Worlds smallest USABLE 1s dual ESC with or without track mixer.

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modler
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Worlds smallest USABLE 1s dual ESC with or without track mixer.

Post by modler »

If you clicked a link from my other threads you are here for UM ESC build.

The 5 channel receiver used in this thread is a Crossover RX-42.xx. Servo ports are Micro JST-SH 1.00mm pitch.

There are two versions of this Ultra Micro ESC
1. Dual ESC with Tank Track mix
2. Dual ESC no mix. This gives you two independent ESC's in a very small package. (Worlds smallest USABLE ESC at this point). Anything smaller would be pretty hard to work with for most RRC hobbyists including myself so we don't care if there is anything smaller as it would not be usable.

Warning! Some Micro JST-SH 3 pin connectors have the +\- swapped. Quick way to tell is, RED wire is in the center is good. Black wire in the center is BAD! This wiring harness shown here powers the receiver through the Micro JST-SH servo ports via the ESC. It is critical that the wiring polarity is correct on the servo port connections else the receiver will be permanently damaged on power up.

THEORY OF OPERATION
This wiring harness has been designed for this particular dual ESC. The thing about it that's different is POWER DISTRIBUTION FROM THE POWER SOURCE. The servo ports YELLOW wires are PPM (Signal x2) outputs to the ESC. The servo ports RED\BLACK wires are SUPPLY VOLTAGE IN to the receiver FROM the ESC.

This design eliminate a seperate power supply connector for the receiver. Also has proper power distribution with the ESC first in line. (least input resistance with respect to voltage supply)

I I have one of these Ultra Micro dual ESC's with mixer in a 1/77 Leopard Tank and getting ready to build up 2 more with wiring harness. I will show the steps involved with that.

I now have two of these ESC' in operation. No.2 is in a 1/72 Tiger 1. These thing work good 8) I will be building a total of 5 for now.

With this Dual ESC, "independence" means there is no ESC internal mixing. The allows for 2 independent ESCs with no mix. This particular ESC configuration could be used in a Tank with old school "twin stick track control" where both stick moved together up for forward and both sticks down for reverse. Then each track can be run independent from each other allowing manual zero turn maneuvering. This type of control could be used in a RC Bulldozer. Where Radio Control Tanks first came out, this was the control method used. There are other applications for this "independence" mode of operation that I will be discussing in this thread. But for now, on with the wiring of the ESC's.

Oh, you can also use this "independence" type ESC in a RC Tank by using Computer TX mixing. I use Elevon mixing to accomplish this type of track mixing. There are others but Elevon is the most straightforward method in my mind.

Note: I edit posted information here for errors or omissions to keep things as accurate as possible B|
Attachments
wires trimmed to length, ends striped of insulation, exposed wires solder tinned, and ready for red wires to be soldered together. This is the proper polarity shown in this picture. RED in the center for CROSSOVER-Servo ports: Micro JST-SH 1.00mm pitch. OTHERS MAY HAVE DIFFERENT POLARITY!
wires trimmed to length, ends striped of insulation, exposed wires solder tinned, and ready for red wires to be soldered together. This is the proper polarity shown in this picture. RED in the center for CROSSOVER-Servo ports: Micro JST-SH 1.00mm pitch. OTHERS MAY HAVE DIFFERENT POLARITY!
IMG_0423.JPG (996.52 KiB) Viewed 377 times
another view of a finished "ESC input" wiring harness. This Harness is for a RX with micro JST 1mm 3 wire channel output connectors. The 2 wire 1.25 mm micro JST connector is the 1s Lipo power in connector which powers the ESC directly through the 28 AWG black\red wires. The RX42 receiver is then powered through the channel connection red\black wires and does not use a seperate input power connection thus eliminating those RX power in wires. The yellow wires are the PPM signal wires for Aileron\elevator channels.
another view of a finished "ESC input" wiring harness. This Harness is for a RX with micro JST 1mm 3 wire channel output connectors. The 2 wire 1.25 mm micro JST connector is the 1s Lipo power in connector which powers the ESC directly through the 28 AWG black\red wires. The RX42 receiver is then powered through the channel connection red\black wires and does not use a seperate input power connection thus eliminating those RX power in wires. The yellow wires are the PPM signal wires for Aileron\elevator channels.
IMG_0424.JPG (986.41 KiB) Viewed 377 times
ESC wiring input\output
ESC wiring input\output
IMG_0315 (1).jpg (1.57 MiB) Viewed 377 times
Last edited by modler on Wed Dec 27, 2023 3:10 pm, edited 22 times in total.
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modler
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Joined: Sat Feb 02, 2019 2:33 pm
Location: North Ridgeville Ohio USA

Re: Worlds smallest 1s dual ESC with or without track mixer.

Post by modler »

One with internal track mixer and one with independent ESC's with no mixer.

tinned = covered or coated in tin or a tin alloy.
"a pair of tinned copper conductors"

Connectors used in this harness.
JST Japanese Solderless Terminal
Micro JST 1.0mm SH Connector 3 pin x2
Micro JST 1.25 PH 2 Pin x1

male connectors have female pins.
female connectors have male pins.
as used here.
Attachments
1s - supply voltage BLACK wires separately tinned then soldered together in parallel. The parallel BLACK wires are then soldered to the tinned pad on the right.
1s - supply voltage BLACK wires separately tinned then soldered together in parallel. The parallel BLACK wires are then soldered to the tinned pad on the right.
IMG_0548.jpg (995.2 KiB) Viewed 336 times
The yellow PPM signal wires are soldered on the back side of the ESC after the center pads are tinned.
The yellow PPM signal wires are soldered on the back side of the ESC after the center pads are tinned.
IMG_0570.jpg (980.36 KiB) Viewed 338 times
This is the OUTPUT side of the ESC. Those are 1.25 mm female micro JST connectors with 26 AWG wire.
This is the OUTPUT side of the ESC. Those are 1.25 mm female micro JST connectors with 26 AWG wire.
IMG_0560.jpg (1.55 MiB) Viewed 338 times
The pads are "tinned" first as are the wires. Also the tinned wire ends are trimmed to lay across the pads then are soldered to the tinned pads.
The pads are "tinned" first as are the wires. Also the tinned wire ends are trimmed to lay across the pads then are soldered to the tinned pads.
IMG_0562.jpg (1.77 MiB) Viewed 339 times
this one looks good.
this one looks good.
IMG_0577.jpg (1.75 MiB) Viewed 339 times
It took 1.5 hours to build these up. Next phase is testing. Then clear tape heat shrink wrap for electrical isolation and keeping dirt from such from very small circuit boards
It took 1.5 hours to build these up. Next phase is testing. Then clear tape heat shrink wrap for electrical isolation and keeping dirt from such from very small circuit boards
IMG_0578.jpg (954.27 KiB) Viewed 339 times
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