Pico_ESC, it's alive!

[braq]

Hi,

since getting more and more into builds using the Losi Micro components I was looking into ESC with small footprint and medium power output.
Couldn't find anything stock, either the amps were too low or the footprint too big so I sat down and tried building my own...and tried...and tried.


Finally it works now, power is a 1s LiPo, power connects through the ESC wire, max current is around 4 Amps, it also has outputs for brake and back-up lights and it is really tiny.



about the length of a nickel's diameter and width is half of the diameter, here along with standard, mini and micro size servos



Uploaded with ImageShack.us

I have one that looks pretty similar to this (using Losi Micro axles, drivetrain),



gonna run it and let you guys know how it holds up.

If it works fine, anyone interested in trying a pico_esc out?

cheers

braq

[airwolfie]

Well done!! I would love to try it out, I have a 1/20th hilux that could do with something this tiny!

Love the tractor too!

[danielk]

Can you show us both sides and give us some specs? I'd love to try one for myself.

[braq]

Hi,

here is a shot from the top-side.


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What would you like to know about it?

cheers

braq

[braq]

It runs nicely in the MB trac, here is a little video

http://www.youtube.com/watch?v=rnz8u...ature=youtu.be

The taillights are on all the time, when braking they get a higher voltage for about 1 sec to simulate the brake lights. Back-up lights work fine also. I ran two batteries through it today with no problems.

[klampykixx]

i think a more refined circuitboard would see this sell pretty well mate good job

[braq]

Hi,

there will be a version on an etched PCB at some point. That will surely bring the time to solder one down

At this point it is aimed at miniature, therefore running stable directly connected to one lipo cell and with the smallest (with my means) footprint.

I am thinking about three more options:

a) 2s version with small BEC, that will be bigger as it needs extra space for a 5V regulator and capacitor

b) a version with connectors. Right now to save on space on the Rx, lights and motor I solder those directly.

With connectors it will require even more space, for the servo connector and breakout pins for the lights, either in 1/10''

http://www.reichelt.de/?ACTION=13;PI...;HEIGHT=150 ;

or 1/20'' pitch

http://www.reichelt.de/?ACTION=13;PI...50;HEIGHT=150;

with matching connectors, also which connectors to use for the battery then?
I prefer the 1/10'' pitch (that is the same as the standard servo connector) for the battery to use one universal type for all my connections (gotta be careful not to plug in a battery directly to the Rx with that ;-)) or should I go with JST male leads
http://ep.yimg.com/ca/I/yhst-6219634...2240_73961320?

c) a version with more juice, using MosFets that can handle around 40 amps
with BEC, 3s capable, of course always the trade-off between capability, number of components and as a result an even bigger footprint.

let me know what you think,

cheers

braq

[spoo76]

Wow awesome! that may be the smallest brushed ESC I have seen used in a crawler, looks like it can get even smaller with a printed board.

the next closest thing Ive seen available is the 10amp version of the XYS esc.
just like the 20amp they come in 2 versions, brake or no brake.
20amp left, under the nickel is the 10amp on the right. Honestly though, making it yourself is even cooler

[8BALL]

Got skill

[minizmodder]

wow amazing work, is that full proportional as well? Those fet legs are the bane of my existance, I have broken so many I can't count them any more

Any more pictures of your tractor? I have a spare set of losi axles and I think it would be a neat build

[braq]

Hi,

it has approx. 45 different PWM steps in each direction, so I think it is fair to call it fully proportional (guess the deadband on a servo might be a bit better).
A bit more on the tractor can be found in the agricultural section together with another short video,

cheers

braq

[braq]

It still works and doesn't get hot or anything with the stock motor.
In the meantime I've soldered one version with a 5V regulator and larger FETs, but it turned out to need more than twice the footprint. Compared to the 10A ESCs that go for $10ish I can't really offer any advantage other than the incorporated back-up and brake light as the parts alone cost me $10

So it will be with the focus on a really small footprint, airwolfie and danielk, could you try the pico_esc out running on 3.7V with the stock motor?
If so, I'd like to send you each one (for free) so you can check it out and look for improvements. It will be with leads to solder onto. Just pm me if interested,

cheers

braq

[sgl]

Braq,
Very impressive. What is the availability? I guess the big question is what is shipping like down hill to California? Thanks
sgl

[braq]

Hi sql,

thanks for the compliment. I have two ready and sealed with JR connector and leads for the motor and lights (to be soldered).
Shipping ideally would be as a letter, than it is something like 2 bucks at the most, but I'd have to stay under 5mm (0.07 inch) height, the weight is 6-8g (depending on the length of the leads).

As a parcel you don't want to know, once it crosses the border they become "gold"...or since we go to the US quite regularily, I'd just mail it from within the states the next time, just shoot me a pm.

cheers

braq

[JatoTheRipper]

Originally Posted by spoo76

Wow awesome! that may be the smallest brushed ESC I have seen used in a crawler, looks like it can get even smaller with a printed board.

the next closest thing Ive seen available is the 10amp version of the XYS esc.
just like the 20amp they come in 2 versions, brake or no brake.
20amp left, under the nickel is the 10amp on the right. Honestly though, making it yourself is even cooler

Where can you buy the ESCs in the photo?