The uncanny valley

[JasonGotaProblem]

I've worked on 2 "13 fishing" reels in the past week. I find them to be an interesting combination of robust features I like, and shortcuts I don't like. But this post is about only one of those details.

I've worked on 2 of these. One was a higher end model with a bronze alloy main and a backup anti reverse. The other was a lower end model with no backup anti reverse and an either aluminum or zinc main. I couldn't tell. Both have the same high gear ratio. This requires a large main gear. Neither has a super robust frame etc. to handle a ton of drag.

So their solution was to use a lesser surface area for the drag disks. And frankly the carbon disks all have large inner diameters so there's a ton of wasted space.

So they decided to save on the amount of metal used in these gears that are likely cast instead of machined by putting that goofy valley between the walls of the drag cavity and the gear teeth.

I've been wrong about things that looked like a lazy shortcut, and later found out it was intentional design whose cleverness I didn't understand at the time. Is this one of those cases or is this just... Lame?

[steelfish]

i dont know but looks like those cases where the Owner of the company wants a reel with high ratio but not much drag so the reel dont brake into parts on a good fish and also dont want to use plastic on the gears but metal to advertise the reel as all-metal-gears, at the same time keep the cost down to have a good profit and just give all that information to the engineering dept to make a reel with all those requirements.

later on, they came up with the reel you have in your hands, everybody's happy even the owner of the reel specially becuase of the low price compared to a shimano reel.

[jurelometer]

Sliding friction is a function of clamping force and the coefficient of friction (relative smoothness of the sliding surface pair).  Surface area has no effect.

Diameter matters, in that you get more braking work per revolution as diameter increases.  A big hole in the center helps, as that makes for a larger average diameter.

Compare to disk brakes on cars.  Big rotors , small pads.

On a reel, the larger the diameter, the better the alignment has to be.  Whatever angular skew is present, the wobble distance will increase with diameter.  And greater diameter cause greater leverage on whatever  is keeping the surfaces aligned.

-J

[jurelometer]

You  design in  max drag reliably by having the star bottom out.  Otherwise someone can always go crazy with some vice grips on a star drag.

There were some fly reels that went for some ridiculously large effective drag diameters (large ID and OD).  The ones that I am aware of developed a reputation  for sticky/jumpy drag.  I suspect as the parts wore in, the misalignment was magnified compared to more typical designs with smaller drag diameters.

So maybe this brand went the opposite way in design strategy, allowing for looser manufacturing tolerances.  A small diameter drag stack with relatively large drag washer ID would make sense here.

Knucklehead design is always a possibility when it comes to reels. Especially for boutique reel brands. But unless I am missing something, this seems to make sense.

-J

[JasonGotaProblem]

this seems to make sense.

-J

So I think there's some miscommunication on my part here. The drag disks had a large OD and a large ID so in my mind the large ID was wasted space. That's what I was trying to say. In my head I'd think the carbon disks should fill the space either way and then mess with stack height to control max drag. But I don't design reels, I just misuse them.

What this thread was about was the "moat" surrounding the drag cavity, highlighted in the pic below. I would think that would be metal filling that space.

[nelz]

I guess it's intended to reduce weight, primarily, and allows using existing parts for the drag stack. Reminds me of a fuller as found on knives. The drag is more than adequate for that type reel and the intended target species.

[steelfish]

What this thread was about was the "moat" surrounding the drag cavity, highlighted in the pic below.

I think there is no misunderstanding here, the way I see this is you're thinking on "how this reel could've been more efficient" because you see a waste of space-material, but the brand owners were thinking on savings, every micro-tiny material of saving x thousands of reels sold = more money on the pocket of the owner.

I tend to dont critique too hard on the off-brand gear mechanisms and I also found out that it just dont worth the time, effort and money to upgrade them and try to make them stronger because the next weak link will break on you on the worst time, it had happened to me already few times on my beginnings as reel-head     

[jurelometer]

I think there is no misunderstanding here, the way I see this is you're thinking on "how this reel could've been more efficient" because you see a waste of space-material, but the brand owners were thinking on savings, every micro-tiny material of saving x thousands of reels sold = more money on the pocket of the owner.

I agree, but I don't think that most of the savings is in shaving off a bit of material.  The design choices make the manufacturing cheaper.  Sometimes you have to be more clever to design an inexpensive product that works OK, vs overbuilding everything and charging a lot more money for it. 

this seems to make sense.

