Yours Truly | Switchblade 40" + eboosted Enc | N.E.S.E. 12s4p | eLofty 58kv | Neptune15 | Go-FOC SV6 | 200A Antispark | Janux hubs

love2scoot · August 23, 2020, 12:23am

Update 2020-08-22

New

The Piggy Back

I love being able to #carvetheworld with this board, and I want to explore greater distances.

Enter the Piggy Back:

This way I can carve while on the way to some carving at some distant location.

Complete Wire Coverage

The RJ12 connectors and phase wire couplings were exposed to allow for maximum flexibility in removing the rear truck and / or the enclosure. With the remaining steps no longer requiring this flexibility, it was time to get these connectors fully covered.

First I covered the glands at the enclosure openings:

Next, I covered the phase wire couplings:

Finally, I added more split loom, enclosing the last of the exposed section:

Multifunction Top Bracket

The goals here were

Create a protective path for the wires to run from the enclosure to the motors while maintaining sufficient slack in the cables.
Maximize clearance by hoisting the wires up just as the leave the enclosure
Maintain some line slack at the motors to accommodate the flex as the rear truck pivots
Protect the wires from being crimped or crushed
Provide a sturdy mount for the brake lights, maintaining high visibility and the ability to easily detach the lights from the board for charging.
Build a mount for a spare hub / tire / tube which also acts as a protective surface on which to invert the board while charging.

After some iteration, I landed on a design where I would mount a new top bracket above the truck. It would be held in place by using the same truck mount bolts but have holes to handle the remaining features described above.

A front hole would allow the wires to be hoisted as they leave the enclosure, maximizing ground clearance
Side holes could be used to zip tie the wires to a specific tension
A square hole would accommodate a 5/16 carriage bolt, allowing for mounting of a spare wheel / tube / tire
The rear bolt holes would also be used to connect brackets for mounting the brake lights

Here’s the design diagrams from the side and top as well as the light bracket

light_bracket

Again, I was able to contract with JnJ Fab to create these parts out of 3/16 stainless steel. After a bit a finishing work, the top bracket came out nicely:

I grabbed some 20mm stainless brackets for the light bracket.
I grabbed some 45mm m5 bolts to accommodate the additional lift of the top bracket.

For the brake lights, the intent was to detach the threaded mount from the bicycle bracket and attach each threaded mount to the light bracket itself (pictured above). Here’s a shot of the brake light mounting hardware:

That said, after assembling the top bracket, I found the bolt spacing afforded by the brackets was just perfect to mount a single light directly in the center of the board using the included bicycle mounting hardware. I really liked this more minimalist and clean look and decided to abandon the light bracket entirely. After some fine tuning to find the exact right number of washers for spacing (13 at truck front / 12 at truck rear), the multifunction top bracket was mounted and ready to go:

Some thoughts on this:

The bracket spacing keeps the wires snug (but not pinched). I’m unsure if I will need to utilize the side holes.
The black zip tie at the front maintains the ground clearance, I will likely have a slightly cleaner looking solution in the long-term.
I love the look of the central brake light. I’d like to get some slightly bigger washers for a more secure hold on the light mounting hardware
Taking this apart to put the spare mount carriage bolt in place is going to be a PITA, however, I decided it would be safer to not have an unprotected post sticking up from the rear truck just in case I fall wrong. Once I manage to get a spare hub (see Help Needed below) I’ll get the spare mounted.

Looking at how the wires route from the enclosure to the motors with this new bracket, I’m very pleased with the results:

Changed

Abandoned the light bracket approach (detailed above)

Complete

This board is now ready to be ridden, day our night. I’m only missing a helmet mounted light to complete my night riding setup. I really like the approach used by @Venom121212 here .

Help Needed

I called Marc @Janux-esk8 and I was hoping to get a spare hub for my set. Regrettably he’s not selling his hubs as one offs, but only in the original sets of (4). This means I need to find 2-3 other people to go in with me on a set. With Marc making an exit from the DIY community I’m hoping to grab these before they are gone.

In the case of a flat, having a new hub ready to go would allow for a tire change in about 3 minutes versus closer to 20 minutes. This would also mean no Allen wrench or tire pump, just a simple nyloc nut.

