okpTow - Jatem's style

Hey,

I’ve taken some delay on the building of my eFoil so I decided to start another build in parallel. A much easier one but with a lot of uncertainty. I’m going for a Tow build, @Jatem 's style.

For the electronics:

  • remote : maytech v2
  • battery : NESE modules and I’ll put some 21700 cells. 14S8P.
  • ESC is a Maker X HI200/HV200
  • Batterie BOX : Pelican 1470
  • Motor : Flipsky 65161 120kv

For the mast, I’ve bought a cheap gong 55cm mast that I will chop to 20/30 cms (TBD).

Quick 3D custom motor mount prints. I’ll keep the mast base to attach the motor to the board.

I plan to use US BOX rails so I can move the mast on the board (more to the front or to the back) as I decided to simplify and put the motor just after the mast. I’ll likely use some risers to have the motor slightly a bit nose down (to lock the board on the water). My plan is to start by having the propeller at the vertical of the rear of the board to have a good weight balance.



Now the challenge is the board design. I plan to go composites (carbon/gf) like my dock start board but with a more “yatch” look on the front. I’m still wondering how to attach the bungie cord and which one to get. Some ideas I’m thinking about.





Any insights ?!

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Nice ! Just make sure that the nese module are really attached between themselves , no play at all and take in account the cells temp building up to the discharge rate wanted :wink:

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happy new year builders!

I’m getting the cells today and in the meanwhile, been working on the mast/motor pod. Of course, the mast will be shortened; probably to 25cm.

I’ve used my dockstart board to see the scale of things and get inspired to build a new board.


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moving on. 14S8P almost done. few photos of the assembly.












It’s tight fit on the 1470 case. Enough and good space but challenging for the ESC. Maybe a vertical fit could do the job.

I’ll shrink-wrap the battery when it’s done and make sure it sits very well in the battery box. Maybe 3M velcro can make it happen.





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Looking really good ! Would yo have a link for these soldereless NESE modules with tin tabs ?

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thanks. here you go

https://18650.lt

If you want to print the modules yourself, you’ll find the STLs here : All the 3D models of 18650・Cults

And all the guidance here : Resources – AMtech

I’m searching for the STL of a 3D printed enclosure for the HI200 @makerX-david is this something you got ?

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For the ESC, I’m going for the FESC. 75200 with water-cooling included.

Does anyone knows the specs/size of the inlet/outlet tubes?

To ensure it’s a super tight assembly and no leaks occur in the inside of the pelicase, I’ll sikaflex the inlets/outlets.

moving on. I received the FS 75002. Overall quality is great but the tubing is very poor quality. I would trust this water tubing. I’ve removed and replace the tubing with a stronger one.

I’m still wondering if I keep the water connectors or replace them with something else. This 3D printer like connectors don’t inspire me too much confidence. I can also put Sikaflex F11C to make the connector/tubing zone waterproof.





I’m launching the 3D print of the modified nose cone with the 8mm water tube intake

moving on to finish the battery (14S8P) with NESE modules. I added loctite on the nuts and decided to solder the balance wires to the strips (thank you Mark!).

I will use an external BMS so I can share it between my upcoming eFoil and this project. AWG10 & QS8-S connectors will be used.


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battery is done and the placement seems good.

Keep a close eye on the bolts remaining tight, or your battery will melt the NESE battery holders. Tow boogies get bounced around a lot.

yes brother! loctite all the way; I’ve also tighten them pretty hard. that’s also one of the reasons I didn’t put some connectors to attach the balancing wires and soldered them on the strip.

big step to finish the battery… charging works using the external BMS. I’ll be also using this method for my upcoming eFoil.