Drag cams and ramps??

Started by gstours, November 23, 2015, 12:59:25 AM

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gstours

In an effort to understand the workings of the lever drag I need some numbers and information to some questions I have.
  Firstly I dont have much to compare the different cams with.  And some of you might have a cam you could measure sitting out of a reel or possibly ready to tear a reel down for service or repair.

  This is what is needed:  the thinnest (free spool) measurement of the ramp in thousandths of inch if possible?
                       and,      the thickest (widest) measure at full drag of the ramp,  also in thousandths if possible.

   Here are two similar somewhat similar sized reel drag cams that were removed.  One has .014'' difference (normal)  and the other .065''(ramp from problem described reel)...... ..The reason i am trying to work on this winter project is specifically to modify the cam to eliminate the long lever travel of the reel between freespool and engaging gradual normal drag as what seems normal.
     Please include the size if the reel with your volunteered measurements if possible so to compare each cam to and use normal reasoning to make a judgement?

     Another question is;   are the ramps strait line from bottom to top or are some curved as this might change the ramp feeling when adding drag?    I would not desire this but some may.
   I want to reduce the lever freeplay mainly and think id i have less difference in the ramp height this might be a solution as long as I dont lose too much drag at max setting.
    Correct me if i,m wrong in assuming that with lever drag reels loss of freespool starts when the dragplate and washer start to slightly contact.  (assuming that the bearings are not starting to slow the spin by sideplay pressure).  And that the high part of the ramp is spreading the ramp follower.  In my application would lessening the height of the ramp reduce the draglever travel as it seems to travel less.  To me this was demonstrated in the normal working reel with a cam width difference of .014.

This last photo is both cams that I have questions with.  to compare with.
I would like to hear some input on this subject if possible and will solve the problem this winter.  Thanks for viewing!    gst.


gstours

I have added this crude illustration of the side view of the drag cam ramp.  see below.

  My question is by reducing the height of the ramp at the fullest part would the lower part engage sooner in the arc of the drag lever???
  All things like total drag available disregarded, I think this might work for a modification to reduce drag lever movement before engaging some light drag pressure.
  Any thoughts????

UKChris

Remember please that the cam has two ramps at 180o whereas the lever arc is usually 120o. This needs to be factored in. You won't be able to use the whole of the height difference on the ram, and where the cam is fixed within the cam housing will also influence things. Not all are correctly positioned and not all are moveable without some remodelling.

My limited experience is that reconfiguring the Belleville washers is usually sufficient to fix problems of excess lever travel between freespool and first engagement of the drag. Only if that proves impossible would I consider reconfiguring the cam ramp angle.

Having said that, one reel (was it the Shimano Tiagra?) used to be available with two different cams (one was a 'blue marlin special' I think, though what the actual difference between them was I don't know - something to do with the ramp angle certainly) but I have not seen that option advertised for some time.

AJ

Avet offers "South Florida and Kodiak cam" for light line applications.  Provides less max drag and a slower ramp-up.  I use one on my SX to fish 12# and it works great.

Rancanfish

Wow, I learn something new everyday around here.

AJ, do you just contact Avet,  or are the cams in stores?
I woke today and suddenly nothing happened.

AJ


SoCalAngler

#6
Quote from: gstours on November 24, 2015, 04:16:14 AM
I have added this crude illustration of the side view of the drag cam ramp.  see below.

 My question is by reducing the height of the ramp at the fullest part would the lower part engage sooner in the arc of the drag lever???
 All things like total drag available disregarded, I think this might work for a modification to reduce drag lever movement before engaging some light drag pressure.
 Any thoughts????

My question is by reducing the height of the ramp at the fullest part would the lower part engage sooner in the arc of the drag lever???

IMO, no it would have the opposite effect. By reducing the height of the cam your reducing the drag output.

All things like total drag available disregarded, I think this might work for a modification to reduce drag lever movement before engaging some light drag pressure.
Any thoughts????


The best way to reduce the lever travel is by tightening the preset knob more. This will cause the reels drag to ramp up quicker but will also increase the total drag pressure.

Another way is to play around with belleville/spring washers. You can add thicker washers or change how their set in the reel. If the washers are set say like this ()() you may be able to change them like this(()). This option of changing the belleville washers is kind of a pain because if you use thicker washers or add more you most likely you will need to remove some shim washers if you have some that came stock in the stack. Adversely if you make the stack thinner by going from what I showed above you may need to add shims to get the stack the right height.

If the new stack of washers are not the same thickness as the stock stack you will most likely have freespool issues.

gstours

Thanks for the feedback on this post.     You all have good info and I am sorting it out.
    I do realize that less height of the cam will lessen the final available values, and adding bellville washers may make up for the total lost.    But I noticed a significant difference in the 2 reel cams total ramp height.  This was a CLUE to the solution??????
  I have rearranged the bellvilles and added them but still have 20-30 degrees of drag lever travel to the lever from freespool to when the drag starts to feel anything. I adjust the drag knob to more at strike untill I start to lose freespool.  Then check the lever travel.....
  I do realize I am treading on dangerous ground for many reasons and am trying to use logic in a way to correct the annoying (problem).     
   Its a design flaw I think.   in a great reel with a lot going for it that doesn,t have a face or name yet.
Its a winter project and I will learn something from it but replacement parts are not obtainable that I can "play" with.

  I wish I had more measurements of cam ramps to compare mine with!      Thanks to all.
 

