Autohelm repair with hydraulic ram...any suggestions?

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Matata

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We have an old autohelm which is a seperate black box on a bulkhead which you set the compass bearing on. As the boat goes off course the box tells a seperate linear ram to move in and out ,hence moving the tiller. The ram is shot. On the basis it is already broken ,I took it apart. Basically it consists of a large "scaleletric" motor turning clock or anticlockwise ,depending on what the black box tells it to do. All very simple. I'm thinking of replacing the ram with a hydraulic ram and a small hydraulic pump. What factors do I need to keep in mind. Has anyone any thoughts,sources or pointers? Its my winter project. Many thanks Nic
 
You would need 2 solenoid powered valves for the hydraulics unless you have a reversable hydraulic pump to push or pull fluid in the ram.
I feel sure it will be simpler to replace the "scalectrix" motor and run it as original or replace the screw jack as necessary. All more doable than hydraulics I would think.
good luck olewill
 
Matata said:
We have an old autohelm which is a seperate black box on a bulkhead which you set the compass bearing on. As the boat goes off course the box tells a seperate linear ram to move in and out ,hence moving the tiller. The ram is shot. On the basis it is already broken ,I took it apart. Basically it consists of a large "scaleletric" motor turning clock or anticlockwise ,depending on what the black box tells it to do. All very simple. I'm thinking of replacing the ram with a hydraulic ram and a small hydraulic pump. What factors do I need to keep in mind. Has anyone any thoughts,sources or pointers? Its my winter project. Many thanks Nic
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I'd suggest it's far simpler to have the actuator serviced by Raymarine.
Mine require servicing every 3 years of so and their prices are not excessive.
 
I have a RAM with a knackered clutch, but a good motor and screw/bearings.......

It's an Autohelm (Raymarine) Type 1 Linear drive, 12v.
 
Thanks for all the help so far ,and thank you fullcircle for the possible deal on those parts. I may very well get back to you on that one. On ideas re the hydraulics where would I start looking for design /dimensions or a good company to deal with.? Anyone into hydraulics out there? I didn't appreciate that the original ram had a clutch mechanism. Regards Nic
 
Matata said:
Thanks for all the help so far ,and thank you fullcircle for the possible deal on those parts. I may very well get back to you on that one. On ideas re the hydraulics where would I start looking for design /dimensions or a good company to deal with.? Anyone into hydraulics out there? I didn't appreciate that the original ram had a clutch mechanism. Regards Nic
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Nic

Try:
http://www.hypro.co.uk/

They are excellent and nice people to deal with.

Yoda
 
I am prepared to be shot down in flames, but a reversing hydraulic pump would not work without a system of relief valves so the helm could operate with the autohelm off.
I know some pumps have the valves incorporated, but they are designed to react with the fluid pressurised by the helm pump.
 
Gordonmc said:
I am prepared to be shot down in flames, but a reversing hydraulic pump would not work without a system of relief valves so the helm could operate with the autohelm off.
I know some pumps have the valves incorporated, but they are designed to react with the fluid pressurised by the helm pump.
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All you need to do is connect a solenoid in parallel with the cylinder. When the autopilot is on the solenoid is energised and prevents flow. Autopilot off solenoid opens and allows oil to flow between cylinder ports
 
Matata said:
Thanks for all the help so far ,and thank you fullcircle for the possible deal on those parts. I may very well get back to you on that one. On ideas re the hydraulics where would I start looking for design /dimensions or a good company to deal with.? Anyone into hydraulics out there? I didn't appreciate that the original ram had a clutch mechanism. Regards Nic
Click to expand...

Look at the Vetus cat.
 
charles_reed said:
I'd suggest it's far simpler to have the actuator serviced by Raymarine.
Mine require servicing every 3 years of so and their prices are not excessive.
Click to expand...

Perhaps you have not dealt with them very recently, they have a new 'standard charge' system for repairs, it seems pricey to me (compared to the old days when they sent you an estimate) in some cases you could buy a replacement component for less.
 
Quandary said:
Perhaps you have not dealt with them very recently, they have a new 'standard charge' system for repairs, it seems pricey to me (compared to the old days when they sent you an estimate) in some cases you could buy a replacement component for less.
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£446 for a ram.....
 
