3D Printed PCB mill

So the design I posted a few days ago, was all kinds of wrong. Well, not all kinds, just one kind. I forgot to flip the image of the stepper driver when doing my design, so the pin locations were not correct. I would have had to of solder the headers into the bottom of the board, and then plugged them in upside down.

Well, I didnt want to do that, so I redesigned it and in the process added a feature for a fan, or some other 12v <1A accessory you want.

Then I milled out that new board, soldered everything into place and then tested it out. The x and y axis's worked just fine, but the Z was all dicked up. Wasnt doing nothing. Then I realized I shouldve tested that pin mapping to the arduino on a bread board before I milled that board. I was trying to use pin's A6 and A7 as digital output pins, but little did I know, you cant. You can only read from those pins.

So to fix that and not have to etch a new board, I figured since there only input, i'll drill two new holes in those lines and put a jumper to 2 unused digital IO pins on the other side of the arduino (thank god I thought semi ahead and made traces from unused pins to drilled holes to easily fix problems like these). So I did that, and it works fine now.

super awesome. I'll post pictures and shit once I get a new housing printed out for the new desing.

Well it finished milling, and it turned out nice, and the bit is just fine. I even used the bit for drilling the holes (i then hand turned a bit into what would have been the larger holes for the headers) cuz I didnt feel like changing it out, and it worked great.

I just need to clean it up a bit, and it'll be good to go for soldering tuesday when my new iron gets in.

Well, I redesigned the controller board so there is no need for any jumpers, and then I etched it out. It took 3 bits to finally get it done, and with the bit replacing it moved like .05mm to the left, and the drill points were a bit off and I said fuck it and threw it away.

One of the reasons I found for the bit braking was, in my routines for milling the different objects, I would have it move the end mill to the desired location at fast slew speed until it was 0.1mm above the board, and then it would transition to the slower milling slew speed. Well, the board isnt exactly the flatest surface and it bows a bit in the middle, so the mill would slew super fast, and contact the board faster then it should have been, and it would break bits err now and then. So, to correct this, I changed the firmware to instead of traveling to a fixed point (0.1mm above board height) above the board, now it travels to 1/4 of the travel height (the height at which the dremel slews at fast speed around the board) and then transition to the slower mill speed. That did help quite a bit, but the 0.5mm with 5mm long point was just too weak and wore out quickly. If it was 0.5mm and only like 1mm long, it would be so much more durable I think, but its not. And I cant just trim it I dont think, or it would change the design of the bottom and not be quite as well for digging into the material vertically and produce more problems.

So I spent a few more kozlowskis and got some nicer bits, and it seems to be working a billion times better. While I was waiting on those to come in the mail, I redesigned the controller board again to reduce the number of lines needed to be etched, making it quicker to etch, and reduce the chance of breaking these new bits.

So with the first revision of the new board, I etched one out and did some testing with the power supply traces, and I ran about 3 constant amps from one end to the other for a few minutes to see if those traces were large enough to handle the current they'll be seeing, and they didnt even feel warm really after the end of it, so I'm sure it will suffice. I used a .7mm bit for that first board, and I'm using a 0.6mm bit for the board after this, so the traces will be even larger to provide a little more room for safety.

The new board is currently etching right now, and I also decided to buy a nice soldering iron and one with a pencil tip so make the soldering of lots of pins in small spaces easier/nicer. Before, I was using a 5 year old radio shack soldering iron with a huge tip I filed down a bit to help with the small pins, but it still sucked.

So thats what I have going on in my life right now. I'll solder up this new board tuesday when I get the soldering iron in the mail (god I love amazon prime) and redesign the enclosure to make it more accommodating to the new board and the connections for the key pad.

I'm still debating if I want to make an acrylic base for this, which would be really nice, but would increase the cost of the project quite a bit from what it already is. The wood is warped just a tad bit, and I would really like to replace it, but #yototheloamiriteboiz.

Well, I finished a new design for my controller that incorporates some headers for the keypad I want, and then included some empty space near unused pins so I can incorporate new stuff in the future without having to mill and a solder a whole new board.

So I drew up the design, pretty close to the last, except it requires way less jumpers (just two wire jumpers, and then 3 PCB cut out jumpers (3 plate white rectangles with 2 drill holes)) and has those headers.

Anyways, I guess I had the feedrate too fast, or my bit was just getting worn, and it broke halfway through. And it was my last bit until I get more in the mail tuesday I think. Or maybe monday. Dont remember.

If you see that little excuse for a line in the middle of the board, thats where it broke.

So errthang is on haitus till I get dem new end mills in. I really want to get this guy hooked up and make sure the software works right.

Edit: I forgot to mention that I also updated the Controller enclosure/housing/whatevers to allow for a female power jack for a dedicated power supply (instead of using that janky ol' power supply I was using) I bought for like 10 kozlowskis. The new models are uploaded in the PCB Mill 17Jul16 sketchup file, and the new arduino code is also uploaded.

