New to us Hunter 40.5

smokey73 · Jan 11, 2022

You can get a rotary drive from RayMarine. There are two sizes. Can't remember which I used but I'll see if I can find my installation manual receipts. If you use a rotary drive, you'll have to spec the sprockets correctly and probably procure those from somebody other than Raymarine. I'll see if I can find my parts list. You'll also need to purchase chain to go from the sprocket on the rotary drive to the sprocket on the end of the wheel shaft extension. See Rich' Stidger's 40.5 Mods post for pictures.

I think the advantage of installation ease far outway the disadvantage. Since it uses the wheel and associated chain/wire drive to move the rudder the disadvantage is that if your steerin fails, like a jamed or broken wire you lose your autopilot. The linear drive moves the radial drive directly so it may work even if the regular steering system fails. However, unless you are planning some serious ocean crossings I don't think that is too much of a big deal.

Where in Maryland are you located?

smokey73 · Jan 11, 2022

I use the EV200 with my Rotary Drive with a P70 head. I don't recall if I used a Type 1 or a Type 2 drive but i'll see if I can find my receipts and specs on the sprockets, etc.

artboas · Jan 11, 2022

SV Maverick said:
Hi artboas. The original question was posted by me (SV Maverick) Great point. Can you direct me to where I can get a rotary drive? I agree it would be much easier if the proper parts can be found.

Yes, of course
It’s a standard Raymarine drive.
There are 2 types ; type 1 & 2
I believe type 1 is fine, but RM can confirm
You’ll need stuff
2 gears, stainless chain, and an aluminum platform for the motor
Essentially, what Hunter had in mind was to directly drive the wheel shaft. Very clever, insofar that ;
Minimal amount of hysteresis if you mount the motor on adjustable supports
The wheel hub is already seriously geared down, owing to the ratio of the radial drive on the quadrant to the expected gear on the wheel shaft
Think about it..
You can steer the boat with one finger on the wheel. Try to do that at the rudder via linear force…..,.
An excellent resource is Joe Kerr at SBO forums. He can guide you.
This was a very clever arrangement for AP drive, and considered myself lucky that Hunter designed it in.

artboas · Jan 11, 2022

artboas said:
Yes, of course
It’s a standard Raymarine drive.
There are 2 types ; type 1 & 2
I believe type 1 is fine, but RM can confirm
You’ll need stuff
2 gears, stainless chain, and an aluminum platform for the motor
Essentially, what Hunter had in mind was to directly drive the wheel shaft. Very clever, insofar that ;
Minimal amount of hysteresis if you mount the motor on adjustable supports
The wheel hub is already seriously geared down, owing to the ratio of the radial drive on the quadrant to the expected gear on the wheel shaft
Think about it..
You can steer the boat with one finger on the wheel. Try to do that at the rudder via linear force…..,.
An excellent resource is Joe Kerr at SBO forums. He can guide you.
This was a very clever arrangement for AP drive, and considered myself lucky that Hunter designed it in.

You are going to need a Fenner Trantorque coupling.
This is the easy way to make this all work.
Pm me for more info

smokey73 · Jan 11, 2022

@artboas and @SV Maverick I agree with artboas. I am very pleased with the installation and performance of the rotary drive. Now that I think about it I think I used the Type 1 drive. The 40.5 is up at the upper limit, but within the specs for the Type 1 drive. I'm not sure about artboas need for a "platform" for the motor. On mine, and I think on Rich Stidger's the foot of the motor mounts to a "pre-installed" platform that has two threaded studs sticking up. Fit right up. Also I'm not sure what a "Fenner Trantorque coupling" is but I know I did not have to use that. Would be interested in what it looks like, what it is, and what i does though. Mine works fine without it.

artboas · Jan 11, 2022

SV Maverick said:
View attachment 201693

Thanks so much for the positive comments. I spent a lot of time on my drive install. I had never seen this drawing, and Hunter never mentioned it to me, although they did say that the boat was designed for a rotary drive under the ice chest.
But, this drawing is confusing

The actual motor doesn’t mount like that.
In. Fact it looks very different

As you can see, the bracket does indeed mount to the pilot with the ears downwards, but in the Hunter Drw, the mounting bracket mounts to the shaft area of the motor; not on the back of it

