CNC PCB milling
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According to FedEx package tracking, I may be receiving the CNC2418 as early as this Friday. Weighs 5 kilograms. Just posting this because some people here seem concerned about picking a seller who is not based in China. Maybe you don't need to.
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grrr :)
I think people concerns are about import fees (customs+vat) when using fedex, dhl.. if you don't get any fee, you're lucky! in France for example, they wouldn't miss me.@scalz Ditto here...
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Hmm... Not sure if there are any applicable import fees here in the US. Anyone know the rules? They recently opened one of my PCB packages "as a security check," but there were no fees I had to pay.
EU has the VAT tax, which presumably they force upon you no matter where the seller is.
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Hmm... Not sure if there are any applicable import fees here in the US. Anyone know the rules? They recently opened one of my PCB packages "as a security check," but there were no fees I had to pay.
EU has the VAT tax, which presumably they force upon you no matter where the seller is.
@neverdie VAT is applied across the EU by the receiving country, by purchasing from another EU country VAT is already paid therefore no additional tax is due.
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It's the same, I never had problem when I get my order through regular shipping (and letters are in big bags, less easy for them i guess). hopefully!
But when fedex, dhl etc are concerned, they always declare it to the customs (price order+shipping).
They pay in advance the customs tax at airport, and then at home ask for the customs tax+little fee for the paper and because they advanced the money (approx 12€) + the VAT (20% of the total).Chinese fabhouse already told me a few times, for example, that they have to declare the price when they ship it and if I wanted to cheat it, that would be at my own risk, due to law reinforcements.
Maybe US don't tax importation, I have no idea how it works in US. you're lucky then
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Is there some minimum dollar (or Euro) threshold before the VAT or other fees kick in? If so, then on a CNC2418, it's easily avoided: just divide and conquer. i.e. just buy it as separate parts that get shipped separately instead of all at once in a giant kit.
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Is there some minimum dollar (or Euro) threshold before the VAT or other fees kick in? If so, then on a CNC2418, it's easily avoided: just divide and conquer. i.e. just buy it as separate parts that get shipped separately instead of all at once in a giant kit.
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Is there some minimum dollar (or Euro) threshold before the VAT or other fees kick in? If so, then on a CNC2418, it's easily avoided: just divide and conquer. i.e. just buy it as separate parts that get shipped separately instead of all at once in a giant kit.
@neverdie 10 EUR here, 20 GBP in the UK from memory.
Postal service rarely refer small packages to customs, large packages almost without fail, although I did get called in by them over a small DAC before. The problem here is the bureaucracy, form filling and general heel-dragging.
DHL etc are more trouble than they are worth unless high value items, they declare everything as @scalz noted..
I can't imagine a chinese supplier being happy to send a pre-packaged machine in bits at no additional cost, and the risk of a part going missing grows exponentially.
The cost difference from EU and China suppliers is sometimes not that great if you look around, it avoids hassle if EU source is acceptable price.
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Is there some minimum dollar (or Euro) threshold before the VAT or other fees kick in? If so, then on a CNC2418, it's easily avoided: just divide and conquer. i.e. just buy it as separate parts that get shipped separately instead of all at once in a giant kit.
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I've used my CNC for milling PCBs for more than a year now.
Here are a few tips:
1st: don't skimp on the machine itself, the 3020 and 3040 are ages ahead of 2018 in terms of quality and reliability (the numbers show the machine size in cm) as the the 3020 and 3040 have no moving bed, but a moving gantry instead, search for the ballscrew ones (normally Z-DQ but also some T-DQ, initially T meant Trapezoidal screws and Z ballscrewZ, but now a lot of T-DQ come with ballscrews). Get the parallel port ones, the usb ones are flaky, you can run an old parallel port (centronix) computer with old WinXP or LinuxCNC or attach an arduino nano/uno (328p) and run GRBL, just attach that to the parallel cable and you're set.
https://www.ebay.co.uk/itm/USB-CNC-ROUTER-ENGRAVER-ENGRAVING-CUTTER-3-AXIS-3040T-DQ-WOODWORKING-3-USB-PORT/282593206065?hash=item41cbde1f31:g:ibsAAOSwC9VZfuV02nd: if you buy it stock it comes with a 300-400W aircooled 12,000rpm ER11 spindle, good but not good enough, I've upgraded for a watercooled 300W 60,000rpm spindle (costs almost as much as the machine itself) but I can run it at 1400mm/min and being watercooled it doesn't spread the "deadly" fiberglass dust everywhere.
