SCX24 with Dig

[vinceherman]

I just saw a video for adding dig to the SCX24.
Looks like fun so I ordered the pieces.
What do you think?
https://www.youtube.com/watch?v=3vBcDcX5hDI&t=4s
https://www.youtube.com/watch?v=UXova1bpF1w

[Brake Weight]

Simple mod but he’s using a $250 Tx.

[GuyOverThere]

I mean i would guess that most peeps on this website have a Tx that can handle mixing on a third channel. I have a 4pl laying around that i could use :P

[vinceherman]

My Gen8 Axe came with a nice transmitter. FlySky FS-GT5. Six channels of no mixing. Meh.
Hope my arduino-foo will let me mix.

[spoo76]

It's the same setup electronically as any other dual motor setup. There's a few cheap transmitters that can do it. A hacked GT3 is still my favorite inexpensive setup.

Sent from my Pixel 3 XL using Tapatalk

[Brake Weight]

I’ve got a decent 4 channel RadioLink but it doesn’t do what his does. DasMicro used to make a single ESC capable of this with a normal 3ch Tx.

[Bray D]

I saw those videos and was thoroughly impressed. I also have a GT5 - post up if you find a way to allow mixing.

[Dogahn]

I'd be happy with just a driveline clutch pack on ch3.

[vinceherman]

I have ordered some AFHDS 2A micro receivers to experiment with connecting an ardino.
Nice micro things. But PWM only. This is less convenient for the arduino.
I have since found and ordered some even more micro AFHDS 2A PPM receivers intended for drones. I assume that I will be able to bind them to my GT5.
The single PPM pin is much easier to read on the arduino.
Then is should be fairly easy to connect the receiver in to the arduino, and signals out to the steering servo and the 2 ESCs.
I imagine that I will use one of the switches for motor modes.
One of the cool things is that I can pick the modes.
I want to experiment with overdrive, where when going forward, the front ESC is driven a little faster than the rear and when backwards, the rear is faster.

But, I have to wait for the receivers to arrive.

[Brake Weight]

This Rx/ESC combo has a dual motor setup that could potentially be configured as a dig. It is only 1S capable and 1amp per channel.

https://banggood.com/DasMikro-Das87-...p-1682701.html

The ESC I remembered seeing, I thought was 2S capable and was large enough to push a 1/24. I can’t seem to find it now.

[vinceherman]

So far it looks like I will use an independent receiver and 2 ESCs.
My issue is that neither of my transmitters do much for mixing. I want to be able to have both motor powered until I change to dig mode.
I also like the idea of a pseudo-overdrive. Running the front ESC at a higher throttle than the rear.
At the moment, I am looking to use an arduino chip to let me use the aux channel to control different drive modes.

[Vmax]

Hey that is pretty cool. As a noob to crawling, it was cool to see the dig in action. I thought it was only used to pivot the rear, I've got a lot to learn!

[vinceherman]

I am slowly getting all the pieces lined up.
The receivers are a few days away. I ordered some from AliExpress which will take a month. I also ordered some from HobbyKing which will take a few days.
FS-A8S https://hobbyking.com/en_us/fs-a8s-2...us-output.html
FS82 https://www.aliexpress.com/item/32811405676.html
Mini Flysky https://www.aliexpress.com/item/4000878505856.html
I assume (????) that I will be able to bind these to my FS-GT5

I do have a PPM receiver that I have bound to my aircraft stick transmitter that I have been using for testing.
I am able to read the PPM stream on my arduino. It should be trivial from there to do my mixing and push it out to the 2 ESCs.

I am thinking that I can use one of the dials to control the drive mode.
In the middle will be normal drive. Forward, stop or backward the 2 ESCs will be given the same throttle.
To the right will be dig. Rear ESC stopped. Front ESC given the forward or back throttle.
To the left will be overdrive. The further to the left, the more differential will be used. The front ESC will be given a higher throttle than the rear.
Maybe while in overdrive mode, if you go backward, the rear ESC will be given more throttle than the front. I will have to see how this works in actual use.

I have the 2 motors and the 2 ESCs as listed in the video up top.
I am also waiting on the print of the motor box.

I might consider other things as well.
The FS-GT5 has 6 channels.
Throttle, steering, 3-pos aux, 2-pos aux and 2 dials.
I could use the 3-pos for turn signals. :-D
The 2-pos could turn on and off the headlights.
Who knows?

But first, I want to get the receivers, actually bind them and hook them up to my arduino.

[vinceherman]

Originally Posted by Vmax

Hey that is pretty cool. As a noob to crawling, it was cool to see the dig in action. I thought it was only used to pivot the rear, I've got a lot to learn!

