Schematics and Circuit Board layout with Fusion 360

[djberta]

Hi Tom. Have you had a chance to work on your boards?

 

[jcdammeyer]

How many is 'volume'? 10? 100?

I guess I mean how would you connect different "sections" of a machine, or maybe they are separate machines, together. Just musing here - Say your band saw has a control to cut up stock, and a robot arm to grab the pieces and load them into your mill with an automatic vise, the program runs on the mill, and then the arm unloads the part and puts it into the spray booth where it is painted. How would scenarios like this be managed? A single master control controlling those machines to do their operations - or would each machine tell the next - ready for you - and then the first machine gets on with the next operation. @Susquatch I bet you have several answers and yes I'm dragging you out of retirement to think about it!

Wow!
If you talk to LinuxCNC people they will run everything with modules inside the LinuxCNC environment. The problem with that is it's so centralized.

Both MODBUS and CAN (Controller Area Network) were designed to break a complicated project into modules; each which could be developed and tested independently.

So how do those systems work?
Let's pretend you have a tool changer for a milling machine. Most of the systems have that as part of the CNC system. But what if we made it modular?

CMC system requests Tool #17 Request.
Tool Changer replies with Busy. Tool Holder brings Tool #17 into a tool swap location.
Tool Holder replies with Ready.
Tool Changer sees Ready and moves Tool Holder onto Tool in Mill and asks DrawBar To release current tool with a Request.
Drawbar reports Busy. Releases the tool and reports Available.
Tool Holder grabs tool from spindle and swaps with Tool Changer Tool and reports Ready.
Finally Tool Changer reports Ready to the CNC system that a new tool has been loaded. Then grabs the old tool and places it into the carousel.

Or something to that effect. Made it up as I wrote it.

The point is the Request/Busy/Available/Ready sequence can be used as CAN bus or even MODBUS messages to independent modules that do certain operations. Each module can be tested, improved etc without impacting the overall system. The handshaking messages between modules don't really change.

Hopefully that makes sense?

 

[Arbutus]

Wow!
If you talk to LinuxCNC people they will run everything with modules inside the LinuxCNC environment. The problem with that is it's so centralized.

Both MODBUS and CAN (Controller Area Network) were designed to break a complicated project into modules; each which could be developed and tested independently.
....
....
Or something to that effect. Made it up as I wrote it.

The point is the Request/Busy/Available/Ready sequence can be used as CAN bus or even MODBUS messages to independent modules that do certain operations. Each module can be tested, improved etc without impacting the overall system. The handshaking messages between modules don't really change.

Hopefully that makes sense?

FWIW, I am using MQTT with ESP32 based hardware nodes to provide local compute/actuate/sense functions with a distributed broker system running on a Teensy 4.1 MCU. The benefit is a much simpler m/c control system that is inexpensive and easily extended, even between machines and their support systems such as coolant, lighting, pumps, conveyors, packers, etc.

I developed the system using open-source libraries and modules specifically to distribute tasks and decentralize the control of a machine, to reduce wiring and improve telemetry. This type of system has built-in redundancy and 1-10ms response time.

Don

 

[Tomc938]

So time for an update:

I took a run at those boards, but man the components are small!

Hi Tom. Have you had a chance to work on your boards?

Thanks for asking! I kind of forgot about this thread with everything happening with them the last few weeks.

So I was waiting for connectors to comes through CP, and they arrived a couple weeks ago.

I tried hand soldering some SMD components about same size as were used in the board design and realized I wasn't able to do this. Read about using solder paste for these smaller components, so I ordered some and when it arrived the first little bit of the paste worked really well. Came out smooth and in a controlled fashion, and when I hit it with heat it flowed well and made good connections. But then I seemed to hit a dry patch in the paste. Could hardly push it out of the syringe - it came in a 5 ml type syringe. Was able to make it work, but it was harder to control, and I had to push so hard that I ended up a good chunk of the night with the arthritis in my thumbs killing me. When it came time to connect the large connectors with a soldering gun, one of the resistors popped up and ended pointing straight up on one pad. Got that fixed, but as I looked at things I had some concerns:

1) With poor control on the amount of solder dispensed, did I maybe had a dead short I could not see?
2) With the small components, did I have a good connection on each pad?
3) Was I ready to miss sleep a couple more nights due to thumb pain to finish populating the board ?
4) If the adaptor didn't work, how would I ever figure out where the fault was?

@slow-poke was very helpful along the way, answering all my newbie questions and offering advice. At a certain point I think he realized (before I did) that I was in over my head and offered to populate the boards I needed with the components if I sent him everything I had gathered. It was hard to throw in the towel, but I knew I was beat. Had a nice visit with him on the phone, and found out we lived a couple miles apart in Winnipeg!