LE. you can also buy just the frame and buy separately the spindle, 3 nema 23 steppers, 3 tb6560 or 6600 drivers and a 24v or 36v PSU, we are tinkerers after all, aren't we?
https://www.ebay.co.uk/itm/300W-ER8-Spindle-Motor-Water-Cooled-60000rpm-1-5KW-VFD-Inverter-Bracket-Pump-Kit/192035995150?hash=item2cb63cbe0e:g:kz8AAOSw-0xYNoey3rd: it is said that milling fiberglass boards (FR4) can create very very very small dust ("charf") under 3 microns which when inhaled is never released from the lungs, gets it's way to the pleural membrane where it creates small cysts that can degenerate in lung cancer, a very slow an painful death. So a good vacuum cleaner which exhausts OUTSIDE is a must, unless you buy very high end and expensive professional HEPA filters. I use a Philips HEPA vacuum cleaner, being a hepa means all exhaust is from the back port and no additional airflow is created (my shopvac has dual airflow, one for debris and one to cool the motor, guess what they are not at all isolated between them) and after the exhaust filter I 3d printed a 50mm hose adapter and exhaust it outside. I've wrapped the contraption in a thick garbage bag and sealed it with tape so no air can escape inside.
Another way of doing it would be wet milling using a lubricant as WD40, oil or even liquid soap but might interfere with number 4 below (swell the mdf sacrificial layer).4th: you have 3 options to fix the blank pcb to the sacrificial layer:
-clamps/screws: easiest, cheapest way, buy you will almost always get a bow in the board, it can be as bad as 0.5mm in a 100x150mm board, especially if you don't want to waste real estate and mill the whole board from side to side, I know you could use a 200x150mm board and leave an inch or two as a border and clamp there but that doubles the costs, I use 148x98mm out of the 150x100mm blank
-double sided tape: use 3M Scotch 665, it handles well, sticks well but is not very hard to remove the board from the mdf sacrificial layer in the end, some other double sided tapes hold so well that you bend the board trying to remove it, or jut let loose and you lose alignment
-vacuum table: I've just bought a vacuum pump but haven't got the time to play with it yet.5th: ALWAYS use registration holes, put a small known size hole at a known position, if you reset or stop any GRBL controller you lose position, specially when milling small traces 0.1mm out of alignment can make a huge difference
6th: don't be afraid to test feeds and speeds, as other people said buy mills in bulk and sacrifice one of each to make tests, you can learn a bit GCODE and write a simple program to mill a zig-zag pattern at different feedrates (G1 X100 Y10 F300; G1 X0 Y20 F300; G1 X100 Y30 F350; G1 X0 Y 40 F350; etc) then inspect using a magnifier/microscope and settle for the best quality speed. I use titanium coated engraving bits from 0.1mm 10deg for very very small smd traces up to 0.4-0.5mm 30 deg for normal th boards. A 0.4mm 30 deg titanium coated bit can last for up to 10 heavily packed 100x150mm boards as you can see below. At the price it comes ( under $1/piece) it's cheaper to use a new bit then to destroy a blank board, which you will anyway at least a few dozen times :tongue:
https://www.aliexpress.com/item/10x-Titanium-Coated-Carbide-PCB-Engraving-CNC-Bit-Router-Tool-10-Degree-0-1mm-Tip/1535712782.html?spm=2114.search0104.3.60.32Or0K&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10344_10068_5000016_10345_10342_10343_51102_10340_5060016_10341_5130016_10609_10541_10084_10083_10304_10307_10301_10539_5080015_10312_10059_10313_10314_10534_100031_10604_10603_10103_10605_10594_10596_10142_10107,searchweb201603_14,ppcSwitch_3&algo_expid=e598dd4d-29ef-4a85-af37-7bfefdd92c46-7&algo_pvid=e598dd4d-29ef-4a85-af37-7bfefdd92c46&rmStoreLevelAB=07th: after milling sandpaper or use a scothbrite sponge on the board to remove copper edges
Here are some pics of a few boards, I mainly do through hole since I find easier (cheaper) to buy modules from ali than to order the original circuits, none has failed until now :)
LE. before you ask, the boards are HA light switches, 6 way, rotary encoded, led ring lights, led halo around them (as in car switches), MQTT enabled, w5500 eth connected, 100% designed and home made, 3d printed frame and buttons, laser cut acrylic and faceplates, cnc milled pcbs.
