A lot of baking but no cake
I’ve been working on different types of e-freeboards since 2019 and launched my Indiegogo campaign in 2021 for the Driftboard drive kit http://www.drftb.com. There have been a few posts in this forum mentioning the campaign and the build but I’ve never been active but sorta followed the discussions about e-freeboards from a distance.
The campaign didn’t succeed for many reasons and I’ve also moved back to Sweden from the US and a lot of things came between the final product and me. But, in the downwind of Freebord rise again (delivery of the Freebord 5X) it’s time to start over and make an even better build that pushes the interest in e-freeboards further down the line. The aim here is to make a concept board that people can DIY, ride in different terrains (hence the all-terrain in the subject) and upgrade to make it better and better.
My thoughts and learnings so far:
The most important part of an e-freeboard is the electrical slipring, without a functional slipring no e-freeboard. In my book there is only one option for the slipring and it’s the capsule slipring, any other slipring and in particular the pancake slipring (seen on the Summerboard) is not suited for this kind of application. The reason for this is two; the load from the 360 caster is massive and any slipring affected from the load is going to brake or be dysfunctional. The capsule slipring can easily be put inside a large bearing and protected from the load.
The second reason is that a capsule slipring is more resilient against dust, humidity and strong vibrations such as landing a jump or just putting the board on the ground. I’ve tested a lot of other slipring options and the capsule slipring has never failed once.
360-degree rotating casters
The second most important part (that also separates the e-freeboard from a standard esk8) is the two 360-degree rotating casters that makes the board slide and spin in any direction. These casters need to be really, really strong and be able to hold the load from riding the board. My last iteration (4 mm aluminum) was to week and started to bend after some extensive riding (jumps included).
Selecting material for the casters and finalize the shape is still something that I struggle with. On one hand I want a nice-looking caster, pretty much the one you see above but on the other hand it should also be multifaceted and support several different drive trains. The ultimate build should support interchangeable drivetrains. If you first want to use a belt drive you could easily switch to hub motors or later change it to a gear drive. In that sense I think function is more important than design.
When it comes to the material of the caster it should probably be steel that you could bend, drill and shape to a final caster to support the DIY aim of the build.
Spring loaded and spring locked casters?
In the early days of freeboarding the Freebord was equipped with spring loaded casters (see picture) but they were replaced later on with non-spring loaded casters.
The reason for this is not clear, but there is a quite big advantage of having suspension. First, the load on the 360-casters will be less, second, you could adjust the suspension depending on weight, riding style and different terrains. The obvious downside is that the build will have more moving parts and that is something that should be avoided to make the build as simple and maintenance free as possible and probably also the reason why Freebord took that away in the first place.
So, suspension is, good but a lot of moving parts are bad. So how to solve this, is there a middle way? One solution that I really like is @Fosterqc bushing solution, it’s simple and less moving parts compared to a spring solution. This concept is still untested, but the potential is huge.
https://forum.esk8.news/t/veiftech-diy-upgraded-leiftech-v2/
The other thing to consider is the choice between spring-locked casters and freely moving casters. The Freebord is equipped with spring-locked casters and the Summerboard is not. The Freebord is propelled by gravity and the Summerboard is motorized. Does a motorized freeboard really need spring-locked casters or is that just for going down a steep, steep hill?
The main idea with a spring-locked caster is to simulate the snowboard feeling and the tendency for a snowboard to go straight down instead of moving sideways.
From the Freebord 5X patent:
“A biased caster was developed for more positive control over the laterally-sliding rollerboard. The center caster was connected to a spring and biased through spring-loading to align with the longitudinal board axis, and the rider had to overcome the spring’s threshold force, or moment, so the caster wheel would caster to move the board laterally. Snowboards have a natural tendency to go straight and biased casters were designed to simulate that tendency.”
From my experience, the spring-locked casters makes most use when going in high speeds, when moving slow they are actually making it harder to ride because of the tendency to go straight. When going slow you really have to force the board to turn and probably ending up catching an edge. In my opinion the spring locked casters are the number one reasons why people are struggling with learning how to freeboard when trying the gravity freeboard for the first time. In that sense the motorized version of the freeboard is easier to learn but could experience less control when going really fast.
The complexity of making the spring-based caster function makes it less attractive when making a DIY e-freeboard and the upside is pretty small compared to the whole riding experience of the freeboard.
What kind of drivetrain?
The choice between the different drivetrains, hub motors, belt drive or gear drive is really a personal preference, in my book there is no difference in riding experience but of course there are pros and cons with the different ones, but it shouldn’t affect the riding experience. The difference is more of a maintenance issue, more experience and a lot of tools, use belt and gear drive, with less experience you benefit from using hubs.
My choice of drivetrain has always been the hub motor and for me it’s the simplicity and maintenance free motors that’s appealing. My search for the optimal hub motor has been extensive, I started using a large simple e-scooter hub motor with my first center wheel prototype. The motor worked for a prototype setup but after some riding the rubber wheel started to deform suffering from heat dissipation.
One of the best choices (in my opinion) for this application is the MaxFind M5 hub motor. This motor is really strong and also have the possibility to change the sleve to the CloudWheel donout for the all-terrain setup.
Electronics
When it comes to electronic it’s no different than a normal esk8. In my last build I used a 216wh Samsung 30q battery pack, Flipsky VX1 remote and two Flipsky Mini FSESC4.20 50A and it worked fine. The search for the ultimate electronic setup is not the aim with this build, this is something that should be different for every kind of setup, just as any other eksk8 build. The aim is to build a base that you could use to build your own e-freeboard.
The new plan
- Making a custom deck
- Making a custom enclosure
- Making a custom 360-degree rotating caster for all kinds of drive systems
- OTC VESC, slipring, battery, hub motors, trucks and bindings
