beto_pty
1 kW
So just like a billion other people I saw the boosted boards ted conference and thought an electric skateboard was the coolest thing ever. Throughout the conference boosted made it sound like the electric skateboard was their inventions.. i have never seen one... so I never even thought to look up a forum where people build Super-UBER-boosted boards...
So I looked up boosted with my credit card in hand ready to pay the 1450 or so in cost plus dhl priority shipping to panama... and couldnt buy one...pissed off i decided to build one myself... I have a cnc i built from buildyourcnc.com a while back (awesome toy by the way) which i converted to milling aluminum... i have loads of experience with gears, welding, some electronics, thermoforming and assemblies... have a semi complete workshop at my disposal...what could ever possibly go wrong...
Back to my tale of ignorance...So I looked up outrunners up and found out they were little itsy bitsy motors... figured out i neded to get me a,suitable ESC whatever that was.... later found out it was an electric speed controller... batteries.. oh man.. thought as soon as a lipo touched my hand it would explode.. and burn up my car.. that they all failed the first day, and got all bloated inmediatelly.. and charging them was not only a dark science but also extremely dangerous and expolosive..... stumbled upon Hobbyking and realized i could buy all this in one place and a gun permit was not required to buy batteries, right then I decided this might actually be something that could be done.
I had never longboarded/skateboarded so I again had no idea what I was doing. A guy was selling his "slighly used" board on a local website ( I live in the Repubic of Panama), and had been doing so for like a year.. so he was asking 40 bucks (down from 100) or best offer for it, so I got that for cheap and I purchased it had good trucks and 98mm abec11s on it (talk about luck) the wood was destroyed.. so no wonder he was having a hard time selling it. II decided to be unique so I set up to mill my own skateboard.. the only aluminum board on the planet... a funky 38"x10" 1/4" thick with 1/2" support longboard.. (only to later realize that someone had beaten me to this...by like 5 years!!)
![ScreenHunter_19 Jan. 27 19.04.jpg ScreenHunter_19 Jan. 27 19.04.jpg](https://endless-sphere.com/sphere/data/attachments/70/70351-883f91f751a3e4eeed0f6d2c3c6935cd.jpg)
![ScreenHunter_20 Jan. 27 19.04.jpg ScreenHunter_20 Jan. 27 19.04.jpg](https://endless-sphere.com/sphere/data/attachments/70/70352-004268bb3c6002ce3da29d02c06b4e71.jpg)
Bookmarked boosted webpage, read everything 10 times over and reverse engineered the whole thing..given the known wheel diameters/width the diameter/width of the motors was sort of possible to guesstimate, so I spent a couple days figuring out what could go with what... and just ordered what sounded appropiate..
Here is my reverse engineered sheet LOL...
![ScreenHunter_09 Jan. 24 18.09.jpg ScreenHunter_09 Jan. 24 18.09.jpg](https://endless-sphere.com/sphere/data/attachments/70/70350-0a9406870dbf7c0e8c91e459d7a1b6e9.jpg)
"Huge" powered 4038 motors LOL they were 750 KW each... actually 750 Kv and had nothing to do with KW... they were 26 bucks each...
http://www.hobbyking.com/hobbyking/store/__30864__NTM_Prop_Drive_Series_42_38_750kv_785w_USA_warehouse_.html
Then a huge ESC.. man Im talking 60 amps!... again a pair for a cheap $30 bucks each...
Batteries were the awesome 5000 mah 4s for 26 bucks...
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html
Charger was 9 bucks... and I had an old laptop power supply that worked fine...
http://www.hobbyking.com/hobbyking/store/__36906__Hobbyking_DC_4S_Balance_Charger_Cell_Checker_30w_2s_4s_USA_Warehouse_.html
Figured Id have a 5:1 ratio gearing on the motor to wheels, as well as a 3:1 in case the 5:1 was overkill.. (100 tooth wheel gear, 20 and 32 tooth motor gears)
got those from sdi gt2 2mm ones that i have used before (although not for anything this tough) they were around $60 for the two systems.