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I've used my CNC for milling PCBs for more than a year now.
Here are a few tips:
1st: don't skimp on the machine itself, the 3020 and 3040 are ages ahead of 2018 in terms of quality and reliability (the numbers show the machine size in cm) as the the 3020 and 3040 have no moving bed, but a moving gantry instead, search for the ballscrew ones (normally Z-DQ but also some T-DQ, initially T meant Trapezoidal screws and Z ballscrewZ, but now a lot of T-DQ come with ballscrews). Get the parallel port ones, the usb ones are flaky, you can run an old parallel port (centronix) computer with old WinXP or LinuxCNC or attach an arduino nano/uno (328p) and run GRBL, just attach that to the parallel cable and you're set.
https://www.ebay.co.uk/itm/USB-CNC-ROUTER-ENGRAVER-ENGRAVING-CUTTER-3-AXIS-3040T-DQ-WOODWORKING-3-USB-PORT/282593206065?hash=item41cbde1f31:g:ibsAAOSwC9VZfuV02nd: if you buy it stock it comes with a 300-400W aircooled 12,000rpm ER11 spindle, good but not good enough, I've upgraded for a watercooled 300W 60,000rpm spindle (costs almost as much as the machine itself) but I can run it at 1400mm/min and being watercooled it doesn't spread the "deadly" fiberglass dust everywhere.
LE. you can also buy just the frame and buy separately the spindle, 3 nema 23 steppers, 3 tb6560 or 6600 drivers and a 24v or 36v PSU, we are tinkerers after all, aren't we?
https://www.ebay.co.uk/itm/300W-ER8-Spindle-Motor-Water-Cooled-60000rpm-1-5KW-VFD-Inverter-Bracket-Pump-Kit/192035995150?hash=item2cb63cbe0e:g:kz8AAOSw-0xYNoey3rd: it is said that milling fiberglass boards (FR4) can create very very very small dust ("charf") under 3 microns which when inhaled is never released from the lungs, gets it's way to the pleural membrane where it creates small cysts that can degenerate in lung cancer, a very slow an painful death. So a good vacuum cleaner which exhausts OUTSIDE is a must, unless you buy very high end and expensive professional HEPA filters. I use a Philips HEPA vacuum cleaner, being a hepa means all exhaust is from the back port and no additional airflow is created (my shopvac has dual airflow, one for debris and one to cool the motor, guess what they are not at all isolated between them) and after the exhaust filter I 3d printed a 50mm hose adapter and exhaust it outside. I've wrapped the contraption in a thick garbage bag and sealed it with tape so no air can escape inside.
Another way of doing it would be wet milling using a lubricant as WD40, oil or even liquid soap but might interfere with number 4 below (swell the mdf sacrificial layer).4th: you have 3 options to fix the blank pcb to the sacrificial layer:
-clamps/screws: easiest, cheapest way, buy you will almost always get a bow in the board, it can be as bad as 0.5mm in a 100x150mm board, especially if you don't want to waste real estate and mill the whole board from side to side, I know you could use a 200x150mm board and leave an inch or two as a border and clamp there but that doubles the costs, I use 148x98mm out of the 150x100mm blank
-double sided tape: use 3M Scotch 665, it handles well, sticks well but is not very hard to remove the board from the mdf sacrificial layer in the end, some other double sided tapes hold so well that you bend the board trying to remove it, or jut let loose and you lose alignment
-vacuum table: I've just bought a vacuum pump but haven't got the time to play with it yet.5th: ALWAYS use registration holes, put a small known size hole at a known position, if you reset or stop any GRBL controller you lose position, specially when milling small traces 0.1mm out of alignment can make a huge difference
6th: don't be afraid to test feeds and speeds, as other people said buy mills in bulk and sacrifice one of each to make tests, you can learn a bit GCODE and write a simple program to mill a zig-zag pattern at different feedrates (G1 X100 Y10 F300; G1 X0 Y20 F300; G1 X100 Y30 F350; G1 X0 Y 40 F350; etc) then inspect using a magnifier/microscope and settle for the best quality speed. I use titanium coated engraving bits from 0.1mm 10deg for very very small smd traces up to 0.4-0.5mm 30 deg for normal th boards. A 0.4mm 30 deg titanium coated bit can last for up to 10 heavily packed 100x150mm boards as you can see below. At the price it comes ( under $1/piece) it's cheaper to use a new bit then to destroy a blank board, which you will anyway at least a few dozen times :tongue:
https://www.aliexpress.com/item/10x-Titanium-Coated-Carbide-PCB-Engraving-CNC-Bit-Router-Tool-10-Degree-0-1mm-Tip/1535712782.html?spm=2114.search0104.3.60.32Or0K&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10344_10068_5000016_10345_10342_10343_51102_10340_5060016_10341_5130016_10609_10541_10084_10083_10304_10307_10301_10539_5080015_10312_10059_10313_10314_10534_100031_10604_10603_10103_10605_10594_10596_10142_10107,searchweb201603_14,ppcSwitch_3&algo_expid=e598dd4d-29ef-4a85-af37-7bfefdd92c46-7&algo_pvid=e598dd4d-29ef-4a85-af37-7bfefdd92c46&rmStoreLevelAB=07th: after milling sandpaper or use a scothbrite sponge on the board to remove copper edges
Here are some pics of a few boards, I mainly do through hole since I find easier (cheaper) to buy modules from ali than to order the original circuits, none has failed until now :)
LE. before you ask, the boards are HA light switches, 6 way, rotary encoded, led ring lights, led halo around them (as in car switches), MQTT enabled, w5500 eth connected, 100% designed and home made, 3d printed frame and buttons, laser cut acrylic and faceplates, cnc milled pcbs. @executivul Thanks!
