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Bought a motor but need direction on what pulleys and timing belt to buy


#1

Hello there everyone,

I’m building an electric longboard currently and I’m following this guide: http://www.instructables.com/id/Electric-Skateboard-v20/

I bought a motor but it’s a bit different than the one that he uses in the guide. It has a lower kv rating (149kv compared to his 280kv) and the shaft is larger on mine. I chose a lower kv motor because where I live there are more hills (South Dakota) and was advised by some that a smoother acceleration is worth it. I already fabricated the motor mount shown in the guide (except I didn’t drill the motor mount holes yet). Now the only thing I need to do is buy the correct pulleys and belt. I’m not very experienced with any of this so I decided to come here for some advice.

The stuff I’m currently looking to purchase:

Small Pulley: http://shop.sdp-si.com/catalog/product/?id=A_6A25M017DF0908

Big Pulley: http://shop.sdp-si.com/catalog/product/?id=A%206A25-036NF0910

Note: This big pulley is the same one he uses in the guide. I want to get the same one so that it fit’s into my longboard wheel as shown in the guide.

Belt: According to my calculations, this is that should work with this set up although I’m not sure if my calculations are correct.

http://www.bbman.com/catalog/product/280-5M-09
OR
http://shop.sdp-si.com/catalog/product/?id=A_6R25M056090

But most likely the second option as I’m getting the other parts from that site so I may as well just get them all together for one shipping cost from one site.

Thoughts? Suggestions? Will this work?

Thanks,

Alex


#2

This kit is well worth the price:

It’s everything you need. Getting each piece separate with shipping will probably be more.

Fits right into these wheels:

http://m.ebay.com/itm/Blank-Pro-83mm-Longboard-White-Flywheels-ABEC-7-Bearings-Spacers-/140872659422

Go to this site to do the calculations for the motor and wheel pulley sizes:


#3

Thanks for the info man!

Does this seem like a realistic top speed to you? I entered my info into that calculator and these are the results I got. http://prntscr.com/cm13yl

Pretty slow if you ask me. Maybe getting a 149 kv motor was a bad idea?

I got this one. http://www.hobbyking.com/hobbyking/store/__18184__Turnigy_Aerodrive_SK3_6374_149kv_Brushless_Outrunner_Motor.html


#4

80% efficiency would be more accurate. But those speeds are realistic.


#5

The other benefit of esk8 motors is that @torqueboards and @onloop key the shafts really well. So you know that the pulley is set. I’m not entirely sure about that motor. It looks like it uses one set screw.

I have mine keyed from @torqueboards with 2 set screws thru the pulley. That thing is not going to move.


#6

I had the same setup with my first board, I’m pretty light so I actually got up to like 16mph… If you want to go faster, get a faster motor (I got the 245kv SK3, or you could get a bigger motor pulley)


#7

Hey! How was the torque with that setup? Could it accelerate from still? Thanks!


#8

Which? I used to run a 16:36 6S with 70mm wheels, now running a 20:36 with 83mm wheels. They can both accelerate from still easy.


#9

Great! What speed are you getting with the 20:36 and 83mm wheels? Thanks!


#10

Almost 30mph, but I switched from a 149kv motor to a 245kv.


#11

What if i just kept the motor and threw in another battery in series to make it 9s? 8 believe my motor supports that.s


#12

You would need a VESC, or similar ESC. But it would be fine