RC Deck - Performance Power Supply With Radio Control

[Krxlion]

One note from my side regarding pre-defined receiver if included. Please aim with something that has gyro functionality. This thing can really help control fast models and mostly those are the ones we aim for if we are using 3rd party solutions. :)
As everyone else mentioned geek-servo is the best solution for small motor that could be used not only as servomotor, but as switch for locking differentials or switching gears.

[NoEXIST]

56 minutes ago, Ryokeen said:

@NoEXIST as a side node, the two 14500 cells will, as other ppl said, give around 8.4v fully charged, that's fine for motors as i think those are rated for 9v. But a lot of 14500 cells are rated only for 10A drain, that could be a problem if you use at leat 2 30A esc. Yes they will only suck as much as the motors need, but alone the possibility that an esc can request more Amps than a battery can provide is not good. That's why most of the time you see high C-Rating LiPos in rc projects. For 2x30A esc you would preferr a lipo with lets say 2000mAh and a 30C-35C rating.

Hm, that's interesting. I found just a bit of information about this on Google, but they are also saying that you can damage your battery only if your motors consume more than battery can provide.

Also in this case I wonder how is bw 3.0 working with 3s 800mah 5c lipo battery

1 hour ago, Ryokeen said:

@NoEXIST
So your product would serve as an interface between a LiPo and an rc receiver, offering PF/PU and 3-Pin servo connections. That way ppl could also use receivers they already have, switch the channel layout and you save on hardware.
One would just connect the motors/servos to your thing, then connect a LiPo and a receiver. Sure not an all in one package, but that way the receiver could also be somewhere else utilizing space.

That's actually a backside of such projects, ppl will need a bit different preferences and you can't actually make universal product as it is possible for buwizz because of Bluetooth control. 

Maybe I'll let customers choose what they want for their Deck:)

22 minutes ago, Krxlion said:

One note from my side regarding pre-defined receiver if included. Please aim with something that has gyro functionality. This thing can really help control fast models and mostly those are the ones we aim for if we are using 3rd party solutions. :)
As everyone else mentioned geek-servo is the best solution for small motor that could be used not only as servomotor, but as switch for locking differentials or switching gears.

Got myself some time ago rc kit for Lego, receiver with gyro is pretty fun!

One of the pros of dumbo receivers that even smallest 4CH receiver has a gyro version. However it might affect count of channels you can use for motors

[Lixander]

1 hour ago, NoEXIST said:

Also in this case I wonder how is bw 3.0 working with 3s 800mah 5c lipo battery

I am not sure, but maybe because of the discharge rate.

Usually, hobby-grade Li-Po˙s dont go under 10C.

My 2S battery has about 30C, if I remember correctly, for example

Edited January 12 by Lixander

[Ryokeen]

33 minutes ago, Lixander said:

Usually, hobby-grade Li-Po˙s dont go under 10C.

Yep Lipo packs have higher discharge rate than single 14500 style cells. Also 14500 are of Li-ion types

2 hours ago, NoEXIST said:

That's actually a backside of such projects, ppl will need a bit different preferences and you can't actually make universal product as it is possible for buwizz because of Bluetooth control.

You don't need BT for that :) just let customers choose their components. The biggest problem i see is just connecting lego motors to an RC system. You can provide a sollution for that problem, or yeah have different versions like with receivers or without.

As an example, what if i have a car with propulsion(1 channel), steering(2nd channel), gearbox(3rd channel), a winch(4th channel) but also want difflock(at least 1 more channel). I can't use your product if i can't switch out the receiver and just plug in a servo directly(but it will be powered by your box).
I also can't just buy 2 of your boxes cause a single transmitter only binds to 1 receiver(normally).
But if the receiver is not in your box, then i can use 2 of them. As i can plug in 4 channels of the receiver to box 1 and the other to box 2. Only need to watch out for the bec, so the receiver won't be powered by both boxes, but that is just a matter of using a cable with only sig and ground.