The remote was the cheap $19 gt-2 i believe...
When I received the hobbyking box i was surprised..the 2 motors and the 2 escs fit in the palm of my hand...this could not be good... also didnt realize the esc came without bullets... the batteries with 4mm, the motor with 3.5mm, and the battery charger with alligator clips... so i had to send away for all of these.. overnighted them and a bit over a week later they were here.. (yeah overnight is 7-10 days in my world)
Welded bullets, connected escs to receivers to motors... thought both motors were damaged.. I grabed them by the body and tried to turn the sprocket and they would not turn... laughed at my ignorance when i realized (what I assume) is the reason for their name... awesome! Connected batteries and heard a battery count and tarara...
Started milling the motor mounts and working out the kinks... I cut wooden parts initially to test for fit as my machine cuts wood literally 10 or 20 times faster than aluminum, I also have tons of left over hdo from other proyects so making changes is quick cheap and painless...3 or 4 iterations into the design I had a wooden piece that I mounted and spun the wheel...man it was fast.. here is the link (remember the support is wooden just to verify measurements)
https://www.dropbox.com/s/l0r8lbxuofbz6el/20140106_133034.mp4
Didnt want to make double mounts till I figured out if the design was sound.. so I threw a 44 lb bag of raw material on it and checked it to see if it would roll.. it did.. threw another one..88 lbs and it accelerated away..nothing blew up.. no magic smoke, no explosion from the lipos...
https://www.dropbox.com/s/r6x5tmplvkprhdn/20140107_163720.mp4
Might have stopped there.. the design called for 2 motors (i weigh 190 lbs so the experiment was a clear sign that two motors would be able to pull me along) however I figured at less than 30 bucks for the motor and the esc i could afford to see which burned up first... the motor or the esc... so I jumped on it... andit pulled an cut out..pulled and cut out.. over and over.. figured i was over amping the esc or the motor and this was the motor's protection system turning on and off the current to save itself.. along came no shortage of problems, ... motor gear was loose... tightened it with larger set screws, stripped the belt, retightened the motor.. it ran on and off.. not so much fun.. but not dispointed in any way either
https://www.dropbox.com/s/9z1h8mdrq9dhnpr/20140107_163919.mp4
That night I found this website and reordered all the "correct parts"...150 amps esc, 6364 etc, differnt stuff from sdi etc... so I knew I was looking at minumum 15 days before the stuff got here......figured the on/off behavior was just my incorrect choice of parts and decided to turn my mini-motor board into a board for my kids.. the oldest girl weighs 44 lbs so this was a perfect fit (yeah nice responsible dad right.)..
I continued working on it while my stuff got here and by chance realized that my remote control antena was disconnected..it had come loose when i took apart the huge hobbyking remote in an effort to shrink it down...i reexamined my esc-minimotor system and reread the instructions.. if overamped the motor turns itself off.. and has to be manually reset, however if the remote looses signal it turns itself off.. if it regains signal it turns on again. this was not an esc amp problem it was a transmission one... I reset all the connections..and tried again... Magic... my single motor aluminum skateboard made with all the incorrect parts at half the cost of a "real" one was pulling me along at 20.3 mph on flats acording to gprride... I rode it for about 10 minutes till I stripped the belt.. one of the screws had come loose, i checked the voltage and it was warm.. not hot just warm and the esc was room temperature.
View attachment 2
I did the math 750kv (rpm) x 3.7 (volts) x 4 (# of bateries) x .307 (wheel perimeter) x (1/5) (gearing ratio) x 60 (minutes/hour) gave me a theoretical speed of 41 km/ hour (25 mph)!! subtract all my inefficiencies/errors/misalignments and Endomondo`s calculations sounds correct! I was so Happy... a single motor! a single tiny motor doing this..so I got to work on the second mount inmediately..
Today my new parts arrived however I have refused to open the box up untill Im done with this mini challenge...
It is awesome it purrs.. it hums.. is has power ... rode it today and maxed at 24.2 mph...with a 4s battery voltage of 16.1
https://www.dropbox.com/s/0ax7ld050qppuma/20140127_145223.mp4
happy as a clam...