What’s Next

Helmet light
Get spare hub and build as a quick swap spare
VESC: Add additional low speed torque
Tear down, sand, and paint
Regrip

Research

VESC: Add additional low speed torque

Venom121212 · August 23, 2020, 12:42am

I really like that back bracket spacer idea. I just noticed my mtb cable braids are ground through the outer wire sleeve from rubbing on the grip tape on the edge of the deck. I’m going to borrow some inspiration from you.

The helmet mounted light is stellar. So much visibility and being up high let’s you see stuff in the road much better than low lights.

Board lights vs helmet:

Is that the xlite100?

Edit: read through your thread.

This would be a nice riser made out of metal.

rusins · August 23, 2020, 4:44pm

Shoot, wish I had seen this post earlier. You should set this back to whatever the default is for your ESC (usually above 100A). That settings is for current spikes, which can and will happen, as you found out yourself by having it too low. 45A is too low imo, it should be set higher so that you don’t get a cut-out at speed

Since you have temperature sensors in the motors, you can increase the motor current as well if you want, no harm done. Also, I know your settings are within the battery safety limits, but if you care more about your life than your cell lifespan, you should increase battery regen by 2x. Just remember to brake conservatively when casually riding, but you will be very glad when a situation comes up where the increased braking power saves you!

love2scoot · August 24, 2020, 5:33pm

Ah- thanks for the tip. I will certainly set this back up to the higher value (I think it was 150A)

I made the Hall Sensor adapters to accommodate all (6) wires, but the eLofty motors do not have an internal thermistor. With the AT setup on these, things do get quite warm when riding hard or on hills, so I’m reticent to push these too much farther.

The battery regen is also an excellent point. I believe 8A regen per VESC is spec with 30Q cells (4A Max per cell). The 10A I’m using definitely helps slow the board, but your point stands. You suggest closer to 20A per VESC?

rusins · August 24, 2020, 6:57pm

Yeah, 20A per vesc I think is something the batteries can still handle safely for an emergency stop. Since your motors don’t have temperature sensors, then probably best to leave their current as is, good call

love2scoot · September 19, 2020, 3:46am

Update 2020-09-18

New

A Lesson in Balancing

In late August I was checking my BMS and found that my battery had fallen out of balance. I chronicled the process of bringing it back along with some thoughts on a root cause and some hard data here.

The Charging Stand

I wanted an easy way to store and charge YT. Requirements:

Minimal floor space
Charger can easily mount to stand, but can also be easily removed for travel charging
No metal on metal contact
Board is positioned so that charging port is easily accessible
Brake light fixture is protected from contact
Addition of spare (at a later time) will not impact the fit
Could balance well on its own as well as when loaded
Remote storage

I toyed around with different designs, eventually landing on a design using:

2x2 wood pieces
Sunk holes to ensure no metal extended beyond the wood
Vinyl covered eye bolts (bent) with heat shrink on the bolt ends
1/4" hardware for affixing the wood pieces to each other
Wood spools with spacers to affix the DC charger to the stand
S-hook for Remote storage
Soft pads to protect the floor and wall

Here’s the design:

And here’s the finished product:

Changed

Nothing

Complete

The charging stand and balancing knowledge, as mentioned above.

Still need a spare…

You can check my thoughts from previous postings above, but I still need to get that spare hub in place.

What’s Next

Helmet light- I have a great idea here, working out the details now and will get back here to post more info soon.
Get spare hub and build as a quick swap spare
VESC: Bump absolute max and battery regen as per the note from @rusins above
VESC: Add additional low speed torque
Tear down, sand, and paint
Regrip

Research

VESC: Add additional low speed torque

will_manners · September 19, 2020, 4:35am

I love your liberal use of dot points

Obsidian · September 25, 2020, 2:54pm

I love this thread. Your attention to detail and the way you describe your thought process is sure to help budding DIYers (including myself). Thank you for putting so much time and effort into your journey. Keep up the awesome work!

love2scoot · October 13, 2020, 6:20am

Update 2020-10-12

New

Blowout

On vacation in Pismo beach, I had a great few days cruising around this great beach town.