What sold me on the CNC2418, aside from its low price, was @andrew stating that he can mill isolation at 6 mil, which is no worse than what I could get from using a fab like OSH-PARK. What mill isolation are you able to get down to reliably using your gantry based CNC machine with ball screws and everything else you mentioned?
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About 0.2mm (8 mil I believe). Never needed to get smaller than that. Smallest chips I use are rfm69 or atsha 8 pin. The problem is not on a 20x30mm board but on a much larger one where having x and y axis not square makes a difference, where you need faster speeds since traces are much longer, etc.
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I've used my CNC for milling PCBs for more than a year now.
Here are a few tips:
1st: don't skimp on the machine itself, the 3020 and 3040 are ages ahead of 2018 in terms of quality and reliability (the numbers show the machine size in cm) as the the 3020 and 3040 have no moving bed, but a moving gantry instead, search for the ballscrew ones (normally Z-DQ but also some T-DQ, initially T meant Trapezoidal screws and Z ballscrewZ, but now a lot of T-DQ come with ballscrews). Get the parallel port ones, the usb ones are flaky, you can run an old parallel port (centronix) computer with old WinXP or LinuxCNC or attach an arduino nano/uno (328p) and run GRBL, just attach that to the parallel cable and you're set.
https://www.ebay.co.uk/itm/USB-CNC-ROUTER-ENGRAVER-ENGRAVING-CUTTER-3-AXIS-3040T-DQ-WOODWORKING-3-USB-PORT/282593206065?hash=item41cbde1f31:g:ibsAAOSwC9VZfuV02nd: if you buy it stock it comes with a 300-400W aircooled 12,000rpm ER11 spindle, good but not good enough, I've upgraded for a watercooled 300W 60,000rpm spindle (costs almost as much as the machine itself) but I can run it at 1400mm/min and being watercooled it doesn't spread the "deadly" fiberglass dust everywhere.
LE. you can also buy just the frame and buy separately the spindle, 3 nema 23 steppers, 3 tb6560 or 6600 drivers and a 24v or 36v PSU, we are tinkerers after all, aren't we?
https://www.ebay.co.uk/itm/300W-ER8-Spindle-Motor-Water-Cooled-60000rpm-1-5KW-VFD-Inverter-Bracket-Pump-Kit/192035995150?hash=item2cb63cbe0e:g:kz8AAOSw-0xYNoey3rd: it is said that milling fiberglass boards (FR4) can create very very very small dust ("charf") under 3 microns which when inhaled is never released from the lungs, gets it's way to the pleural membrane where it creates small cysts that can degenerate in lung cancer, a very slow an painful death. So a good vacuum cleaner which exhausts OUTSIDE is a must, unless you buy very high end and expensive professional HEPA filters. I use a Philips HEPA vacuum cleaner, being a hepa means all exhaust is from the back port and no additional airflow is created (my shopvac has dual airflow, one for debris and one to cool the motor, guess what they are not at all isolated between them) and after the exhaust filter I 3d printed a 50mm hose adapter and exhaust it outside. I've wrapped the contraption in a thick garbage bag and sealed it with tape so no air can escape inside.
