Motor and battery choice

[jeroenimo]

Ladies and Gents..

I've been reading a lot and I'm about to order some stuff. I'm pretty confident that this setup will work, but I could be really wrong!. But since this is the first time I'm about to build a DIY longboard. Some criticism will be greatly appreciated!

Idea for a first build:

single engine 6s and 12s config.

-Generic longboard (still to decide, probably bought locally, at least something stiff with a lot of room for 90mm Flywheels)
-Caliber II trucks (bought locally)
-DIY mount for 63mm
-Turnigy 168KV 63mm SK3 brushless
- 2 Zippy 5000 30C 6s (seemed allright to me with a 30C discharge)
-DIY ESC 120A (dunno where to buy a VESC!)
-DIY Flywheels 90mm
-Generic Bearings (locally bought)
-Imax Battery charger (i'm not sure, this looked allright, so advice is appreciated!)
-Sprockets and belts, which I hope to be able to order at DIY or other supplier.
-Sweet reliable little 2.4 ghz DIY remote

6S

12S

Some explanation, I might be wrong though, please correct me, I played with excel to try get it right..

A is KV, B Max V is 6s,C Wheel diameter 90 mm, D theoretical top speed in KM/h. E gear ratio 2:1, F RPS (revs per second), G roll dist per R is distance per rotation of wheel, H RPM engine is theoretical max rpm's

So I would start with a 6s config, this will make a not too fast but rideable board. I could then double to a 12s (ESC and motor can handle this) and go faster and more acceleration. My idea would be that I can hand the "tame board" to my small nephew, or friend who has never long boarded before with a 6s configuration, but when I want to ride myself, the 12s configuration is put on. (Dr. Jackell and Mr. Hyde modes).

My doubts and questions:
-Is that 2:1 ratio realistic? Is DIY boards able to deliver such sprockets and belts, does that fit on a engine mount? What should I order?
-Should I go for a higher KV and different ratio?
-Is my Dr. Jackal and Mr. Hyde mode idea feasible?
-Where do I buy a VESC, should I or is the DIY ESC a good option too, that VESC sound really awesome, especially while the motor is senseless.

P.S. Here is my excel sheet, just fill out the KV, wheel diameter and all the other numbers appear

 

[LEVer]

You will have crazy torque and brake steer on 12s with a single motor and your gear ratio. Your small nephew might actually be ok with 5s or 4s, while you go 10s or 8s.

Welcome to the board!

 

[sl33py]

nice first post. Welcome to ES!

Looks like you have a solid plan. Here's my .02

DIYes motor mount - any reason you are only getting hte mount only? I would strongly recommend you get the kit which gives you both motor and wheel gears plus a belt. You will probably save $ that way vs getting individual gears and getting them modified to fit.

I have a similar calculator (from beetbocks), which is more about gearing and top speed:

Diameter		Motor KV		Battery S/V		M pully		Hub pulley
								
90		168		6		15		36
								
Speed= KPH	28.504224							
Speed= MPH	17.17121928							
actual speed	14.42382419

This is as close to your top one i could find for 6s.

Diameter		Motor KV		Battery S/V		M pully		Hub pulley
								
90		168		12		15		36
								
Speed= KPH	57.008448							
Speed= MPH	34.34243855							
actual speed	28.84764839

And same on 12s

It's been really close to accurate when i've tested on the flats. I usually gear for a top speed of 25mph which is more than fast enough for me.

I like your Jeckyll/Hyde idea. This is what i do on my GF's board (Vanguard 41 single 63mm motor setup). She gets a 6s setup and i ride 8 or 12s w/o changing gearing. She likes slow - i don't!

VESC - i'd get one from Jamesonotc, Chaka, or Enertion. It looks like most of them have one ready or almost ready to ship. I've also heard great things about Torque/DIYes 12s ESC. Simple plug and play. It would really depend on your willingness and comfort to configure the motor to the VESC in BLDC. Not hard, but a couple steps and takes time the first time to sort it out. Can be a bit daunting, but actually pretty quick after a time or three. I like the advantages of VESC personally, but don't think you can go wrong between the two. Also i'm not positive but think you might need a BEC w/ DIYes 12s as it doesn't put out the 5v for your Rx? Link to his 12s isn't working right now (work connection)

HTH - GL!

 

[jeroenimo]

@LEVer

Torque is what I like, I'm certainly not into a high speed machine. I live in the Netherlands, which are most of the time as flat as your 9 year old sister. But since E-board are illegal here I'm hoping to blend in with the non-e-boards. High speed would let me stand out between the others. Also I'm old and I have a sports bike for speed kicks

@sl33py

Nice answer, thanks for putting in effort on my n00b questions.