SoCalAngler

A cam for one manufacture to another manufacture should be different, so I can't see how that will help you as far as a measurement. Heck, cam's from the same manufacture will be different in certain models of their reels. A cam for, let's say a Penn Torque LD will be different from a Penn VSX as a Avet SX, MX will be different to a JX, HX or a 30 or 50 sized reels. I just don't see how measuring cam heights for other reels will help you. I may be missing something but would you take cam shaft measurements in a Ford engine and use those in a Chevy and expect the engine to run correctly?

Don't get me wrong I can see your logic in what your trying to do but I think you are going about it in the incorrect way as far as trimming down the cam.

SoCalAngler

You may be able to address your issue with a very easy solution.

I see on that cam there is no detents to go from strike to full with the lever so I assume there is a button or something on the reel to move the lever from strike position up towards full is this correct?

Also are you setting your drag pressure at the 1/4 to 1/3 of the lines breaking strength at strike or at full?

gstours

Thanks for the reply mr socal A; I do appreciate info at any cost. I,m sure you have several (or more) lever drag reels and they all are different.  Different in size, manufacturer, and possibly with some differences in the design of how drag is applied and how the ramps feel as they travel thru the full range of the arc.
   That said I found a reel that I like almost everything about......The complaint is simply there is 20-30+ degrees of drag lever travel from freespool to the first feeling of drag on the spool when the reel is preset to just barely noticeable loss of freespool setting at strike position.......
  I showed pictures of the two cams side by side and the only noticeable difference to me is the difference in height of the problem reel as it is greater.  (the lesser one is a similar sized tiagra ant it works fine)
  I have enough drag at full to spare some at the present factory bellville arrangement of ()()......
    If I lose freespool it doesnt lessen the drag lever arc mentioned earlier I just lose freespool and then the ramp up starts in the same position but with of course more aggression.....
   Any Ideas other  than live with it or go buy a ????reel!




SoCalAngler

#11
Well Sir I set my lever drag reels with about 1/4 or closer to 1/3rd of the lines breaking strength at strike and not full. This way if I need more drag while fighting a fish I can move the lever past strike to get the drag I need. Doing this may get your reel to start to engage the drag quicker where you won't have as much lever movement. Try setting your drags this way at strike before you start playing around with the belleville washers and way before you starting shaving down the the cam.

gstours

Thanks for the answer again.  I have followed your advise on the preset at 1/4 line strength and have not lost freespool spin at the freespool setting.  When looking at my crude diagram this puts the strike  position somewhere between B and C I,m imagining
.
  The Problem Still Is that there is quite a bit of travel from A to near B where some drag seems to be felt.
On my other leverdrag reels this  moving forward of the drag lever from Free immediately starts turning resistance of the spool  on the medium to high preset drag pressure setting.
  On this problem (Project) reel there is 20-30+ degrees of arc of the lever movement before any normal drag seems to begin.
I am sure there is a solution to this.  I just need to understand whats going on in there by further study and possibly substituting or comparing similar parts.
  Thats why when I started this post I was hoping for some measurements of size 16-20-30 size reels to compare mine with.   currently I only had a 16 tiagra apart.      Thanks for the dialog.   Its all good.   I am learning some thing every day.

Tightlines667

Gary,
You can achieve what you are looking for in terms of early ramp up by modifying the ramp on the cam.  Total height on the cam is not going to change when it engages following freespool, or the ramp up.  Most cams are typically designed to with a slower/more linear build up intially, and a steeper ramp at the end.  This means when the preset I'd adjusted properly, and stock Bellevilles are ysed, moving the lever from free to strike will result in a roughly 50% of max drag, and moving the drag lever the last little bit from strike to full will give you the last ~50%.  If the tail end is too agrees I've and you prefer a more linear, 'tournament' type ramp up.. you can file the tallest parts of the ramp down to a more gradual ramp up, and use thinner Bellevilles in a more springy/soft config.  Shims can be used to maintain proper preset adjust, and proper stack height to get freespool at the recommended max effective strike setting.  Conversely, you can steeper the early ramp up to get a more agrees I've drag curve with regards to lever movement.  You can also flatten the top end, cut a slight notch in the cam for freespool, and steeper the first part to get immediate engagement of drag out of freespool and a steeper in til ramp up, with a more linear tail end.  Usually reels with steeper cams will have heavier, more aggressive Bellevilles as well.  The only problem when modifying cams is to go slow, and make sure both ramps are identical.  Total thickness is not important, as you can shim to make up any lost material.  Also, these cams get costly if you end up with less then desirable results.  2 good cams to compare are the Tiagras 50W vs. the Tiagra 50WLRS.  Another interesting comparison is the first gen. International 130 vs the newer one.  In both cases the first reels have thinner/springier bellevilles, and a more linear initial cam ramp.  The original internationals also have a notch in the bottom of the cam, to positively engage the reel in and out of freespool.

Good luck with your experimentation and keep us posted
Hope springs eternal
for the consumate fishermen.

jaypeegee

Hmm. Struggling to understand it all TBH but wonder (If not wildly off track) if either

a flattened "S" shaped cam would help. Essentially starting as a convex hump to gradually increasing middle area to concave finish
or
Experimenting with the Belleville's by using different strength washers in the stack maintaining the correct stack height so that early drag pressure will be set by the ones with the least amount of strength. Perhaps setting those in parallel then returning to series for the heavier gauged washers.

I looked at the SF cam for my Avet LX a while ago and instead opted for the lighter Belleville's. I played with different combinations for a while but shelved it as the washers I had weren't quite the right strength and getting more in NZ is a PITA. Also, when I called McMasters-Carr I may have gotten on a "list" somewhere. :o