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Sesat's 1st build thread [not ready for public consumption]

this is my first build thread

i have barely gotten anything done - i’m posting this to keep myself accountable of my progress. if i never finish this build, this thread will attest to my extraordinary ability to procrastinate. i’ll also be subjecting my ideas to public scrutiny. i’m still a n00b so it will be good exercise to defend my ideas rigorously to criticism. i’m not to afraid to change course when it appears that i was wrong all along.

i’ll keep updating the first post as i continue to acquire stuff, crystallize my ideas, and put things together. i’ll tag the folks involved once this post is fit for public consumption

target metrics

  • top speed 38-40mph, electronically limited to 32mph
  • range 10 miles
  • motor currents 100A/-100A
  • battery currents 200A/-200A
  • water resistance - limited to none, chill summer riding

what i have

deck - subsonic century 40

purple stain
purchased from tipsy who wanted a bigger battery and bought a double-stack evo instead
tipsy did a good job of installing inserts

manufactured in south park seattle washington by subsonic_paul, adman, and bradley for subsonic llc

enclosure - eboosted single stack

purchased from tipsy with the deck, already mounted
interior dimensions go here. gotta measure it.
pix from eboards peru website:



made in peru or in texas (i’m not sure) for eboards peru

moon lrv drive

red color gearbox case
designed by moon
white glove customer service by moon
purchased from moon with 44/12 pinion & spur coprime ratio, surf rod adapters, and bergmeister wheel bolts
made in china for moon, machine shop is a trade secret

electronic speed control - two jedbox v6

fetching shade of red that matches the moon’s gear covers

purchased from jeffwuneo in the so-called test batch
made in china (not sure by whom and for whom, company registration for rideneo not found)

motors - two 6374 190kv

i think the motor kv = 190, it might be 170 i have to look into it
taken it off batman which now sports a pair of maytech’s

purchased from korryh who in turn purchased it from kaly
i assume it was made in dongguan, china for freerchobby co

trucks - surf rodz 200mm rkp

purchased from bradley at subsonic with 80mm axles and an assortment of spacers
manufactured in or around seymour, connecticut by people who don’t skate

antispark - haggy toughwire

designed by gamer43
purchased from haggyboard.timo 01 of 15
bought it because of my faith in kai yin, not sure it can handle the current i hope to draw
made in or around taipei, taiwan for wertrimo ltd
sitting in skyarts place i gotta go pick it up

"wheels - mbs rockstar ii

nylon hubs, kenda inner tubes, kenda 8" outer tires
purchased from On1yBluu who took them off the nazare that he bought from arch and rode them on the colab before selling them to me


i decided against haggywheels because i wanted to run bigger bearings
i will dump these and buy kaly hellcats and an additional set of bx-one 30mm x 10mm bearings if funds allow. while kaly said no that won’t work, i think it was a misunderstanding. precisely machined hubs and SKF 3200A-2RS sounds dope

bearings - nsk 16100-2rs & hch 6900-2rs

wheel bearings are made from 52100 cr+mn steel, made in fujisawa japan. purchased from access bearings via ebay. datasheet

gear drive bearings are made for huanchi in either xingtai, hebei, or in their facility in ningbo, zhejiang. made from an unknown steel alloy, details are printed on the outer race instead of being laser engraved like the nsk’s. purchased from jst great bearings via ebay. while no datasheet is available, i’m expecting these to be better quality than the no-name bearings marketed by skateboard brands

telemetry - metr pro

software designed and continually improved by rpasichnyk in sweden
hardware designed by hexacopter in germany
while i don’t know where they are made, they are superbly manufactured to meet hexacopter’s expectations
isn’t my first metr, won’t be my last metr. will buy their can logger (and will try to power it separately) when available

esk8 news

i got the brain trust on tap, and the love & support of this community

what i don’t have

radio

i’ve had such a great experience with hoyt i can’t imagine using a different radio system.

as a radio amateur, i know when to roll my own, build from kit, adapt & repurpose… and when to use a fully integrated system off the shelf that just works.
i’ll place my order, once i’ve figured out if i’m going to be painting the deck red or not. at that time I’ll be able to decide on a puck color

grip tape

i’d like to remove the grip tape and apply new grip tape to cover the holes with the inserts in them. or maybe patina’d copper veneer + glass frit

esc-to-deck mounting plate

i need to cut aluminum and countersink holes on both sides

i need to buy tools to cut and countersink aluminum plate, unless i find someone else to do this job for me

spot welder

i know i don’t want a sunkko or other mains-powered device. should a n00b buy a malectrics or a k-weld? while the k-weld is much more expensive, it is cheaper than buying twice. i may build at least 2-3 more batteries after this project is over. if i end up buying pre-welded p-groups, i will not need to buy a spot welder and nickel. i will not have to buy fishpaper and heatshrink if the p-groups already come with a balance lead and insulation.

money

no joke there is only so much free cashflow around to throw at this project, which limits what i can do. that brings us to the most expensive part of every pev…

cells

this is my biggest unknown right now. if i can throw money at the problem, i’d buy cells to build a 13s4p molicel p42a pack, it would leave me space for a large smart bms. however, at this time i’m looking to spend $2/cell. i’d like to make up for using cheap cells by using more of them.

there was a sweet deal on hg6 cells that i missed, it would have made a great 13s4p pack. there was an even sweeter deal on 30q cells that i missed, it would have made a great 13s5p pack. there was an even better deal on vtc5 cells that i missed, it would have made an even higher power density 13s5p pack.

