140kmh Delta\Wye switch explanation

lots of people have asked me about the delta\wye switch that i have
so i made a video explaining what it is and showing what it does with no load
Enjoy!!
[youtube]sm9STU4sIKE[/youtube]

If you want to see it WITH load you can check out this video -
[youtube]_aLrTRaEMOE[/youtube]

Great videos!

Maybe time to balance your wheel :lol:

Also NEVER forget to slow down BEFORE going back to STAR mode!!!!! otherwise the BEMF of the motor will blow your mosfet.

Doc

A setup with a 140kph no-load speed that only goes 90kph with a load is running at high system stress, because the gearing is too steep. If you decrease the wheel size, not only will you increase acceleration, but you will also get a higher top speed.

John in CR said:

A setup with a 140kph no-load speed that only goes 90kph with a load is running at high system stress, because the gearing is too steep. If you decrease the wheel size, not only will you increase acceleration, but you will also get a higher top speed.

Click to expand...

i know all about the un-efficiency of this system, this is why i use li-po's, my continues current (at 100% delta mode and full throttle is 75-90a, i take about 1ah per k'm
the ideal thing to have is something like a 3t v3 mxus with drilled caps, or a 3kw QS, but i live in Israel and its very hard to get those (illegal) motors here... this one cost me about 600$ which is crazy for a motor like this... but what can you do...

btw, my other bike that i was showing in the picture in the end of the video currently has a 13x5 1500w leafmotor, and its going at 80kmh in star and 105kmh in delta. so to ditch the delta i ordered myself a 16x4 stator for it, gonna pick it up from China when im visiting in May, and the bike will go probably about 90kmh with no delta, and if i want to i can allways make the switch.... maybe when this bike will have lipo's as well...

Doctorbass said:

Maybe time to balance your wheel :lol:

Also NEVER forget to slow down BEFORE going back to STAR mode!!!!! otherwise the BEMF of the motor will blow your mosfet.

Doc

Click to expand...

good to hear from the great Delta\wye Guru
the most imprtant reason i have to finish my other bike is so i could put this one aside for a few weeks and fix all the small (and big) issues i have...
right now i have a torn temp wire for the motor which sometimes cuts off the temp guage, my freewheel starts to make noises and needs to be replaced... and to fix this god damn wheel... i suppose my breaks need bleeding too.... so lots to do in the next month
oh and i once fried an 18fet infineon when i accidently switched to delta without letting go of the throttle... im way more careful since lol
btw i have a friend which i installed a delta\wye switch for him, and i made it with only 1 3pdt relay for it, so he can switch when he's at full throttle and its switching smooth! too bad i can't find a 3pdt 150a relay...

Noamsal said:

i live in Israel and its very hard to get those (illegal) motors here... this one cost me about 600$ which is crazy for a motor like this... but what can you do...

Click to expand...

What can you do?...Use a smaller diameter wheel for greater all around performance and efficiency.

John in CR said:

Noamsal said:

i live in Israel and its very hard to get those (illegal) motors here... this one cost me about 600$ which is crazy for a motor like this... but what can you do...

Click to expand...

What can you do?...Use a smaller diameter wheel for greater all around performance and efficiency.

Click to expand...

my goal is not best efficiency, my goal is best speed i can get without overheating the motor or ruin any other part, thanks for the concern but im okay with this setup im doing lots of offroad with this bike and i need the BB high, even with a 24" rear tyre i can feel the geometry change, i tried a 19" moto tyre and it was too low for this bike
on my other bike though.... i do have 20" wheels and i get to 100kmh with just 4.5kw and not 10kw, and this one is really low and suitable for the road

This is some really great work noamsal!!

If other's wanted to, we would need to rewind and add the relays/switching? I'm wondering why don't more motors (and/or diy) use this?

nutspecial said:

This is some really great work noamsal!!

If other's wanted to, we would need to rewind and add the relays/switching? I'm wondering why don't more motors (and/or diy) use this?

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More possible points of failure maybe? Or added cost/manhours even for DIY. And for factories even small pennies added in material cost can mean big dollar extra for customer.

I think recumpence (matt) did delta/wye switch and then felled back to just adding another motor, making a triple drive Astro.

nutspecial said:

This is some really great work noamsal!!

If other's wanted to, we would need to rewind and add the relays/switching? I'm wondering why don't more motors (and/or diy) use this?

Click to expand...

im not the first one,
Dr bass have tried it, and a few others youtube users have uploaded videos of this
i also have a friend living nearby who's using this

the disatvantages of this is that its taking the efficiency down (in delta mode, star stays the same), and the consumption up, and you need a strong battery to take the continues current of it, so if you dont make it with the right tools - you will have a big chance of failure, but just like other things in life you need to do it right...
still i can ignore all those disatvantages and ride in star mode.... this is why i like it, i still have the torque for offroading and the speed for the highway

Yes but still you have done good work with implementing and documenting the success!

So it's basically the added switching/relaying, and an extra set of windings I assume. Sounds like a great way to add a 2nd higher speed to any brushless motor with minimal weight/ complication/ expense-

Everything has a cost, and I think using delta/wye is a great way to get a 2 speed 'transmission'. Good job.

Could you do this for a small electric skateboard hub motor?

would three of these do the job

http://www.ebay.com/itm/110VAC-80A-...506137?hash=item3d080452d9:g:YRgAAOxyyFhTdvR0

They are 80a but I am not sure what voltage I need (running 16s lifepo4 so 58.4v) controller can do 4kw.

whereswally606 said:

would three of these do the job

http://www.ebay.com/itm/110VAC-80A-...506137?hash=item3d080452d9:g:YRgAAOxyyFhTdvR0

They are 80a but I am not sure what voltage I need (running 16s lifepo4 so 58.4v) controller can do 4kw.

Click to expand...

i use relays rated for 12v, with a 12v converter to activate them
these are the best ones i found, but they only ship on Australia
http://www.jaycar.com.au/Electromechanical-Components/Relays-%26-Accessories/Automotive/Automotive-Relay-150A-SPDT/p/SY4073

if youre using 72v you can connect in series 6 relays rated for 12v, so each one gets 12v, or 3 relays rated for 24v