helpin do the math on square area calculations!

[Ron Jones]

You increase drag, I don't believe it would be absolutly double due to ineficiencies, because you are applying the same force to multiple friction surfaces. The pressure seen by the top washer will be seen by the bottom washer.
Ron

[George4741]

hmm... i sorta get the feeling that this is leaning towards the more-surface-equals-more-drag-line-of-thinking, is that right?

I don't mean to intrude or dim your light bulb or anything, but if that is the case, then you'll be disappointed. It just simply isn't true.

So, from Doc's and others comments, I get the impression that adding additional drag washers doesn't increase drag.  If this is so, then what is the advantage of increasing a drag stack from, say, a 1+3 to a 1+5 or 1+7?

[Ron Jones]

That is not true. Stacked drag washers are subjected to the same force, so each friction surface increases drag. Increasing drag washer size decreases the force per unit square that the washer is exposed to.As it happens, the decrease in force is equivalent to the increase in friction due to surface area.So there is no net increase in drag.
Ronald

[johndtuttle]

hmm... i sorta get the feeling that this is leaning towards the more-surface-equals-more-drag-line-of-thinking, is that right?

I don't mean to intrude or dim your light bulb or anything, but if that is the case, then you'll be disappointed. It just simply isn't true.

So, from Doc's and others comments, I get the impression that adding additional drag washers doesn't increase drag.  If this is so, then what is the advantage of increasing a drag stack from, say, a 1+3 to a 1+5 or 1+7?

No, they add drag because instead of distributing the limited force of one pressure plate they magnify it when they are place in sequence. When you add surface area under the pressure plate of a lever drag all you are doing is distributing the force over that larger area (and as well that extra area doesn't have as much effect being close to the spindle). You would need a larger drag surface *and* a larger pressure plate to create more drag ie instead of a 30w you have to go to a 50w reel.

Take a look at this picture:



If you add surface area in "A" it has virtually no effect. Area "B" is doing all the work because it has some distance from the spindle and you would just be spreading out the force from the pressure plate. If you added the surface area in "C" by increasing the diameter you would have a dramatic increase in drag and it would continue to increase the farther you got from the spindle assuming we had a pressure plate to cover the new diameter. This is also why drag increases as the line runs off the spool. The diameter of the spool is decreasing as line gets run off reducing the force on the spindle. The drag disc, conversely gets effectively larger in diameter in relation and the drag force effectively increases. Of course this is due to the effective leverage changing, getting less for the spool and more for the drag itself.

If you add another carbon fiber drag washer under the pressure plate like Avet does in their "dual drag" design then you do increase the drag for the same force from the pressure plate. In the case of the drag "stack" in an Avet or in a star drag we are adding washers in sequence so we are effectively adding another area "B"  for every washer we add but we are not diluting the force of the pressure plate. Similarly, Accurate is doing effectively the same thing but they have the extra drag on the other side with another pressure plate.

So, it's not a case of simply increasing surface area it depends on *where* you do it and how you apply pressure.

TL;DR if you can increase the surface area and apply equal force to that new area and it has the same relationship (leverage) to the spindle as the existing drag then you will increase drag. But filling in the center of a lever drag's disc has minimal effect because you have just spread out the force from the pressure plate and the center of the disc has minimal effective braking power.

Hope this makes sense! 


regards


ps sorry hard to explain in words, very easy if we could rapidly draw a picture to address various points. Think of a bike wheel and how little pressure it takes to brake when the cantilever brakes work on the rim as compared to the old hub brakes right next to the axle that took all our weight and leg strength to stop the bike. This is what increasing the diameter of the disc does for braking power and also why the interior of the disc has so little effective power: different leverage.

[gstours]

Hello again. and I,m sure glad that I ducked down after asking a question like this for their reply.  and thanks too for the feedback.   Its good for all of us to learn something here. I learn by listening. so here goes my explanation of why I asked the question to start with.....    I was thinking that for this popular older lever drag reel if I could increase the pounds of available drag at strike position,  that  I would get a non dragging freespool  at the slightly higher strike position settings......I have added bellville washers and reconfigured them, and at lower drag setting the freespool is good,  its when the drag settings are increased that you begin to lose freespool......so it seems like if I had more available drag the settings would not have to be so high........I hope that I explained my intent?
 This reel could easily have an additional 1/4inch larger O.D. to the drag washer on the plate, and maybe 3/8inch larger at the inner diameter as well.  to me this is a significant change,   Bur what would I really achieve??.
 I welcome all Ideas, and we can do the math soon.  and I can be more specific with measurements. to help calculations and comparisons.  I think this will be a good place to learn something........thanks to all so far......

