Video: I14 Rudder Cassette with 3d printed parts

[14berlin]

I needed to build a new rudder cassette and tested some ideas in the process. I used 3d printing both for functional parts and for tooling. The result is a super light cassette with perfect fit and a rudder that slides in easily.
The printed inserts might have potential for further improvements. I'm thinking of universal cassettes that can be adapted to different foils / centerboards in short time.

All this was accomplished by an amateur with free/cheap tools in my bedroom.

I'm still learning and there are already a hundred things I would do different next time. But I'm proud of the result and wanted to give some inspiration to other homebuilders. It's great how good free software has become and how fast and precise some things can be accomplished with 3d printing that were reserved for the pros a few years ago.

Tools I used:

• airfoil design: xflr5 - free
• CAD: Fusion 360 - free
• Slicer: Cura - free
• Printer: Mega S - 140€ + Upgrades
• Vacuum Pump: fridge compressor - 40€

 

[Talchotali]

Cool! Looks great!

Go out an use it, and tell us about the design for the MK II.

By the way, tell me more about the 40€ "refrigerator compressor" you used for V-bagging. What was the source of this?

 

[kprice]

I needed to build a new rudder cassette and tested some ideas in the process. I used 3d printing both for functional parts and for tooling. The result is a super light cassette with perfect fit and a rudder that slides in easily.
The printed inserts might have potential for further improvements. I'm thinking of universal cassettes that can be adapted to different foils / centerboards in short time.

All this was accomplished by an amateur with free/cheap tools in my bedroom.

I'm still learning and there are already a hundred things I would do different next time. But I'm proud of the result and wanted to give some inspiration to other homebuilders. It's great how good free software has become and how fast and precise some things can be accomplished with 3d printing that were reserved for the pros a few years ago.

Tools I used:

• airfoil design: xflr5 - free
• CAD: Fusion 360 - free
• Slicer: Cura - free
• Printer: Mega S - 140€ + Upgrades
• Vacuum Pump: fridge compressor - 40€

Looks great. I am about to make one similar, but with 20th century tech. How thick are the flanges?

 

[14berlin]

By the way, tell me more about the 40€ "refrigerator compressor" you used for V-bagging. What was the source of this?

There are lots of it on eBay, used and new. I got a new one and it has been running great for hundreds of hours. They achieve very high vacuum and are almost silent (like a fridge). Downside is they have very little throughput so your assembly has to be sealed very well. But for my little projects this has never been an issue.
I added a little oil trap to the exhaust to see how much oil it's losing (almost nothing) and from time to time I put a little oil into the intake.

How thick are the flanges?

They are 5mm carbon plate + 6x200g biax on each side. The bottom one takes all the vertical load from the foil. My axle is just 20 mm in front of the foil, if this was more I would have gone with more reinforcements.

 

[CaptainAhab]

Do you print with PLA? Then laminate with carbon fibre/epoxy?

 

[14berlin]

Do you print with PLA? Then laminate with carbon fibre/epoxy?

Yes, blue parts are PLA, black parts are PETG. PLA is not resistant to higher temperatures, it can get soft in the sun.

 

[CaptainAhab]

Yes, blue parts are PLA, black parts are PETG. PLA is not resistant to higher temperatures, it can get soft in the sun.

Are you concerned about the epoxy/pla bond? Did you do any destructive testing on a straight ruler size piece. Classic peel/shear testing of laminates?

 

[14berlin]

Are you concerned about the epoxy/pla bond? Did you do any destructive testing on a straight ruler size piece. Classic peel/shear testing of laminates?

I didn't do any testing because the bond doesn't need to take any loads. The inserts are glued in with three drops of epoxy. As long as they don't fall out wehen sliding in the rudder it's fine. This way I can change them easily later.

 

[nota]

real vacuum pumps used are 20 to 60 usd
I got a 5 cfm real volume for $40
likely far more then any ref pump most will not do a single cubic foot/min

try a swap meet or hock/pawn shop

btw add oil to any pump trying to vacuum

 

[garthreynolds]

really nice one, thanks for sharing! I've been collecting the materials to build one similar...but haven't yet started.

 

[Skaf]

Offsetting the tiller to one side is an out-of-the-box thought that would solve a lot of issues that I can think of (though maybe it will introduce a few new surprises). Very cool. I've often thought about how the combination of 3d printing and home boat projects would come together so nicely - not printing the parts directly but for producing high (by home standards) tolerance moulds for those composite pieces.