Hi
I have updated the links in this topic, and if any body is interested I do have scale drawings of my lifting mechanism


Original post below.

Hello
I am in the process of making an electric motor drive for the keel on Aztec.
Has anybody else done a conversion or got an electric keel winding mechanism.
If it all goes well I hope to document the process.
Is anybody else interested in this sort of project.

Mike Edwards
Seal 28 "Aztec"

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Mike,
if you find a solution which still allows moving the keel by hand if necessary, I would be interested (my wife even more [;)]).

Gerold

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Hello Gerold
My plan is to keep all the existing hand mechanism as it is so it can be used in the event of a failure.
I wont know for certain how well my design will work until I have had the extension to the existing screw made and tested with the motor.
The plan relies on a belt drive and clutch made so that by slackening a single nut on the clutch will disengage the electric motor and the handle can then be refitted to wind by hand.
I am hoping to be able to test by the end of February, I will keep you posted.

Mike Edwards
Seal 28 "Aztec"

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Very interested! I have pondered this for some years. I had in mind one of those 12v trailer winches, but as Gerold points out, reverting to hand power in case of flat batteries is very desirable and not easily arranged. I even bought a cheap trailer winch to play with. It was uni-directional, ie it only pulled. To go the other way, it had a friction clutch controlled by a clamp screw. It had a hand crank, too, but it was a very flimsy affair and I didn't feel it was up to serious use. That comment really applies to the whole winch, too. Besides, I wanted to mount the winch somewhere out of the way which meant getting at the hand crank was impossible. I understand that some of the Parker boats have electric keel lifters based on a rather more up-market variety of trailer winch, though. I have been directed to the one marketed by Compass (I can't confirm that that's the one Parker's use). It's quite expensive! Good luck with your design effort - you've started me thinking again...


Neil Sinclair
Seal 28/27
'Andiamo of Exe'

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Hi Mike and Neil,
I hope you don't mind a Parker 275 owner straying onto your patch. I have a retrofitted 12v winch on my keel, and when it has failed (mainly due to breaking the wire) I have had to put a block and tackle onto the keel eye and haul it up manually using the spinnaker D ring on the mast ( which then bends, but that's a small price to pay for survival!)

If you want to come and have a look Beeline is in the yard at Topsham SC until March 25 when we launch for the season. I don't think a manual system would work without at least an 8:1 ratio as the Parker keel is so heavy.


Kate

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Hello Kate
My plans rely on not changing the basic operation of the existing lifting mechanism, I am just planning to add a very slow RPM motor (60-80rpm) to turn the handle.
The motor will be able to be disengaged so if the handle is fitted it can be used to take over in the event of a failure.

Mike Edwards
Seal 28 "Aztec"

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Hello
I have finished fitting the electric motor to operate the lift keel on Aztec.
All I have to do now is make a wooden cover to go over the gearbox to match the existing table top.
The operation of the motor is exactly as planned and all my worries about the power of the motor, or the belt and clutch mechanism not taking the load were groundless.
To revert to manual winding all I have to do is slacken the nut on the end of the shaft by a 1/4 turn and fit the handle back in its original position at the after end of the shaft.
I feel very pleased to have accomplished this.

Full details of the construction plans and equipment/parts used and where to source them, can be made available to anyone who is interested.

Please see picture below.

http://www.swatchway.pwp.blueyo...jects/aztec-projects.htm 

Below is a link to a Movie file showing the motor lifting the keel, it should play with Windows Media Player.
The movie shows lifting the keel the last 10 inches or so. You will see the belt drive and clutch discs rotating, then the cable being pulled, and then the top of the keel moving upwards,the clip finishes with the top limit switch cam being operated and the motor stopping.
http://www.swatchway.pwp.blueyo...ts/aztecelectrickeel.wmv 


Mike Edwards
Seal 28 "Aztec"

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Well done - Mike! Very impressive. I particularly liked the idea of extending the leadscrew out the front of the keel box and fitting the motor out of the way of the hatch. I guess you had to make a new leadscrew? The linkages to keep the limit switches out of the keel box is also well thought.



Neil Sinclair
Seal 28/27
'Andiamo of Exe'

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Hello Neil
No I have used the original screw and bronze nut which was in very good condition.
The screw shaft has been extended with a new shaft extension to take it out of the keel case and to take the pulley and clutch plates.

The whole affair draws about 13 amps whilst raising the keel so it draws equivalent to just over 1/2 amp per hour, operating for 2.5 min. to raise the keel.

Mike Edwards
Seal 28 "Aztec"

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Hi Mike - The leadscrew can't be very efficient but considering that we only operate the keel a small number of times every day, that consumption is not very much at all. Compared with the winch I was considering your system has the enormous advantage that when it stops, the keel just stays where it is - and, of course, manual control is easily arranged. I shall have to have a go next winter. Will you be publishing your design?



Neil Sinclair
Seal 28/27
'Andiamo of Exe'

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hello Neil
Yes any PSSA member can have my plans provided they are not passed on or used commercially without my permission.

Mike

Mike Edwards
Seal 28 "Aztec"

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