Will work on some enclosures and such... just amazed at the power of those tiny motors...
So I looked up boosted with my credit card in hand ready to pay the 1450 or so in cost plus dhl priority shipping to panama... and couldnt buy one...pissed off i decided to build one myself... I have a cnc i built from buildyourcnc.com a while back (awesome toy by the way) which i converted to milling aluminum... i have loads of experience with gears, welding, some electronics, thermoforming and assemblies... have a semi complete workshop at my disposal...what could ever possibly go wrong...
Back to my tale of ignorance...So I looked up outrunners up and found out they were little itsy bitsy motors... figured out i neded to get me a,suitable ESC whatever that was.... later found out it was an electric speed controller... batteries.. oh man.. thought as soon as a lipo touched my hand it would explode.. and burn up my car.. that they all failed the first day, and got all bloated inmediatelly.. and charging them was not only a dark science but also extremely dangerous and expolosive..... stumbled upon Hobbyking and realized i could buy all this in one place and a gun permit was not required to buy batteries, right then I decided this might actually be something that could be done.
I had never longboarded/skateboarded so I again had no idea what I was doing. A guy was selling his "slighly used" board on a local website ( I live in the Repubic of Panama), and had been doing so for like a year.. so he was asking 40 bucks (down from 100) or best offer for it, so I got that for cheap and I purchased it had good trucks and 98mm abec11s on it (talk about luck) the wood was destroyed.. so no wonder he was having a hard time selling it. II decided to be unique so I set up to mill my own skateboard.. the only aluminum board on the planet... a funky 38"x10" 1/4" thick with 1/2" support longboard.. (only to later realize that someone had beaten me to this...by like 5 years!!)
![ScreenHunter_19 Jan. 27 19.04.jpg ScreenHunter_19 Jan. 27 19.04.jpg](https://endless-sphere.com/sphere/data/attachments/70/70351-883f91f751a3e4eeed0f6d2c3c6935cd.jpg)
![ScreenHunter_20 Jan. 27 19.04.jpg ScreenHunter_20 Jan. 27 19.04.jpg](https://endless-sphere.com/sphere/data/attachments/70/70352-004268bb3c6002ce3da29d02c06b4e71.jpg)
Bookmarked boosted webpage, read everything 10 times over and reverse engineered the whole thing..given the known wheel diameters/width the diameter/width of the motors was sort of possible to guesstimate, so I spent a couple days figuring out what could go with what... and just ordered what sounded appropiate..
Here is my reverse engineered sheet LOL...
![ScreenHunter_09 Jan. 24 18.09.jpg ScreenHunter_09 Jan. 24 18.09.jpg](https://endless-sphere.com/sphere/data/attachments/70/70350-0a9406870dbf7c0e8c91e459d7a1b6e9.jpg)
"Huge" powered 4038 motors LOL they were 750 KW each... actually 750 Kv and had nothing to do with KW... they were 26 bucks each...
http://www.hobbyking.com/hobbyking/store/__30864__NTM_Prop_Drive_Series_42_38_750kv_785w_USA_warehouse_.html
Then a huge ESC.. man Im talking 60 amps!... again a pair for a cheap $30 bucks each...
Batteries were the awesome 5000 mah 4s for 26 bucks...
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html
Charger was 9 bucks... and I had an old laptop power supply that worked fine...
http://www.hobbyking.com/hobbyking/store/__36906__Hobbyking_DC_4S_Balance_Charger_Cell_Checker_30w_2s_4s_USA_Warehouse_.html
Figured Id have a 5:1 ratio gearing on the motor to wheels, as well as a 3:1 in case the 5:1 was overkill.. (100 tooth wheel gear, 20 and 32 tooth motor gears)
got those from sdi gt2 2mm ones that i have used before (although not for anything this tough) they were around $60 for the two systems.
The remote was the cheap $19 gt-2 i believe...