So I felt that a keypad to control the motors installed on the fixture itself would greatly ease zeroing this bad boy in when I'm going to mill a board.

So, I designed a simple board to house the keys and etched it out. Then designed a housing for that board so I can mount it to the fixture, and printed it out. 3D printers are so freaking handy. I went from designing the board and housing to having a physical product in just a few hours.

I havent done any code for it yet, but I imagine that I will add a command that will disable the board inputs when you start etching a board, and it will enable itself during the bit changes and when the board is done being etched, all other times it will be enabled to allow you to control the steppers without having to be at the PC.

Below are pictures of the yet to be labeled product. The left two buttons will control the Z axis, and the 3 in the cross formation will be the x and y.

Maybe I should have included an indicator LED to show that it is enabled for input? Maybe in the future.

I made a lot of modifications to my controller circuit board. I reduced the foot print and also added in a disable/enable line for the stepper drivers to save energy when its idle.

With that, I included 2 new commands into the controller software, disable steppers, and enable steppers, updated code is uploaded.

Below is a modified screen shot of the board. I just took a screen shot and filled in the areas with paint to make sure everything made sense before I milled it.

Well, I got the female headers in the mail so I can finish up my controller board. I soldered those bad girls in, and plugged everything up. I got two of the jumper wires mixed up for the step and direction pins in the Y axis. So instead of desoldering and fixing those wires, I just fixed it in the software.

So now instead of having a bread board sit awkwardly in the corner, I have a small enclosure fixed to the corner of the assembly.

Much more portable now, all I have to do it disconnect the power wires and the USB cable and I can take it where I want for cleaning, or putting it outside and having a fan blow all the shit away as its milled.

So I spent yesterday evening drawing up the schematic for the controller, and then designing a board in my CAD software so I can route out a board on the machine that the board will be used in. Because I'm currently using a breadboard.

Heres the design I came up with, not real fancy considering the basicness of my CAD program, but it should work just fine. Dont judge the mess, it took about 1.5 hours to throw together. Mass object selection (so I can move/delete groups of objects) would be a really nice feature for me to add in.

So then I etched it to a board. And this is what I got

I had a few female headers around, and all the male headers I need and the capacitor, so I went ahead and soldered them, but I'm still waiting on more female headers to come in the mail before I can fully assemble it.

I found I like soldering on routed PCB's as its much harder to bridge traces. And I also found that I cant find any cheap off brand arduino micros, so I'm going to use my arduino micro in this project and just buy a $7 off brand one to replace in my inventory. At first I wasnt going to use an arduino in the final version, but then I realized why not? It provides an easy to use and setup computer interface and I can redesign the board to fit a $7 version (well, not an exact one, but it would work) if I ever make more. So fuck it.

Now I just wait on a package in the mail so I can fully assemble it and replace the breadboard.

In the mean time I'll design a housing and print it out to keep dust out of it, and so I can mount a small fan to keep the stepper drivers cool.

Well, I got in some 0.5mm bits, and did some testing on my new x carriage (has slots for screws to hold the board in place instead of using vice grips). I also noticed that one of the z nuts that move the dremel in the up and down direction was loose and causing vibration, which could have been the cause for my messy cuts in the copper. Anyways, I did all that and it looks like that did the trick for fixing it.

Looks better, just need to actually sit down and draw the design for the board that will house the arduino and stepper drivers, and then I can just fiddle with the software forever.

I also uploaded the code for the arduino. It interprets the commands from the computer, and controls the steppers.

So I got finished the firmware on the arduino that interprets commands sent to it by the CAD software.

I decided to test it out, so I made a useless etch that will accept one of the extra Pololu stepper driver for funsies.

Here is a pictured of it in the CAD program

I didnt not accurately model Tool0, the width should have been larger for the depth I programmed for it. But, its testing, so whatevs.

Next, I opened up the controller dialog, which looks like this.

Once the dialog is opened, you can control the steppers to zero in the dremel to where you want zero to be. Lower to head right to where it barely touches the board, then hit start.

Once you hit start, it will tell you to load a bit, in this case the bit with the ID 0.

The dialog allows you to move the head in the Z direction (up and down) to allow for configuring it. Once you're done installing the bit, rezero it in the Z direction, and click "Done." and it will etch all the objects with that bit ID.

This dialog will popup for any bit changes that need to happen until the board is done being etched.

Here is a video of the etching taking place, including the bit changes and all that.

Here is the after math after being cleaned up. For some reason, I dont know if I was etching too fast, too slow, too deep, or the bits all messed up, but the cuts arent as clean as some of my first testing. The copper is all dicked up looking, but whatever, hopefully I'll figure that out.

#showtowt2myboicown