Physics Gurus wanted

[Gill-T]

So my Cannon HS downriggers were touted to handle 15 lb weights have blown mother-boards twice in 3 years.  This is getting old.  Cannon reps have said I should really be using 12 lb weights.  So it got me thinking about mechanical advantage and how pulleys and block systems work to lessen the load.  Perhaps I could use two double pulley blocks instead of two single pulleys and gain some mechanical advantage that would translate to less power load on the downrigger system.  What I don't know is how the direction of the force that the motor pulls vs the 90 degree angle the load is pulled from negates the mechanical advantage of adding additional pulleys?  Would I just be adding more friction and therefore more strain to the motor?  Picture the two pulleys on a Big Jon downrigger.  Now picture the two pulleys replaced by double pulleys with the downrigger cable going over pulley 1 to pulley 2, over and back to pulley 1, over and back to pulley 2 then over and down to the downrigger weight.

[AnglingAddict]

It won't do any good - you need a fixed position pulley and one which is movable for it to work as you are thinking.  When you move the end applying the force a distance of 2x, it then moves the load on the original cable by 1x in distance thus halving the tension in the cable (force required to lift the rigger weight).  For this to work you would need a movable pulley which would end up underwater.  The additional drag by the pulley in the fluid medium at trolling speeds would also increase tension on the cable (although probably not to the original value if you choose a small pulley).  You can't just wrap a cable around a bunch of pulleys and get mechanical advantage. One set of pulleys needs to move in the direction that the cable is being taken up. 

[BSmaster]

Can the cables handle the radius?

[Gill-T]

Having a pulley on the downrigger ball would not work the way we fish.  You would be relegated to using a pinch-pad style of release off the tail to the rigger ball.  The doubling of the rigger cable and the extra pulley above the weight would cause blow-back to be much worse.  Thanks for the input.

[skipper19]

Put a pulley on the weight. Hold one end fixed on the boom. The other end on the rigger reel....works on my come along ...blow back could be wicked but ya should be able to hoist 24lb ball with same effort

[skipper19]

Awe jeeze!

[tlr426]

If you could rig a block and tackle setup it may work. But the there would be some disadvantages like increased load on your boom. Maybe braid would work though.

[skipper19]

Your best bet would be to...and I mean seriously..first go with 12 lb...second change the size of the diameter of the spool to a smaller one..you loose speed gain power.

Better yet use on enough cable to reach the maximum depths you fish..not 200 feet or more. Less cable reduces the overall diameter of the coil of cable on the spool. Same as the smaller spool would do.

Edited January 15, 2016 by skipper19

[AnglingAddict]

One thing to consider - especially using the high speeds - is to make sure you are using the right gauge wiring to the rigger.  When you have long runs and undersize wiring you will encounter a lot more resistance - this will cause the motor to operate at a lower current which isn't always the best option - especially under load.  That's something that probably deserves a look as well.   I have the Canon high speeds as well and have not had any issues yet and am using 15-17 pound sharks depending on how deep I am fishing.  

Edited January 15, 2016 by AnglingAddict

[rolmops]

Forget about extra pulleys. What you need is a system that requires less energy per revolution. The way to achieve that is by making the circumference of your spool smaller,while retaining the same RPM on this spool,so that the amount of wire -wound up- per revolution is less. That is the way to use less energy per revolution which will translate in less work for the motor per revolution and extend the life of the motor. Maybe Tom (Longline) who is an engineer has a different solution.

Edited January 15, 2016 by rolmops

[TrophySeeker]

What model rigger? I use 16 lb torpedo weights on my 2 probe riggers with no issue. The motherboard controls relays that control the motor. I'm not sure how the weight is destroying the motherboard, unless motor heat is the issue.

[spoonfed-1]

Simple fix......

 

Buy Scottys.

[Troubles1]

Simple fix......

 

Buy Scottys.

 

Agree

[jason]

Buy new riggers

[TileMan Dan]

The cannon stx's handle 20# weights and are high speed. There swivel bases are garbage as I almost lost a rigger overboard. Luckily I was right next to it and me reflexes fast enough to grab hold of rod holder. Cannon did offer to replace at no charge but my confidence was gone in those lexan swivels. Upgraded to the all metal pedestal bases which I only had to pay difference in price. Good units otherwise. I use 16# torpedos now for three years on them.

[dawg]

Agree

X2

[Iceman]

I Pull up 20lb sharks with my Traxtech riggers all day long with no issues.

[stinger]

So my Cannon HS downriggers were touted to handle 15 lb weights have blown mother-boards twice in 3 years.  This is getting old. 

 

 

You may be getting voltage spikes that are taking the board out.  If the motor is drawing to much amperage then the circuit breaker/fuse should blow. High voltage is the villain in most board failures.

[chinook35]

I agree 100 % on the cannon swivel bases. I rigged up safety lines using parachute cord. Just in case one fails Lot of money gone if a base lets go

[muskiedreams]

Fluctuating voltage could be the culprit. When the motor runs, the voltage at the downrigger could be dropping.  The voltage drop at the downrigger will depend on the wire gauge and length from the battery to the downrigger. It will also depend on how much current the downrigger will draw based on the amount of torque required to lift a particular weight (load). When the voltage drops at the downrigger, components on the control board may draw more current to compensate for the drop in voltage and cause premature failure of the board.

 

CLICK HERE for guidelines on what your minimum wire gauge should be FOR EACH DOWNRIGGER  based distance to battery and back and maximum current rating of the downrigger.

 

If your wiring is up to par based on the guidelines, you should check the voltage at the downrigger and see how much it drops when you raise the weight. Even if you have the proper wire gauge, you are dealing with a marine environment and a device that draws a substantial amount of current. If there is a poor connection somewhere, it can cause a substantial voltage drop. Every connection needs to be clean, not corroded and tight.

 

Another thing I was wondering about is if you are running off of a battery that is being charged by your boat motor charging system, the downriggers could be seeing a higher voltage from the charging system. That voltage could be as high as 15 volts.

 

I would think the downrigger should have been designed to operate with under low or high voltage conditions to a certain extent but maybe a combination with a heavy weight as well is more than it can handle. I would imagine that trolling speed and bouncing on waves could also create added stress.

[brucehookedup]

Get Scottys