It would still be cheaper to repair the existing actuator (or even buy a new one) than trying to convert the system to hydraulic operation. The Raymarine Type 1 linear actuator (if that's what the OP has) is a very rugged and reliable piece of kit.
 
got a hydraulic helm in my boat and you can get away without a steering pump with non return valves if you have a steering lock on the helm. Mine consists of a spoke lock that holds the helm solid when in autopilot.

The auto pilot is an old cetrek unit and the autopilot pump motor is a reversing servo motor plumbed in parallel with the helm pump.

Its a Vetus steering system. Their web sites has a catalogue of all the bits but more importantly tells you how hydraulic steering systems should be set up, sizing of cylinders etc.

http://www.vetus.com/steering-systems.html

You can buy servo pumps and cylinders and drive them from most autopilots. I don't think they have to be from the same vendor just compatible

(The other more significant advantage of not have the non return valves in your helm pump is that you get feedback from the rudder when steering.)
 
EuanMcKenzie said:
got a hydraulic helm in my boat and you can get away without a steering pump with non return valves if you have a steering lock on the helm. Mine consists of a spoke lock that holds the helm solid when in autopilot.

The auto pilot is an old cetrek unit and the autopilot pump motor is a reversing servo motor plumbed in parallel with the helm pump.

Its a Vetus steering system. Their web sites has a catalogue of all the bits but more importantly tells you how hydraulic steering systems should be set up, sizing of cylinders etc.

http://www.vetus.com/steering-systems.html

You can buy servo pumps and cylinders and drive them from most autopilots. I don't think they have to be from the same vendor just compatible

(The other more significant advantage of not have the non return valves in your helm pump is that you get feedback from the rudder when steering.)
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I didn't get the impression from the post that the OP has a hydraulic steering system.
 
FullCircle said:
£446 for a ram.....
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It's most unlikely that the OP needs more than a few parts for his linear electric ram. They also probably cost peanuts.

It's 18-months since I last dealt with Raymarine Service, they quoted me a price, there and then based upon the expected replacement parts required. The service was £36 and the parts were £8.12 (sealing O rings, brushes and replacement leadscrew balls).

It's best to call in the afternoon when some of the service engineers are available - with the best will in the world the girls on reception can have no idea of work, materials and time involved.

I always call on them to leave and collect the units - usually when on grandparental duty in Highfield. I'm still using the same two units after, respectively 21 and 19 years of service and a total of about 38K miles of sea-use.
 
I received an email from Raymarine a few months back setting out their new 'improved' system of out of warranty repair pricing on up to ten year old products, there are two standard charges for each component, a minor repair usually sub £ioo plus vat and a major repair about treble the lower figure, for example a linear drive a minor repair is £168 plus vat. a major repair is around £460. Of course this new system is for the benefit of the customer who can find out how much he is going to be ripped off by just going to their website. Repairs are warranted for a year, the repair on my just out of warranty pilot display was just over £200 inc. vat and it worked OK for exactly that length of time before failing again.
Another frustration was their reluctance to define the nature of the fault after much pressing they described it as 'some faulty chips'
All my experience of Raymarine repairs prior to 2005 was good, good communication, attention to detail and reasonable pricing, sad that it has changed.
 
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charles_reed said:
It's most unlikely that the OP needs more than a few parts for his linear electric ram. They also probably cost peanuts.

It's 18-months since I last dealt with Raymarine Service, they quoted me a price, there and then based upon the expected replacement parts required. The service was £36 and the parts were £8.12 (sealing O rings, brushes and replacement leadscrew balls).

It's best to call in the afternoon when some of the service engineers are available - with the best will in the world the girls on reception can have no idea of work, materials and time involved.

I always call on them to leave and collect the units - usually when on grandparental duty in Highfield. I'm still using the same two units after, respectively 21 and 19 years of service and a total of about 38K miles of sea-use.
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Charles, it has been 'modernised'.
Now a menu pricing system, as described by Quandary.

That is why I bought a new one at £1150, rather than the 10 day turnaround and £460 for a repair to a 20 year old unit.

My clutch unit is in little bronze filings inside the case when I took the lid off. I don't think that would qualify for a minor repair.
 
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