fyi this deck fits a nice 20s3p21700 with tiny bms and stormcore 100d but i’m not going to be able to afford a stormcore and a 13s4p p42a pack just barely saturates a heat-sinked dual focbox setup sooo there’s no point going down this path

i’m thinking this enclosure may be able to fit a 15s4p26650 pack (5mm gasket needed) if the cells face the other direction (3 cells east to west). i need to sketch this out and determine how much space remains for a bms or cell level monitoring device

battery management system

since my budget requires i fill the enclosure with cells, i may not be able to afford the luxury of on board bms. tipsy already mounted a gx connector so i can charge with an external balancer. i might have enough space for a neptune lite (which isn’t cheap). it would be nice to have a small charge-only bms. while simosmcmuffin is working on a 62.5mm x 26.5mm 12s bms and derelictrobot is working on a 15s bms (i know not the dimensions), i’m not sure when they will be available

tires

i think 8" is too big for this deck, but i haven’t checked. i do think that 155mm metroboard would look really, really good on this deck. that’s another $100+ shipping so i’ve been putting off this purchase

miscellaneous

wire, connectors, hacksaw, adhesive, silicone thermal pad, velcro, various heatshrink and cable sleeves. this will get more detailed as i spend more time planning

what i haven’t done

designed & acquired a pack

whether i build or buy, i have planning and buying that needs to be done. this will get more detailed as i spend more time planning

cut & countersink esc plate

on one side, i’ll drill out the surf rodz truck mounting pattern (new school? old school?) and countersink for m5 bolts. on the other side, i’ll drill the mounting pattern for the two jedboxes and countersink (need to find out this pattern and bolt size). i would have to slide the truck bolts through the plate, place the two esc’s on them, and bolt them on from the other side. then, i can lay the assembly down on to the tail of the deck, sliding the bolts through the deck. i’ll slide the trucks through the bolts, and torque down the m5 nuts

prep motors

need to hacksaw the motor shafts down. given the mileage on these puppies, i should see if i can replace their bearings as well. and if i have the cans off i should learn how to epoxy the magnets to keep them safe.

assemble gear drives
  • loosely mount motors to gearbox case, slide them onto the hangers
  • mount hanger clamps on to the hangers, bolt to gearcase
  • dry fit pinions, 6900 bearing, and wheel/spur gear. mark the right depth for the pinion, adjust the motors into place
  • install pinion grub screws adhesive, wait to cure
  • fit back the wheel gear and its bearing, finalize gear mesh, take the wheel gear off and take each motor screw off one at a time, put it back on with adhesive. wait to cure
  • finalize gearcase to hanger clamp fit (i’d like the motors as high off the ground as possible without them touching anything even at full lean). apply adhesive to bolts and wait to cure
  • acquire any grub screws and truck bushings i may have lost in my journey
  • mask off screw holes on gearcase for the gear cover (cut painters tape into little bits?)
  • grease me wheel gears up, baby
  • clean up, unmask screw holes, q-tip screw holes with propanol and wait for it to dry
  • bolt on gear case using adhesive, wait to cure
more stuff

this will get more detailed as i spend more time planning

what i don’t know

cells, battery layout, bms, charger

this will get more detailed as i spend more time planning

what i’ve done so far

this will get more detailed as spend more time planning

haven’t done diddly squat
i can’t even get the hanger clamps onto the hangers

17 Likes

I’d participate in “the sisterhood of the traveling spotwelder”.

6 Likes

Well laid out plan Ram, can’t wait to see this come to fruition. You got this.

1 Like

Why would you want to have your top speed at 38-40 mph when you’ll limit it to 32. Wouldn’t it be better to gear it differently to get more torque? Otherwise seems like a great build.

I pledge a battery for this

2 Likes

200a battery is a ton… like a ton ton… PS this is going to be sick

1 Like

thanks for asking, the idea is that i will have headroom when going downhill, so that i’m still operating within system limits when “overspeeding”

it’s important to me that everything (especially brakes) work in that situation

while it is true i would have better torque gearing for a lower top speed, i’m hoping to make up for it by having so much power on tap to make up it

1 Like

Really nicely organized build thread, I didn’t know MBS hubs would fit surfrodz.
How do you do it?

You say dump
I say how much?

1 Like

Buy a dremel. No joke :rofl: I cut two motor shafts by hacksaw this past weekend and although it turned out pretty good (With some help from a metal file) it was a PITA. 1h-ish to cut both shafts and then 20 minutes to file them. I would recommend making a slight entrance cut using a hacksaw for the dremel to sit in, then cut the rest with a dremel :stuck_out_tongue_closed_eyes:

2 Likes

If you ever want your antispark and pulleys you got shoot me a text lol!

Also i recomend not getting to creative with the battery, and really think about a realistic range that you need/want. The “Lazy lightning” @abusfullofnuns with a 12s4p 40t pack is consistently getting 16miles with probably another 5 maybe more in the charge on bergs with 16:47 ratio.

3 Likes

Can confirm stats are real. 3000+ of elevation gain in the 16 miles too. Lots of 29-34mph runs. Still too scared to open it up on full charge but there is some more left in the tank. I’m every bit of 250lbs if that helps at all.

3 Likes

thanks. i used 16100 sized bearings, which fit wheel hubs with 28mm bearing seats

3 Likes

Lol, dude! Same here…

2 Likes

Duuuuuude

2 Likes

Your post is so organized. I feel small in comparison. :smiley: well done.

3 Likes

Quote of my day😎
How’s the build??