So, this was odd.
Not having this drw, I contracted a 3/8” aluminum plate which dropped into the two 1/2” studs, abs mounted a steadying foot
This consistent if 2 pieces of stainless threaded 3/8 -16, going through the plate, abs keeping it stable with the cockpit floor.
It was also for chain tensioning (USE stainless )
Now, I originally got a Ceterk motor, because the RM unit was SOL. Last word being “stick”
Basically the same motor, excepts that it’s a $4000 piece of non-returnable garbage. Serious crap.
So, the rm mounted on my aluminum plate just fine, and I used bolts on the 1:2” studs to adjust the platform up snd down ti fix tension between the wheel hub, and the motor.
There can basically be NO slack in the chain, as that will cause huge “play” in the steering.
Also, no way to can adjust the up & down bolts once the drive is in. Just no hand or tool.
access
The trick is a trantorque coupling.
VERY simply, it permits a gear hub with a larger bore than the shaft to mats to it with zero keywsys
The coupling has a variable inner ID, and fixed outer id.
It has an adjustment nut.
When you tighten the nut, it contricts the internal id directing to size., This means that you are effectively very precisely bringing the CL of both gear hubs further apart because the id is now gripping the shaft, centetjng it, and pulling away from the other gear.
When the motors are installed, with chain around gears (already very closely cut it length, you slip both gears over each shafts
As you tighten the coupling, it tighten tye C-C distance between motor and other shaft
Magicall!!!!
You then put some strength into the tightening of the nut, and it’s stronger than a jeywsy

thus trick will save you DAYS of figuring out how to align and get rid ofslack.
I got really good at this.

Had left over parts from job.
pm me

Arthur Boad.

smokey73 · Jan 12, 2022

Thanks @artboas for the info.
I used a Raymarine Type 1 motor rather than a Certek and have not had a problem at all with the RM Type 1 unit.

I wish I knew about the Trantorque coupling when I installed it. Like you said, it was a POS to install the RM drive motor using "shims" to get the tension right and it is not adjustable like the Trantorque but it works with the shims and I have no noticable "slop" or slack in the chain. It took some patience and a few bruises/cuts trying to get my fat hands into the tight spaces to get the right chain tension.

On my RM Type 1, the motor does mount to the shaft side of the motor so other than the "shape of the motor" shown in the drawing, the Hunter drawing is essentially correct. Here is a link of the RM Type 1 from Defender, where I bought mine. Note the boat displacement max is listed at 24,000 lbs on the Type 1, which is more than a 40.5 could be if fully loaded down but I figure there is probably some engineering "safety factor" already built into the specs and the power draw of the Type 1 is about half that of the Type 2.

The SS chain is not cheap nor are the gears but the installation is straightforward and can be done by youself if you have the technical skills and patience and have the wiring to the pedestal for the power and drive signal already there.

Raymarine Type 1 Autopilot Rotary Drive - M81135

The Raymarine Type 1 Autopilot Rotary Drive is designed for steering systems that can be driven from the helm position through a chain and sprocket. The outstanding design of the Raymarine rotary drive unit provides smooth, powerful autopilot-controlled s

www.defender.com

artboas · Jan 12, 2022

smokey73 said:
Thanks @artboas for the info.
I used a Raymarine Type 1 motor rather than a Certek and have not had a problem at all with the RM Type 1 unit.

I wish I knew about the Trantorque coupling when I installed it. Like you said, it was a POS to install the RM drive motor using "shims" to get the tension right and it is not adjustable like the Trantorque but it works with the shims and I have no noticable "slop" or slack in the chain. It took some patience and a few bruises/cuts trying to get my fat hands into the tight spaces to get the right chain tension.

On my RM Type 1, the motor does mount to the shaft side of the motor so other than the "shape of the motor" shown in the drawing, the Hunter drawing is essentially correct. Here is a link of the RM Type 1 from Defender, where I bought mine. Note the boat displacement max is listed at 24,000 lbs on the Type 1, which is more than a 40.5 could be if fully loaded down but I figure there is probably some engineering "safety factor" already built into the specs and the power draw of the Type 1 is about half that of the Type 2.

The SS chain is not cheap nor are the gears but the installation is straightforward and can be done by youself if you have the technical skills and patience and have the wiring to the pedestal for the power and drive signal already there.

Raymarine Type 1 Autopilot Rotary Drive - M81135

The Raymarine Type 1 Autopilot Rotary Drive is designed for steering systems that can be driven from the helm position through a chain and sprocket. The outstanding design of the Raymarine rotary drive unit provides smooth, powerful autopilot-controlled s

www.defender.com

Sounds great
Good online resource for people reading this.
I originally used a cetrek motor, but switched over to the RM
The cetrek motor was awful.
The advantage of the trantorque coupling is that it permits you to get the motor all mounted, and then simply slip the gear / chain assy on.
Once you start to tighten the coupling, it draws the gear hub towards the centre of the steering shaft.
So,,,
The trick is to make the chain & shims a teeny bit too short. You can fit it together because of the coupling slop, but once you tighten the coupling, it draws the hub towards centre of the shaft, snugging the chain.
Make sense???

baycloud · Feb 23, 2022

SV Maverick said:
Update. I have been working on the boat a little at a time. I have been cleaning bilges and cleaning the engine compartment. Fixed the throttle detent (you pull the ring up to unlock the lever) and got the slop out of the transmission linkage at the engine.

Installed all new LED bulbs. Some of them looked exactly like the replacement but had slight variations in wire diameter or design that had to be worked on to make them fit the original fixtures. Might add diffuser even though they are warm in color they are also very bright.