-J

So I think there's some miscommunication on my part here. The drag disks had a large OD and a large ID so in my mind the large ID was wasted space. That's what I was trying to say. In my head I'd think the carbon disks should fill the space either way and then mess with stack height to control max drag. But I don't design reels, I just misuse them.

For the TLDR crowd:

1. Drag surface area does not directly affect maximum drag.

2. A larger OD means more braking work per revolution.

3.  A larger  ID means MORE braking work per revolution. (the greater the surface area for a fixed diameter, the less braking work per revolution-  that empty area is NOT WASTED SPACE)

4.  It is harder and more expensive to make a stable/non-chattering drag with a large diameter.

5.  The channel/valley serves two purposes- it helps with heat dissipation, but more importantly, it allows for a more uniform wall thickness which is necessary for injection molding.

----

Some details:

The drag disk has a smaller OD than could fit in the main gear.  typically a manufacturer prefers to use up that real estate in order to push up the drag capacity for advertising purposes, but it requires a more robust and accurate set of parts.  As noted in my post:

Sliding friction is a function of clamping force and the coefficient of friction (relative smoothness of the sliding surface pair).  Surface area has no effect.

Diameter matters, in that you get more braking work per revolution as diameter (and therefore circumference) increases.  A big hole in the center helps, as that makes for a larger average diameter.

It is the CoF, the clamping load, and the distance traveled that determines how much kinetic energy is converted to heat (i.e., braking) per revolution.  Surface area is irrelevant.  The distance traveled is the circumference, since the part is rotating.  But there is actaully a range of circumferences between the ID and the OD. There is some semi-basic math that lets you weight this range in circumference to get a sort-of average circumference to plug into the friction equation.  If you search for a thread mentioning pressure/velocity rating on drag materials, you should find the details.

But to limit it for this discussion- the greater the ID, the greater the average circumference, so the more braking you will get for the same OD and the same clamping load. As strange as it sounds, increasing the surface area by decreasing the ID actually gives you less drag.  You are not alone- there is a thread or two where folk proposed "improving" (actually degrading)  a drag stack by shrinking the ID. Tribology is strange stuff.  I read just a bit about it, and it is freaky.

The  greater the OD the more travel per degree of misalignment and the greater the leverage for uneven clamping load.  You have to make a better quality reel to have a larger diameter drag stack.

What this thread was about was the "moat" surrounding the drag cavity, highlighted in the pic below. I would think that would be metal filling that space.

If you want to make an inexpensive high gear ratio reel, one approach is to use small OD/large ID washers, and possibly stack a few extra if you don't have enough drag. So now you have some extra real estate on the main gear to deal with. You could just leave it there but...

When designing an injection molded part, a major goal is to have uniform wall thickness to avoid shrinking unevenly during cooling, which leads to  warping, cracking, and/or developing internal stresses. 

So if you want a reduced OD drag stack, and a high gear ratio (large main gear), and an injection molded main gear, this design makes sense.  There are also some thermal conduction advantages for your main gear "moat", but I doubt that this was a consideration.

Mechanical design sure is fun stuff!

-J

[Gfish]

Main looks like it could be die-cast aluminum. The moat maybe saves some material cost?

Would a smaller I.d. Drag disc, with a relatively large o.d. be better at disappating heat?

[jurelometer]

Main looks like it could be die-cast aluminum. The moat maybe saves some material cost?

Answered in the previous post.  Die casting is just the metal flavor of injection molding. You want to avoid a major difference in wall thickness.  The moat does this.

Would a smaller I.d. Drag disc, with a relatively large o.d. be better at disappating heat?

It depends. Probably not. You get a greater surface area.  The farther the heat has to travel through the  conducting metal, the longer it will take for the process of conduction,convection etc.  to normalize the temperature with ambient air temp.

Still air is a great insulator, and there is not much air moving though the inside of a star drag.  The still air is actually making the inside of the reel work like a thermos. 

I would wager that escaping heat will mostly travel up the main shaft and dissipate on the the star and handle arm.  Unless of course you "upgraded" to a stainless star ( I'll save this for another day). So the flow of heat is going to mostly go from the inside of the metal washers and up the main shaft.  A larger surface area will probably work slightly against you, as some of the heat has more metal to pass through.

