Linear drives

[jkim1]

I do have an Autohelm 1000, now "people" say its a bit light for my boat. Autohelm say its big enough (on the selection guide).
I have found out however that the power that drives the motor is burst control, ie a pulse of varying length and it of course reverses to drive the rod back or in or whatever the case may be.
Now what I am thinking is that, could I used the 4000 linear drive with an interface box (which is easy to make) and then I would have a much more powerful piece of kit.
Or if Raytheon are too expensive I could use a linear actuator from a Satellite controller. At the moment this seems the best way as the satellite actuator has limit switches, and at 12 volts about 350 pounds thrust.
Anyone done this before?
Or any thoughts?

 

[steve28]

Do you mean autohelm or raymarine because the older 1000 autohelm
units that are obselete seemed to have more than the modern st1000.

For your other question about the actuator, would you intend on driving it from the existing electronics or something else ?

If you are then you would ned to increase the output transistors capability, also the motors are mostly more than 12 volts. i would say it is possible but maybe some relays would be needed.

these are my thoughts and others will no doubt dissagree

steve

 

[Graham_Wright]

Are you using the full stroke of the actuator? If not, you can increase the mechanical advantage by lengthening the tiller.

 

[jkim1]

Yes the motors are 12 volts and the model is the ST1000. I have made a circuit that will use the power to the motor to switch two relays either one or the other or neither, this I was going to connect to the other linear actuator. I am if I go ahead, going to fit a double pole centre off switch to disable the normal motor,and bring the signals out on a 2.5 mm power connection socket. that gives me the advantage of locking the tiller, and or installing a remote control box that I could wonder around the boat with. I will have to fit the Autohelm or rather have two mountings, one of which is fixed across the boat and the normal one. And possibly another mounting system for the bigger actuator. Which I will marinise, (paint and seal up). they are meant for outside anyway. I will use a self resetting circuit breaker on the additional power input for the larger actuator. I would like to use the 4000 linear actuator, but I feel that they may be a lot more expensive than a satellite actuator which are about£38. Basically getting an Autohelm 4000 for about £50, by using the sensors and electronics from the ST1000.

 

[pappaecho]

Be useful if we knew what boat you have from your bio. I have a 30ft Kingfisher which weighs 5.5 tonnes and the ST1000 which came with the boat works very well, except when the boat is on beam ends because I have failed to reef in time.

 

[jkim1]

I have a Southerly28, and the 1000st seems to battle a bit in heavy weather. I agree that if the boat is reefed and balanced its ok. Some people say always buy the one bigger than recommended, as there is always a bit to spare. And as I leave the inside wheel connected it is a bit of extra load. The difference between the 1000 and the 2000 is just a special sort of nut, which at £100 more, is a rip off. Using a sat actuator is the cheapest way of getting a more powerful, or less stressed unit. I intend getting it hooked up to the chart plotter this year now that I have found a seatalk box. If I had not found one I would have probably bought a tiller pilot as they are more powerful per £ than the autohelmn.

 

[steve28]

if your interested i can tell you how to make it react like a st2000 autopilot. This involves a sequence of button presses which can be reverted back to an st1000.

pm me if you want the info


steve