I do have a confirmed leak from inside the mast which has rusted the counter weight and the table base. I did get the table base to rotate after a few days of PB blaster. Still no vertical movement. I would hate to have it stuck in the down position, so I'll take my time with this one. View attachment 202911

Removed the CNG range. That was easy. Cleaned the area and it looks great. Removed the CNG tank only to find it still had a good charge after 25 years of never being used. Figures.

No progress on the windlass project. I have seen modifications using vertical windlass on a platform to the left of the locker or the vertical windlass in the horizontal position as intended by the factory.

No progress on getting updated electronics. Ordered a windex and knot/depth transducer, but it must be passing through the netherworld with the nonexistent autopilot and rotary drive.

I did get quotes on a new poly holding tank and new aluminum fuel tank. I would like to inspect the holding tank first to see the scope of what has to be done. Probably should just order the holding tank so it is there when needed. The fuel tank does not have an external gauge (on top of the tank under a panel) so it is a pain to see what is going on. Never a good idea to run a tank dry.

Also finally realized why some of the hatch latches seemed to latch lower than they are supposed to. The gaskets are so compressed that the hatch closes more and latches on the bottom of the fixture. They won't leak, but that is not correct. I think this site has replacement material at a reasonable cost.

Each little project takes 4x more time than expected not that is really a surprise.
Got quotes for new sails from North Sails and Precision Sails and a few others.

Looks like I might need a new hot water exchange/heater.

Nice update. What are you doing for a stove? I'm going induction.

JamesG161 · Feb 24, 2022

baycloud said:
I'm going induction.

When operating, induction creates an oscillating magnetic field. Caution!
Jim...

baycloud · Feb 24, 2022

SV Maverick said:
How are you planning to do that? I originally was thinking the same thing but.....

Well I have 840Ah batteries and am planning a 180amp alternator; potentially a generator down the road. My only issue right now is that it trips the breaker, so will probably have a separate breaker box directly connected to the battery. I'm doing an electric oven as well, but plan to hardly use it.

JamesG161 said:
When operating, induction creates an oscillating magnetic field. Caution!
Jim...

Are you speaking about messing with other instruments or something else?

JamesG161 · Feb 24, 2022

baycloud said:
Are you speaking about messing with other instruments or something else?

just saying it takes a large transformer to do induction cooking.

Any magnetic field should urge caution on its placement.
Jim...

artboas · Feb 24, 2022

SV Maverick said:
Update. I have been working on the boat a little at a time. I have been cleaning bilges and cleaning the engine compartment. Fixed the throttle detent (you pull the ring up to unlock the lever) and got the slop out of the transmission linkage at the engine.

Installed all new LED bulbs. Some of them looked exactly like the replacement but had slight variations in wire diameter or design that had to be worked on to make them fit the original fixtures. Might add diffuser even though they are warm in color they are also very bright.

I do have a confirmed leak from inside the mast which has rusted the counter weight and the table base. I did get the table base to rotate after a few days of PB blaster. Still no vertical movement. I would hate to have it stuck in the down position, so I'll take my time with this one. View attachment 202911

Removed the CNG range. That was easy. Cleaned the area and it looks great. Removed the CNG tank only to find it still had a good charge after 25 years of never being used. Figures.

No progress on the windlass project. I have seen modifications using vertical windlass on a platform to the left of the locker or the vertical windlass in the horizontal position as intended by the factory.

No progress on getting updated electronics. Ordered a windex and knot/depth transducer, but it must be passing through the netherworld with the nonexistent autopilot and rotary drive.

I did get quotes on a new poly holding tank and new aluminum fuel tank. I would like to inspect the holding tank first to see the scope of what has to be done. Probably should just order the holding tank so it is there when needed. The fuel tank does not have an external gauge (on top of the tank under a panel) so it is a pain to see what is going on. Never a good idea to run a tank dry.

Also finally realized why some of the hatch latches seemed to latch lower than they are supposed to. The gaskets are so compressed that the hatch closes more and latches on the bottom of the fixture. They won't leak, but that is not correct. I think this site has replacement material at a reasonable cost.

Each little project takes 4x more time than expected not that is really a surprise.
Got quotes for new sails from North Sails and Precision Sails and a few others.

Looks like I might need a new hot water exchange/heater.

This windlass install was not the way that Hunter did it at the factory.
They took a SL Anchorman 1000, and mounted it horizontally, so that the motor was inside the Fiberglas moulding on the stbd side.
This allows the chain to fall quite nicely into the locker. So, basically took a vertical windlass and mounted it horizontal.
My boat did not have the factory windlass, (I stupidly thought I wouldn’t need it), and ended up installing it halfway through my first cruise., it was either that, or turn around.
I highly recommend the horizontal mounting. It also keeps the motor totally dry.

New to us Hunter 40.5

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