Search found 64 matches

by brent
Nov 13 2015 12:40pm
Forum: Stand-up E-scooters and E-skateboards
Topic: 3D Gear models Electric Longboard thread
Replies: 10
Views: 1929

Re: 3D Gear models Electric Longboard thread

If you're still considering getting the pulleys printed, it's probably worth taking a look at 3DHubs or MakeXYZ -- it should be quite a bit cheaper than professional SLA or SLS prints.
by brent
Oct 30 2015 11:48am
Forum: Stand-up E-scooters and E-skateboards
Topic: FVT Firmware for E-Skateboards
Replies: 8
Views: 1754

Re: FVT Firmware for E-Skateboards

There's a firmware flash option in their USB interface software.

I have one or two FVTs that I can't quite get to work, so I might try flashing them and see if doing so fixes anything... (would be good to know how it differs from the regular firmware, though)
by brent
Sep 26 2015 9:55pm
Forum: Stand-up E-scooters and E-skateboards
Topic: FVT 120A ESC Help?
Replies: 3
Views: 764

Re: FVT 120A ESC Help?

Did you turn the transmitter on? I also had to play with the throttle trim on mine before it started working. You needed to play with the throttle trim before you could calibrate the throttle? That seems a little counter-intuitive. Ijust tried sending every possible PWM signal between 1000us and 20...
by brent
Sep 26 2015 8:12pm
Forum: Stand-up E-scooters and E-skateboards
Topic: FVT 120A ESC Help?
Replies: 3
Views: 764

FVT 120A ESC Help?

I'm having issues with getting two FVT 120A ESCs I just bought working -- attempting to do a throttle calibration, but nothing happens when I hold down the SET button as I flip the switch to turn them on. Motor is plugged in, the fan turns on, and the programming card works fine. (motor beeps when I...
by brent
Jul 14 2015 2:45am
Forum: Stand-up E-scooters and E-skateboards
Topic: Screw-reinforced printed motor mount?
Replies: 14
Views: 2097

Re: Screw-reinforced printed motor mount?

Hi All, I was thinking about that, and I found this new material for 3d printer, the IGLIDUR, is 50x more resistant thant other material for 3d printing and designed specifically for mechanical and moving parts : http://www.laboutiquedu3d.com/igus/365-fil-3d-iglidur-180-175-mm.html Sorry it's in fr...
by brent
Jun 30 2015 8:12pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Estimating accelerations?
Replies: 4
Views: 588

Re: Estimating accelerations?

kT's a constant, but your applied torque will fall as speed rises.

If your torque was always equal to T_max you wouldn't have a top speed. ;)
by brent
Apr 27 2015 3:18am
Forum: Stand-up E-scooters and E-skateboards
Topic: Lipo Torkinator ESR help required
Replies: 6
Views: 1026

Re: Lipo Torkinator ESR help required

Poking around with a multimeter is a good idea. Or, can you take a closer or better focused photo of the board, perhaps so the text on each component is readable? If you can figure out where there's a pin or something with a positive voltage only when your goped is on, it'd be easy enough to use it ...
by brent
Apr 25 2015 4:20am
Forum: Stand-up E-scooters and E-skateboards
Topic: Sprocket Size Speed vs. Torque--Rookie Question...
Replies: 5
Views: 692

Re: Sprocket Size Speed vs. Torque--Rookie Question...

I think it'd actually be no, for both. For the same wheel pulley, more teeth on the motor pulley would make your board faster, not slower.
by brent
Apr 23 2015 2:28am
Forum: Stand-up E-scooters and E-skateboards
Topic: Post Your Electric Longboard or Electric Mountainboard Build
Replies: 236
Views: 87125

Re: Post Your Electric Longboard or Electric Mountainboard B

I think somebody just needs to find some time to design a decent BMS... it's on my to-do list but I probably won't get around to it until the summer.

In the meantime: http://endless-sphere.com/forums/viewto ... 35&t=61171
by brent
Apr 20 2015 4:42pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Drilling a keyway in a motor shaft : advice needed
Replies: 10
Views: 1220

Re: Drilling a keyway in a motor shaft : advice needed

A short carbide endmill did the trick for me. It took me a couple passes but just go slow and it's pretty simple.

Gives you a much nicer finish than a dremel, haha. Not that that really matters...
by brent
Mar 22 2015 9:46pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Top Speed Calc with Load
Replies: 13
Views: 1417

Re: Top Speed Calc with Load

http://lancet.mit.edu/motors/torquepowerspeed.jpg If your mechanical setup is 100% efficient and there's no rolling resistance, your speed will creep upwards to approach the point on the graph above when (the radius of your wheel) x (force from air resistance) is equal to (your motor's torque) * (1...
by brent
Mar 08 2015 4:30am
Forum: Stand-up E-scooters and E-skateboards
Topic: Will this ESC + Motor Combo work?
Replies: 5
Views: 729

Re: Will this ESC + Motor Combo work?

