2020-01-12, 02:07 AM
Love the Pypilot project. Have been following it for some time.
I have always wanted a below deck linear actuator but have not wanted to pay for it. Over the last few months Pypilot has inspired me to try to come up with a "homebrew" unit.
This has crossed my mind in the past but each time the biggest challenges always seems to be how to implement a clutch system that doesn't drive the price up to the cost of a commercialy available unit. Recently there has been a sell off of Ogura micro clutches on eBay for about $25 USD. Ogura sells high quality electromagnet clutches of all sizes.
Using the specifications of the Raymarine Type I linear actuator as a general guide I pieced together an electrical linear actuator using a ball screw, planetary geared motor, Ogura clutch, stainless tubing and some miscellaneous aluminum parts/hardware.
The current configuration is for bench testing purposes and has the long lower square tube to allow for load testing. The aluminum mounts for the motor and clutch are crude and will be refined in the next revision.
Here are the test results so far:
So far it has cost a total of about $325 USD to piece together. Pretty sure it the pricing could drop with better parts sourcing.
Any ideas/comments greatly appreciated.
I have always wanted a below deck linear actuator but have not wanted to pay for it. Over the last few months Pypilot has inspired me to try to come up with a "homebrew" unit.
This has crossed my mind in the past but each time the biggest challenges always seems to be how to implement a clutch system that doesn't drive the price up to the cost of a commercialy available unit. Recently there has been a sell off of Ogura micro clutches on eBay for about $25 USD. Ogura sells high quality electromagnet clutches of all sizes.
Using the specifications of the Raymarine Type I linear actuator as a general guide I pieced together an electrical linear actuator using a ball screw, planetary geared motor, Ogura clutch, stainless tubing and some miscellaneous aluminum parts/hardware.
The current configuration is for bench testing purposes and has the long lower square tube to allow for load testing. The aluminum mounts for the motor and clutch are crude and will be refined in the next revision.
Here are the test results so far:
- Free travel requires about 22-25 LBS of force to manually move the actuator with the clutch disengaged.
- The clutch will not slip until it reaches 850 LBS of force (measured) at 130 watts of power (The clutch is the limiting factor for power output at this point)
- With the clutch engaged and the actuator at rest it consumes 7 watts
- No load movement is 17 watts
- When the unit is producing 130 LBS of force it consumes 32 watts
- Stroke length 11"
- Stop to stop travel time 10.5 seconds
So far it has cost a total of about $325 USD to piece together. Pretty sure it the pricing could drop with better parts sourcing.
Any ideas/comments greatly appreciated.