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Clutch Connections
#1
I am having trouble with how to connect a 12v clutch that will allow the wheel and rudder to turn while autopilot is not operating.  The schematics have two connections for clutch at pins 1 and 2 of J10 on the controller.  I also see one connection labelled MOSI (PB3) which has a clutch output, I think.  However, I don't see see a connection for a switch where all the other switches would connect on the Tinypilot. 

I may be misunderstanding the whole idea of a clutch.  I am thinking that it is the equivalent of engaging the belt tension lever on a wheel pilot.  That being said, I can imagine just wiring up a switch to positive and attaching a positive and negative to a 12v clutch motor, such as one like on an air conditioner pump.  That would not need anything to go through the computer. 

Are there some additional functions to a clutch that I am missing that would necessitate a connection to the computer?  Also, what are the connections on the switch side and the clutch side?

Thanks
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#2
the computer does not have to control the clutch but you may find it useful. Normally the clutch is only powered when the autopilot is enabled, or if you make a manual command. Without it, you would have to manually switch the clutch often.

If you do use the motor controller to control the clutch I would advise having a series switch to ensure you can always take manual control easily.
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#3
This issue is still bothering me.  I have no problem with the architecture of Pypilot or the implementation that Sean has outlined above.  I just don't which way to design my system.  Sean has a video of a steel boat with the motor driving the wheel via a belt.  I can't see any sort of tensioner in the video. 

I would like to know what people are doing to disconnect the drive from the wheel when they need to steer manually.  I didn't get any replies to my earlier thread on clutches so I assume that not many people are using a clutch.  Does the wiper motor turn freely when the wheel is turned?  I haven't actually tried that. 

I would really like to know what others are doing to solve this issue.
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#4
As a rule, wheel pilots and tiller pilots don't have automated clutches - you clutch them manually and then you activate the autopilot. When clutched, the motors won't spin when you turn the wheel/tiller yourself, and if they do, they should not. You have to declutch them to take over manually.

The drives that attach to the rudder stock below deck, so-marketed 'linear drive units', do have electro-magnetic clutches, and these clutches require electrical current to engage. They require more current to engage than they require to stay engaged, and to save power, pypilot accommodates for this with an initial pulse to engage, and limiting the power to the clutch after a predefined short time period. So the clutch is not a motor turning one way to engage, and turning the other way to disengage, if that's what you're thinking.

For hydraulic drives, I don't know much about these, but this might already answer some of your questions.
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#5
Hydraulic drives vary. Some have valves that use a clutch, other systems use the hydraulic piston even in manual steering so the manual and autopilot pumps can be connected hydraulically in parallel.

Either way, backdriving hydraulics adds friction so my friend removes his hydraulic piston when manually steering.

As for the wheel drive: It is a really good question. Manual clutching is annoying. It should be possible to hinge the motor to tension the belt, or possibly use an automotive A/C compressor clutch on the wiper motor shaft. What do you think? I also have considered the 3d printed pulley on the wheel mounted in such a way (with roller bearings) so that a clutch lever can engage there...
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#6
(2023-12-29, 12:30 AM)seandepagnier Wrote: Hydraulic drives vary.  Some have valves that use a clutch,  other systems use the hydraulic piston even in manual steering so the manual and autopilot pumps can be connected hydraulically in parallel.

Either way, backdriving hydraulics adds friction so my friend removes his hydraulic piston when manually steering.

As for the wheel drive:  It is a really good question.  Manual clutching is annoying.  It should be possible to hinge the motor to tension the belt, or possibly use an automotive A/C compressor clutch on the wiper motor shaft.  What do you think?  I also have considered the 3d printed pulley on the wheel mounted in such a way (with roller bearings) so that a clutch lever can engage there...

Sean,

The wheel pilots have a lever that can tension the belt when you want it engaged or disengaged.  That would be a possibility for me but my wheel shaft sticks out from under the seat and goes forward to the wheel.  This complicates the installation.  It is also at an angle, further complicating matters.  Automotive tensioners just get bolted in and usually have a spring, no lever.   Did you have a lever on the steel boat in the video?  

I have a wiper motor like the video and worm gear steering for rudder.  I would like to use an electric clutch but I am having trouble finding anything that will work with wiper motor and the a/c type have large pulleys.  I am thinking that this is a critical part of the install and I was hoping people would chime in about what their solutions were.
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#7
(2023-12-28, 05:20 PM)ironman Wrote: As a rule, wheel pilots and tiller pilots don't have automated clutches - you clutch them manually and then you activate the autopilot. When clutched, the motors won't spin when you turn the wheel/tiller yourself, and if they do, they should not. You have to declutch them to take over manually.

The drives that attach to the rudder stock below deck, so-marketed 'linear drive units', do have electro-magnetic clutches, and these clutches require electrical current to engage. They require more current to engage than they require to stay engaged, and to save power, pypilot accommodates for this with an initial pulse to engage, and limiting the power to the clutch after a predefined short time period. So the clutch is not a motor turning one way to engage, and turning the other way to disengage, if that's what you're thinking.

For hydraulic drives, I don't know much about these, but this might already answer some of your questions.

I kind of figured that the wiper motor shouldn't be rotated with tension on the belt.  This being the case, what are you or others doing to take tension off the belt?

I cannot use a RAM because my rudder cannot be moved without rotating the wheel.  I have worm gear steering.
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#8
In the video no, the belt was stretched on and off. That boat had two hydraulic steering wheels so it was not a huge deal to leave the autopilot always attached to one.
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