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If you’re having trouble with iron losses, you can try adjust your gearing for less torque. This will reduce the rpm of the motor while you’re cruising, which will also reduce the heating due to iron losses.
Beyond that…there’s a reason I don’t run 7490s on Ankle Wreacher anymore
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Not sure if pole pairs matters, but the 7490 I think has 10 pole pairs instead of the usual 7. So the ERPM is much higher.
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That’s correct
These motors have 20 poles(10 pole pairs) you need the 135kv version for 12s
This is the way!
I am very excited about your tits
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24 slot stator 20 pole rotor is what it looks like to me. im not an expert though just a guy with hot motors haha.
I just swaped them out actually for the flipsky 6384 140kv that I had kicking around. I’ll grab some reacher 6485 when the flipsky get cooked.
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Correct it has 20 poles not 24
it does matter with respect to iron losses.
iron losses come from hysteresis. and eddy currents.
these things are a function of the erpm. (among other things) which ends up being the frequency at which the magnetic fields in the coils are flipping directions.
erpm = rpm of motor * motor pole pairs.
so for the same kv and similar construction a motor with more pole pairs has higher erpm and higher iron losses.
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Past couple months have been all about race events.
Before the con, gave my helmet a nice rattlecan paint job
Pretty happy with the result
At esk8con, I fell 6 times, 4 of which were on Ankle Wreacher, and I’ve got 3 of them on camera.
I fell twice on the slippery patch
Once while getting eliminated from the drag race
And again during the 2nd heat race
cutting these together into a proper crash cut is on my todo list… at some point. We’ll see if it ever happens
Qualified 10th out of 95 racers, and scraped just enough points together in the heat races to make it to the final,
finishing 9th overall. Such an incredibly talented group a riders in the pro final, 'twas an honor racing with ya’ll… competition is really heating up this year!
I love how incredibly different everyone’s board is, and how tuned they are to everyone’s respective riding style. Such a cool part of the sport.
Next up was Electrify Expo Arizona
With the air temperature around 95~100F, both days were about tire management. Mine got all the way up at 75C(~167F) at the end of the 6-lap final 
.
With live tire temps, it was super cool to be racing and be able to know exactly where my tires were at (and confirm what I was feeling) with just a quick glance downward 
I’ll be making a full thread about this system once it’s more mature.
An absolute blast racing with Team SKP, Incredibly proud to be racing with y’all.
Cat break
@HAIRYMANJACK Finally talked me into swapping bushings from KranK to APS in the front. About time too- my Krank had some serious permanent deformation!
Everything came off easily enough (with some heat)
And going back on was just as easy. Swapped the old yellow hardware for some sleeker black stuff too
With the two of us working, and a drill to spin the hanger, we managed to swap out the front bushings in only 90 minutes- woot!
Riding it for the first time last night… I should’ve done this so much earlier!! Instantly felt a faster pace. I was confidently sliding the tires on heel and toeside, not something that I’ve been able to do before.
“I’ve never see your board move like that”
Only footage I’ve got is @R2trivv taking some easy laps, but you can really see how much more responsive the board is.
10/10 would recommend.
What’s next?
I got invited/sponsored by xerace to go race in their European Indoor Championships! It’s a genuine honor to be invited out, I can’t wait!
How am I getting my board out there?
Right now, the plan is to pack the board/tools/charger into a pelican case, check it (sans batteries), and carry-on the batteries.
I’ve got a ton of work to get done to prep before my flight next week;
- Fixing grip tape
- Ripping apart my 8x 4s lipos into 16x 2s lipos to get under the 100Wh limit, so I can fly with them
- Modifying my BMS harness to accept this new configuration
- Building the interior structure to the pelican case (for safe transport)
Going to be busy week!
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That slippery patch was also an issue for me during esk8con, I kept sliding out on it so many times trying to get used to the track, luckily I was able to correct myself before my board went too far.
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Definitely interested to see what you did to make the temp sensors there. Of course, now that you’ve got digital feedback, you can hook up a misting system and 4 heat guns to make your tire temps PID controlled.
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FTFY
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I know people who race usually know how to fall and stuff but it really does amaze me sometimes how somebody can make a 30+mph crash look both painless and almost a little bit fun.
Also I think the drag race crash is my favorite esk8 crash that I’ve seen on camera.
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I’ve got plenty of practice at it 
No binding and trusting my good gear really does all the work. Once I was on my back, I was just chillin, waiting to slow down.
Speaking of, I got another Bionic Action V2. (well, I got a spare for my dad to race with at esk8con. Now, because I shredded my old one with so many falls, I’m now going to use it)
Had to give it a paint job.
Took several days of painting, but psyched with the result. Same paint that I used on my helmet and board… Going to be awesome matching head-to-toe 
Grip Tape
I don’t run a binding, so my griptape is super critical. I think because I don’t run a binding, I stress my grip a lot more then other people do.
Before esk8con, I was pushing Vicious to the limit, having to replace the rear griptape every 4~5 weeks. Additionally, on hot race days, Vicious would melt, accelerating it’s wear even further. If I left the board out in the sun, I’d end the raceday without any griptape left 
Looking for an alternative, I switched my griptape from Vicious to Seismic Skate Lokton 36-grit. It has a paper backing (instead of a vulcunus one), so it doesn’t melt in hot weather like vicious. In fact, the heat-sensitive adhesive actually gets stickier with hot weather! Requires a heat gun to apply to the board.
Even better, this stuff is way shaper (basically glass frit, it’ll draw blood).
And the best part? It’s blue.
A month later of hard racing, it’s showing zero wear. Not an easy feat, super happy with this grip.
Unforunately, it seems to have trouble sticking to my front MBS concave pad.
Over the past couple weeks, it’s actually slid a non-insignificant amount.
It kinda makes sense… the MBS pad has a glossy surface that doesn’t seem like it would be conducive to adhesives.
As a bodge fix, I gave the pad a nice sanding, and re-applied the grip with a heat gun.
Long-term I’ll probably replace the pad with a material that this griptape’s adhesive sticks to better (perhaps 3D printed), but this will do for now.
New Camera
Watching everyone’s POV shots from esk8con this year were sick.
Wanting some of my own, I recently purchased a Insta360 Go3s from a sketchy marketplace deal.
Unfortunately, My helmet doesn’t make mounting it easy. There’s no nice, flat surface to mount it to.
Some creative use of wire snips and VHB later, this was solved.
Pulled the non-stick backing off the Insta360 mount,
And we’ve got a mount that Louie approves of
Man, I love VHB
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This stuff works wonders, I use it all the time at work. Clean your surface, apply this stuff, and it’ll be twice as sticky after it dries.
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