NuVoL CityRunner V1

Hi everyone, my name’s Stefan, I’m an architect and I’m from Bucharest

Together with my friend Adrian who’s a last year student at polytechnics university (electronics) we upgraded my original eskating.eu 10s3p single motor kit to a dual motor 10s5p 11.5kg board great for city riding and commuting.

I’ll also add a small history to explain some of the decisions and hopefully give you guys some insights into the process and the lessons learned

So I got the original kit from Alberto in july 2018 and until last year I probably put around 4k miles on it mostly using it as a commuter board in Bucharest (9km round trip to my office) and weekend joyrides

I got a cheap “mall brand” wooden board that lasted me for about 2 years but I felt it started to wear down especially on the front where it got a lot of impacts and started vibrating strangely which told me I needed to upgrade it.

So in 2020 I upgraded to Landyachtz Switchblade 40 which looks pretty cool and it did give me a lot more “feel” for the movements of the board and trucks


But it came with 2 downsides that I didn’t initially consider: weight, it probably added 2 kg extra and stifness - it became a less comfortable board to ride. Switchblades are very stiff boards apparently

A few months later, after multiple problems with the original 4.12 50A Maytech VESC which in the end had a DRV failure, I “upgraded” to SuperFOC 6.8 50A Maytech VESC which kind of solved the issues with the cutoffs (but not entirely)
from this:


to this

I think the problem with the cutoffs was the fact that I kept a pretty aggressive setting in the VESC, going for 50 amps for the battery max which even though should be the max setting it seems that in reality maytechs and flipsky small VESCs like this need to be configured more conservative (40-45amps)

But the main issue was the riding experience, a very stiff board coupled with the MBS “All-Terrain” wheels, it became a not so fun board to ride. So I started to look for softer wheels and I upgraded to ONSRA’s 115 rubber wheels:


And they were perfect, a lot smoother ride, not so many vibrations… I thought finally the setup is finished. But… the downsides of these guys:

battery almost halved and sagged very bad starting at 35-40%
motor overheating
the bigger 45t pulley on the wheel vs the small 14t that was also very close meant I had a lot of belt slip
I kind of fixed this by modifying Alberto’s original mount and adding a tensioner:

But this lasted me around another half of year and the experience degraded so much that I kind of stopped using the board.

So last year (2022) around this time I decided that after 4 years of service the battery was probably also one of the issues and together with Adrian who had experience building batteries we planned a bigger upgrade. It was clear that the new wheels needed 2 motors and a bigger battery to push them even though it meant having a heavier board (the original one was approx 6-7kg). But I didn’t want a very thick, very heavy board.
I also wanted to keep motors mounted under the board (inbound?) because the shape of the board gives me the option to kick-rotate it on the spot which is a good thing to have in a big city with tight corners.

So the 2022 build started with an order for new wider trucks, new mounts, 33 new Samsung 30q cells (17 of the old ones Adrian tested and seemed fine) and new motors

and the plan was to try to initally use the 2 old 50A VESCs in dual mode. I knew they were different versions and one of them had the DRV problem but my hope was that I could run them in BLDC mode and be fine.

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Nice write-up!

FYI, that’s not a Switchblade deck you have, the Switchblade has a drop. I think you have the drop-hammer?

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So I placed an order with Nexusboards, Ben was helpful with choosing the right belt lengths :

The BN trucks, DM mounts and 6355 motors were in stock and seemed that will be shipped soon but… they were in the end sent in October, so I kind of missed the whole summer :sweat_smile:

I did a lot of followup and pushing, I think Ben went through some trouble in that period but in the end he sent upgraded 6374 motors instead of the 6355s free of charge (even though they were a little used)

So now we started working on the battery, cleaning up the old cells and preparing the new ones

We used a Forex divider between the 2 rows that should also give the whole pack more structural strength

Where the BMS wires crossed the Forex divider we cut some small slits into it so it won’t friction wear the wires. This was before some extra foam membrane cushioning and shrinkwrap:

I also 3d printed some extender parts because the Slim enclosure from eskating was not going to fit the bigger battery and VESC

This was also a good opportunity to integrate all the connectors and buttons, fittings etc


So now it was starting to take shape and Adrian did a great job on the VESCs cable management

but…disaster struck in the first minutes of the first test ride:

The newer VESC had a spark and stoped working

After analising we realised that the idea to have the battery on the bottom of the enclosure and the VESC on the top wasn’t the best way to utilise the space inside even with the extenders and we actually put physical pressure on the controllers which probably was what led to the spark.

Part 2/3

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You are correct it’s not the switchblade, it’s actually Landyachtz 10 two 4 Wolf
Thanks for the observation

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Classic nexus boards customer experience :smoking:

Is there any insulation at all between the adjacent p-groups? If not, then all it takes is for the cell shrink wrap to get worn off even a little to cause an immediate short-circuit and fire. That battery is a bomb ready to go off at any moment until that’s fixed! :scream:

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Yup, you need fishpaper to separate/isolate the p-groups.

Also, do I understand that you mixed the old cells with new cells?

