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This Instructable documents the improving of a Proline 600 Altered Electric Longboard. It also serves as a useful resource for anyone attempting their own electric skateboard/longboard build. It ALSO serves as documentation for a mini-build: a new drive-train for the ever-so-popular CIM motors, which are often used in FIRST robotics competitions.
Altered/Exkate electric skateboards/longboards are not known for their turning radius (it's HUGE), their weight (the one we used was 48 pounds stock!), nor their performance (1, yes ONE, wheel drive). In fact, about the only thing they are known for is being one of the first companies to produce electric skateboards/longboards. So we decided to make it better. The further we went, the more we realized we could have started with a deck and built up; thus, I will endeavor to make this Instructable useful to both types of builders.
CIM motors have been without a cheap, easy, and compact gear-reduction drive-train since their beginning. Now the wait is over. Read on!
The team was part of MIT's Edgerton Center Summer 2010 Engineering and Design Class, a month-long class where high school students learn and apply real-world engineering skills to various projects.
Note: I'll apologize in advance for any bad quality photos.
Also Note: I am in no way affiliated with any of the companies mentioned in this Instructable.
Altered/Exkate electric skateboards/longboards are not known for their turning radius (it's HUGE), their weight (the one we used was 48 pounds stock!), nor their performance (1, yes ONE, wheel drive). In fact, about the only thing they are known for is being one of the first companies to produce electric skateboards/longboards. So we decided to make it better. The further we went, the more we realized we could have started with a deck and built up; thus, I will endeavor to make this Instructable useful to both types of builders.
CIM motors have been without a cheap, easy, and compact gear-reduction drive-train since their beginning. Now the wait is over. Read on!
The team was part of MIT's Edgerton Center Summer 2010 Engineering and Design Class, a month-long class where high school students learn and apply real-world engineering skills to various projects.
Note: I'll apologize in advance for any bad quality photos.
Also Note: I am in no way affiliated with any of the companies mentioned in this Instructable.
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Signing UpStep 1Parts and Tools
Note: All parts listed are for/from the Proline 600 model. Other models' parts may be able to be used with modifications.
Parts:
Option A: Rebuild an Exkate.
1) Proline 600 Exkate (It's not worth buying one for $600. Go to option B if you don't already have one)
2) Two CIM motors
3) Two of these planetary gearboxes .
4) Some ¼" aluminum plate. At least 12" x 12".
5) Some 2" Aluminum round. At least 2" in length.
6) Two timing belt gears. A good source for these is: http://www.sdp-si.com/
7) Two timing belts . (We used 400-5M)
8) Two ball bearings that have OD’s small enough to fit inside the timing belt gear hubs and have a 5/16" ID. McMaster has cheap ones.
9) Two MBS mountain-board trucks .
10) Four ¼" rubber shock absorption (soft) risers
11) Nine lithium polymer batteries. We used these wired in 3S3P for a total of 9S3P (~36V and 6600mAh). Read up on safety information before using LiPo's!!! They can explode if used improperly!
12) Nine electronic project boxes (used as battery boxes). Preferably plastic and as close to the size of your batteries as possible.
13) About 6 feet of 14+AWG wire.
14) PTC fuses~1Amp. At least 24
15) Deans connectors or other low resistance battery connector. 1 pair
16) Three of these charger s or equivalent. (why you need three will become clear)
17) Three of these power supplies or equivalent.
18) Low voltage detectors or equivalent.
19) electrical tape/ assorted heat shrink tubing
20) Blue RTV silicon sealant or equivalent.
21) LED strips. We used two 12V 16" Red strips and one 12V 8" white strip.
22) Lots of various machine screws.
23) Loctite
Optional: 3 balloons (for waterproofing LVD's), some extra hard bushings (rider's preference, but due to the extra long trucks, harder seems to be better), a small switch for the LED circuit
Option B: Build from ground up.
All of Option A minus the Exkate and plus the following:
1) A deck
2) An Altered electronics module .
3) Exkate Wheels: Two regular (http://www.alteredexkate.com/servlet/Detail?no=104 ) and two with drive gears (http://www.alteredexkate.com/servlet/Detail?no=103 )
Tools:
Soldering Iron
Band Saw
Belt sander
Drill press
Drill
Dremel with cut off, sanding, grinding bits
Hot glue gun
Hex keys, screw drivers, wrenches etc.
Tap and die set
Files (various)
Optional: Metal Lathe (very helpful), Cold saw
Parts:
Option A: Rebuild an Exkate.
1) Proline 600 Exkate (It's not worth buying one for $600. Go to option B if you don't already have one)
2) Two CIM motors
3) Two of these planetary gearboxes .
4) Some ¼" aluminum plate. At least 12" x 12".
5) Some 2" Aluminum round. At least 2" in length.
6) Two timing belt gears. A good source for these is: http://www.sdp-si.com/
7) Two timing belts . (We used 400-5M)
8) Two ball bearings that have OD’s small enough to fit inside the timing belt gear hubs and have a 5/16" ID. McMaster has cheap ones.
9) Two MBS mountain-board trucks .
10) Four ¼" rubber shock absorption (soft) risers
11) Nine lithium polymer batteries. We used these wired in 3S3P for a total of 9S3P (~36V and 6600mAh). Read up on safety information before using LiPo's!!! They can explode if used improperly!
12) Nine electronic project boxes (used as battery boxes). Preferably plastic and as close to the size of your batteries as possible.
13) About 6 feet of 14+AWG wire.
14) PTC fuses~1Amp. At least 24
15) Deans connectors or other low resistance battery connector. 1 pair
16) Three of these charger s or equivalent. (why you need three will become clear)
17) Three of these power supplies or equivalent.
18) Low voltage detectors or equivalent.