When I received the hobbyking box i was surprised..the 2 motors and the 2 escs fit in the palm of my hand...this could not be good... also didnt realize the esc came without bullets... the batteries with 4mm, the motor with 3.5mm, and the battery charger with alligator clips... so i had to send away for all of these.. overnighted them and a bit over a week later they were here.. (yeah overnight is 7-10 days in my world)
Welded bullets, connected escs to receivers to motors... thought both motors were damaged.. I grabed them by the body and tried to turn the sprocket and they would not turn... laughed at my ignorance when i realized (what I assume) is the reason for their name... awesome! Connected batteries and heard a battery count and tarara...
Started milling the motor mounts and working out the kinks... I cut wooden parts initially to test for fit as my machine cuts wood literally 10 or 20 times faster than aluminum, I also have tons of left over hdo from other proyects so making changes is quick cheap and painless...3 or 4 iterations into the design I had a wooden piece that I mounted and spun the wheel...man it was fast.. here is the link (remember the support is wooden just to verify measurements)
https://www.dropbox.com/s/l0r8lbxuofbz6el/20140106_133034.mp4
Didnt want to make double mounts till I figured out if the design was sound.. so I threw a 44 lb bag of raw material on it and checked it to see if it would roll.. it did.. threw another one..88 lbs and it accelerated away..nothing blew up.. no magic smoke, no explosion from the lipos...
https://www.dropbox.com/s/r6x5tmplvkprhdn/20140107_163720.mp4
Might have stopped there.. the design called for 2 motors (i weigh 190 lbs so the experiment was a clear sign that two motors would be able to pull me along) however I figured at less than 30 bucks for the motor and the esc i could afford to see which burned up first... the motor or the esc... so I jumped on it... andit pulled an cut out..pulled and cut out.. over and over.. figured i was over amping the esc or the motor and this was the motor's protection system turning on and off the current to save itself.. along came no shortage of problems, ... motor gear was loose... tightened it with larger set screws, stripped the belt, retightened the motor.. it ran on and off.. not so much fun.. but not dispointed in any way either
https://www.dropbox.com/s/9z1h8mdrq9dhnpr/20140107_163919.mp4
That night I found this website and reordered all the "correct parts"...150 amps esc, 6364 etc, differnt stuff from sdi etc... so I knew I was looking at minumum 15 days before the stuff got here......figured the on/off behavior was just my incorrect choice of parts and decided to turn my mini-motor board into a board for my kids.. the oldest girl weighs 44 lbs so this was a perfect fit (yeah nice responsible dad right.)..
I continued working on it while my stuff got here and by chance realized that my remote control antena was disconnected..it had come loose when i took apart the huge hobbyking remote in an effort to shrink it down...i reexamined my esc-minimotor system and reread the instructions.. if overamped the motor turns itself off.. and has to be manually reset, however if the remote looses signal it turns itself off.. if it regains signal it turns on again. this was not an esc amp problem it was a transmission one... I reset all the connections..and tried again... Magic... my single motor aluminum skateboard made with all the incorrect parts at half the cost of a "real" one was pulling me along at 20.3 mph on flats acording to gprride... I rode it for about 10 minutes till I stripped the belt.. one of the screws had come loose, i checked the voltage and it was warm.. not hot just warm and the esc was room temperature.
View attachment 2
I did the math 750kv (rpm) x 3.7 (volts) x 4 (# of bateries) x .307 (wheel perimeter) x (1/5) (gearing ratio) x 60 (minutes/hour) gave me a theoretical speed of 41 km/ hour (25 mph)!! subtract all my inefficiencies/errors/misalignments and Endomondo`s calculations sounds correct! I was so Happy... a single motor! a single tiny motor doing this..so I got to work on the second mount inmediately..
Today my new parts arrived however I have refused to open the box up untill Im done with this mini challenge...
It is awesome it purrs.. it hums.. is has power ... rode it today and maxed at 24.2 mph...with a 4s battery voltage of 16.1
https://www.dropbox.com/s/0ax7ld050qppuma/20140127_145223.mp4
happy as a clam...
Will work on some enclosures and such... just amazed at the power of those tiny motors...