Project to be named later, ?18s? tbdd longboard grocery getter

Electric Skateboards
1

project to be named later.

Warning

This post is a work in progress and I intend to make several edits over the coming days, with adding links, correcting horrible spelling and grammar, so don’t follow the thread if you are adverse to alerts when I make small changes.

This project is a bit of a stretch goal for me but hope that by publishing here it’ll keep me committed.

Background

I really love my @torqueboards Direct Drive. They are quiet, take a beating and keep eating the watts. BUT, as pretty much EVERYONE here will attest to, I’ve got a bit of baggage (@SeanHacker - I refuse to stop eating). So this means my beloved TBDD doesn’t get the love it deserves.

The specific challenge I’ve experienced has been motors overheating when I ask too much of them - nothing like loosing those brakes on the way downhill. Particularly during the summer heat. I know, I know, @skate420 will say, “uh you ain’t seen hot until you ride here.”
I tried, in vain, to redo the build with some amazing @avx Herringbone gears and do a build for my nephew with the TBDD. Then COVID happened, @Abusfullofnuns took advantage of my moment of weakness, and relieved me of those gear drives (glad they have a good home though).

With the rainy season coming up I thought it would be fun (for me, maddening for you all) to work on tweaking my build to breathe new life into it. My hypothesis is using a higher voltage like 18s (75.6v) will generate less heat and overcome the motor heating issues experienced with 12s (50.4v) under reasonable conditions.

I’ll be logging my updates in this thread on an infrequent basis; I’m targeting better than once a month. (@Lee_Wright is rolling his eyes right now, “M8 AT LEAST once a week to keep 'em interested”).

Goals

My Goal is to reuse as much of the components and equipment I already have on hand. @tamatoa will attest that living on an island in the middle of the pacific can be as frustrating as it is enjoyable when we have to wait weeks for some seemingly innocuous thing that holds up the entire project.

Reliable, like weld the hood closed reliable. I agree with @b256 with “if it a’int broke don’t fix it” so once its at a spot where the board is working as expected, imma close her up with the intent of rarely if ever reopening that casket.

Reasonably thin: the deck i’m repurposing is quite thin so keeping a low and aesthetically pleasing profile is the goal.

Accessible what I mean here is the ability to interrogate and or make changes to the board without intrusion.

Logging Data is king, i want the ability to log issues to have educated input for targeted troubleshooting. but i don’t want the data “in my face”, yes i hear the community cries for me to cover more and more of my face but i’m speaking about when data can become a distraction. this his highly personal and i do not assert one method is superior over or another. but for me, and this board i’m thinking less of a DaveGa and something more paired down. Probably similar to what we have seen on the vaporware called FreeSk8 Remote.

Components

Way to track and log data
metr pro https://metr.at/shop and or robocotchi https://derelictrobot.com/collections/production/products/freesk8-robogotchi?variant=34942887133344

Remote
hoyt st puck https://www.hoytskate.com/collections/accessories/products/bamboo-puck
or
FreeSk8 Remote https://derelictrobot.com/collections/production/products/freesk8-remote-control?variant=33768466841735

Deck
121c afterburner https://www.121cboards.com/shop/afterburner/

Trucks
Caliber II

Bushings/pivot cups
Riptide KranK Chubby https://www.riptidesports.com/longboard-bushings/chubby/krank-chubby/
Riptide Caliber II Pivot Cups

Motors
TBDD 75kv https://diyelectricskateboard.com/products/torqueboards-direct-drive-motor-kit

Wheels
TB110 85a (blacks), maybe something squishier later https://diyelectricskateboard.com/collections/longboard-wheels/products/110mm-78a-black-torque-wheels-tb110

Bearings
Zealous Bearings https://www.muirskate.com/longboard/bearings/70875/zealous-ceramic-built-in-bearings

ESC
StormCore 100D https://lacroixboards.com/products/stormcore

BMS
currently have a 12s LLT BT BMS, this may take longer than i expected…

Cells
P42a 18s2P, Liion Wholesale https://liionwholesale.com/products/molicel-npe-inr-21700-p42a-45a-4200mah-flat-top-21700-battery-authorized-distributor?variant=15913210675294

Battery PCB
DRI modular 4p 20700 pcb https://derelictrobot.com/collections/garage/products/modular-4p-battery-pcb

i’ll be perving on @Benjamin 's thread for top tips
Derelict Robot Industries - 12S4P FlexPCB Build Guide

Enclosure
DIY - probably a wrap of fiberglass/carbon hoping for some guidance from @glyphiks and @linny

Misc
Fish Paper, DRI https://derelictrobot.com/collections/diy-supply/products/fishpaper-100x70mm-adhesive-backed-sheets
Cell Rings, DRI https://derelictrobot.com/collections/diy-supply/products/fishpaper-21700-4p-ring-insulator-strips
Accessory Port, TBD, prolly CLinko style
LP-20 Charge Port, https://derelictrobot.com/collections/diy-supply/products/lp-20-high-amperage-panel-mount-charge-port-set-m-f
Charger, - this poses an interesting problem, that has not yet been thought through. i have a 12s charger that i wished to re-purpose but clearly cannot charge 18s pack with 12s charger - can already feel this plan falling apart…