I have seen it used for tighter turns that the steering geometry normally allows.
I have also seen it used for cautious downhills. Lock the rear and just use the front to gently pull you down. Hopefully without nosing over.

[spoo76]

Haven't read the whole thread so maybe I missed something. Is the end goal just dual ESCs and individual control of each ESC? Couldn't you just do that with mixing like other dual ESC setups? I'm not sure what the arduino is for in this case

Sent from my Pixel 3 XL using Tapatalk

[Bray D]

He can't mix with his GT5.

I'm also not sure it'll bind to any receiver other than the BS6, but I've never tried so I can't say for certain.

[vinceherman]

Yes, individual control. I had hoped that the FS-GT5 had mixing for this. It does not.
And it is something that I CAN do with an arduino.
Assuming, as Bray points out, that I can bind other afhds 2a receivers, specifically one that lets me read a PPM stream rather than an individual pin for each channel.
I hope to find out in a few days when the receivers show up.

[vinceherman]

Just a status update.
I did get 2 AFHDS 2A receivers with PPM in the mail.
https://hobbyking.com/en_us/fs-a8s-2...us-output.html
I was able to power them from the 5v pin on my arduino and bind it to my FS GT5
But the software that I have been experimenting with that reads the PPM signal is not reading the PPM out of this receiver.
I am not sure what the issue is. I have only started to play with this.
I do see in the instructions that you can swap the SBUS port from SBUS to IBUS, but the PPM port is separate and not mentioned as anything that has to be configured.
On a whim I pulled down an SBUS library and connected the SBUS port to the arduino pin.
And it works!
I have the FS-GT5 bound to the receiver and driving a servo.
It should be a simple task now to set up my mixing in the arduino and drive the steering and 2 ESCs with mode select. (and maybe turn signals)

[vinceherman]

https://youtu.be/Duy6PuA2Eb4
And no, I am not a youtue guru. Likely a cruddy quality video.

This was the first time I got it all put together.
I did notice an occasional twitch. It is likely something happening with the SBus frames and how I am using the data.
I'll look into it later.

It is going to be a bear to get all of the wires cleaned up. The ESCs came with the red JST plugs for both the battery and the motor. I unsoldered the motor plugs and put in whatever the matching plug for the motor is (JST PH2.0 I think)
I just made a quickie battery adapter. I will put in a matching JST PH2.0 plug and solder it to both ESCs.
I do not like the idea of having 2 power switches.
I am going to try ganging them. Or maybe simple hard wiring them to be on all the time.

But much of this means actually determining what wire lengths will be needed. And to do that I will need to perform open heart surgery on the truck.
I am looking forward to that but I think I'll wait.
1. This truck is really just the 'companion' to my wife's Christmas present. So it needs to stay hidden for 6 weeks.
2. All the other upgrades that I want to install at the same time are not in at my LHS. I told him my time schedule and he promises to get them in before the holiday.

[Brake Weight]

Originally Posted by vinceherman

https://youtu.be/Duy6PuA2Eb4
And no, I am not a youtue guru. Likely a cruddy quality video.

This was the first time I got it all put together.
I did notice an occasional twitch. It is likely something happening with the SBus frames and how I am using the data.
I'll look into it later.

It is going to be a bear to get all of the wires cleaned up. The ESCs came with the red JST plugs for both the battery and the motor. I unsoldered the motor plugs and put in whatever the matching plug for the motor is (JST PH2.0 I think)
I just made a quickie battery adapter. I will put in a matching JST PH2.0 plug and solder it to both ESCs.
I do not like the idea of having 2 power switches.
I am going to try ganging them. Or maybe simple hard wiring them to be on all the time.

But much of this means actually determining what wire lengths will be needed. And to do that I will need to perform open heart surgery on the truck.
I am looking forward to that but I think I'll wait.
1. This truck is really just the 'companion' to my wife's Christmas present. So it needs to stay hidden for 6 weeks.
2. All the other upgrades that I want to install at the same time are not in at my LHS. I told him my time schedule and he promises to get them in before the holiday.

With these little ESCs you can do all sorts of modding/deleting. First thing I do is remove the heatshrink and desolder the switch from the the board. Then add a drop of solder across those holes to make the connection to always be power on.

Second is to shorten the leads as much as possible. You'll need a decent iron and some patience to shorten the 3wire Rx lead but it is doable. Direct wire solder to the motor terminals as well.

If you open the servo you can desolder, shorten, and resolder that wire lead as well.

If you're running one battery and 2 motors/2 ESCs, I'd solder a 'Y' in there so that the only connection would be the battery plugging in.