Cutting Keyway in Rudder Shaft for AP

[silverp40]

Originally Posted by popeye2818

You could have milled the keyway to half thickness and had a local welder tig weld it on with a full pen weld,depending where you are it probably would be 75 to 150 dollar welding job.Im not fond of set screws ,even with divits.They tend to losen at the worst time.

Not sure what you mean but I am doing away with the previous set bolts...plus welds on a tiller arm are hard to trust (this one was bronze)

[popeye2818]

I was saying to weld the keyway to the rudder stock which should be stainless steel .The tiller arm you could removed and have the keyway cut in a shop .Instead of cutting a slot in the rudder stock you would weld it on there .Only if the stock is stainless though,if its brass I wouldnt trust a brass key welded to a brass shaft.A stainless weld done by a real welder with a heliarc(tig) welder will not break.Thats if I am visioning this rite.Just a Idea. hope it helps.

[boden36]

Do you need to key it at all? The reason I ask is that our Aquadrive propeller shaft coupling is split axially and has six high tensile allen head set screws to clamp it to the prop shaft. Despite years of full engine thrust and forward/reverse shock loading it has never moved. Maybe you could have something along these lines made up.
Regards,
Richard.

[silverp40]

Originally Posted by boden36

Do you need to key it at all? The reason I ask is that our Aquadrive propeller shaft coupling is split axially and has six high tensile allen head set screws to clamp it to the prop shaft. Despite years of full engine thrust and forward/reverse shock loading it has never moved. Maybe you could have something along these lines made up.
Regards,
Richard.

I think that couplings do not get as much torque as a ruddershaft, although coupling bolts get sheared all the time (and it is no fun getting the studs out!!!). Normally, the rudder is not normally loaded much provided the sails are well balanced. Those times when runninig or broad reaching in heavier weather with seas to match, even with small balanced fore and aft sails REALLY load the rudder and that could be for many hours. Boats with semi balanced rudders will get even more loading.

As far as welding a key to the shaft, it is a bit like the proverbial ultimate test of welding skill: weld a razor blade to a railroad track...When the shaft get preheated, the fiberglass "seal" around the top of the rudder (that keeps the water from getting in the rudder) will probably burn as well as the packing material in the packing gland and maybe the bearing material...whew!

[popeye2818]

Originally Posted by silverp40

I think that couplings do not get as much torque as a ruddershaft, although coupling bolts get sheared all the time (and it is no fun getting the studs out!!!). Normally, the rudder is not normally loaded much provided the sails are well balanced. Those times when runninig or broad reaching in heavier weather with seas to match, even with small balanced fore and aft sails REALLY load the rudder and that could be for many hours. Boats with semi balanced rudders will get even more loading.

As far as welding a key to the shaft, it is a bit like the proverbial ultimate test of welding skill: weld a razor blade to a railroad track...When the shaft get preheated, the fiberglass "seal" around the top of the rudder (that keeps the water from getting in the rudder) will probably burn as well as the packing material in the packing gland and maybe the bearing material...whew!

The key word there is skill,a tig welder is a very fine line welder.no sparks ,and there should'nt be that much heat and you would use a wet rag for the heat that is there to disipate it if it were neccesary .Ive been a welder for 15 years ,its my daily job.Should not get that hot..

[Blue Stocking]

If you presently have an existing steering quadrant, and not a tiller arm as you originally stated, fill and thru bolt the wedge shaped opening in the quad with hardwood fillers and aluminum top and bottom plates to hold the ball joint.
Have fitted a number of A/Ps like this.

[Sailmonkey]

Originally Posted by silverp40

So I decided to use the upper section of square cut rudder shaft that is above the quadrant and install the tiller arm there.

Isn't that where your emergency tiller fits?

[silverp40]

Re: Cutting Keyway in Rudder Shaft for AP
If you presently have an existing steering quadrant, and not a tiller arm as you originally stated, fill and thru bolt the wedge shaped opening in the quad with hardwood fillers and aluminum top and bottom plates to hold the ball joint.
Have fitted a number of A/Ps like this.

I was referring to the AP tiller arm, sorry for the confusion. I also installed an ap on another boat on the quadrant because the owner really wanted it that way. I personally like the shaft idea because if one of the quadrant cables ever breaks(I got spares and check the existing ones), I can use the AP to steer the boat.

Yes, the emergency tiller fits on top of the shaft and there is still about 2 1/2" of room but I think it will not be enough. If one cable breaks, then the AP also breaks down, I can unbolt the tiller arm and then fit the emergency tiller there.
Sounds like a harsh day!

[Blue Stocking]

Originally Posted by silverp40

Re: Cutting Keyway in Rudder Shaft for AP
If you presently have an existing steering quadrant, and not a tiller arm as you originally stated, fill and thru bolt the wedge shaped opening in the quad with hardwood fillers and aluminum top and bottom plates to hold the ball joint.
Have fitted a number of A/Ps like this.

I was referring to the AP tiller arm, sorry for the confusion. I also installed an ap on another boat on the quadrant because the owner really wanted it that way. I personally like the shaft idea because if one of the quadrant cables ever breaks(I got spares and check the existing ones), I can use the AP to steer the boat.

Yes, the emergency tiller fits on top of the shaft and there is still about 2 1/2" of room but I think it will not be enough. If one cable breaks, then the AP also breaks down, I can unbolt the tiller arm and then fit the emergency tiller there.
Sounds like a harsh day!

A/p push/ pulls the quadrant directly. Came home this way when boat lost a pin in a steering sheave. Still have access to square top for aux tiller if a/p fails as well.