What i'm saying is, don't limit the usecases by trying to make a fixed package for a fixed set of use-cases. Splitting it up gives more freedom to how it can be used and combined, broadening the possible use-cases.

But that's just my opinion it's your product after all.

[NoEXIST]

@Ryokeen so your idea is to make a box for esc's and the receivers are just separately? This is pretty interesting concept. Similar to a classic rc setup but with more channels;)

In this case dumbo X10 can be used for a crazy amount of functions

[Ryokeen]

@NoEXIST Exactly. You would sell a box that has esc's, lego compatible ports(and standart servo ports maybe) a batterie connection port(a lipo protection is needed then) and input ports for receiver channels. And the receivers are separate.
Having the esc's and the receiver separate just opens up a lot of possibilites, not only free choice of receiver. One is then also able to intercept the signals from a receiver and modify them, for stuff like range extensions for a geekservo(signal spreader).
Or hooking in an microcontroller and using one receiver channel as a 2 way trigger for some coded signal sequence to servos. That also means your box wouldn't be restricted to rc receivers as any proper pwm input could be used.

All in all it would make it way more flexible because you're not limited by how many chanels the build in receiver got or how much ports/esc's are in the box, you just daisy chain them and get more.

 

[NoEXIST]

Some updates for today! I've tried to design universal version of the deck as requested!

Now receiver isn't in the box, whatever receiver you have can be connected from the side. Under signal  ports there is a power port. Another improvement is that I moved PF ports to reduce wire bending as was mentioned. Also geekservo port was finally added.

 

[Lixander]

5 hours ago, NoEXIST said:

Some updates for today! I've tried to design universal version of the deck as requested!

Now receiver isn't in the box, whatever receiver you have can be connected from the side. Under signal  ports there is a power port. Another improvement is that I moved PF ports to reduce wire bending as was mentioned. Also geekservo port was finally added.

 

Sounds and looks more versatile. I like the update.

I see that the height of the whole unit seems smaller, which is definitely a great thing maybe even an advantage.

[NoEXIST]

4 minutes ago, Lixander said:

Sounds and looks more versatile. I like the update.

I see that the height of the whole unit seems smaller, which is definitely a great thing maybe even an advantage.

Size is the same, but bottom cover is a bit different as it don't need to slide on battery as it has battery and receiver outside

[amorti]

So, what would the finished package look like? If the receiver is separate and the battery, does that mean there are now three items to house? And some of those without any Lego connections, so you have to zip tie them on?

I think that pushes it further into a niche of people who are already proficient in RC gear, as opposed to the originally presented design where it could more or less replace a buwizz unit within a moc.

Edited January 14 by amorti

[NoEXIST]

24 minutes ago, amorti said:

So, what would the finished package look like? If the receiver is separate and the battery, does that mean there are now three items to house? And some of those without any Lego connections, so you have to zip tie them on?

I think that pushes it further into a niche of people who are already proficient in RC gear, as opposed to the originally presented design where it could more or less replace a buwizz unit within a moc.

Well, I think it's possible to make few versions instead of trying to compromise everything in one.

First one is RTR kit as I showed in the beginning, there we can't change receivers and battery is inside.

Second one is a box with esc's where you should connect everything from outside. I'm also going to attempt to reduce size of the deck as it now has less components.

[Ryokeen]

@NoEXIST Nice update so far. One thing that came in mind was that most esc have some sort of switch for a break functionality. Also a lot of ESCs are asymmetric, means they deliver less power in reverse than they do in forward. So you might have to keep that in mind when choosing esc's and designing the housings

[NoEXIST]

23 minutes ago, Ryokeen said:

@NoEXIST Nice update so far. One thing that came in mind was that most esc have some sort of switch for a break functionality. Also a lot of ESCs are asymmetric, means they deliver less power in reverse than they do in forward. So you might have to keep that in mind when choosing esc's and designing the housings

The ESC I choose has one, I hope I will be able to make top cover of the deck be easily openable so it gives access to that switch.