Another way of doing it would be wet milling using a lubricant as WD40, oil or even liquid soap but might interfere with number 4 below (swell the mdf sacrificial layer).4th: you have 3 options to fix the blank pcb to the sacrificial layer:
-clamps/screws: easiest, cheapest way, buy you will almost always get a bow in the board, it can be as bad as 0.5mm in a 100x150mm board, especially if you don't want to waste real estate and mill the whole board from side to side, I know you could use a 200x150mm board and leave an inch or two as a border and clamp there but that doubles the costs, I use 148x98mm out of the 150x100mm blank
-double sided tape: use 3M Scotch 665, it handles well, sticks well but is not very hard to remove the board from the mdf sacrificial layer in the end, some other double sided tapes hold so well that you bend the board trying to remove it, or jut let loose and you lose alignment
-vacuum table: I've just bought a vacuum pump but haven't got the time to play with it yet.5th: ALWAYS use registration holes, put a small known size hole at a known position, if you reset or stop any GRBL controller you lose position, specially when milling small traces 0.1mm out of alignment can make a huge difference
6th: don't be afraid to test feeds and speeds, as other people said buy mills in bulk and sacrifice one of each to make tests, you can learn a bit GCODE and write a simple program to mill a zig-zag pattern at different feedrates (G1 X100 Y10 F300; G1 X0 Y20 F300; G1 X100 Y30 F350; G1 X0 Y 40 F350; etc) then inspect using a magnifier/microscope and settle for the best quality speed. I use titanium coated engraving bits from 0.1mm 10deg for very very small smd traces up to 0.4-0.5mm 30 deg for normal th boards. A 0.4mm 30 deg titanium coated bit can last for up to 10 heavily packed 100x150mm boards as you can see below. At the price it comes ( under $1/piece) it's cheaper to use a new bit then to destroy a blank board, which you will anyway at least a few dozen times :tongue:
https://www.aliexpress.com/item/10x-Titanium-Coated-Carbide-PCB-Engraving-CNC-Bit-Router-Tool-10-Degree-0-1mm-Tip/1535712782.html?spm=2114.search0104.3.60.32Or0K&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10344_10068_5000016_10345_10342_10343_51102_10340_5060016_10341_5130016_10609_10541_10084_10083_10304_10307_10301_10539_5080015_10312_10059_10313_10314_10534_100031_10604_10603_10103_10605_10594_10596_10142_10107,searchweb201603_14,ppcSwitch_3&algo_expid=e598dd4d-29ef-4a85-af37-7bfefdd92c46-7&algo_pvid=e598dd4d-29ef-4a85-af37-7bfefdd92c46&rmStoreLevelAB=07th: after milling sandpaper or use a scothbrite sponge on the board to remove copper edges
Here are some pics of a few boards, I mainly do through hole since I find easier (cheaper) to buy modules from ali than to order the original circuits, none has failed until now :)
LE. before you ask, the boards are HA light switches, 6 way, rotary encoded, led ring lights, led halo around them (as in car switches), MQTT enabled, w5500 eth connected, 100% designed and home made, 3d printed frame and buttons, laser cut acrylic and faceplates, cnc milled pcbs. @executivul said in CNC PCB milling:
-double sided tape: use 3M Scotch 665
How much do you apply? i.e. Do you cover the entire back of the PCB, or use just a few strips of it, or....?
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@executivul said in CNC PCB milling:
-double sided tape: use 3M Scotch 665
How much do you apply? i.e. Do you cover the entire back of the PCB, or use just a few strips of it, or....?
@neverdie a few strips, 20mm width each, 30-40mm apart.
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in Hungary the VAT is pretty high (27%) which we have to pay on top of the customs fee. moreover, our customs and post response and processing time is very bad. the process could be speeded up if the shipping happens with e.g. dhl and they are allowed to do the customs, but then it also costs extra.
in the past year customs started to focus very much on packages coming from China, even cheaper and smaller products are captured by them and you are forced to pay them before you can get your stuff :(so for me it was better to buy the cnc from EU, even if it was more expensive compared to the direct Chinese sellers, because at the end of the day, the overall cost was about the same (assuming that I would had to pay the customs and the VAT) but I received the package much more faster.
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I've used my CNC for milling PCBs for more than a year now.