[johndtuttle]

Yes, you are correct, if you were to increase the OD of the drag disc and had extra pressure plate to cover it should take less preset force to have the same effective drag at strike.  Increasing coverage in the center will have virtually no effect.

This *may* reduce handle pressure (and pressure on the pinion bearing which is the source of the handle pressure and loss of freespool) depending on the design of the pressure plate. As I understand it as the force from the pressure hub has to apply pressure to the pressure plate it does not uniformly apply pressure to the drag across it's entire surface, particularly near the center.

Usually the pressure plate is designed to mate to the characteristics of the diameter/surface of the drag disc. So you may not experience any gains.

Or, the smaller disc is intended for structural reasons by the manufacturer and other components may not be designed to handle the additional pressure if you increase the size.

But heck, if it's not your last reel it may be worth a try!

[Alto Mare]

You increase drag, I don't believe it would be absolutly double due to ineficiencies, because you are applying the same force to multiple friction surfaces. The pressure seen by the top washer will be seen by the bottom washer.
Ron

.
Ron, from some of my tests with drags I found that adding additional drag will increase the numbers, more so with the custom hex inserts.
I placed a bunch of washers in a stock 9/0, I believe (11) carbon fiber washers. Thant 9/0 wasn't holding drag at 15lb, but was ok from there .

[BMITCH]

John, thanks so much for the bicycle caliper brake analogy. Anyone who has adjusted or even taken a close look at the stopping power of these breaks will understand the principal behind it. Great stopping power for such a small contact area. The lightbulb came "on". I wasn't able to wrap my head around the fact that more surface area on a single washer couldn't increase the drag. It just depends on where the surface area comes in contact with the pressure plate/drag washer. Thanks again.
Bob

[wallacewt]

by increasing the drag washer  size,id,will the drag be smoother?
cheers

[BMITCH]

Good question Wallace. I dunno?

[Mandelstam]

John, thanks so much for the bicycle caliper brake analogy. Anyone who has adjusted or even taken a close look at the stopping power of these breaks will understand the principal behind it. Great stopping power for such a small contact area. The lightbulb came "on". I wasn't able to wrap my head around the fact that more surface area on a single washer couldn't increase the drag. It just depends on where the surface area comes in contact with the pressure plate/drag washer. Thanks again.
Bob

That analogy helped me as well!

And I think this is why so many people get confused. The math states that an increase in surface area doesn't effect drag, but because an increase in area can result in greater leverage it clearly can. But then it's not a discussion about the surface area anymore but of the placement of the break in relation to the axle. Two different things.

Karl

[Keta]

I have some miss cut 114H washers that are undersize, one of these days I'll do some testing but I want to make a socket so I can set the drag with a inch pound torque wrench first.

The best way to increase drag is to add washers in the stack.

[Bryan Young]

I have some miss cut 114H washers that are undersize, one of these days I'll do some testing but I want to make a socket so I can set the drag with a inch pound torque wrench first.

The best way to increase drag is to add washers in the stack.

Hey Lee, I miss cut some 114 washers that are oversized (that I sent to you)...too bad we could not magically combine them and separate them and it would be all good 

[johndtuttle]

John, thanks so much for the bicycle caliper brake analogy. Anyone who has adjusted or even taken a close look at the stopping power of these breaks will understand the principal behind it. Great stopping power for such a small contact area. The lightbulb came "on". I wasn't able to wrap my head around the fact that more surface area on a single washer couldn't increase the drag. It just depends on where the surface area comes in contact with the pressure plate/drag washer. Thanks again.
Bob

Not to worry. I used to tutor Chem and Organic Chem and it helps me to think through how things work by putting it into words.

The analogy I chose is a simplification that ignores certain things but should hold up in our simple example and for our purposes of basic understanding.

[Bryan Young]

Not to worry. I used to tutor Chem and Organic Chem

Those are the 2 very courses that kept me from being a pharmacist