Destroyer 12s Urban Racer Build

[galp]

The wires (copper inside) in all motors are coated with thin layer of non-conductive material. Probably a motor isn't waterproof, because water gets in the space between magnets on the rotor and copper on the stator part of the motor. It doesn't affect on any electrical characteristics of the motor, i think it is just a mechanical thing.

My idea how to protect the motors? I would cover them with a plastic box or something like that and add a fan on top of it. That wouldn't really proof the motor from water, but for sure it will be water resistant.

I put all my english in this post, hope it helps.

 

[beto_pty]

Thanks for the info..your english is excellent. . Where are you from?

Same problem today... tiny puddle, drove through it and my motor got the jitters.... I of course had showed down to a crawl so no drama... but still the jitters. 39 seconds of hand spinning later iwas rolling away.

I'll use this spring break to come up with a semicover that will cover the "towards the front advance lateral", and rear of the motor, as th front is well covered by the motor mount...

Attached is the initial idea sketch in CAD (crayon aided design)

 

[galp]

Thanks. I'm from Slovenia, the litlle country that no one knows it exists.

 

[beto_pty]

Well the republic of Panama has 4 million people. . That is less than most large cities LOL...

 

[torqueboards]

Beto is your motors directly in line of the water when you go over a puddle? I typically go over wet floors and occasionally maybe a small little puddle but haven't had any issues. Although, I try to avoid the puddles as much as possible. My bearings sounded so bad after I rode in rain one time.

An enclosure would be nice though for our motors. I've been thinking of making one but haven't got to it yet.

 

[beto_pty]

Hi, yes they catch most of the spray when igo over puddles,
However yesterday I was getting some jitters on the motor and found one of the three motot leads was sort of loose.. will test again Monday morning
If my motor has "magically" become splash proof I'll leave it be. Otherwise ill give it an 18 gauge steel semicover....

 

[torqueboards]

An ABS or Kydex might work too. You could possibly use a heatgun and half a cup that's a bit bigger than the motor and create a bit of a base so you can bolt it to the trucks. The water just needs to redirect to the top of the board than on the motor itself. Completely covering it would be fine but would probably be better with vents and/or vent holes that still prevent dust/dirt/water from coming in - it would need a bit of a lip.

 

[beto_pty]

I'll keep that in mind... but im hoping for the "magical" solution.. tightening of the.loose contacts will do it.
Lol id like to walk into a store here in the republic of Panama asking for kydex lol..
I'll update as soon as I know... however i might make a cover just to prove I'm the man...

 

[beto_pty]

https://www.dropbox.com/s/x79xhljaanqe7c2/VID-20140419-WA0001.mp4

The destroyer as a family vehicle LOL

 

[LEVer]

So cute and sweet! The little guy's just so relaxed.

 

[beto_pty]

He had a blast and so did I

 

[beetbocks]

You've got to get them young.... my son loves using my boards.. But there all too fast for him..lol...

 

[beetbocks]

i made some covers for my urban deck but they proved difficult to attach and i was concerned about the heat build up.. I have also run in light rain and its been fine..i wouldn't attempt heavy rain although i'd be more concerned about grip..
I made them with my vacuum former .
the former (made from foam on my CNC milling machine)

2 halves before trimming

 

[beto_pty]

Cool cover
I might look into thermoforming it instead of making it our of galvanized steel.. humm...

 

[beto_pty]

Magic solution...
drove through puddles after having tightened my 5mm connectors between my esc and motor, and taped the "hoodies" so that they could not make contact and the issue seems solved.
However just to be super cool I will be working on an enclosure, the termoformed one looks cool, metal is sturdier... might have to sleep on it....

 

[Barndom]

...The 12s setup was just plain ignorance on my part.. I had no idea then what the power available on 12s batteries was like. It is not fun, it is not cool, it is not something you want to do voluntarily.. I tried it for about maybe 5 minutes and did not enjoy it.. it was like skateboarding on a Saturn V rocket on steroids,,, any movement of the trigger meant just unrestrained acceleration.. went from 0 to 20 kph in perhaps 2 secs.. maybe less.. and I was being careful. So I went down to 8s.. and down geared from a 14 tooth sprocket to an 11 tooth..

Wasn't the wheel spinning at that setup? I think it would be fun to do burnouts and drifting At low speed.

 

[beto_pty]

Nope.. no wheel spin..just infinite pulling power...
8s is the sweet spot in my case. . Enough power so that its scary to go full throttle... not so much that my Armour will fail. ..
Also at high speeds a half milimeter off target meant a speed difference of 5 or so kph. Making the ride jittery. . And terrifying. ..
Too much excitement. . Too often. .
Guess I just got old....

 

[beto_pty]

So I just got the coolest toy.
This watts up meter...
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXLMV0
it is avalable from hobbyking as well but it had been over 60 days on backorder.. of course i bought mine and 3 days later it got restocked... :?
http://www.hobbyking.com/hobbyking/store/__6380__Watt_Meter_Power_Analyzer_Watts_up_Ver_2_.html

Tried it today on the destroyer, which by the way is no longer an 8s destroyer but a 7s destroyed due to a dead cell on one of the cells.
Went to my favorite fast running area.. which is quite flat and did a couple loops, maxing out at 47.3 kph over a real riding distance of aprox 1200 meters.

Then I video`d the info as the watts up meter deletes the info upon disconnection.
The Peak Amps registered was under 54 amps. There is no information if this lasted a second or twenty seconds, however i'd be veri inclined to thing it was a fraction of a second.

