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I have succeeded in making my first pc boards. I need to know the optimum speed for drilling fiberglass with two copper sides with 1/8" shank carbide pc drills. I'm shopping for a mini drill press and I believe a Dremel is too fast. Any ideas are appreciated. Ray
"The gift of imagination is a gift of the Gods imparted to a few who receive innumerable kicks in the a$$ their entire life." Le Corbusier (Charles-Édouard Jeanneret)
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Hi all
Rule of thumb for almost all drilling:
Small diameter drill=high speed
Large diameter drill=low speed
“If you don't like what you're doing, you can always pick up your needle and move to another groove.” Timothy Leary
I thought from the memory of my visits to PCB manufacturing plants that high speed drilling was the norm so I checked.
This from Wiki - "Coated tungsten carbide is recommended since many board materials are very abrasive and drilling must be high RPM and high feed to be cost effective. Drill bits must also remain sharp so as not to mar or tear the traces. Drilling with high-speed-steel is simply not feasible since the drill bits will dull quickly and thus tear the copper and ruin the boards."
Cheers,
Naz
nt
"The gift of imagination is a gift of the Gods imparted to a few who receive innumerable kicks in the a$$ their entire life." Le Corbusier (Charles-Édouard Jeanneret)
I seem to recall speeds upwards of 100,000RPM in volume production using multiple drill presses but this is for efficiency no doubt. There are many small, specialised PCB drilling machines using 10,000 - 30,0000RPM but I'm sure 8,000RPM or so is fine.
My understanding is that the high speed provides a much cleaner hole through the different layers, especially the copper. And it's fast, like a hot knife through butter!
Naz
...watch those feed rates however. Carbide is brittle amd if it doesn't like your speed and feed it will snap instantly with pieces flying who knows where. Obviously, wear goggles.
I use a sharp bit at 1200 RPM and it goes thru in less than 1/2 a second with a small bit and slightly longer with a larger bit (1/8'). The key is a sharp bit.
I thought I would try and sandwich the 3x3 inch board against a piece of formica and a 3/4 inch thick piece of MDF, the formica contact cemented to the MDF. I thought about covering the 2 sides with tape but it leaves residue. I thought I would drill from the circuit copper side and not the ground plane-component side. I will spring center punch each hole dot on the circuit side first and drill all the holes with each respective size bit. Then turn the board over to the ground plane side against the formica and burr each hole with a larger countersink. The board is bare copper so I will try to flow copper all over it after I have mounted all the components. I wonder if I could use an oven or a heat sink gun to flow it. I found a friend with a bench top drill press with a variable speed rheostat so I'll use that before I buy one. Thanks for any advice. Ray
"The gift of imagination is a gift of the Gods imparted to a few who receive innumerable kicks in the a$$ their entire life." Le Corbusier (Charles-Édouard Jeanneret)
Speed Controllers are available; even a large Variac will help slow down a Dremel. In order to save the copper traces, I would drill through them first. I might even tape the traces with tape; for some more protection.
I would also use a pilot bit first. About 1/32" or 1/16" are safer than hitting the PCB with 1/8" bit. Good Luck...
Drilling a .1250 Dia hole in a fiberglass PC board using a carbide drill I would suggest a fairly slow RPM because the fiberglass may want to melt.
Start at 750RMP and work up if needed. It could be a very high speed (RPM) could work best depending on the board I've never drilled a PC board but I know you should be good going slow.
I'll give you some safety tips because I don't know if you have ever used a drill press or drilled anything other than wood.
Don't wear gloves.
Wear safety glasses.
Clamp the workpiece or make a stop to prevent it from spinning. Do not hold it with your hand.
I don't know about hobby drill presses on the market been using big toys the past 35 years. Good luck.
I would say go slow. You can also use a pin chuck with "wire guage" small bits to make good-fitting holes if you are using through-hole components and soldering them in without eyelets. Sometimes I will use finger pressure only with the pin chuck when working with #55 and higher numbers. It will dig in and drill just fine, but it takes longer than a drill. The finger pressuer is less likely to break tiny bits, a risk when using a power drill.
Otherwise you can slip the pin chuck into a variable speed drill, and go slow at first. On metal you want to take it slow. If you need to drill through a layer of copper and then out the other side with a layer of copper for a two-sided connection, use a waste piece of MDF or wood to back it up so you don't push the copper off the back or leave a burr.
If you are in the USA, Woodcraft stores sell a pin chuck and a nice set of the smallest #61-80 bits (or someting like that range). Both pin chucks and small bits are also available on Ebay. For thicker wires like those on on wirewound resistors, diodes and snap-in 'lytics, etc., get a few bits in the #48 - 59 range at a hardware store like TrueValue. They sell them singly. You can skip numbers and get a few -- four or five -- you don't need them all. I seem to use 53, 55 and 57 for a lot of things.
Hope this helps,
Jeff
My friend hooks up his scroll saw to a variac, by adjusting the voltage, he can get any speed he want according. Since a mini drill press's current draw is fairly low, so I think you may try the same trick.
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