The Simrad hydraulic motor that came with the system on the 18m proa is a neat little unit. It has a compact machined valve block that has 2 check valves and 2 pilot operated check valves. From memory the motor is rated at 50W continuous and certainly well constructed.
The problem with making anything like this is underestimating the development time. Also not many people actually understand electrics let alone electronics.
I was surprised how easy it was to set up the hydraulic steering with the orbital pump motors. With just closed loop operation there was cogging when the system was cold and oil volume shrunk but that was overcome by fitting a small accumulator in the closed system that is easy to precharge by closing a circuit valve and winding the helm until the accumulator is compressed to 50% of its volume while feeding oil into the low pressure leg.
Rick
On 5 Dec 2018, at 4:26 pm, realink@iprimus.com.au [harryproa] <harryproa@yahoogroups.com.au> wrote:Just keep in mind Im clueless and have no idea what Im talking aboutHaving said that, 'if' this machine was electric ...Ive never quite appreciated how expensive AP is, and if you look at Raymarine stuff its really bonkers cheap built with the cheapest of parts and fails regularly. The tiller pilots are a bunch of plastic gear wheels and rubber belts, a 'very' cheap motor that wouldnt exceed 20 watts which is like $5 on todays technology and a simple inbuilt fluxgate compass, which it probably doesnt need. Dont get me started on their wheel steer AP.Looking around the business I used to have a throw away line about helicopter technology being somewhat underdone, as at the time you could buy a model helicopter with features like heading hold and altitude hold that would make a chopper pilots life much simpler that full sized helos costing millions didnt have. In the interim decades how ever newer design helos have incorporated these features.Back to the toys, they have a simple gyro costing in the order of $70 - $250 that allows a trim which you can set first statically then control via radio. Its job is to position the fuselage direction in such a way that when deviated from path the circuitry activates a servo which re-establishes the heading. Its called simply heading hold. Rather like tiller steer, you establish a heading and press a button for the equipments linear drive to hold you on course automatically. Push the model off course and heading hold will bring it back unfailingly.Now Im aware the marine product can do other things like work with a chart plotter to eliminate leeway, but Ive always felt like the former course keeping is all I really need. I just find it curious that a few hundred bucks in parts and a linear drive becomes $4 grand.Having made you read all this nonse nse and deviated somewhat from the question at hand I should just mention that the aforementioned model is an electric machine, and you use the same equipment to steer the thing with or without the gyro 'on'. Just an idea but if the energy consumed by 30 watts of current could easily be replaced wouldnt linear drives make things just a tad simpler, and more useful to have a form of autopilot to boot.Well just a thought, .... as you were ...cheers to all BTW ..
__._,_.___
Posted by: Rick Willoughby <rickwill@bigpond.net.au>
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a new topic | • | Messages in this topic (7) |
SPONSORED LINKS
.