-The reason I would like the DIY mounts is that I'll be able to remove the e motor completely, but I would certainly opt for the gears also delivered by DIY. But since gearing is still a little bit voodoo for me, I had not found out yet what I need.
-Dr. Jeckel and Mr. Hyde sounds like a good plan then, but even 4s and 8s could work? How do characteristics change, are these linear? Does a ESC/VESC need reconfiguring? Theoretically a VESC could also tweak a 12s setup down to humane levels, maybe with some sort of profiling? (just daydreaming)
-Buying a VESC vs a ESC would certainly be the best IMHO. And I'm not afraid configuring it, have multiple linux machines at disposal. I can RTFM, trial and error until I get it just right. So if someone can hook me up!?
-That BEC is for sure an item, I had not forgotten about. I'm not too sure if this is needed with a VESC. Doesn't this have a separate 5V output for the remote?

 

[206monkey32]

Hey man, welcome to the board!
It sounds like you are heading the right direction. I would second sl33pys recommendation for the drive train ( pullys and belt) from DIY on your first run here just to make life easier. Ive run an 8s on my board both with pneumatics and 83/90 skate wheels. I would recommend you start with the 6s and 12s- it leaves you with plenty of room to grow with speed and/or as the nephew grows. If you further need to manage to speed or acceleration for the younger rider DIY ESC is programmable and you can tweek the brake, neutral drag and if I remember correctly throttle. Torques ESC is great but the way.... I'm saving up for VESC currently.

VESC is for sale from a number of vendors here....Enertion will have some soon, if you look at the new for sale section of ES you will see Chaka is currently selling v 10 with free shipping stateside and Jamesonotc is also building and selling them as well.... avoid Marcin.......he disappeared and many had to get money back through PayPal.

Looks good though....keep us updated

 

[jeroenimo]

@206monkey32 I contacted Chaka (ollinboards) to give me an estimate for shipping to NL (EU)

The motormount+gears that DIY sells are in fact exactly what I need:

16T 36T gives me a nice 1:2,25 ratio which would perfectly fit my needs AFAIK:

6S

KV	Volt	Diam Wheel	Km/h	Ratio x:1	Max RP/s	Dist per rpm	Max RPM
168	20	 0,09	     25,333056	  2,25	     56	   0,282735	3360

12S

KV	Volt	Diam Wheel	Km/h	Ratio x:1	Max RP/s	Dist per rpm	Max RPM
168	40	0,09	     50,666112	  2,25	    112	      0,282735	  6720

Lets await answers from Chaka and I'll get ready to order at HK/DIY (when VESC is not available I'll opt for the Torqueboard ESC) and then go and look for a suitable deck!

 

[206monkey32]

I went through the site to just before checkout and it was 20euros to ship two to Europe.....I'm headed to Florida for Christmas so I'll probably just take advantage of free US shipping til I can pick them up.

 

[torqueboards]

I would go with higher KV rating. The KV rating for a 168kv and 1:2.25 would be a bit slow.

IMO more torque does absolutely nothing except lower top speed and no power.

I would like others to try it themselves as I and a few others whom tested it have come to the same conclusion.

Low KV and High Gearing + any battery pack does no good and no benefit even on 12s. If motors can't spin with the current load = heat.

You'll end up noticing your setup running harder because it has no momentum or RPMs to push you quicker.

IMO for any setup. 230-260KV a little lower, higher isn't too bad either 200-280KV. I wouldn't go higher than 280KV. Then adjust as needed through your gearing ratio.

It's much more effective to adjust higher gearing through your gearing ratio versus changing to a lower KV motor. Lower KV motor will add to drag and RPMs will be much lower for the exchange of what people say "more torque" but in actuality you don't get any benefit from it.

Your motors will struggle to make a revolution/rotation due to "torque" and very low RPMs.

We are better off aiming for a decent 25-30mph range even if you only go 15mph. IMO since higher torque + higher gearing = no benefit.

 

[beetbocks]

fully agree with torques on that..going lower on the KV is not an effective method of gaining more torque..
I also always gear my boards for a 25-30mph top speed even if if i'm never at that speed at allows you to run in the middle 'sweet spot' 90% of the time..
I've tried special wound 150KV 5065 motors and they just didn't want to move.. better to get the motor spinning up and reduce the speed with gearing.. as just like a small 2 stroke engine all the power is really developed from the high RPM..
my 2 pence - for what its worth..

 

[Vanarian]

Would you replace your Turnigy SK3 168Kv with one of my E-Max 63mm 195Kv?

These are too big for me (I build inline skates I need slim profile hubs ), still these are a bit more compact than SK3 and I got 2 brand new for sale on the sale section , motors are solid and all powerful.

Well that's just if you follow Torqueboards ' advice.

 

[jeroenimo]

Substantial criticism! I like it

So I could opt for the 260 for HK
Then this baby is only 10s, therefor my 6s-12s Dr. Jeckell and Mr. Hyde plan needs adjustment.

5s

10s

So on 5s it will be a docile board but on 10sit will hit something like 50KM/h which is fast enough in my opinion. Back are Jeckell and Hyde!

@Vanarian I haven't bought anything yet.. only figuring out what I should do.