Nickel, 1kg https://liionwholesale.com/collections/new-products/products/pure-nickel-strip-roll-0-15mm-0-2mm-thickness-6mm-10mm-widths?variant=31351278501957

Battery Welder, Malectrics https://malectrics.eu/product/diy-arduino-battery-spot-welder-kit-v3-2-2-full_bundle_car_battery/
Battery Welder battery, Hobbietat http://hobbietat.com/, local hobby supply

Images

Donor Build
lorax
lorax548×549 172 KB

IMG_20190811_062209
IMG_20190811_0622092112×4608 2.62 MB

Deck Top

20200901_115724
20200901_1157242252×4000 1.68 MB

Deck n trucks n drive train

20200901_115817
20200901_1158174000×2252 2.24 MB

I don’t intend to do a bunch of flagging for off topic discussion in this thread but do try to keep it at least in the ball park. Unless @BillGordon shakes some sense into me - only @k00k will be exempt from said egregious off topic items.

b/c _i JuSt KaN't G3T 3nUfF 0f tHaT k00KiN3Ss_

k00k_laugh

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Nice. Seems like it will be a sweet project! If there’s one thing I know about, it’s how to fuck up fibreglass. Happy to help when the time comes :call_me_hand:

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Yep it sucks but wouldn’t feel right to complain at the same time so it’s a weird feeling.

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This looks like its going to be an awesome build!

Just FYI, BulkBattery has better prices on the P42A than LiIonWholesale.

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Thanks I already have them in hand got them last year during the holiday sale!

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They’ll be stale by now. Better send them to me and get some fresh ones.

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Good point, I’ll just use the “cheap” shipping method and toss 'em in the rip current. And send em your way

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Don’t know the currents but I’ll keep an eye out in case I can intercept.

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Interesting, if you’d want to go for an enclosure, the 121c Afterburner is a flexy deck, so two enclosures? Or a segmented enclosure?

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IMG_20200728_200232995
IMG_20200728_2002329951560×2080 1.56 MB

My design isn’t sexy, but this 3D printed enclosure with TPU works well with a flexy deck. It would work fine as one piece, but my print bed size drives the segmentation.

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@Wandagoner Glad you like em! We may just switch over to the TB DD XL as standard as it does a lot better with heat.

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It’s fine. Just stick to those feet pics then… :yawning_face:

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My nuts groan looking at that deck! That’s a 121c Afterburner isn’t it?

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yessir i like the deck more that i expected. but will concede it wasnt the best esk8 selection, primarily b/c there were not any slick enclosures like Alan or Big Ben make

seems i’m the only one who likes the grip tape, i mean it glows in the dark johann.

my wife actively averts her eyes from it when she comes into my office.

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I’ve needed one ever since I laid eyes on it.

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That’s all well and good but unless you lower the KV as well as increasing the voltage. I think you won’t gain anything except more heat in the vesc at same speeds. Gearing is the other way of acheving this but that’s not a option with DD

Edit: you can gear down a DD by using a smaller wheel TB110 to a 80mm Kegel is almost 2/3

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Your right if every thing is = to achieve the same W more voltage less amps will be less effected by resistance produce less heat

A simplified example with the same KV with wattage making the desired tork/speed

12s 50v 30A 1500w 90kv 20mph
18s 75v 20A 1500w 90kv 30mph

For the 18s to achieve 20mph it have to run at 2/3 duty cycle with simplified means it’s averaging 2/3rds of the voltage

18s (2/3 duty cycle 50v) 20A 1000w 90kv 14mph

Now we don’t have the total watts needed to maintain the speed/tork to balance the wattage out with out increasing the max speed we need to add more amps

18s (2/3 duty cycle 50v) 30A 1500w 90Kv 20Mph
Vs
12s 50v 30A 1500w 90Kv 20Mph

Now you back at square 1 using 30amps producing the same amount of heat in your motors

(In reality I’d expect the higher voltage running at 66% duty cycle to produce more heat due the the PWM back emf resistance)

If you could reduce the gearing or KV by the same % you increase the voltage eg

12s 50v 30A 90Kv 1500w 20Mph
18s 75v 20A 60Kv 1500w 20Mph

(disclaimer I know there is other factories going on but I hope this simplified version shows a basic idea of what increasing the voltage would do and how to use it to your advantage)

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What about the hanger bending? My pair of used drives show small signs of it, not sure I’d want even wider ones unless they were beefed up.

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We are planning on making them stronger so far no signs of bending with the latest setup. Usually when you hit potholes it’s sometimes possible esp on the xl. I wouldn’t go larger than xl for this reason though.

With the latest hangers they have been more durable though.

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I want to like this twice. maybe 3 times. and then jokingly say… “but more S is always better!!! more torque and more speed and less heat and more range”

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