New Brushless Motor not Spinning Properly

[butters86]

Hi All,
I've just got a brand new Hobbyking 120A esc and Turnigy trackstar 9.5T motor. I've soldered it all up (checked the joints) and the motor spins (bit flaky) with no pinion on.

If I put the pinion on and hold the car up, it will spin the wheels but it slows down to a crawl at full throttle.

If I put the car down on the ground it'll not move, it'll just sound like the motor is stalling.

I've tried two sensor cables and disabled low battery cut out using the programming lead.

I'm using NiHM Batteries (which used to run brushed 12 turn modified OK, and I'm using a Futaba micro receiver.

Any ideas what could be wrong? The motor sounds really groggy when it's spinning under a bit of load.

[butters86]

Sorry, this was resolved by using a brand new stick pack.
Obviously the old battery musn't of been man enough

Now too late and dark to try new brushless setup but I just put it on the grass to test and it seemed ridiculously fast!

Will have a play tomorrow night.

[Ashlandchris]

And I'd really recommend looking at lipos as they will make everything easier - more even power, longer runs etc

[200sx]

If you think it's fast now, wait until you try a lipo!

[butters86]

Well now I only have one pack out of 4 which will actually run it, I'll be swapping to lipo sooner. Less of a "ohhh but that'll leave all my old nimh packs dormant"

I ran it tonight around the garden and it's just ridiculous it accelerates to full speed almost instantly and after a 10 min+ run the motor and batteries where cool.

My only gripe is that when the shell is on it fouls on the speedo fan so I need to make some adjustments.

Regarding the gearing, I'll start a new thread as I think my pinion is too small to get the most out of it.

[200sx]

You don't need the fan with a 9.5. I replied to your gearing question, you'll need a 25-26t pinion (0 timing on esc, aka blinky). I used a 24t on a 7.5 blinky.

[butters86]

So if I disconnect the fan it'll be fine with this motor?
Is it more for when you have a more "ampy" motor?

I actually have some larger pinions such as 25 & 27 from my schumacher touring car which would fit so will give one a go and lower timing from the stock 17.5 (I believe).

[mattr]

Generally speaking it's fans with faster (Lower turn) motors, heavier cars and grippier track surfaces (and cars that develop more traction in a particular configuration). Gearing also has a bearing on it.

It's different for each configuration/track/surface/driver.

But with your particular set up, you are pretty close to the most non-fan combination possible.

It's also worth getting a car set up as cool as possible without a fan, before you add one. Then you have a stable set up, with less risk of cooking stuff (obviously with some cars this is impossible, just moving of the line needs a fan!!)

(You can also get low profile fans, or put the fan next to the ESC to get more clearance)

[butters86]

I just tried running the ESC without the fan for 5 mins to discharge batteries (a more fun way than with discharge function on charger) and it only got mildly warm.

I'll see what its like with a freshly charged pack on Sunday with some more volts running through it.