Poor Throttle Response with TowerPro ESC

[Shaun K]

Hi electric flight afficionados,

I'm a keen IC flyer with no EP experience. I recently got a collection of electric flight bits from a friend who didn't realise a shock flyer wouldn't make a good trainer. The fact that I've got the motor, ESC and 3 micro servos explains how that ended up...

The ESC is a TowerPro Mag8 18A, motor is a small, cheap brushless bell type outrunner and I'm testing with a 3-cell 800mAh lipo.

While I'm generally about as keen on the thought of electric power up front as the esteemed Mr Whittaker, I figured I should make something that could use the gear but in bench testing I just can't get it to run with anything close to a linear throttle response.

The throttle needs to be moved 4-5 clicks before there's any action then it speeds away in a great hurry, gaining close to full RPM by half throttle and only a tiny increase in RPM from half throttle to full throttle.

Likewise, dropping the throttle back from WOT sees almost no change until it suddenly stops at just above idle position.

I'm a computer nerd by profession, so I understand gadgets in general and know the value of organised troubleshooting steps, I just prefer noisy and oily so I don't know much about ESC's yet. I've done a little homework on this and other forums and here's what I've done to date, with no change in the motor's behaviour:

• Set the transmitter to all default settings - 100% ATV, no trims, no sub-trims, no expo etc etc...
• Found a programming guide for the ESC and set to 3-cell lipo battery type
• Set the ESC timing to the lowest and second lowest advanced values to test for changes (more timing advance just did the same thing with a higher top RPM)
• Tested advice found in another thread in this forum which advised simply putting the ESC into programming mode with high throttle then dropping it to low throttle at the appropriate time.

So far, none of the above has worked. Has anyone else had similar experiences with a TowerPro Mag8 18A ESC? Any ideas?

Thanks,

Shaun.

[Olly P]

Hi Shaun,

I don't know that ESC in particullar, but many need training to your throttle, I'd suggest that this could be the problem.

Thanks

Olly

[Shaun K]

Thanks Olly,

I think you're right and I tried the advice given in the Throttle Probs thread but that hasn't worked for me.

Shaun.

[Olly P]

I think GC sell these? If so there forums are often useful. Failing that an email to Tower pro is often worthwhile.

[Josip Vrandecic -Mes]

Hello Shaun,I have recently moved to the "dark side" ,new leccy flyer,I was told by my friend Stephen just so.....I was helped ,in similar issue, by programmable card

Cheers

Jo

[Steve Hargreaves - Moderator]

You do sometimes find that the cheaper ESC are less than linear......I have one that reaches "full throttle" at about the 3/4 point....moving the stick any further forward doesn't do anything......I live with it 'cos its a cheap ESC......

To be honest not many of my IC engines have very linear throttles either.....the last few degrees of carb opening doesn't seem to do much.....

[Olly P]

The other option is to adjust the throttle curve in your tx if this is possible.

[Shaun K]

Thanks for the quick response guys.

I suspect that it may be the fact that the ESC is of the old and cheap variety. I can't do throttle curves with my older radio but I might play with the ATV and see if I can't make it a bit normal.

Do the programming cards that Josep mentions suit any ESC or are they all model or brand specific?

Still keen to hear any other ideas though.

It's very late at night out here in the land down under so I'm signing off fo the night.

Thanks again,

Shaun.

Edited By Shaun K on 28/02/2012 12:07:50

[PatMc]

Shaun,

here's the Towerpoo esc instructions I suggest if this doesn't help that you scrap it or use it in something like a small motor glider (Full power/glide) & get this for £11 or similar.

[Josip Vrandecic -Mes]

Shoun,the same manufacturer for everything you baying ,will be the safest option ,including a program card,...ohhhh in the deep of the night-down,goodnight

Jo

Edited By Josip Vrandecic -Mes on 28/02/2012 13:13:41

Edited By Josip Vrandecic -Mes on 28/02/2012 13:15:50

[Shaun K]

Thanks again gents.

Pat - I've already been through the programming steps to set he basics so the idea of an alternative ESC looks to be the solution to poor throttling. Shaun.

[Tom Wright 2]

Shaun

Have you done a watt meter test to monitor the current draw ? The meter should show a progressive increase as the throttle is opened ....if the current draw is high before half throttle is reached then the motor could be over propped.

Tom.

[Shaun K]

Thanks Tom, I thought of that and to be honest I think the prop that was with it is too big in diameter.

I have done most of the testing with no prop fitted, but aside from the difference in actual RPM, the rate at which the motor accelerates is pretty much the same with prop on or off.

Last night I played around with the ATV a little bit and strangely enough it seems to be a softer acceleration with the ATV at maximum, 150%. That's backward to what I expected, but it's softened it up a little...

Shaun.