So last week I packaged everything up and sent it out to him. Ordered some replacement connectors from Ali that will ship direct to him. He has also graciously offered to test the boards with scales and see how they work.

Assuming the boards work (it is a schematic from the internet, after all) I have 6 additional boards I will be making available to anyone who wants one or two at my cost ($2 each) and $10 to @slow-poke for the design work he did to make the boards manufacturable. Can ship in an envelope also at cost. Cost of the components is not a lot. (I think $10 per board including shipping from Digikey) You do have to be sure that you can source an ESP32 WROOM-32U. Check the pin out on the board, because a couple I saw that said there 32U had a very different pin out and would not have worked. (about $10 on Ali or Amazon) You also have to be confident in your soldering skills. Parts are SMALL!

Let me know if you would be interested in one or two and I'll keep you posted as things progress.

 

[Tomc938]

As I mentioned in the original post, components would be on top of this. This is just the assembly.

At least that's how I read the information.

And I think it's likely an introductory offer. Just based on life experience.

As far as them populating the boards you order from them, I misread the website. It would be about $30 PER BOARD on an order of 10. Depends on how many discrete components and through holes there are.

But if you had something you wanted to build a few of it would make sense, in my mind, to pay for the assembly. It was beyond my skills, that's for sure!

 

[djberta]

Hi Tom surface mount stuff takes a bit of learning but it is easier in the long run. The resistor popping up is called a tombstone. I use my rework heat gun with its smallest nozzle on decent heat.

Also for the syringe for the solder paste. I always electrical tape the end and put it in the fridge. It can dry out if left out in the open. I have also used the little rubber ends for them. There are 3d printed dispensers for the syringes as well. Those help so much.

 

[Janger]

So time for an update:

Assuming the boards work (it is a schematic from the internet, after all) I have 6 additional boards I will be making available to anyone who wants one or two at my cost ($2 each) and $10 to @slow-poke for the design work he did to make the boards manufacturable. Can ship in an envelope also at cost. Cost of the components is not a lot. (I think $10 per board including shipping from Digikey) You do have to be sure that you can source an ESP32 WROOM-32U. Check the pin out on the board, because a couple I saw that said there 32U had a very different pin out and would not have worked. (about $10 on Ali or Amazon) You also have to be confident in your soldering skills. Parts are SMALL!

Let me know if you would be interested in one or two and I'll keep you posted as things progress.

Tell us, maybe tell us again, Tom what will these boards do for people, how to apply them and what other parts are needed, and what are you doing with the boards?

 

[Tomc938]

Tell us, maybe tell us again, Tom what will these boards do for people, how to apply them and what other parts are needed, and what are you doing with the boards?

Sure. A quick review: My mill and lathe came with DROs that kind of work, but not well, and they are 80's tech. The mill only had one axis that worked, and the lathe has lots of issues with burned out segments in the display.

After looking around for options, TouchDRO came highly recommended y several people on the board for whom I have great respect. So I looked into that as an option.

TouchDRO started with a freeware/open source type model I found attractive. The schematics and software to build the interface between the scales and the Android tablet that is used for the display are available from the developer for free. You can also buy pre-built adapters from the designer.

I wanted to go the self-built route, and so started using the design features of Fusion 360 to turn the schematic into a board design. Unfortunately, I only know enough about circuit design to come up with a reasonable looking layout that would be non-functional. That's when @slow-poke offered to design the circuit, having done this kind of thing as a career.

And that is a quick review that gets you up to the last couple of posts I just posted.

These adapter boards should allow you to connect various scales to an Android device to open up some pretty nice, highly capable DRO features at a fraction of the cost. See touchdro.com for more information in the setup.

You would need to add resistors, capacitors, ICs, power supply, case and an ESP-32 board to make it functional. If anyone is interested, I can send the parts list @slow-poke put together.

This is a project for someone who knows what they are doing. The boards are capable of connecting X,Y,Z and knee scales, as well as a touch probe and tach. Once you know what you want to connect, you would be able to figure out what you need to order. As far as scales, look to the webpage I mentioned for more information about what types of scales can be connected.

You will also need to have some basic understanding about terminal commands so you can flash the program to the ESP32 chip. The program is available for download. I have the steps needed to do this on a Mac computer, but a PC person would need to be able identify the comm port the chip is connected to. The code is in Python, but when I started I knew about nothing about Python and still got her done.

I'm willing to assist in the selection of an ESP32 chip. As I mentioned there are many configurations that are manufacturer dependent. And can also give some guidance as to how the boards are set up.

I also mentioned the parts you would be working with are small, so you have to be comfortable with that. Just so you know, here's a picture of the board I did. This was for my lathe, so I just did the X and Y axis. (a banana for scale would have been useless. Even a dime is kinda big)

Everything is in testing, so we'll need to wait and see how everything comes together.