The Max voltage was 27.5 volts

Max wattage was 1486 w (which of course adds up to the max amps X max voltage)

Here is a tiny vid of the event...
https://www.dropbox.com/s/cq7e1rqrcsu1act/20140503_143040.mp4
Disclaimer: 100% flat area, and startup on "very slow" acceleration. So there might be a difference if your setup is set to high accel or such...I weigh 195 lbs, the destroyer weighs 20, so we are talking of 215 lbs of combined weight. This is a single event, sincle reading and things might change tomorrow when i try it again at much lower speeds but much higher stop/start events... as well as crossing the overpass bridges and such...

For now i conclude.. the posibility of burning up my 2400 watt motor... are exactly zero (unless I manage to go like 80 kph on it )... it will expect it will someday fail due to mechanical or manufacturing malfunction..not because of power concerns.Same goes for my 12s 100 amp esc.
Could have cabled all the destroyer using 16 gauge cable.. will probably change all my horribly tight xt90 connectors to the nicer and more manageable xt60s, am infinitly more confident of getting positive results using the "risky low" 90 amp 2 boat escs i just ordered.

Feeling cool and scientifiky right now... 8)

 

[torqueboards]

Which explains why even evolve are using deans style plugs from the battery. I seen a maintenance video for evolve and they pulled out their battery pack w/ a deans connector. I was like really? I just got a watt meter from HK too. I'll try and install it this week and find out how much amps I'm putting as well.

 

[beto_pty]

I went out this morning on a longer ride pf 16.5 km.. relaxed pace 50% of the time..full throttle the rest..
View attachment 2
First measurement was after I went up and down and then back to measure both overpasses going up... and measured the higest amp load (i actually think the angles on both are very similar) which was under 25 amps, under 690 watts.
One overpass is straight the other circular. No idea at what speed I was going but I passed joggers going up...



I then went for a long ride.
When i finished i took measurements again.
84.3 peak amps, 2195 watts, 8.23 ah out of my 8.5 ah 7s batteries (oops cutting that a little close )
https://www.dropbox.com/s/dc75e1x4f5ao46w/20140504_080343.mp4

I believe this amp load was due to a couple "bumps" or 1/2" lips where my board slams into the lip at over 35-40kh and there is an instantaneous load on the system... which then goes back to the standard max 55 amp load. Will look for a way to prove this next run.. as i think i know where the "slamming lips" lie.

 

[made_in_the_alps_legacy]

Interresting if your wattemeter speaks [Wh] feel free to tell us watt he says
Asking u an other one: With the wheel in the air, what is the Wp reading if u press instantly the throttle from a standstill state up to full speed? once at full speed, what is the watt reading?

 

[beto_pty]

Hi

Is the video link working? If so all the numbers are there.

Acording to it we had 215.6 Wh..



so 13.1 wh per km (at 16.5 km) ...
and 0.6 (0.0595) wh/km/lb of total (rider+board) weight? (at 220 LBS TOTAL weight of me my armour and the board)

I'll post a vid of max throttle punch on a free wheel on monday when i go for my morning ride.

 

[beto_pty]

Alps here is your video

https://www.dropbox.com/s/jvx2056bv6nezjd/20140505_065050.mp4

Well interestingly my max pull is still around 45-50 amps rode hard for about 4.5 km and could not get a reading above this... I get the 85-90 amp spikes when i slam into the lips... actually i believe that im going full throttle on my board and then sort of bracing for impact i release the trigger before slamming into them.. and then as soon as i pass them I pull 100% on the trigger again to regain max speed.. in this very small amount of time my motor goes from being spun by my boards inertia.. to pulling 100%... So the spike must be very small, probably under a second..

I currently have 14 teeth on my motor sprocket...So help me out you physicists/electricians out there..
In my experience motors han handle amp loads above their design specifications if these loads are applied for very short periods of time... 1 or 2 seconds or fractions of seconds... So I believe that a motor with a theoretical 2400 watt design, 90 continious amp loading rate should be able to handle any speed I can handle, andy acceleration I can handle...

My esc can theoretically handle 100 amps continious, 120 max... So if my maximum instanataneous load so far has been 90 amps... I could theoretically increase my sprocket size by 33% and end up with a continious (60x1.33%) load at 80 amps and spikes in the vecinity of the 120 amp instantaneous capacity...
Humm something to ponder..

Surprisingly as well the difference between flats and going up a ramp (at what felt like similar speeds) is not very large.. 2.5-3.5 amps on flats, 4.5 amps going up a ramp... The ramp goes up about 5 meters in a 50 meter lenght.. so lets go with a 10% incline.. not necesarily the K2.. but still something you would feel on your legs walking up for extended periods of time...

 

[made_in_the_alps_legacy]

Thxs bto_pty, runs very nicely.
could not rely on the Wp reading since the test was started without resetting the wattmeter,
but I have seen a 216W while the wheel accelerates, and then the reading settles at 115W at steady full speed.
I have similar readings on mine for the acceleration to full speed Wp, about 200W, but my power settles around 50W at steady full speed, curious.
it gives us some ideas of power required to only accelerate and eventually sustain the speed of 4 wheels...

I could theoretically increase my sprocket size by 33% and end up with a continious (60x1.33%) load at 80 amps and spikes in the vecinity of the 120 amp instantaneous capacity...
Humm something to ponder..

Yes, this would be the best option.

 

[Murfix]

This measurement can also give you an insight of how well your sprocket alignment is. I'm going to improve my alignment tonight, I'll take a measurement before and after to see the difference. The power usage should be lower afterwards.