Here are a few tips:
1st: don't skimp on the machine itself, the 3020 and 3040 are ages ahead of 2018 in terms of quality and reliability (the numbers show the machine size in cm) as the the 3020 and 3040 have no moving bed, but a moving gantry instead, search for the ballscrew ones (normally Z-DQ but also some T-DQ, initially T meant Trapezoidal screws and Z ballscrewZ, but now a lot of T-DQ come with ballscrews). Get the parallel port ones, the usb ones are flaky, you can run an old parallel port (centronix) computer with old WinXP or LinuxCNC or attach an arduino nano/uno (328p) and run GRBL, just attach that to the parallel cable and you're set.
https://www.ebay.co.uk/itm/USB-CNC-ROUTER-ENGRAVER-ENGRAVING-CUTTER-3-AXIS-3040T-DQ-WOODWORKING-3-USB-PORT/282593206065?hash=item41cbde1f31:g:ibsAAOSwC9VZfuV02nd: if you buy it stock it comes with a 300-400W aircooled 12,000rpm ER11 spindle, good but not good enough, I've upgraded for a watercooled 300W 60,000rpm spindle (costs almost as much as the machine itself) but I can run it at 1400mm/min and being watercooled it doesn't spread the "deadly" fiberglass dust everywhere.
LE. you can also buy just the frame and buy separately the spindle, 3 nema 23 steppers, 3 tb6560 or 6600 drivers and a 24v or 36v PSU, we are tinkerers after all, aren't we?
https://www.ebay.co.uk/itm/300W-ER8-Spindle-Motor-Water-Cooled-60000rpm-1-5KW-VFD-Inverter-Bracket-Pump-Kit/192035995150?hash=item2cb63cbe0e:g:kz8AAOSw-0xYNoey3rd: it is said that milling fiberglass boards (FR4) can create very very very small dust ("charf") under 3 microns which when inhaled is never released from the lungs, gets it's way to the pleural membrane where it creates small cysts that can degenerate in lung cancer, a very slow an painful death. So a good vacuum cleaner which exhausts OUTSIDE is a must, unless you buy very high end and expensive professional HEPA filters. I use a Philips HEPA vacuum cleaner, being a hepa means all exhaust is from the back port and no additional airflow is created (my shopvac has dual airflow, one for debris and one to cool the motor, guess what they are not at all isolated between them) and after the exhaust filter I 3d printed a 50mm hose adapter and exhaust it outside. I've wrapped the contraption in a thick garbage bag and sealed it with tape so no air can escape inside.
Another way of doing it would be wet milling using a lubricant as WD40, oil or even liquid soap but might interfere with number 4 below (swell the mdf sacrificial layer).4th: you have 3 options to fix the blank pcb to the sacrificial layer:
-clamps/screws: easiest, cheapest way, buy you will almost always get a bow in the board, it can be as bad as 0.5mm in a 100x150mm board, especially if you don't want to waste real estate and mill the whole board from side to side, I know you could use a 200x150mm board and leave an inch or two as a border and clamp there but that doubles the costs, I use 148x98mm out of the 150x100mm blank
-double sided tape: use 3M Scotch 665, it handles well, sticks well but is not very hard to remove the board from the mdf sacrificial layer in the end, some other double sided tapes hold so well that you bend the board trying to remove it, or jut let loose and you lose alignment
-vacuum table: I've just bought a vacuum pump but haven't got the time to play with it yet.5th: ALWAYS use registration holes, put a small known size hole at a known position, if you reset or stop any GRBL controller you lose position, specially when milling small traces 0.1mm out of alignment can make a huge difference
6th: don't be afraid to test feeds and speeds, as other people said buy mills in bulk and sacrifice one of each to make tests, you can learn a bit GCODE and write a simple program to mill a zig-zag pattern at different feedrates (G1 X100 Y10 F300; G1 X0 Y20 F300; G1 X100 Y30 F350; G1 X0 Y 40 F350; etc) then inspect using a magnifier/microscope and settle for the best quality speed. I use titanium coated engraving bits from 0.1mm 10deg for very very small smd traces up to 0.4-0.5mm 30 deg for normal th boards. A 0.4mm 30 deg titanium coated bit can last for up to 10 heavily packed 100x150mm boards as you can see below. At the price it comes ( under $1/piece) it's cheaper to use a new bit then to destroy a blank board, which you will anyway at least a few dozen times :tongue:
https://www.aliexpress.com/item/10x-Titanium-Coated-Carbide-PCB-Engraving-CNC-Bit-Router-Tool-10-Degree-0-1mm-Tip/1535712782.html?spm=2114.search0104.3.60.32Or0K&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10344_10068_5000016_10345_10342_10343_51102_10340_5060016_10341_5130016_10609_10541_10084_10083_10304_10307_10301_10539_5080015_10312_10059_10313_10314_10534_100031_10604_10603_10103_10605_10594_10596_10142_10107,searchweb201603_14,ppcSwitch_3&algo_expid=e598dd4d-29ef-4a85-af37-7bfefdd92c46-7&algo_pvid=e598dd4d-29ef-4a85-af37-7bfefdd92c46&rmStoreLevelAB=07th: after milling sandpaper or use a scothbrite sponge on the board to remove copper edges
Here are some pics of a few boards, I mainly do through hole since I find easier (cheaper) to buy modules from ali than to order the original circuits, none has failed until now :)
LE. before you ask, the boards are HA light switches, 6 way, rotary encoded, led ring lights, led halo around them (as in car switches), MQTT enabled, w5500 eth connected, 100% designed and home made, 3d printed frame and buttons, laser cut acrylic and faceplates, cnc milled pcbs. @executivul thank you for the tips and for the shared experience.
