Circuit Cubes

[jburgt]

Who has worked already with “circuit cubes” to motorize your locomotives? I understand there’s a Bluetooth version. In this movie you see two types of motor cubes. What is the difference?

See: 

 

Edited October 28, 2021 by jburgt

[Hod Carrier]

I’ve just started using the Bluetooth version today, so I’m still exploring. The motors seem to be quite powerful for their size and the hub too is a nice size which makes it a good option for small models. The ability to daisy-chain the motors is a nice feature too. 
 

The app is reasonably good but seems to come without any documentation so I’m going to have to play with it and work out what it can do and how to make it do it. 

[jburgt]

Here’s a guideline to use the cubes in the LEGO crocodile. But this is the non Bluetooth version. The used motor is different.

see:

https://plaatjesvoorforum.files.wordpress.com/2021/10/crocodile_locomotive_10277_motorized_with_circuit_cubes-1.pdf

Edited October 29, 2021 by jburgt

[ivanlan9]

404 not found! 

[jburgt]

I changed the link. Now you can read the PDF file.

[LEGOTrainBuilderSG]

I use the smaller motors shown at 1:55 of the video you posted. 

They are pretty powerful! The app works fine. The only downside, in my opinion, is the 'scream' it makes when it motion. 

Have a listen:

MR 15 Class shunter (Powered by 1x Circuit Cube and 2x Small Motors), also I've lowered the video's sound because it was just too unbearable to listen to:

https://www.flickr.com/photos/108174470@N03/51632972199/in/dateposted-public/

 

Edited October 29, 2021 by LEGOTrainBuilderSG

[HoMa]

I've ordered 2x Bluetooth upgrade kit a few month ago. The boxes arrived super fast from US to Germany and I had no trouble with customs. This years Octrainber contest was for me the initial starting point to use Curcuit Cubes. And yes, they are tiny and overall great in building LEGO MOCs like small Critters.

The Bluetooth kit comes with two of the transparent boxed motors which are used in the tank chassis shown in the video. I don't have the "pink" motor and other 4x4 electric devices which are available from Curcuit Cubes. Integrating the motors in a MOC is a lot of fun, they offer a lot of attachment points for it's size, e.g. hollow studs on top or Technic Pin holes on each side. For a compact axle configuration I had to cut a 2L Technic axle down to a 1.5L version (upps, sorry).

The control app is not documented well, that's right. But you will get through it and find a way how to remote controll your motors. The latest update for iOS now offers a custom control panel where you can select two Bluetooth hubs and then select the outputs on the hubs (1A, 2A, 3A, 1B, 2B, 3B). The custom control panel only allows to add 5 controls (as far as I could figure out), so you could control 5 motors on 2 BT hubs at the same time. Unfortunatelly the app does not remember the outputs you've addressed to each control, so this has to be repeated each time you've connected the hubs. But I hope the development of the app will continue and bring more stability and more options. To play around, it works for me.

[cptkent]

Has anyone tried using a combination of "bluetooth circuit cube / motor" as a replacement for the old 9V electric motor?

I've had a look, and don't think both will fit. But I think the motor could be made to fit in a chassis to replace the old 9V motor, and I could run the power wires to the hub placed inside the cab.

 

My specific interest would be so that I could have my 9V trains running on RC track, just by replacing the 9V motor with a Circuit Cube replacement.

I've got a few 9V trains that I'd like to run, I don't want to go to the lengths of trying a LEGO solution as I'd need to fit in in a Power up hub or RC battery box or something. Alll the LEGO solutions seem too bulky.

 

My Circuit cube kit should be here shortly, so I may try it myself.

David

[pollymath]

Bumping this back up. 

As David said nearly two years ago, I too would be interested in wiring these up to PF wires for use with PF Battery Boxes. That'd allow you to use a physical controller vs a Bluetooth one. 

I like the fact that the Circuit Cube geared motor cube is high torque low RPM. That might allow a control to be full-speed, while running a train at a slow pace. 

[UltraViolet]

6 hours ago, pollymath said:

Bumping this back up. 

As David said nearly two years ago, I too would be interested in wiring these up to PF wires for use with PF Battery Boxes. That'd allow you to use a physical controller vs a Bluetooth one. 

I like the fact that the Circuit Cube geared motor cube is high torque low RPM. That might allow a control to be full-speed, while running a train at a slow pace. 

  Take note that both types of Circuit Cubes motors are not rated to handle full voltage from a standard PF source.  Operating them at 9V would likely burn out the coils very quickly, and even the lower voltage PF rechargeable battery box would be unsafe.  Here are the specifications I received from John Schuster at Circuit Cubes in response to my questions about the smaller motor:

"The motors in the Cubit (2x4 stud pattern, 2 bricks tall) operate at 3-6 VDC.  RPM about 160 at 4.2 VDC no load.  Approximately 5.5 N.cm torque."

