A build with a feminine touch?

EFOIL.builders Builds
#1

Hi every body, sorry for this weird title, but I figured people would be more likely to read my post this way.

I’ve been thinking about building an eFoil for a while, so now is the time to take the big plunge! My training and experience is in signal processing for fax modems (for those who remember, yes, that was a long time ago), so I need all the help I can get.

I am starting my build with the following elements, the challenge being to make it as cheap as possible, while optimizing its performance:

Motor Maytech MTI65162 100Kv
Why? it seemed reasonable and it was on sale over the holidays.

ESC: homemade by my husband
Why? To keep him busy and out of trouble. He’s relentlessly working on it as I type. Just walked by to say he’s stumped. Not good. But I have faith.

Battery
Not sure if to buy or build.

Foil mast and wing
Old Liquid Force model.

Board
Old windsurfer donated by a friend.

#2

To get started, I printed the motor mast clamp, just because it seemed like something I could do.
Following the method used by YAHEF, I adapted the design to my mast and motor using fusion 360, and to make a long story short, ended up printing it in PETG with 100% fill.

QUESTION: has anybody used a PETG mast clamp without any additional processing (fiberglassing, epoxy filling, etc…)? I just reinforced mine with a couple of heavy duty (200lb) tie wraps around the circumference…

EDIT: after reading here about improving the strength of the print, i might reprint the clamp with:

  • PETG
  • layer height: 0.15mm
  • layer width: 0.56 mm (140% of nozzle width)
  • perimeters, top and base layers: 10
  • infill: 100% honeycomb (don’t know if patterns matters at that point)

Not taking any chances!

Screen Shot 2021-02-01 at 5.11.45 PM
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#3

Hi there. I 'm using my PETG mastclamp without additional reinforcement for over a year now, but with the lightweight-motor APS63100. If you like to use a printed clamp for the maytech motor i would recommend printing it with 0.6mm extrusion width (even with a 0.4mm nozzle) and placing it not vertical but 30degree tilted.
I’ve never heard of a “MTI54162”, are you shure or do you mean the 65162?

In my opinion the best way to mount a heavy motor is this way, @superlefax and i are using it on our latest build.

1 Like
#4

Oops, yes MTI65162. Thank you for your suggestion

#5

Is there a way to edit / correct a post?

#6

Jup, there should be a pencil under your post

#7

by the way we just finished our Surf’n’Destroy rifle case eFoil which was pretty cheap although we just used “high quality” components.

1 Like
#8

Can you point me to a more detailed explanation of your mount? Thanks!

#9

Here is my work in progress mount for FS65161 to Gong mast. It is quite similar to the one used in the rifle case eFoil. It comes with a water pass thru (brass tube) in the nosecone. As the design is still a work in progress, it should only be used as a reference. If someone decides to print it, I cannot guarantee fitment. I will be able to finish the mount when my Gong mast arrives, so I can properly reverse engineer the shape. This current shape is my best guesstimate based on some pictures and diagrams in the mast database.

image
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https://drive.google.com/file/d/1Et4W3YV--E1TMtXZQCNFqqCd2dzqegVb/view?usp=sharing

4 Likes
#10

My first Mast clamp I did 2 perimeter with 75% infill and noticed water dripping out while letting it dry. After I changed to a 6 Perimeter with 75% infill I haven’t had any issues either with durability and water tightness.

1 Like
#11

I can also recommend to print the traditional mast clamp with 0% infill and like 6 perimeter/wall. Afterwards fill the hollow clamp with epoxy. You can have a look in my build (Newcomer build)

1 Like
#12

Thank you for the suggestion. I was considering the epoxy fill, but my building buddy tells me PETG seems harder than epoxy. Any research on that?

(100% fill PETG with 200lb tie wraps that I printed for a friend who needed to route the motor wires around the mast)

Screen Shot 2021-02-02 at 10.31.15 AM
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#13

Printed petg at >95% infill works perfect. I did the same in 2 builds.
The filled-with-epoxy solution is proven too.

1 Like
#14

I did pretty similiar except I used a gyroid infill which let the epoxy flow throughout the whole part. Worked pretty well!

I don’t think I’ve actually see anyone that broke their mount yet regardless of method… has anyone else?

2 Likes
#15

There are some broken clamps which has been print only. Don’t ask me about the infill. I chose the epoxy because it’s more like a mold and strong in every direction.

2 Likes
#16

Thank you for sharing! Wow, that’s quite a refined design. Mine in contrast is very basic. I will refine it later, using ideas offered here.

I live in the SF Bay area too. Where are you testing your eFoil?

#17

Concerning POM, I found some 100 x 100 x 8 mm pieces on eBay. How easy/hard is it to cut and drill it to size ?

#18

Thanks for the feedback! I haven’t built my board yet, I am still waiting for a few parts such as the foil assy (ordered, on its way) and a board from Noahark. That should arrive in the near future. My friend lives and surfs in Santa Cruz so I’ll probably do most of my testing and learning there.

#19

Ah, too bad. I will be mostly at 3rd ave in Foster City. It might be fun to share our experiments.

#20

POWER and SPEED considerations
So the next step for me was to figure out how much power is required (even though I already bought the MTI65162 motor because it seemed like a good deal).
My assumptions:

  • total weight of rider+eFoil : 100kg / 220lb
  • foil and mast: old Liquid Force model

Using my friend’s java foiling simulator I determined that:

  • speed of least drag = 6 m/s (13.5 mph 21.5 km/h)

I am thinking of optimizing the propulsion design so I can have the longest ride possible at that speed. Does it make sense?