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PyPilot with Servo Pendulum Windvane
#1
Dear Sean,

Your development of PyPilot comes at a good time, because my 24 year old Raymarine ST4000 Wheel control is leaking and has been taken apart three times, been dried out and reassembled...

I assume a PyPilot AP & Controller could be used with my Wheelpilot, but I am considering making a light servo pendulum water blade, for use with your PyPilot, because it has many merits, such as low power with amplification by the servo pendulum to turn a rudder or a wheel.  If Pypilot can be used with the servo pendulum water blade in lighter air and in other heavier conditions, you have pointed out that the windvane can then be added for use in heavier air.

My question is if PyPilot + gear above works well in both light and heavy air, with a small low powered motor and lead or ball screw on the servo pendulum, why would you need any other autopilot motor (such as direct to tiller or wheel)?

Would it just be a backup, with the expense of another more powerful motor which uses greater power in case the servo pendulum broke?

I suppose one could just have a second small motor + lead/ball screw available as backup for use on your Moniter/Windvane too.

Note: I have added a PyPilot Section on the OpenCPN > Supplemental Hardware > RPI Accessories Page. I will probably move that to it's own page at some point.

While looking into servo pendulums (yet again), three links stood out to me, regarding improvements to the servo pendulum & windvane for light air: I would be interested in your thoughts.

Regardless, I think it is useful to have several self-steering options, (including hybrid solutions which include electrical autopilot with a motor & sensors). Thank you for showing me the way.
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#2
Quote:I assume a PyPilot AP & Controller could be used with my Wheelpilot, but I am considering making a light servo pendulum water blade, for use with your PyPilot, because it has many merits, such as low power with amplification by the servo pendulum to turn a rudder or a wheel.  If Pypilot can be used with the servo pendulum water blade in lighter air and in other heavier conditions, you have pointed out that the windvane can then be added for use in heavier air.
It can probably be used with your wheel pilot. If you can apply power to it to turn the wheel, and reverse the leads to turn the wheel the other way it will work.
Quote:My question is if PyPilot + gear above works well in both light and heavy air, with a small low powered motor and lead or ball screw on the servo pendulum, why would you need any other autopilot motor (such as direct to tiller or wheel)?
A motor for the rudder compared to a servo oar would give faster response time, and also be less complicated,
Quote:Would it just be a backup, with the expense of another more powerful motor which uses greater power in case the servo pendulum broke?
I suppose one could just have a second small motor + lead/ball screw available as backup for use on your Moniter/Windvane too.
maybe.


So far, the 3dprinter lead screw is working and strong enough to lift several pounds. I'm going to try to connect it tomorrow. It is sealed in pvc pipe. It is also extremely quiet compared to my other drives. I think this is because there are no gears or belts. I think the motor might not have enough torque though,
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#3
This one reverses with reverse in polarity, but has gears. 6mm shaft. Not much about the motor's speed or power though.
https://www.ebay.com/p/DC-12v-6rpm-6mm-S...1520808302

Here is another one that looks like it is more powerful....
RS-550s 18v (6v - 24v) DC Motor - High Power & Torque for DIY Electric/Electronic Projects, Drills, Robots, RC Vehicals, Remote Controlled Cars/Robot, Saw
https://www.amazon.com/RS-550s-18v-Elect...BB304QMVXB
Brand ProTechTrader
Item Weight 7.7 ounces
Product Dimensions 1.5 x 1.5 x 2.2 inches
Item model number CECOMINOD043921
Manufacturer Part Number CECOMINOD043921
Folding No
Amperage 10 A
Voltage 12 volts
• Model RS-550S 18v
• Shape of Motor Housing: Round
• Type of Motor: Carbon Brushes
• Construction: Anisotropic Magnet or Rare Earth Magnet
• Operating Voltage: ~6v - 24v
• No Load RPM: ~19300
• No Load Current: ~1.2A
• Stall Torque: ~70.55oz-in (498.2mN-m)
• Efficiency: ~70% • RPM Peak Efficiency: ~17250
• Current Peak Efficiency: ~8-10A Dimensions
• Weight: ~7.7oz (218g) • L: 2.24in (57mm) D: 1.46in (37mm)
• Mounting holes (2): M3
• Mounting Holes: 25mm apart
• Shaft Diameter: 3.15mm (~1/8in)
• Shaft Style: "D"
• Shaft Length: 8.2mm
• Motor Body Diameter: 35mm-37mm
• Motor Body Length: 57mm
• Weight: 7.8oz

Here is a geared motor with forward and reverse
https://www.youtube.com/watch?v=6fjzvRp_XrI

Main motor sources:
https://www.servocity.com/motors-actuators/gear-motors
http://www.lynxmotion.com/c-71-planetary-motors.aspx
http://www.robotshop.com/en/dc-motors.html
http://www.banebots.com/category/GEARBOXES.html

https://www.anaheimautomation.com/produc...4&cdID=212
https://www.sciplus.com/s/c_15/sf_139
https://www.sciplus.com/s/c_15/sf_138

This one is more expensive, but something like it might be good.
https://www.servocity.com/1621-rpm-hd-pr...-w-encoder

https://www.servocity.com/1621-rpm-hd-pr...-w-encoder
  Reply
#4
Looks very interesting, thanks.

A little motor should be not too difficult to rig up using a wind vane to do the work.

Sent from my SGP511 using Tapatalk
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#5
Paddy B, the Wind Vane would not be used, but the servo pendulum would be.
  Reply
#6
(10-31-2017, 04:28 PM)rgleason Wrote: Paddy B, the Wind Vane would not be used, but the servo pendulum would be.

It works OK with an actuator moving the vane instead of the wind, or take off the vane altogether. I've had it sort of working with a tiller pilot but need lots of damping.
  Reply
#7
(10-31-2017, 05:56 PM)PaddyB Wrote:
(10-31-2017, 04:28 PM)rgleason Wrote: Paddy B, the Wind Vane would not be used, but the servo pendulum would be.

It works OK with an actuator moving the vane instead of the wind, or take off the vane altogether. I've had it sort of working with a tiller pilot but need lots of damping.

What kind of damping did you use?   Isn't the tiller pilot overkill?   I think it probably moves too far, and also consumes too  much power compared to what a smaller actuator would.


The one I have built is basically silent, but consumes 1/3rd of what a tiller pilot uses (should be 1/5th) is only strong enough to use in light wind.
  Reply
#8
(11-03-2017, 07:51 AM)seandepagnier Wrote:
(10-31-2017, 05:56 PM)PaddyB Wrote:
(10-31-2017, 04:28 PM)rgleason Wrote: Paddy B, the Wind Vane would not be used, but the servo pendulum would be.

It works OK with an actuator moving the vane instead of the wind, or take off the vane altogether. I've had it sort of working with a tiller pilot but need lots of damping.

What kind of damping did you use?   Isn't the tiller pilot overkill?   I think it probably moves too far, and also consumes too  much power compared to what a smaller actuator would.


The one I have built is basically silent, but consumes 1/3rd of what a tiller pilot uses (should be 1/5th) is only strong enough to use in light wind.

It was a while ago, from memory I just jury rigged a loop of cord between the tiller pilot & wind vane. Draws little power when it's doing nothing, power isn't an issue anyway as it would only ever get used motoring, any wind at all the aries steers the boat plenty good enough. A little actuator would be useful for motoring in light airs, any kind of swell the tiller pilot I have can't cope, it's too small. Again from memory I had to fiddle of the damping to get it to work.
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