I agree, that the mentioned CNCs, have more robust structure, more powerful spindle, but I guess that the mentioned extra upgrade on the spindle is a bit overkill, especially just to create ad hoc proto PCBs at home.
just be clear, I know that higher rpm and more powerful spindle could produce better and faster result, ballscrews provide smother and more precise movement, I don't questioning that, but for the price/value/reason of the usage combo I think the cheap smaller versions also do their job quite acceptably.
2418 is not the fastest, not the strongest, but precise enough for this purpose and it is pretty cheap.btw, once I'll have a dedicated working area for my hw hacking stuffs, I'll definitely buy a 6040 or 9060, it is long time ago on my wish list :)
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I've used my CNC for milling PCBs for more than a year now.
Here are a few tips:
1st: don't skimp on the machine itself, the 3020 and 3040 are ages ahead of 2018 in terms of quality and reliability (the numbers show the machine size in cm) as the the 3020 and 3040 have no moving bed, but a moving gantry instead, search for the ballscrew ones (normally Z-DQ but also some T-DQ, initially T meant Trapezoidal screws and Z ballscrewZ, but now a lot of T-DQ come with ballscrews). Get the parallel port ones, the usb ones are flaky, you can run an old parallel port (centronix) computer with old WinXP or LinuxCNC or attach an arduino nano/uno (328p) and run GRBL, just attach that to the parallel cable and you're set.
https://www.ebay.co.uk/itm/USB-CNC-ROUTER-ENGRAVER-ENGRAVING-CUTTER-3-AXIS-3040T-DQ-WOODWORKING-3-USB-PORT/282593206065?hash=item41cbde1f31:g:ibsAAOSwC9VZfuV02nd: if you buy it stock it comes with a 300-400W aircooled 12,000rpm ER11 spindle, good but not good enough, I've upgraded for a watercooled 300W 60,000rpm spindle (costs almost as much as the machine itself) but I can run it at 1400mm/min and being watercooled it doesn't spread the "deadly" fiberglass dust everywhere.
LE. you can also buy just the frame and buy separately the spindle, 3 nema 23 steppers, 3 tb6560 or 6600 drivers and a 24v or 36v PSU, we are tinkerers after all, aren't we?
https://www.ebay.co.uk/itm/300W-ER8-Spindle-Motor-Water-Cooled-60000rpm-1-5KW-VFD-Inverter-Bracket-Pump-Kit/192035995150?hash=item2cb63cbe0e:g:kz8AAOSw-0xYNoey3rd: it is said that milling fiberglass boards (FR4) can create very very very small dust ("charf") under 3 microns which when inhaled is never released from the lungs, gets it's way to the pleural membrane where it creates small cysts that can degenerate in lung cancer, a very slow an painful death. So a good vacuum cleaner which exhausts OUTSIDE is a must, unless you buy very high end and expensive professional HEPA filters. I use a Philips HEPA vacuum cleaner, being a hepa means all exhaust is from the back port and no additional airflow is created (my shopvac has dual airflow, one for debris and one to cool the motor, guess what they are not at all isolated between them) and after the exhaust filter I 3d printed a 50mm hose adapter and exhaust it outside. I've wrapped the contraption in a thick garbage bag and sealed it with tape so no air can escape inside.