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So now, a lot more measuring and modelling:

A new concept for the vesc placement and modifying the ABS enclosure:

from this:

to this (who knew I was going to cook some plastic on the stove at one point in my life?)

Not wanting to have any parts touching anymore and inspired by some Bioboards pictures, a new battery mounting system was created from an old tape measuring ruler:


Which works surprinsingly well, the wooden screws I checked multiple times and haven’t slacked.

And the new VESC, a flipsky dual mini 4.2 plus, 100amp:

I wanted to be sure to keep it cool and stable so I started looking into a custom aluminium radiator and eventually decided to design and CNC one that also fitted the VESC’s mosfets:



This is how it turned out:


So after a few hundred kms the NuVoL CityRunner is finally finished (almost, it needs a new griptape and some cosmetics) but good enough for now:




The acceleration on the 45T is brutal… even with conservative settings (75a total battery max) I reach the max speed of 40kmph in about 3 seconds.

Range I did around 1h total time aggressive riding without battery sag, my feet were tired… probably over 35km with an 80kg rider and all of this in a 11.5kg package.

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Indeed, the old cells with the new ones wasn’t a good idea as one of the packs is staying lower then the rest with around 1.5-2V depending on the charge. I’ve already ordered 17 new cells to replace the old ones. Btw, Adrian put hotglue between the cells when adding them together but definitely we will do the fishwrap for the packs individually now when we open it up :ok_hand:

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This is actually genius :open_mouth:

I’ve wanted to do this in the past but could never find the right material for it.

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Thanks! It also adds almost no weight

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Dude.
Really cool to see all the work and the progression.

I hope you enjoy riding!!!

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Thanks! It’s been a journey… :nerd_face:

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Quick update here after 1 month of almost daily use the ruler bands broke, so I don’t recommend using this solution unless you add more and/or check them more often. They seem to not be so strong as I initially thought.

Yesterday the longboard wasn’t working so this is what I found inside… the ruler bands basically cut through the wires connected to the BMS, luckily the fishpaper and Kapton tape did their job and limited the short. On first inspection only 2 packs of the 10 seem to have failed.

I’ll probably switch to 3d printed mounts or just rely on the enclosure and find another way hold the space above de VESC.

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Update on the battery and the City Runner

The battery had damage to 3 of the 10 p packs so we discarded all of these cells. We also discarded all the cells we had harvested from the original battery even though they tested well. In the end we kept 20 of the 50 cells that were in the battery - the ones that I bought in 2022 and had only around 20 cycles on them.
Conclusion is the harvesting of already used cells is a lot more time consuming than starting with brand new ones, when you factor the capacity measurements, the weld cleaning, the wrap replacement (white)



I then bought 20 new 30Qs and 10 Molicel P28A - so all the p packs have now 4 30Qs and one P28A in them. I did this for the added discharge rate 15Ax4 + 35A = 95 amps cont. sacrificing a little bit of capacity.

We then measured and entered all the capacities of the cells to get the optimum balanced p packs composition


The welding went well. Note the fishpaper between the p packs. I didn’t want to individually wrap the P packs with fishpaper because it will introduce extra stresses between these packs, I think for this type of battery shape the stresses should be evenly distributed as it flexes.

Over the nickel strips we soldered some extra soder wick


fishpapered the battery

The battery got 2 PVC 3mm strips in the middle for structural support in which small grooves were dremmel-ed for the passing of the BMS wires.

Some extra PVC for the protection of the connecting 8AWH in the front and some duct tape for lateral protection.

Extra foam double sided sticky tape on the middle to prottect the BMS wires

Shrink wrap

Now, for the mounting system.
We decided on Velcro-ing the whole battery and we tested it.

For regular flexing it hold up very well but for impacts (dropping the board on the floor) it eventually got unstuck.



This time I got some construction grade metal bands - 2mm thick

Which we wrapped in some rubber bands and tape

And it was ready to be closed for now

After a 2am 10km ride the battery went to 91% which I guess is a good sign, but will test further. Acceleration and braking is good and top speed was not tested but should get to around 50kmph on the new 32T pulleys.

Some cosmetic stuff are still to do but it seems it’s finally almost finished… :face_holding_back_tears:

Final touches to the board:








  • 2 anti-sink plates 3D printed with “tactile stopppers” - which turns out work very well to feel the positioning on the board and also give some stability
  • Front plate integrates the battery voltage module
  • Wavy Grip tape by YOC, custom first cut for Landyachtz 10-two-4 deck, also used some strips of grip for front and back bumpers

Final results:

  • Range 32-35kms with agressive riding, flat city, 80kg rider
  • Top speed on 15/40T around 45kmph with pretty strong acceleration
  • 11.7kg
    Very smooth ride, stable and nice “GT” feel, carving at top speed with confidence

Special thanks to Adrian for the awesome work on the battery and electronics :call_me_hand:

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I love the grip tape dude.

Glad you are enjoying it!!!

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Some upgrades and some touch-ups:

Almost done. Maybe never actually done…? :face_with_spiral_eyes: