CNC PCB milling

[NeverDie]

@dbemowsk said in CNC PCB milling:

@neverdie Actually, I am working on my Z axis and am trying to gauge how long I should have my rods. They are currently 8.25 in (209.55 mm). Wondering if there would be any benefit to leaving them that long or shortening them up some more.

In that case, what matters is whether you can raise the spindle high enough on the z-axis to remove the used bit and insert the next one. I wish my z-axis had a bit more height on it. Sometimes I have to move the spindle away from the workpiece in order to get enough clearance for a tool change. I suppose it doesn't help that I'm using a 3/4" waste board. ;)

[dbemowsk]

@neverdie said in CNC PCB milling:

I suppose it doesn't help that I'm using a 3/4" waste board.

Do you need 3/4"? Wouldn't 1/4" or 1/2" work? Do you drill in that far?

[NeverDie]

@dbemowsk 1/2" is probably ideal for my particular setup. 3/4" is simply what I tried first. 1/4" might work, but with less margin for error.

[NeverDie]

@dbemowsk Shouldn't you have some linear ball bearings gripping those z-axis rods?

[NeverDie]

Here is the above PCB after assembly:

As you can see, it offers more potential functionality than the earlier version. It still has a buzzer, which is now mounted underneath the pro mini.

[dbemowsk]

@neverdie FOr starters I am trying 3D printed rod bearings. I';ll see how that goes. The beauty of designing this myself is that I can alter the design whenever I want.

[zboblamont]

@neverdie Di the relocation of the buzzer increase audibility as you were seeking?

[NeverDie]

@dbemowsk said in CNC PCB milling:

I am trying 3D printed rod bearings

What are those? Is it like this?

or this?

[dbemowsk]

@neverdie mine are similar 3D printed ones

[NeverDie]

@dbemowsk what kind of material?

[dbemowsk]

@neverdie I just printed them in PLA and they seem to slide pretty smoothly on the rods, but someone told me that printing them in nylon is better.

[NeverDie]

@dbemowsk said in CNC PCB milling:

printing them in nylon is better.

It would seem so: http://www.craftechind.com/top-5-materials-for-plastic-bearings-used-on-metal-surfaces/

If you had a multi-filament printer, I wonder if you could print the nylon bearing within another plastic piece (e.g. the part that holds the spindle to the z-axis)? That would would be pretty cool and would also save assembly time.

[dbemowsk]

@neverdie the way i have it designed, the printed bearings get sandwiched by a rear plate that holds the bearings and coupler nut that goes on the threaded rod to drive the assembly up and down.

[dbemowsk]

I wasn't home before to get a pic, but here is the layout.

[NeverDie]

Anyone tried Trinamic drivers, such as the TMC2130? They seem to produce superior 3D prints, and so I would guess they would yield some improvement for CNC as well.

So far I've only found two boards that appear to be made for them, a ramps and a rumba:
https://www.aliexpress.com/item/MKS-Gen-V1-4-control-board-5PCS-TMC2130-V1-0-And-Heatsink-stepper-motor-compatible-with/32836389832.html?spm=2114.search0204.3.2.3e5a8105IWdaWH&ws_ab_test=searchweb0_0,searchweb201602_5_10152_5711320_10151_10065_10344_10068_10130_10324_10342_10547_10325_10343_10546_10340_10548_10341_10545_10084_10083_10618_10630_10307_5711220_5722320_10313_10059_10534_100031_10103_10627_10626_10624_10623_10622_10621_10620_10142,searchweb201603_2,ppcSwitch_5_ppcChannel&algo_expid=875aa997-05fe-4eda-9d76-0aaefcaeff83-0&algo_pvid=875aa997-05fe-4eda-9d76-0aaefcaeff83&priceBeautifyAB=0

https://www.aliexpress.com/item/3D-Printer-Rumba-Board-With-6pcs-TMC2130-Stepper-Driver-6pcs-Heatsink-High-Quality-3D-Printer-Parts/32839321651.html?spm=2114.search0204.3.49.3e5a8105IWdaWH&ws_ab_test=searchweb0_0,searchweb201602_5_10152_5711320_10151_10065_10344_10068_10130_10324_10342_10547_10325_10343_10546_10340_10548_10341_10545_10084_10083_10618_10630_10307_5711220_5722320_10313_10059_10534_100031_10103_10627_10626_10624_10623_10622_10621_10620_10142,searchweb201603_2,ppcSwitch_5_ppcChannel&algo_expid=875aa997-05fe-4eda-9d76-0aaefcaeff83-7&algo_pvid=875aa997-05fe-4eda-9d76-0aaefcaeff83&priceBeautifyAB=0

I have no experience with either board, so I don't know if either would be desirable.

The pinout of the TMC2130 is different than the A4988 driver currently used in my Woodpecker. However, I could perhaps make an adapter board to re-route the pins so as to be compatible. In that case, maybe I could plug them into my Woodpecker board. A video by Sanladerer seems to imply that might actually work:
https://www.youtube.com/watch?v=sPvTB3irCxQ

Note: from what I've read, the v1.1 TMC2130 modules are much better for adapting than the v1.0 modules.

[NeverDie]

I'm unsure what kind of firmware runs on the Woodpecker board, so I have doubts whether it could exploit the Trinamic features. Anyone here know?

So.... I'm looking at a Smoothieboard as perhaps one possibility, although I'm not sure yet as to whether Chillipepr will talkto it.

https://www.panucatt.com/azteeg_X5_mini_reprap_3d_printer_controller_p/ax5mini.htm

[dbemowsk]

Are you looking at this for a 3D printer or for your CNC? If you are looking at it for a 3D printer, have you looked at the RAMPS 1.4 boards? I like their modular design over a fully integrated board for the simple fact that if a part dies, you are only replacing the one part and not an entire board. This make repairs cheaper if something goes wrong.

[dbemowsk]

@NeverDie I have one more question of measurements on your CNC. If you look at the pic, can you tell me the measurements of the red and blue arrows on your machine? I have some idea of how tall I want my bracket for the red arrow area, but you were mentioning that you wish you had more travel in that area and I am curious if I have enough room.

[NeverDie]

@dbemowsk
red: 100mm
blue: 53mm

[RFM69]

Perhaps slightly off topic but I wanted to share very interesting youtube channel of FRANK from Germany link text who's been working on a PCB pick and place module along with a CNC tool changer in the video above.

Very inginious, and clever work if you've not come accross his videos and work yet.!