Another way of doing it would be wet milling using a lubricant as WD40, oil or even liquid soap but might interfere with number 4 below (swell the mdf sacrificial layer).4th: you have 3 options to fix the blank pcb to the sacrificial layer:
-clamps/screws: easiest, cheapest way, buy you will almost always get a bow in the board, it can be as bad as 0.5mm in a 100x150mm board, especially if you don't want to waste real estate and mill the whole board from side to side, I know you could use a 200x150mm board and leave an inch or two as a border and clamp there but that doubles the costs, I use 148x98mm out of the 150x100mm blank
-double sided tape: use 3M Scotch 665, it handles well, sticks well but is not very hard to remove the board from the mdf sacrificial layer in the end, some other double sided tapes hold so well that you bend the board trying to remove it, or jut let loose and you lose alignment
-vacuum table: I've just bought a vacuum pump but haven't got the time to play with it yet.5th: ALWAYS use registration holes, put a small known size hole at a known position, if you reset or stop any GRBL controller you lose position, specially when milling small traces 0.1mm out of alignment can make a huge difference
6th: don't be afraid to test feeds and speeds, as other people said buy mills in bulk and sacrifice one of each to make tests, you can learn a bit GCODE and write a simple program to mill a zig-zag pattern at different feedrates (G1 X100 Y10 F300; G1 X0 Y20 F300; G1 X100 Y30 F350; G1 X0 Y 40 F350; etc) then inspect using a magnifier/microscope and settle for the best quality speed. I use titanium coated engraving bits from 0.1mm 10deg for very very small smd traces up to 0.4-0.5mm 30 deg for normal th boards. A 0.4mm 30 deg titanium coated bit can last for up to 10 heavily packed 100x150mm boards as you can see below. At the price it comes ( under $1/piece) it's cheaper to use a new bit then to destroy a blank board, which you will anyway at least a few dozen times :tongue:
https://www.aliexpress.com/item/10x-Titanium-Coated-Carbide-PCB-Engraving-CNC-Bit-Router-Tool-10-Degree-0-1mm-Tip/1535712782.html?spm=2114.search0104.3.60.32Or0K&ws_ab_test=searchweb0_0,searchweb201602_5_10152_10065_10151_10344_10068_5000016_10345_10342_10343_51102_10340_5060016_10341_5130016_10609_10541_10084_10083_10304_10307_10301_10539_5080015_10312_10059_10313_10314_10534_100031_10604_10603_10103_10605_10594_10596_10142_10107,searchweb201603_14,ppcSwitch_3&algo_expid=e598dd4d-29ef-4a85-af37-7bfefdd92c46-7&algo_pvid=e598dd4d-29ef-4a85-af37-7bfefdd92c46&rmStoreLevelAB=07th: after milling sandpaper or use a scothbrite sponge on the board to remove copper edges
Here are some pics of a few boards, I mainly do through hole since I find easier (cheaper) to buy modules from ali than to order the original circuits, none has failed until now :)
LE. before you ask, the boards are HA light switches, 6 way, rotary encoded, led ring lights, led halo around them (as in car switches), MQTT enabled, w5500 eth connected, 100% designed and home made, 3d printed frame and buttons, laser cut acrylic and faceplates, cnc milled pcbs. @executivul regarding to the parallel port question, these days, for these tasks it is worth to have compatibility with the latest open source toolsets, so usb and grbl compatibility is a key point.
if you do professional cnc work, then you might need something different.
btw, it does not mean that parallel port version could not work, most of them could be easily "upgraded" to support the mentioned needs. e.g:
https://www.youtube.com/watch?v=42ew5xjIBWM -
very interresting post guys
I have one of these in the garage (top of my head table is 10x15cm)
I have never used it for pcb but @andrew tikkled my curiosity... very narrow tracks!
For what it is worth and because i don't recall reading anything about it here, i have added endstops to my CNC
It is well supported by the standard board supplied and GRBL takes care of it.
I dont want to get involved in a fight between "Normaly Open" people and "Normaly Closed" people, so i wont tell you which i chose :D again GRBL and board can manage both
https://www.ebay.com/itm/New-10PCS-Tact-Switch-KW11-3Z-5A-250V-Microswitch-3PIN-Buckle/173021165954?hash=item2848dd7982:g:xFsAAOSwGotWjjHoI get a very reliable "zero" on each axis. I actually home the 3 axis even after a tool change, just to be on the safe side
It all runs on an old windows XP laptop. AutoCad for drawings, Dxf2GCode for... dxf to Gcode conversion :D and GCodeSender for feeding GCode to CNC.