Your combination looks fine; the motor voltage won't be an issue. Ideally, your batteries should be able to handle 100 amps continuous; you can get your battery's maximum continuous discharge current by multiplying your discharge rating in C with your capacity in Ah. ( ie 5Ah battery * 20C discharge...
by brent
Mar 05 2015 2:34am
Forum: Stand-up E-scooters and E-skateboards
Topic: Customizable Electric Longboard- Design Input
Replies: 7
Views: 1086

Re: Customizable Electric Longboard- Design Input

Nice Carl.. I see that one of your co-founders works at Gorilla Circuits. I've passed by that place a few times. Funny, so have I. Went to elementary school only a couple miles away. If you're looking for versatility, one suggestion I'd have is to make your motor mount rotatable; it adds an immense...
by brent
Feb 27 2015 6:56am
Forum: Stand-up E-scooters and E-skateboards
Topic: how come it takes so many watts and 8s escs
Replies: 8
Views: 859

Re: how come it takes so many watts and 8s escs

http://kreuzotter.de/english/espeed.htm It works, given correct data. Misread the original post, oops. Thought he was referring to a hub motor rated for 350W. If you live in a world covered with float glass or polished steel plates, your results may be different. Or somewhere covered with decently ...
by brent
Feb 27 2015 5:11am
Forum: Stand-up E-scooters and E-skateboards
Topic: how come it takes so many watts and 8s escs
Replies: 8
Views: 859

Re: how come it takes so many watts and 8s escs

My calculator says that assuming a city bike and a 200 pound rider, 350W at the wheel yields 19 mph. Bigger wheels are more efficient than smaller ones. Pneumatic tires are more efficient than solid ones. And standing up straight in the airstream is less efficient than crouching down even a little ...
by brent
Feb 03 2015 12:09pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Step down converter for esc possible ?
Replies: 5
Views: 755

Re: Step down converter for esc possible ?

A UBEC is just a 5V/6V/7V regulator with a fancy name; essentially just the circuit you posted but with a fixed voltage.

Don't see why it would be any more isolated.
by brent
Feb 02 2015 5:44pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Step down converter for esc possible ?
Replies: 5
Views: 755

Re: Step down converter for esc possible ?

If you adjust the regulator before plugging it into your controller, it shouldn't be a problem. You can glue down the pot adjustment screw if you're paranoid about it turning, but the one in your link uses a worm gear and should basically be vibration-proof. 10S lipos peak at 42v, and the standard n...
by brent
Jan 13 2015 1:01am
Forum: Stand-up E-scooters and E-skateboards
Topic: Longboard 660kv motor HELP!!
Replies: 10
Views: 1477

Re: Longboard 660kv motor HELP!!

I did multiple hole patterns for tensioning, but I haven't found a need for tensioning yet; the "middle" pattern is just the calculated center-to-center for a 17:40 reduction + 3 thou; the other two are spaced at something like ctc + 8 thou and ctc - 15 thou. Turning down the trucks and clamping mak...
by brent
Jan 12 2015 11:58pm
Forum: Stand-up E-scooters and E-skateboards
Topic: Longboard 660kv motor HELP!!
Replies: 10
Views: 1477

Re: Longboard 660kv motor HELP!!

I think $250 is doable. 5065 270kV motors are common and good for flat ground.



I have a bunch laying around and could probably send them to you for cheap.
+ motor mounts, printed & polycarbonate pulleys, 6S 120A car escs, etc
Image

/shameless plug
by brent
Dec 26 2014 3:31am
Forum: Stand-up E-scooters and E-skateboards
Topic: 3D printed parts Depository
Replies: 178
Views: 23517

Re: 3D printed parts Depository

Just a note: my Flashforge extruder doesn't really agree with flexible filaments. The filament path isn't constrained well enough, and the filament buckles in between the drive gear and the actual hot end. I think there are printable extruders on Thingiverse that'd let you print with the flexible st...
by brent
Dec 14 2014 2:49am
Forum: Stand-up E-scooters and E-skateboards
Topic: Simple Charging Port (Plug n Play)
Replies: 17
Views: 1398

Re: Simple Charging Port (Plug n Play)

Onloop's connector (which I think looks really, really nice) sounds like the safest bet, especially if you eventually want to upgrade your charger. @onloop I think he meant the balance leads can handle charging up to 40 amps, which shouldn't at all be a problem if your batteries are properly balance...
by brent
Dec 03 2014 1:14am
Forum: Stand-up E-scooters and E-skateboards
Topic: 3D printed parts Depository
Replies: 178
Views: 23517

Re: 3D printed parts Depository

Huh, okay. I've been having trouble tensioning the belt tightly enough so that it doesn't slip when breaking, without obvious resistance during some parts of the revolution.

Bolts through my drawing?
by brent
Dec 02 2014 10:48am
Forum: Stand-up E-scooters and E-skateboards
Topic: 3D printed parts Depository
Replies: 178
Views: 23517

Re: 3D printed parts Depository

Assuming wheel runout means the belt slides off the gear towards the metal motor mount? It only happened to me on my rear wheel board a long time ago. As soon as i changed to front wheel drive (which spins the tire in the oposite direction) the runout is towards the wheel itself where the iner end ...
by brent
Dec 02 2014 12:39am
Forum: Stand-up E-scooters and E-skateboards
Topic: 3D printed parts Depository
Replies: 178
Views: 23517

Re: 3D printed parts Depository

Is anybody else having issues with the wheel running out? The pulley insert seems fine, but the entire wheel (and the pulley with it) does a sort of wobble when it spins, with a visible runout of <1mm. Possibly because one of the bearings is partially(or fully?) sitting on the threads, which are un...
by brent
Nov 29 2014 4:34am
Forum: Stand-up E-scooters and E-skateboards
Topic: Here come the clones..
Replies: 146
Views: 27317

Re: Here come the clones..

The fan grill looks exactly like the one on the FVT 120A car ESC.