Jake's Direct Drive build, NSW, Australia - Success!


#21

Thanks for the reply. One more test hopefully today with the Boma motor and if that doesn’t work, I’m going with the dual 6364.

I have the Cyclone on the EEB frame and another on a Kona Stinky. Both setups are beasts. I know its off topic, but how did you attach the BMX sprocket? I’m running a single speed on the EEB with a single speed conversion kit using BMX chain, but would love to have something tougher. Only problem with the Cyclone is having to beef up the motor mounts. I wish they’d fix that. I still have to spend time dealing with chain issues due to flex randomly. I’m going to make a custom mount when I get time to work on that project. I did end up buying the Sur-ron which is awesome and in the long run will probably costs less.


#22

I remember a while back you were looking at using 2 motors to drive a single shaft in order to increase the power. It seems it has been done on the onean boards if you look at motor system diagram: https://www.produzionidalbasso.com/media/projects/15589/files/Specifiche%20Tecniche%20ONEAN%20JET%20PACK.jpg

It would be very interesting to see what speed controller they are using to drive this setup!


#23

Good work here Jake !
How did you go from 1 minute ride-time to 15 minutes ride time ? Watercooling the FETS of the Vescs ?


#24

What is the Boma motor?

Nice bikes to do it on :slight_smile:

To make it single speed is fairly straightforward, you can buy single speed sprockets that slide on where the cassette mounts on the free-hub, so you just have to unbolt the cassette, slide on the single speed sprocket and space it with washers to suit the chain alignment, and screw back in the lock ring. Then I just modified an old derailleur for single speed chain tensioner by holding it steady with hose clamps. It is very sturdy and there is no chain skip or coming off because the teeth are much higher. You can do away with a chain tensioner if the bike isn’t dual suspension.

To minimise motor flex I made a bracket to attach the far side of the motor to the clamp, the takes away the flex and it can easily take to torque of the motor from this. here’s a picture:


#25

Thanks! I have different ESC’s now, YEP 120A HV. They do get warm but not to bad.


#26

It looks like a nice setup they have, I’d imagine there is a separate ESC for each motor, but i think its possible to use one ESC for two motors if the stators and rotors are perfectly aligned.


#27

I’m not quite sure about onean, from the picture it seems there is a single unit, but it may be a double ESC unit.
I have also fount that AXI used to make a dual motor setup: https://www.modelmotors.cz/product/detail/256/ which gave around 5kw I think.


#28

Wow, this certainly isnt a new idea!


#29

Hi Jake!

I am new to this hobby, but already have plenty of experience in the rc hobby. I got really interested in the relative simplicity in your build compared to other, geared builds. I am planning to order two 6s 16ah lipos, two vescs and two of the same motors you use from hobbyking and design the control circuit including temperature, current, voltage and consumed mah monitoring with an arduino pro mini. I am firstly going to build it on a surfboard for primary testing.

The main components that i’m worried about are the propellers. I already converted smaller foam bodybords to electric for kids with smaller brushless motors, escs and lipos, but I used rigid miniquad propellers cut down to size and they worked great. Now that I’m planning to build a “real” electric surfboard, I am figuring out about 3D printed props, since they are the best option for me because I own a 3D printer (with a volume of 200mm x 200mm x 250mm). Can you post your cad files for the props you`re using? Also, is the rigidity of them enough for long term use (considering that I will only run it in freshwater)?


#30

If you want to go with this setup, I do not recommend VESCS, they overheated after 1.5 min of riding with heat sinks installed. I would go with dual flier 300amp or similar. the 3D printed props are a long term solution in my opinion, ill post all files for this build below. However I recommend going with a single 80100 motor for better efficiency. Although this build is cheap apart from the ESC’s and does work reasonably well.


#31

https://a360.co/2FtMzGu Motor mount Dual 6364 KEDA

https://a360.co/2J4ZD1J Puller Prop 110mm

https://a360.co/2zjaTrz Pusher Prop 110mm


#32

Thanks a lot Jake!

Do you have recommendations for prop material, or PLA works fine?
I prefer the vescs (maybe I can try the vesc 6) because they are programmable and are well known by the community, but it’s just a case of preference.


#33

No worries. I used PLA and I never wore out the props. Maybe a VESC 6 would work with good cooling.


#34

Credit to @pacificmeister and @tylerclark for the propeller design…