During one of the day rides, I must have hit something pretty hard. After arriving at my destination and chilling for 20 minutes or so, I noticed the right rear tire was totally flat. I saw no evidence of a puncture, but trying to inflate the tube resulted in instant loss of pressure. Luckily I had brought a spare tire/tube + tools with me. After an hour of work (or so) I was inflated and back on the road.

Post-mortem:

Puncture in the tube:

tubepuncture882×881 221 KB
(2) of (5) motor Kegel adapter pins broke off(!). I’ve ordered a new set of the (10) pin Kegel adapters from esk8supply; hoping these hold up better.
This experience clarified the importance of finishing off the spare mounting on the board. Changing out the Evolve 6" tires on the Janux hub is tough: the sidewall of the tire is very low profile, which makes extraction from the hub difficult and finicky, especially while away from a workbench.

Changed

Spare hub approach

Not sure why I didn’t think of this before: all (4) Janux hubs have the Kegel adapter slots built into the hub but only the rear hubs require these slots. This means that I can carry an Evolve hub as a spare (since it works fine as a front wheel on the 8mm axles). If I blow a front tire, this is a simple swap. If I blow a rear tire, I simply move the front wheel (with Janux hub) to the rear and replace the front with the Evolve spare. This cuts way down on repair time.

Evolve lets you order custom hubs one at a time (with tire and tube!). I ordered a black hub with the 6" street tire to use as the spare. I sourced some inexpensive bearings from my local shop, and started the build process.

When I designed the stainless plate for the rear truck, I made sure to include a cutout for the square of a 5/16" carriage bolt. I grabbed some 5/16 hardware from my local hardware store and started sizing up the best fit for the clearance on the Evolve hub. After playing with washers, nuts, nyloc nuts, lock washers, bearing spacers, and different bolt lengths, I arrived at this following setup:

(1) 2" x 5/16" Carriage Bolt
(3) 5/16 washers
(1) 5/16" Nyloc

Dropping the Evolve spare onto the 5/16" bolt and securing with a simple 5/16" nut finishes off the mounting process:

I really like how this came out. The mount is far enough back that it doesn’t interfere with my back foot on the board. In fact, if I decide to try out Urban Treads on these hubs, I should still have clearance. The next step here is to figure out a new mounting option for the brake light.

New Wire Suspension

The black zip tie I used for suspending the wires under the board (to maintain ground clearance) was only ever intended as a temporary solution. With the final plate mounting complete it was time to finalize the wire suspension.

In using the black zip tie and Velcro combo, this resulted in a twist of the zip tie 90 degrees between the plate and the Velcro loop. To resolve this I added a small aluminum carabiner (from a Sierra Nevada growler fill) and ran the zip tie in a full loop. This results in better clearance on the top of the stainless plate and no twist. I also think it looks rather fetching:

Complete

Stainless Plate

Now that both the spare mounting bolt and the wiring suspension are completed, the stainless plate can be considered completed.

A quick note on washer counts:

Rear truck, rear bolts use:
- (12) M5 washers between the stainless plate and top of the base plate
- (2) M5 washers between the bottom of the board and the M5 Nyloc
Rear truck, front bolts use:
- (13) M5 washers between the stainless plate and top of the base plate
- (2) M5 washers between the bottom of the board and the M5 Nyloc

What’s Next

Helmet light- I have a great idea here, working out the details now and will get back here to post more info soon.
Tail light remounting with the new spare
VESC: Bump absolute max and battery regen as per the note from @rusins above
VESC: Add additional low speed torque
Tear down, sand, and paint
Regrip

Research

VESC: Add additional low speed torque

love2scoot · November 23, 2020, 10:56am

Update 2020-11-23

New

eLofty 10 pin Kegel Adapters

After the blowout and adapter destruction (detailed in my notes above) I ordered some replacement Kegel adapters for the eLofty motors. Here’s a quick shot of the 5pin adapter destruction:

The new adapters required a little bit of time to ship from overseas, and when they arrived, I knew this wouldn’t be a simple swap. Here’s a quick run down of the differences and modifications required to make the new adapters work.

Multiple pieces

The new adapters arrive in more pieces:

It seems like a cost saving measure to ship a single adapter baseplate, and then include the wheel adapter pins separately. Considering the wear and tear eSkates experience, this multi part adapter assembly seems like a step backward.

