[Surf n' Destroy] Building a flying sniper rifle case

Great,

can you share the files of this new mast clamp, you can PM. I would really like step files or fusion 360, so i can add water inlet?

Br

Here are my files. The Front part is same Unfortunately I dont have *.step file of that front part

I wanted to ask, what are potential disadvantages for using a rifle case as a beginner. I’m thinking of also pursuing the idea as a new user. Thanks!

It’s not made for foiling and it isn’t made to be a watercraft😄

For a beginner:
Too narrow
Too low buoyancy
Stuff to injure yourself on when falling (like ribs, corners and flanges)

For everyone:
high drag in water
Bad in waves
Bad in touchdowns
Requires a lot more power to start, putting extra requirements on your drive system

I think for a beginner foiler and builder you might as well give yourself the easier tool to learn on, not added challenges (there are plenty of used boards out there that can be adapted to efoil.)

For a foiler with some previous experience, no issues. The board is not so important after you get up and getting up with a motor isn’t really a problem if you have the right drive system.

Well, I didn’t have time for setting up a logger, but I grab myself a giant heat sink and it just works well. I have the speed needed so I can learn basics. Weight distribution etc. now I am happy. I am going to seaside for a week. So I will have fun :star_struck:



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I just finished my project. I knew it is not going to be “Friday afternoon project” but it took me more than I expected… maybe not more time but more engineering. I wish there was a step-by-step vide tutorial…. On the oter hand this comunity is amazing and folks here helped me with all my issues. Only think which remains is learn how to ride it :grinning:

Pretty well explained:

If not enough, watch on YouTube, follow IA recommendations on the right. Plenty of other efoil tutorials, each bringing a new point…

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This one is even better as it allows you to see and understand the weight shift:

I have been tweaking my DYI efoil boards a bunch over the past 2 years since I joined the forum. Winter is my rebuilding/tweaking time, so I am just now reviewing some of these posts from a couple of months ago. I try not to ask too many questions without searching a bunch in the existing conversations, but I am puzzled that no one questioned the 16s battery pack with the 65161 120KV motor especially in light of the motor response issues. I have the same motor, and using the same prop (and a FR 6’ pitch). I would have thought 16s would be ill-advised… in favor of something closer to 12s?

Anyway, I am preparing to build a new pack this winter for this year’s tweaking project, but was planning for a 12s 8p using 21700 Molicel P45s. So to summarize my two questions are:

Is 16s truly a viable option?, and not likely to cause:

Second, is a 12s 8p using 21700 Molicel P45s still a good option for the 65161 120KV with one of the typical Flite or FR props?

Also, a quick thank you to all of you providing this wealth of knowledge to us and to Ogy for their posts earlier this year. This particular thread is one of my favorites in the forum!

One of my favorite learning videos! Thanks for posting this one again.

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Hi Tritodd
Regarding the battery. Initially, I didn’t think about it too much. I just copied the design from “Surf n’ Destroy”. However, I had a lot of issues in the beginning.

  • Bending 3d printed prop
  • The motor slid downwards and the prop hit the fuselage
  • Poor VESC cooling
  • Lack of knowledge of VESC
  • Need to downgrade VESC FW

But no issue was connected with the battery.
Right now everything is running smooth and I can foil for 40+ minutes.

I guess that guys recommended 16s9p because it takes a lot of power to get the rifle case out of the water. But it can probably work with 12s8p as well. But I haven’t tested it.

The only thing that remains is to learn to stand up. I can only ride on my knees so far : )

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There are no basic limitations (or musts) to use 16s, with 120kV and a 6516x motor it’s not more than 24kerpm, vescs can do a lot higher than this and it’s not too high frequency for the steel in the stator.

But: 16s is high enough voltage to be an electric shock hazard even with dry skin (and this is the biggest argument, at least for me, to stay at a lower voltage). The breakdown voltage through your skin is even lower with damp or salty skin so stay safe out there!

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Hi Ogy. Strongest print is not made with 100% infill. Put emphasis on the walls (perimeters) instead of infill. Also, print with max temp, slow and minimum layer height and minimum cooling that gets you the bridging needed. All of these help you with better layer adhesion and rigidity. If you wish for prop to be solid then put like 30 or 50 walls/perimeters and top and bottom layers…this is artificial 100% infill but stronger version. Also, PLA is not good for water. Try printing in PC(polycarbonate).


Watch this video:

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Anyone knows power needed for big guy doing sniper rifle case e-foil? I am 195cm and 130kg :slight_smile:
I know that 85165-100kV is overkill but it is only 30€ more expensive then 85135.

I am planning to go for a 20S Li-ion configuration since that is the voltage of my e-bike and my chargers. My whish is to go without problems at least 45-50km/h and to be able to make return trip to 15km distant goal (so 30km).
What ESC would you recommend?

I can understand your motivation to use your existing battery/charger but 20S (84V) yields a risky V level in a water environment. Several threads here about that.

I also think your performance specs are a bit off. To the best of my knowledge the world speed record for efoil is just slightly more than 50kmh.

Splined shaft is not recommended as it does not fit good props (the one that comes with it is not recommended). Better get a 12mm Shaft with M8 thread. 70182 is more than strong enough and has less resistance due to the smaller diameter.

Maytech 70182

I have 3 reasons for going for 20S.:
1: I am afraid that 65161 will not be powerful enough for me and rifle case.
2. I plan to eventually repurpose that system to be main power for rubber boat for 4-6 people.
3. I have chargers for 72V Li-ion.

Cons: 1. Heavier, more expensive.
2. Slightly more dangerous then 16S

Does someone have example of big guys like me riding rifle case efoil with 65161 motor?

I only pointed out to you that 20S V is risky for an Efoil environment where you are in the water. I don’t think you would find many if any builds here using that V level.

You also ignored the unrealistic speed values you wish to foil at.

Good luck on your build

There’s no real benefit in 20s for getting up since the lift speed is nowhere near the limit already at 12s. It’s more a question of streamlining. If you get the right case and wing you’ll have no issues at 12s

Also: For a high drag system you need torque so it’s a better balance to get a 300A esc than a 20s battery if you really need the thrust, since torque is proportional to motor current.

A word of warning, the 6516x motors will only provide so much torque so increasing motor current only works up to a point. I haven’t seen any data showing when it actually is too saturated but one thing is sure: running at 300A for any longer than a few seconds will burn the motor.

OK. I think that I will buy everything tomorrow.
I’ve decided for 65161-120kv motor and very strong FSESC75350. In this way - if the motor is found to be underpowered - I can wait for next Black Friday and buy 85165 :slight_smile: Do I need some kind of bluetooth module?

Am I missing something on the list?
PS: Should I (as big person) opt for 100kv version? Logic is: for the same max power I would get more current which equals more torque (and lower speed, lower voltage)?

You won’t get more current with a lower kV motor but you get more torque per current, up to reaching saturation and the max torque for the motor type. This is independent of kV.

What this means is there’s no benefit getting a 100kV motor when combined with a powerful esc - with a 350A esc you can reach the max torque of also the 120kV motor and get higher speed capability.

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