alan2525

Can anyone suggest a suitable Electronic Speed Control for a small Battery loco - 32mm gauge.

The motor is small RS 380 type, Power is 4.8 Volt nimh battery pack. I'd need the item to be BEC and as small as possible - the loco is tiny! Only 120mm long and 60mm wide!

I've got an esc from an R/C car (LRP) which is just about small enough but it's a little problematic as the speed control pauses for half a second prior to going into reverse. Also it only runs the motor at approx 1/4 speed in reverse without a proportional variable speed.

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new to trains

m troniks do some very small esc's - with it being a 380 size motor then you should be fine with one of their eco range, - i guess the eco 15 should be fine, inputs upto 12 volts and 15amp continuos output rating, the ' marine ' types go into reverse straight away ( no brake type system as with buggy esc's) and all are BEC enabled,
as for size then they are a simlar size to a standard 2 channel rx........at a guess about 40 mm long 30 mm wide and 15 mm in depth....

check them out at

http://www.mtroniks.net/

bogstandard

Hi Alan,
You won't get a reliable BEC supply for your radio from a 4.8volt supply.
You will have to have at least 6volts, preferably 7.2. The only way around it will be either to take a tapping straight off you motor battery, but expect a lot of interferrence and glitching as the power runs down or fit another seperate 4.8v pack for your radio.

John

tag

Hi alan2525
Just to agree Mtroniks are a cracking speed controller with a small footprint BUT even 6v is iffy 7.2 is be min running a BEC

alan2525

The only problem is that this little loco is so small trying to pysically fit another couple of AA batteries inside it will be a real packaging task!

The Speed control I'm using atm to try to fit all the bits in is only 26 x 26 x 20mm - anything larger than that will mean it'll have to have all the electronics in a truck behind it which is really something I wanted to avoid.

The real loco is only about 7 feet long by 4 feet wide!

Is there anything micro sized? I'm using AM radio and the only small receivers seem to be for FM, is there anything like the speed controls used for those Tamiya Tamtech cars or something which will do what I need but in a smaller footprint?

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Bunkerbarge

If you have a squeeze with two AA's what about the old small 9v square battery? That is compact but will give you enough voltage to drive the BEC as well. If you can't get one of those in you might have to consider having a battery specially made, which are not that expensive.

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“Dirty British coaster with a salt-caked smoke stack, Butting through the Channel in the mad March days"

alan2525

Would this esc be suitable? Mtroniks MicroVIPER Marine10?

http://www.mtroniks.net/mtroniks_SC_...ubCategoryID=3

The size would be ideal at a petite L26.0mm x W25.6.0mm x H9.0mm, even at that size it'll only have a couple of mm to spare between the driving wheels!

I can fit a 5 cell humpback AA battery pack under the bonnet and with the 2 cells on one side and three on the other it even just clears the cutaway in the bonnet for the air filter

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tag

Hello again Alan
is there room for a servo as:
http://www.huntersystems.co.uk/

do a manual servo controlled for a Mardave R/C car might be worth a try
or possably a Bobs Board if they still make them Bunkerbarge might advise where to buy them from but they are quite big about 3"x4"
if thats of any use

alan2525

I think the correct term is - there isn't enough room to swing a servo arm - let alone a cat!

3" x 4" is bigger than the loco! It's only 120mm long and 60mm wide.

I've tried the Lrp ESC with reverse in the loco and it works reasoanbly well! Just barely skims the rails and misses shorting itself out against the motor by 0.5 - 1mm! The main problem with it is the fact that the motor and battery wires are quite hefty and there's barely room under the chassis for a nats danglies!

I'll post some photos after I've replaced a few screws with countersunk machine screws and cut them to length! Then I might actualy be able to fit the cab onto the chassis.



My next loco model will be a little larger for practicality sake!

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tag

Hi Mate
Just a thought how about using a servo/mini servo striped out and rewire your motor inplace of the servo motor that would give you a proportional speed control with reverse