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[whiskeyfrank]

On a 24" wooden scratch built, using 2 x 5 cell nicad batteries, 700bb turbo motor.

What esc do i use, ive had advice from 25amp to 100 amp - cant seem to get a straight answer on which make and model?

Any ideas before i dump the lot and go back to nitro!!!

Thanks

[SteamboatPhil]

PM to FLJ he will not only answer your question but he has them for sale (I know I bought 2 from him for the same motor)

[Proteus]

Which 700bb turbo motor do you have , you may find you will need more volts than that if you want  to get any speed out of it,

Proteus

[stallspeed]

There are 10 NICDs but not enough Henries in series with the 700BB to make the 110A E.S.C. work.
As a result, the TOP in his R.O.C.  E.S.C. has issues with the 700BB as it does have H.E.C.

[Shipmate60]

?

Bob

[OMK]

"There are 10 NICDs but not enough Henries in series"

Not enough Henries?

Message to Henry:

Oi!... 'Enry! Get yer finger out yer butt and go give your other 'Enries a helping hand with that 700bb.

[DickyD]

There are 10 NICDs but not enough Henries in series with the 700BB to make the 110A E.S.C. work.
As a result, the TOP in his R.O.C.  E.S.C. has issues with the 700BB as it does have H.E.C.

I agree with Bob, ?  

[catengineman]

Hi shipmate,

On a 24" wooden scratch built, using 2 x 5 cell nicad batteries, 700bb turbo motor.

What esc do i use, ive had advice from 25amp to 100 amp - cant seem to get a straight answer on which make and model?

Any ideas before i dump the lot and go back to nitro!!!

Thanks

I will try to steer you on a course to happiness. I have run the motor (700bb turbo [Graupner type]) via a 15amp mTroniks marine ESC
If you know how to check the amps drawn on your motor while under load it would give you an indication as to the size of ESC you actually require and go above the highest reading you get so that if the prop becomes stuck then your chosen ESC should stay safe (fit a fuse slightly lower than the rating of your ESC to protect the ESC

R, hope this is of some help.

[Martin (Admin)]

Good sound advice there catengineman.   

Found these:
https://shop.graupner.de/webuerp/servlet/AA 
http://homepage.ntlworld.com/edward.matthews/ddmbc_files/motors/graupner.htm

There are 6 basic types of 700BB motors with Current drain at max. efficiency between 12A - 18A
So I would say you need an ESC of about 15-25A.
                                 

[stallspeed]

There are a bunch of acronyms on the speed controller page of my Robbe Catalogue (1991)

Frank's Chinese esc was rated at 110 amp and it didn't work.
The Chinese esc has what Robbe call T.O.P. with double overload 
It didn't work with the 700bb as the esc lacked a fast switching frequency.  Robbe call that feature H.E.C.
The high stall current of the 700bb ( not the average current ) kept triggering the esc overload
The cure is to boost the motor inductance by adding say 100 micro Henries into the esc-to-motor feed.

[OMK]

Oh, THAT henry.

Ah, right. See what you mean now.