  Now that said, I found that the PF IR receiver operates perfectly fine from a lower than normal supply voltage.  These motors worked great at all speed steps from the PF IR receiver when hooked up to a custom power supply with a suitably lower maximum voltage.  In my case, I used a cheap and readily available adjustable voltage step-up board sourced through eBay to operate at 5 to 6V from an 18650 lithium cell (any format of standard 3.6-4.2 volt lithium cell will do, so choose what physically fits best in you build).  This step-up board maintains precisely the voltage you set no matter the remaining capacity of the lithium cell.  The bonus of this board is that by adjusting the maximum voltage output, you can tune the performance of the motor to your needs if the maximum voltage is too fast for your application.

  If you want to use a PF battery box, you'd have to install dummy cells as spacers in place of two of the AA or AAA batteries so your total max voltage would be 6V.  (Be careful if you're in the habit of using non-rechargeable type lithium AA or AAA cells because they often put out higher than 1.5V at full capacity.)  So long as you respect the 6V maximum supply voltage, you should do no harm.

[ivanlan9]

@jburgt Thank you very much for correcting the link. The PDF was exactly what I wanted.

Guess I'll have to break down & buy some cubes!

[logistiker]

On 1/3/2023 at 11:09 PM, UltraViolet said:

If you want to use a PF battery box, you'd have to install dummy cells as spacers in place of two of the AA or AAA batteries so your total max voltage would be 6V. 

Why?  You could just get an inexpensive buck converter which incidentally is better than a boost converter because at least you're not giving up current for extra voltage (translation: You gain speed when boosting voltage but lose power).

[UltraViolet]

42 minutes ago, logistiker said:

Why?  You could just get an inexpensive buck converter which incidentally is better than a boost converter because at least you're not giving up current for extra voltage (translation: You gain speed when boosting voltage but lose power).

  Obviously yes, you can do that, but I meant if someone wanted to use the stock PF battery box without modification or any further external adaptation.  Many members of the forum are not very 'electronically inclined.'  I am trying to offer straightforward solutions for the average builder that fit within their skill set, particularly if they have demonstrated inadequate knowledge in their posts.  At the very least, I'm attempting to ensure that even some of the least skilled builders don't immediately go and blow up their Circuit Cubes motors without thinking (as has already happened to some members with inadvertent polarity screwups when attempting PF wire hacking experiments on other gear in past discussions).  The phrasing of your response implies You are qualified to make your own modifications with little risk or difficulty.

  I would however note that, unless you are seeking extreme run time, adding a buck converter to a PF battery box is quite likely a much bulkier solution than necessary.  It appears the vast majority of builders working with the Circuit Cubes motors do so because they need physically smaller components than are otherwise available.  The Circuit Cubes motors exhibit extremely low power consumption.  In my view, using a lithium-ion battery, even a single cell, with an adjustable boost converter, is more than likely adequate for the job, while keeping physical size and weight to a minimum.  I have some very small cells which have been extracted from various scrap e-waste devices, many of these from discarded vaping pens (just to be clear, I don't vape.).  The energy density of these cells never fails to impress, even when driving full-size 9V motors.  Safety is a key concern when drawing large motor loads from small lithium-ion cells, obviously, so either my experiments are brief, or I take care to balance the cell current output rating against that of the target draw when going for extended run time.  The Circuit Cubes motors use so little power at a small amount of boost voltage, finding this balance point is not difficult with some cells smaller than a common 18650.  Whether using round cell or flat-pack, there are nearly endless size and capacity variations out there to work with.  I don't know what size the flat-pack cell is inside the Circuit Cubes Bluetooth Module, but it is quite obviously tiny, and yet still offers practical run time for multiple motors.

  For the 'non-electronically inclined', if the most 'daring' thing they ever attempt is splicing a PF cable to a Circuit Cubes cable (and probably without solder), spacers in a PF battery box to lower the maximum output voltage are a simple and viable solution to enable use of the Circuit Cubes motors without instantly destroying them.

P.S.  If any of the 'electronically inclined' out there know of a production PWM-to-voltage converter circuit which tolerates a power supply input down to 7.2V and has an adjustable maximum output voltage, I'm very interested to know of it.  (What I've seen so far need 12-15V minimum DC supply.)  Something like that could accept the four-wire PF input from any PF device for fixed supply voltage and PWM control signal, and function as a universal PF-to-Circuit-Cubes motor driver, as it would work with a fixed battery box voltage or any of the PWM-based boxes or controllers.  Is it complete overkill?  Absolutely.  Is it virtually idiot-proof?  Probably.  Would it amuse me?  Most definitely!