 I don't think many reel drag designs focus much on transporting heat.  Heck, they even put those shields on the big game lever drag mechanisms that turn them into a double thermos  .

Think of a reel drag as being sort of like a drag race motor.  The drag has to perform well, but only for a short duration (probably less than a minute or two on an "epic battle", the rest of the time you are winding or drinking beer resting). The investment is in short duration performance.  Long duration performance is not as valuable.

-J

[boon]

If the reel makes enough drag for its intended purpose, and the gear is strong enough for the intended purpose, then it saves weight (and a tiny tiny bit of inertia) and some manufacturing cost. Everybody wins.

More metal is not always better.

EDIT: I looked on their website and these all look to be Bass or very much inshore light tackle reels. Despite that, they quote somewhere between 20 and 22lb of max drag. Even if we take that with a large grain of salt, nobody in their right mind is fishing these as 40-50lb (15-17lb drag) reels. They hold 125 yards of 12lb mono and will likely do 99% of their fishing at drag settings around 2lb.

[steelfish]

If the reel makes enough drag for its intended purpose, and the gear is strong enough for the intended purpose, then it saves weight (and a tiny tiny bit of inertia) and some manufacturing cost. Everybody wins.

More metal is not always better.

2x

[Gfish]

If the reel makes enough drag for its intended purpose, and the gear is strong enough for the intended purpose, then it saves weight (and a tiny tiny bit of inertia) and some manufacturing cost. Everybody wins.

More metal is not always better.

EDIT: I looked on their website and these all look to be Bass or very much inshore light tackle reels. Despite that, they quote somewhere between 20 and 22lb of max drag. Even if we take that with a large grain of salt, nobody in their right mind is fishing these as 40-50lb (15-17lb drag) reels. They hold 125 yards of 12lb mono and will likely do 99% of their fishing at drag settings around 2lb.

I doubt the manufacturer will pass-on the cost savings to the customer. Maybe it's my prejudiced thinking, but it didn't seem to happen so much when graphite composite came on the scene.
I'll take the extra weight of a solid gear and perhaps more weight from a more robust supporting gear shaft.

[jurelometer]

Ooh.  Just looked up the "manufacturer ".  They are not inexpensive. 

The reason for going with the valley might be to trim some weight if the main gear is not cast.  The smaller than possible drag diameter is probably the same reason that I discussed above.  It might also allow them to use the same drag parts with the different gear ratios.

13 Fishing has also started using plastic plain bearings (oops- "high tech polymer").  Could be something relatively inexpensive like UHMWPE, or something nicer like Rulon. Hopefully not nylon.  But plain bearings made from the right type of plastic is a good idea for a bass reel, as there is zero bearing maintenance, and probably will be more quiet  and will outcast a ball bearing reel that is not maintained perfectly.

I didn't see a bearing supporting the outside of the main shaft.  And there were some reports of the main gear shredding at on the spool side edge, which is consistent with the main shaft flexing from helical gears being wound under load. Also looks like the main gear in most models is aluminum. Everything is riding on that sleeved roller clutch bearing.  Blech.

22-30  lb max drag rating on these reels is more of a joke than usual for small levelwinds. I would be very surprised if it held under load as well as the Lexa, Tranx, or Komodo in the same size class.  In reality, this is just yet another bass reel.

As Boon noted, it could be a fine reel if used for its intended purposes. But there is nothing special about it.  It is not a particularly strong reel design where it matters most, and it is not inexpensive.  Couldn't find a schematic anywhere. Don't know what parts availability is like.

Meh...

-J

[JasonGotaProblem]

Ooh.  Just looked up the "manufacturer ".  They are not inexpensive. 
...
Meh...

-J

Overpriced BS. They're not terrible. But it really strikes me as someone put some time and effort into designing a reel that can still be decent with crap components.

Everyone I know who fishes these uses them with braid. And none are using it at 2# of drag. The star is flimsy feeling plastic. The roller clutch is weak looking garbage. One of them had a silent dog too so that was nice.

Both had those "ceramic bearings" as he called them. Yeah they're bearings but not ball bearings. He liked them. And the disengaging levelwind reels will freespool for about 10 sec with them in. Kinda spongey for "ceramic" For comparison I got one up closer to 40 on one with hybrid ceramics installed.

I'd give it a C+ if they were half the price.