This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.

  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
3D printed linear actuator
#1
Hey there! 

I am willing to build an pypilot for my 23 foot sailboat. It must be said that I am not planning on overnight passages and that this system will mostly used in the Netherlands while sailing in fresh water. 

Therefore reliability and corrosion resistance is a little less of a problem for me than for most of you guys. 

I've seen Sean writing about a 3dprinted actuator and I am really curious if this idea has ever been worked out. I would love to build one or start designing one. Can anyone tell me if this has already been done or if there has been some progress? 

As a mechanical engineer and a 3D printing enthousiast I absolutely do not mind contributing to this amazing pypilot project so if there are any designs out there that need further development I would love to hear about them. 

- Vatuhiva
  Reply
#2
Interesting. What material would you print with? (I can't imagine PLA being strong enough)
  Reply
#3
(08-08-2019, 05:56 PM)CapnKernel Wrote: Interesting. What material would you print with? (I can't imagine PLA being strong enough)
Most parts on my boat are printed in black PETG with a solid infill. In my experience this material with these parameters is strong enough for most applications and uv resistant.

In a actuator I think in would use a leadscrew possible with a stainless steel or brass nut. The 3dprinted parts will mostly consist out of a enclosure, seating the bearings and some sort of mount for some sort of motor.

Has anyone build an pypilot with a steppermotor and for instance a DRV8825 driver and adapted the motor.ino file for it?

Verstuurd vanaf mijn Nokia 6.1 met Tapatalk
  Reply
#4
(08-09-2019, 02:02 AM)vatuhiva Wrote: Most parts on my boat are printed in black PETG with a solid infill.

I'm trying to get the courage to print in nylon.  I believe it will be tough, UV resistant, and adjacent filaments will bond well.

Quote:vatuhiva


Has anyone build an pypilot with a steppermotor and for instance a DRV8825 driver?

@partyvi has done one with a TI DRV8873:

  http://forum.openmarine.net/showthread.php?tid=1900

Mitch.
  Reply
#5
(08-10-2019, 05:20 AM)CapnKernel Wrote: [quote='vatuhiva' pid='9831' dateline='1565330562']
Most parts on my boat are printed in black PETG with a solid infill.

I'm trying to get the courage to print in nylon.  I believe it will be tough, UV resistant, and adjacent filaments will bond well.

[quote]

I've been printing in nylon and my experience is that is relatively expensive compared to PETG, only slightly stronger and way more difficult to print. Also the moisture that will be absorbed by the nylon make it in my opinion unsuitable for dimensional tolerances and (electronic) enclosures. The moisture is also what makes it a pain to print.

If you want tough, go for the filled filaments. For instance a PETG-Carbon blend. Be sure to invest in a hardend nozzle and go for it. Also think about a larger nozzle size. I had the best results with a .6mm nozzle. An easier and also slightly cheaper option for strong 3d prints is a filament with PC added. For instance a PBT-PC filament.

By far the easiest and cheapest option for strong 3d prints is to maximize the design for this production process and start optimizing your print settings for solid infill prints.




Verstuurd vanaf mijn Nokia 6.1 met Tapatalk
  Reply
#6
(08-09-2019, 02:02 AM)vatuhiva Wrote:
(08-08-2019, 05:56 PM)CapnKernel Wrote: Interesting.  What material would you print with?  (I can't imagine PLA being strong enough)

... In a actuator I think in would use a leadscrew possible with a stainless steel or brass nut. The 3dprinted parts will mostly consist out of a enclosure, seating the bearings and some sort of mount for some sort of motor. ...

I am assuming your referencing a tiller actuator!
How much "throw" do manufactured autopilots provide;  100, 150mm or more?
Anyone think it is feasible to machine out of solid HDPE or some other plastic?
What are the typical dimensions of a tiller-autopilot?
  Reply
#7
The standard tiller pilot has roughly 400mm of throw, 50-80kg of force and can move 40-60mm/s. This is probably good enough for most boats up to 30 ft in most conditions.

If you have different mounting points so there is less travel and more force (farther out on tiller) for upwind, and less force more travel downwind, and also can add weather helm (offset to the side) for unbalanced sails, then you can get away with less travel, and a weaker motor too.
  Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)