal

Rivverrat

Any improvements that refine this wonderful reels anti reverse are news worthy....Jeff