PCB milling problem

Hello!
I am glad to join this cozy place. I wish good health and success to all.
I would like to share a problem with you and if anyone can guide me I will be happy.

I haven't been able to solve a problem with cutting a board for 2 weeks. I am working on a project and I went on the road - Kicad - FlatCAM - bCNC. The problem arises at the last stage after auto-leveling. First I worked with CNC Shield v.3. There, the parameters on the Z-axis changed arbitrarily. I changed the board with Annoy tools - 2208 drivers. Everything is fine on the Z axis, but now there is a problem on the Y axis. I noticed that where there is a red zone at the auto-level (higher level of the board) the tracks are cut on top of each other. I tried OpenCNCpilot under Windows and there is the same problem. I repeated the FlatCAM files, but nothing changed.

KiCad - version 5.1.7.
FlatCAM - 8,991 and 8,994.
bCNC - 0.9.14.52

Please direct me where the problem is so that I don't have to print the topology and use old tried and tested methods with an iron.

Thanks!

Quote:

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Originally Posted by ours_polaire

Hello!
I am glad to join this cozy place. I wish good health and success to all.
I would like to share a problem with you and if anyone can guide me I will be happy.

I haven't been able to solve a problem with cutting a board for 2 weeks. I am working on a project and I went on the road - Kicad - FlatCAM - bCNC. The problem arises at the last stage after auto-leveling. First I worked with CNC Shield v.3. There, the parameters on the Z-axis changed arbitrarily. I changed the board with Annoy tools - 2208 drivers. Everything is fine on the Z axis, but now there is a problem on the Y axis. I noticed that where there is a red zone at the auto-level (higher level of the board) the tracks are cut on top of each other. I tried OpenCNCpilot under Windows and there is the same problem. I repeated the FlatCAM files, but nothing changed.

KiCad - version 5.1.7.
FlatCAM - 8,991 and 8,994.
bCNC - 0.9.14.52

Please direct me where the problem is so that I don't have to print the topology and use old tried and tested methods with an iron.

Thanks!

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Hope you might have resolved your issues but take a look at this site,

https://github.com/martin2250/OpenCNCPilot

Cheers.

Quote:

---

Originally Posted by ours_polaire

Hello!
I am glad to join this cozy place. I wish good health and success to all.
I would like to share a problem with you and if anyone can guide me I will be happy.

I haven't been able to solve a problem with cutting a board for 2 weeks. I am working on a project and I went on the road - Kicad - FlatCAM - bCNC. The problem arises at the last stage after auto-leveling. First I worked with CNC Shield v.3. There, the parameters on the Z-axis changed arbitrarily. I changed the board with Annoy tools - 2208 drivers. Everything is fine on the Z axis, but now there is a problem on the Y axis. I noticed that where there is a red zone at the auto-level (higher level of the board) the tracks are cut on top of each other. I tried OpenCNCpilot under Windows and there is the same problem. I repeated the FlatCAM files, but nothing changed.

KiCad - version 5.1.7.
FlatCAM - 8,991 and 8,994.
bCNC - 0.9.14.52

Please direct me where the problem is so that I don't have to print the topology and use old tried and tested methods with an iron.

Thanks!

---

Hi,

I am not sure what size machine you have or any details about it, however, I would recommend fixing the flatness problem as opposed to using software to fix it. I just posted a video showing my setup in this forum...

https://www.cnczone.com/forums/pcb-m...matictool.html

I have never used nor needed to do any software leveling, just proper setup.

Start with a piece of MDF screwed, bolted, or double sided taped to the machine's table. The screw heads must be recessed.
Mill the top surface flat using the largest end mill that will fit in the spindle (in my case 1", however, I have used much smaller).
Using a flat board with sandpaper, lightly sand the top surface of the MDF to knock off any high points that may be there
Use tape to pull off any dust (kind of like using a lint roller to remove lint on a dress shirt) so that the double sided tape adheres good
Use 3M double sided tape that you can get at craft stores or office supply stores. It is clear, and in a traditional tape dispenser used for gift wrap tape
Put this on the back of the PCB - leaving about a 1/2 gap between the strips of the tape which is about 1/2 wide. If there are wrinkles, remove it and try again.
Place the PCB on the MDF, carefully aligning it as needed - press firm, then place some weight on it for a few minutes to help the bond.

This will hold the PCB securely, even for the outline milling. Drilling is no problem up to .156" which is the biggest I have drilled on a PCB. Isolation milling on the copper and engraving on the other side will be VERY consistent as the board is actually flat. I use a 60 V cutter bit from a place called "Think and Tinker" I believe. I run about .007 deep for isolation milling at about 16,000 RPM and about 10 IPM.

This has worked for me every single time over the years. It is clean, simple, and doesn't rely on software to "magically" fix a mechanical problem.

I use this board over and over again as I leave it on my router. When it gets a lot of holes in it and grooves from outline milling, I resurface it, otherwise I just keep using it.

I hope this helps you!

Chris D

Quote:

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Originally Posted by Chris D

Hi,

https://www.cnczone.com/forums/pcb-m...matictool.html

I have never used nor needed to do any software leveling, just proper setup.

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Hi Chris,

By the way what's the purpose of this video? I didn't see the final milled PCB.

Kindly show a video with SMD tracks and pads or just one you milled lying around.

How deep does the bit mill into the FR4 substrate? the copper is about 35um.

Cheers,
Hanspeter.