I think asymmetric pověr curve won't be that matter on secondary functions

[amorti]

Asymmetric power curve can be a problem when you reverse the pf plug.

[NoEXIST]

6 hours ago, amorti said:

Asymmetric power curve can be a problem when you reverse the pf plug.

But it you physically reverse the contacts on the motors signal on the ESC is still the same. There might not be a problem that one of the motors will spin faster then other

[Ryokeen]

Oe Motor spinning faster than the other is actually a big problem if you want to couple motors, like one buggy for front axle, one for rear, or just both hard coupled.

Also if you physically reverse the contacts the motor will just spin the other way but still spin full power. But if the esc drives them in reverse they will(as an example) spin only at 50% throttle at max.

[NoEXIST]

29 minutes ago, Ryokeen said:

Oe Motor spinning faster than the other is actually a big problem if you want to couple motors, like one buggy for front axle, one for rear, or just both hard coupled.

I mean if motors spinning with different rpm is bad, but this not going to happen

Maybe  we don't understand each other, but if you change polarity of one of the motors, esc not going to know about this and just let the motors spin at the same speed. It's not about reversing a channel using receiver, it's about exchange + and - while soldering one of the ports

P.S. there will be only one esc for PF ports, so there's no problem with spinning speed

[NoEXIST]

Quick question. Do you think JR connector is needed on the ESC box? Trying to figure out how small it can actually be

As deck will have receiver outside of the box, maybe even more comfortable way to connect geekservo is directly to receiver 

Edited January 15 by NoEXIST

[Ryokeen]

At least for the ESC input signals yes. Servos could be attached to a receiver directly as the box wouldn't do anything with the signal itself

[gyenesvi]

I think the single unit vs every component having its own unit is kind of a big dilemma. A single unit can possibly become quite a bit smaller than many separate units, because there's less space wasted on boxing / connectors and making things full or at least half stud sized to fit into the lego system. At the same time, having separate units be much more lego-like, components being swappable. Also, in a build, it may actually be easier to hide many smaller components than one bigger component. That being said, the best strategy would be to have both extremes as separate products :)

While I was thinking about how I would design such a product, I came to the conclusion that one useful yet simple combination would be the following:

- Battery unit: two main options here:

1) bare battery just with output connector, simple as possible, would be useful if a model exposes the battery to be easily swappable. Recharging would be solved by an external charger

2) battery with recharging circuit/port, and on-off switch.

In both cases, the connector is kind of problematic, as a single PF connector cannot deliver enough power without melting, so some other connector should be used..

- ESC unit: the simplest option is to have a single ESC for drive, with two PF outputs, that could take 2 buggy motors separately, without risking melting. The switch of the ESC (for braking functionality) could be exposed, but it does not need to be switched around in a build model, just once before building.

- Receiver unit: just a small case for the receiver, exposing the outputs, and having an input from the ESC for power supply and the drive connection.

So the system could have 2 drive motors, and in case of a 4 channel receiver, 3 GeekServos connected at the same time. With a 6 channel receiver, even more servos could be connected. The ESC unit and the receiver units could become quite small in this case.

[NoEXIST]

32 minutes ago, gyenesvi said:

I think the single unit vs every component having its own unit is kind of a big dilemma. A single unit can possibly become quite a bit smaller than many separate units, because there's less space wasted on boxing / connectors and making things full or at least half stud sized to fit into the lego system. At the same time, having separate units be much more lego-like, components being swappable. Also, in a build, it may actually be easier to hide many smaller components than one bigger component. That being said, the best strategy would be to have both extremes as separate products :)

While I was thinking about how I would design such a product, I came to the conclusion that one useful yet simple combination would be the following:

- Battery unit: two main options here:

1) bare battery just with output connector, simple as possible, would be useful if a model exposes the battery to be easily swappable. Recharging would be solved by an external charger

2) battery with recharging circuit/port, and on-off switch.

In both cases, the connector is kind of problematic, as a single PF connector cannot deliver enough power without melting, so some other connector should be used..