19) electrical tape/ assorted heat shrink tubing
20) Blue RTV silicon sealant or equivalent.
21) LED strips. We used two 12V 16" Red strips and one 12V 8" white strip.
22) Lots of various machine screws.
23) Loctite
Optional: 3 balloons (for waterproofing LVD's), some extra hard bushings (rider's preference, but due to the extra long trucks, harder seems to be better), a small switch for the LED circuit
Option B: Build from ground up.
All of Option A minus the Exkate and plus the following:
1) A deck
2) An Altered electronics module .
3) Exkate Wheels: Two regular (http://www.alteredexkate.com/servlet/Detail?no=104 ) and two with drive gears (http://www.alteredexkate.com/servlet/Detail?no=103 )
Tools:
Soldering Iron
Band Saw
Belt sander
Drill press
Drill
Dremel with cut off, sanding, grinding bits
Hot glue gun
Hex keys, screw drivers, wrenches etc.
Tap and die set
Files (various)
Optional: Metal Lathe (very helpful), Cold saw
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Nice job though!
I got a huge problem, how does the brake work?
Can't really see any pictures on any physical brake, so i've started thinking that it got to bve the motor.
The only way i find this possible is that the electronics module runs the motor backwards to make it brake, but that feels a little strange.
Can anyone check how the brakes are set up on any altered or other electric longboard?
If im not wrong, was it this one?
https://sdp-si.com/eStore/PartDetail.asp?Opener=Group&PartID=5370&GroupID=218
Almost all electric (commercial) longboards use regenerative braking.
I honestly don't remember which timing belt gear I used, but it was similar to that. I suggest experimenting with gear (timing) ratios to find one you like best.
Good luck!
I'll read some about the kelly controllers :)
The timing belt gear ratio you use is somewhat dependent on the motor controller(s) you use. If you use the Exkate one like us, then you could try the gear ratio we used. Step 6 mentions the gears we used (44T). https://sdp-si.com/eStore/ , and look under "timing belt pulleys".
Anything else?
Hope that helped.
1. Make sure you make the bracket-claps better than we did. They should match the profile of the trucks. If they don't, they are prone to slipping. Also, I'd suggest using bigger and coarser thread screws for the clamp. Or just braze or weld it.
2. Make sure you use a good bottoming tap with the drive gear - planetary interface because you'll need as much thread engagement as possible to prevent the motor's torque from ripping the screws out. If worst comes to worse, JB Weld the screws in.
No sensorless.
Making your own sensored speed controller won't be eazy and will take mutch more time. + a more expensive motor :)
I don't think it need to be sensored with that power (can be wrong,, ...will see... ) :)
I measure the current of the motor to adjust the controll signal,, its not really the same as sensored control but better than nothing :)
You need more speed but I need more torque :)
For more speed you need better motors. If you use more motors you will have more torque but still the same speed. (II think you already know that) :)
No problem :) I have the same controller as him to drive my revo (http://www.traxxas.com/products/promo/5605_promo.htm)
Massive brushless power!!!! :D Top speed 65mph! :p
I'm running sensored brushless on mine (not the board in this instructable). Like you said, it takes more time and more expensive motors. The reasons for using sensored control are: a. the motors are current (and therefore torque) controlled, allowing for precise acceleration control. b. no cogging because the sensors know what state the motor is in. With sensorless, you might find that you have to kick start the board. As for measuring motor current, I don't see how that could help you control the board if you're using sensorless control. Sensorless control is always voltage control, which means control via RPM and not torque. Another way of putting it is that if you slam on the throttle with a voltage controlled system, it will apply infinite (well, as much as the batteries or motor controller can handle) current until that throttle command (RPM) is reached. There is no direct control of current, so you don't have any direct control over acceleration (indirectly, you do control acceleration by slowly applying throttle so you don't burn out). Sensor vs. sensorless brushless control is a subject I strongly suggest reading up on if it interests you.
I feel "better" is the wrong word, especially because I custom engineered (design and fabrication) them. For more speed, I'd need a motor with one or more of the following: less turns, shorter, weaker magnets, larger diameter tires. However, I felt around 25mph was plenty, so I designed for that.
It is true that if I use more motors, and don't divide the current among the motors, then I will have more torque.
Nice. I used to have a brushless Revo, too. It was an old Gorillamaxx conversion with a Neo 8XL and BK-electronics controller: 1800W. It could hit about 55mph. I sold it because I got sick of replacing twisted Ti driveshafts and shreaded hardened steel diff gears, haha.
Much better than voltage control.
Do you have pictures or videos of your other boards? :)
I'm really interested :)
I have steed drive shafts on it now :)
I don't have much time for it now...
But I see it on the bright side,, no more broken parts :p
I'm building my own speed controller for it.
And I also use a mountainboard wit air tires
Top speed will be (at least) 40 Km/h (25 mph)
If you go faster it becomes a little dangerous...
But it's possible :p
I'll post a video when finished and tested :)
4 500W motors? I think you can reach the 40 mph with that :p
See this link: http://www.hobbycity.com/hobbycity/forum/forum_posts.asp?TID=12064
The board with 4 motors is so awesome!! :p
For my board, I calculated the top speed to be just under 30mph. My wheels are 4" in diameter compared to the 8" for air tires, so for a given power rating, my top speed will be lower (however, my acceleration can be quicker).
THAT IS AWESOME! Haha, wow. Thanks for sharing the link! He's using sensor-less control, so he gets cogging at start up. I like his design though. Very simple and relatively easy to implement. My hub motor design takes a lot of machining and wouldn't be able to handle the kind of shock loads a mountainboard experiences.
Nope. They don't interfere with the ground when turning. The motor bracket will scrape sometimes because of the 1/2" ground clearance, but it protects the gear and belt.