The adapter pin component attaches to the baseplate using 10mm M4 socket head countersunk bolts.

HOWEVER, even when tightened fully, the adapter pin component was not fully seated to the baseplate (there was about 0.5mm of wiggle). Considering the torque being put on these bolts, a loose adapter would likely lead to a premature failure. As a result, I ordered some 8mm M4 socket head countersunk bolts and the adapter now has a solid fit. An extra 1mm of threading in the pin component would have solved this issue; too bad this wasn’t checked at the factory.

Bigger diameter

Since my original purchase, eLofty motors have moved from a 65mm can to a 72mm can. Luckily, the bolt spacing to attach the adapter to the can is the same dimensions

Old (5pin) adapter diameter:

New (10pin) adapter diameter:

Shorter height

This is the biggie. Since there is an ideal spacing for the pin adapters to provide full engagement of the Kegel pins into the wheel hub, changing the height dimension of the adapter is a big deal. Pulling out the calipers, the new 10pin adapter measured at least 3mm smaller than the older 5pin adapter (although the pin length stayed the same at ~10mm). Here’s some of the measurements:

5pin adapter height with pins:

10pin assembled adapter height with pins:

5pin adapter height no pins:

10pin adapter height, no pins, no base:

10pin adapter height, with pins, no base:

10pin adapter base:

Looking at my original photos of the adapter seating to the hubs, I still had about 1mm of room between the adapter and the hub. Adding to this the 3mm+ of extra spacing needed to keep the adapter flush with the hub, and I decided to make another aluminum adapter plate, this time with a 72mm diameter.

Adding this together with the new adapter I was able to get very close to the total height of the original adapter:

When assembled, I was happy with the finished product:

Pin spacing

Looking back to my original decision on the Janux hubs, I decided to go with the Torqueboards kegel adapter spacing since it was reported that the 5pin eLofty adapters would fit (and I thought, why not have the best of both worlds). The fact that there are different size adapters for something that is supposed to be a “standard” was frustrating, but I made the leap. It ended up that the hubs needed a very small amount of filing to get the 5pin adapters to fit, but it worked out. In short, the eLofty Kegel adapter is slightly “larger” (as in, the distance between two pins across the axle is slightly more) than a standard Kegel pin arrangement. With softer wheel cores this may not be an issue, but with aluminum hubs this difference in tolerance is noticeable.

After the new 10pin Kegel adapters arrived, it was obvious that the hubs were going to require a lot more than just filing. Taking into account that my spare solution uses an Evolve hub (so if I get a flat on the rear I would need to move the front hub to the rear and then drop the Evolve hub up front), all (4) Janux hubs needed to be machined to ensure they fit the new 10pin adapters. The key was to make sure to take only enough material that the adapters would seat, but the fit would remain snug. Here’s the before and after:

Janux hubs before machining:

Janux hubs after machining:

Final fitment

Due to the slightly larger <=1mm additional height of the adapters, there’s a little less thread for the axle Nyloc to grab:

That said, it seems like enough and I like the results:

Changed

Bump absolute max and battery regen

As per the suggestion from @rusins above, I bumped per motor regen to 12A and the absolute max current to 150A to handle any transient power spikes.

Helmet Light (or lack thereof)

After trying out several different iterations of mounting a light to my helmet, I decided to change direction and instead relay upon a nice, hand-held, 18650 flashlight with 90deg pivot.

My thoughts here are:

I like keeping the helmet unmodified since it’s designed to help save my brain
Moving the light source slightly farther away from my eyes means that it should be easier to judge the distance to objects illuminated by this light source.
Lights on the board are more for people seeing you and not the other way around.
The 90deg pivot of the flashlight puts the light at an optimal angle while keeping the wrist angle very comfortable (which should avoid fatigue on longer night rides)
Since I ordered (50) 30Q cells (for the price break), this gives me something to do with those last (2) cells.

Complete

Spare swap mid-ride

Field tested! After getting everything reassembled, I took her out for a ride. Lo and behold, about 2/3 through I had a flat, The Evolve spare approach worked flawlessly and I was back riding again within about 5 minutes.

What’s Next

VESC: Add additional low speed torque
Tear down, sand, and paint
Regrip

Research

Nothing right now