- ESC unit: the simplest option is to have a single ESC for drive, with two PF outputs, that could take 2 buggy motors separately, without risking melting. The switch of the ESC (for braking functionality) could be exposed, but it does not need to be switched around in a build model, just once before building.

- Receiver unit: just a small case for the receiver, exposing the outputs, and having an input from the ESC for power supply and the drive connection.

So the system could have 2 drive motors, and in case of a 4 channel receiver, 3 GeekServos connected at the same time. With a 6 channel receiver, even more servos could be connected. The ESC unit and the receiver units could become quite small in this case.

That's what I think about, we need 2-3 separate products!

BATTERY UNIT: I'm defenitely going for external charger as its more simple, faster and safer for the battery.

ESC UNIT: You're right about only 2 motors, it's also good to have power reserve in ESC. This form factor actually allows you to use multiple decks...

RECEIVER UNIT: In my todays opinion this one can be really small only if one driving channel uses ESC and other channels are used for geekservos and similar. ESC's for secondary functions are pretty big too. Maybe I should go for weaker ones for PU ports  in the future. These ones theoretically can handle one buggy motor(each) too.

[gyenesvi]

23 hours ago, NoEXIST said:

In my todays opinion this one can be really small only if one driving channel uses ESC and other channels are used for geekservos and similar.

Exactly, that's what I think could be a useful product: one ESC for drive channel, and all other channels for multiple GeekServos, one for steering, and the others for gearbox, diff locks, or even rear steer. And actually continuous rotation GeekServos can even be used for winch, or opening stuff!

[NoEXIST]

1 hour ago, gyenesvi said:

Exactly, that's what I think could be a useful product: one ESC for drive channel, and all other channels for multiple GeekServos, one for steering, and the others for gearbox, diff locks, or even rear steer. And actually continuous rotation GeekServos can even be used for winch, or opening stuff!

As I can see y'all are pretty okay with forgetting about Lego motors Maybe I should also think about custom motor:) Maybe even brushless

[Ryokeen]

@NoEXIST well PU+ motors with their useage as gear selector and servo are a bit complicated to integrate as you need at least some logic to interface them. PF motors or in general DC motors are easy as they only require a simple esc but they can only "just" rotate :D
Also in terms of power, PF motors are just not good. What 3-4 XL motors can do, one 540er motor can aswell, with at at least 10 times the rpm and it's actually only around the size of one XL motor.
Buuut having something where i can just plug in an receiver, a LiPo and motor(s) would be nice.

I would not suggest supporting brushless this early, cause those mostly very high(even 1000kv at 2s is almost 8k rpm) rpm need so many special/custom parts(bearings) that those ppl have already a sollution for all the electronics.

Then again, the biggest question is, what marked to you want to supply ?

If it's only RC car/bike/boat type stuff one esc for "driving" motors is enough.
If you want to give ppl the freedom to make tracked vehicles, then it's a matter of, 1. put in 2 esc for "drive" motors (can be hard-coupled by an Y-Cable still) or 2. let ppl buy 2 boxes that are connected one receiver

Oh and for that option where the receiver is separate, consider adding a UBEC as those small esc most of the time don't provide much amps(the 2s 20A esc i got only have 1A bec). Best would be 6V and around 3-5amps, so there is enough power for some stalling geekservos.

[Lixander]

Also, even if it's a little off-topic, for the RC version you can sell separately a motor adaptor with the common screw holes distances (I mean something like a case with pin holes somewhere and screw and axle holes for the motor), being a similar process with the making of the case of the RC Deck (I think).

I consider this is one of the main problem (the motor adaptors), because there are some solutions for the differential, frames with ball bearings, wheel hubs and the U-joints, but the motor frames are usually given as 3D files or have a fixed/ restrained motor dimension.

For example, in my country, I can't find too many companies for 3D printing. About 1 of the companies is trustworthy and of that, 0 answers for the printing of the 3D file, most likely because the frame is too narrow at the margins 

Edited January 17 by Lixander