Agreed. You can also use pad patterns in the artwork that have 'drill giude holes'. Your pads become little doughnuts. When drilling, try to use a very light fingertip pressure only as the drill point contacts the material - allowing the drill to pull the board to center. When centered, gently clamp with fingertips and increase quill pressurre. Any off center condition, whether from a centering error or the tip wandering before it bites will cause side pressure on the drill resulting in a ratty hole at best, broken bit at worst. None of this matters if your drillpress has runout or flexes under pressure. My hands are twitchy too so I'm sympathetic to Spin's problem..I guess I should say that making a dent first really helps guide the drill. Anything pointy and hard, only the pressure of your hand. A scratch awl, a center punch (but NOT the spring loaded kind!). And a backer board a la Gopher. Mustn't forget, a hole has two ends.
How many drill bits do you go through in a project?
- Thread starter spinnaker
- Start date
if the problem is with the board or the press moving while drilling then why not add some soft rubber to the underside of the press and to the place where you put your pcb? some of the type that is almost "sticky and moist" and has high friction. alternatively if your board includes holes for mounting on standoffs you could try screwing a heavy mass on them so that it almost too heavy to move without effort. another idea is to use clamps with servos. this is the best idea but the most complicated (heck, use this and mount a servo on the arm and you got an almost fully automated system. all that remains is the x, y, and z controls )
how to mount a servo on the arm? just attach a 90 degree connector from the base to a rod/plank that goes up to the axis of the arm. on that rod/plank place the servo!
for the clamps, get multiple small c type clamps. make sure they are well lubricated and use a fast motor (or a fast spinning continuously rotating servo) to open and close the clamp. there would be some sort of a pressure sensor (could be done purely with transistors if there is a pressure sensor that varies its resistance with pressure) that stops the clamp from destroying the board. this would be mounted to one side of the clamp that touches the pcb. The same idea (without worrying much about pressure, and using powerful motor with more torque) could be used for the whole thing also. or even tightened by hand because you wont be undoing the clamps and moving the machine after 3 holes....
is summary if you use the latter method with the servos, you could have a system where in one press, the machine tightened the c clamps by turning the lubricated bolt on the clamps using continuously rotating fast moving servos with pressure sensors and then the arm servo brought the tool down and made it drill the hole. if done right should take no more than 0.3 sec. then automatically retract and loosen clamps in the same time period. then you move the board and align it on the next hole. press button. suddenly you are saving so much time and effort!
next up is a x, y, and z moving system with a camera auto aligning setup that.......
i think i should calm down, shouldent I
)how to mount a servo on the arm? just attach a 90 degree connector from the base to a rod/plank that goes up to the axis of the arm. on that rod/plank place the servo!
for the clamps, get multiple small c type clamps. make sure they are well lubricated and use a fast motor (or a fast spinning continuously rotating servo) to open and close the clamp. there would be some sort of a pressure sensor (could be done purely with transistors if there is a pressure sensor that varies its resistance with pressure) that stops the clamp from destroying the board. this would be mounted to one side of the clamp that touches the pcb. The same idea (without worrying much about pressure, and using powerful motor with more torque) could be used for the whole thing also. or even tightened by hand because you wont be undoing the clamps and moving the machine after 3 holes....
is summary if you use the latter method with the servos, you could have a system where in one press, the machine tightened the c clamps by turning the lubricated bolt on the clamps using continuously rotating fast moving servos with pressure sensors and then the arm servo brought the tool down and made it drill the hole. if done right should take no more than 0.3 sec. then automatically retract and loosen clamps in the same time period. then you move the board and align it on the next hole. press button. suddenly you are saving so much time and effort!
next up is a x, y, and z moving system with a camera auto aligning setup that.......
i think i should calm down, shouldent I
Steel pen? I don't think I know what that is.
I mentioned it above. Clamping the board down could make it very time consuming to drill out the board.
Maybe that is really my issue. I am pressing down hard on the board as I drill the whole time. What do you use behind the pcb? It would have to be something that would allow the board to move correct?
Currently I have a piece of 1x4 which might be another issues. I probably should have some kind of material actually mounted to the base of the press. Maybe that would help?
Think he means a scriber.
its basically a pen made completely of steel with very sharp tip which you can use to make a centering hole for drill.
One of these?
http://www.ebay.com/itm/General-Too...172828?hash=item565f118b9c:g:kXwAAOSw~OdVeflk
I think I will order one.
Yes,just be careful it takes very littke preassure to go through the FR4 material even if it looks pretty solid.
No way that's worth $7. Check Harbor Freight.
I have one of those, and I don't remember how it got in my tool box, so it must have been cheap or free.
Does the bit flex or wonder while you're drilling? Runout can cause carbide bits to break; HSS are more forgiving, but don't retain their edge as long.
When I'm transferring toner on my boards, I iron until the holes are almost closed. This forms a pilot "hole" to guide the bit. I don't apply "hard" downward pressure until the bit starts to bite.
I use a piece of perfboard or some copper clad (single sided with bare side up). I set the depth so I don't drill through whatever backing I'm using.
Since you mentioned movement in your hand holding the board is an issue, you could try to rig up something that places pressure on the board while the hole is being drilled to prevent it from moving.
My press has a center hole so I don't need a backing board but wood is good if you need one. The backing board should be softer than the work so you'll know when you break through. EDIT: either clamp the backing board to the press (so that the drill always hits the same place) or attach the PCB to the backing board. You waht to avoid the possibility of the drill breeaking through to an off center hole in the BB due to them shifting around.
Chips will accumulate between so clean them out as you drill. Use a brush to sweep them. You might try a different technique on the quill lever..instead of gripping it firmly, try a gentler hold. Sometimes I'll kind of place my palm on the quill axle then use gentle thumb pressure to feed the drill for delicate work. The idea is to let the drill do the cutting, using only enough pressure to keep it in contact with the work.
Last edited:
There is one just a short distance from here. But checked online, they don't seem to carry them.
http://www.harborfreight.com/catalo...s&RequestData=CA_CategoryExpand&p=2&q=scriber
Lots of punches no scriber.
Yup... always done it by hand. The trick is how you hold the drill, with one hand guiding the chuck, while the other lifts the drill's weight. The trick is to NOT use the drill motor directly, but to use a flex extension instead. That way I'm able to drill around one hole per second.
This week I'll be doing some drilling, and I'm going to ask a friend to take some video for me. A video's worth a million words.
When it goes viral and you become a big star, will you remember all of us little people?
Biggest problem ours had was sloppy tolerances on the motor to guide shaft(s) fit. The motor would cock to one side because of the slop, which would break the carbide bit.
If you want to make the thing automated i looked up some parts that might be suitable:
https://www.sparkfun.com/products/9375
http://www.hobbyking.com/hobbyking/...og_Servo_1_4kg_0_09sec_10g_AU_Warehouse_.html (R$7.68 when you wait for a minute, but only one time offer. you could modify it to make it continuously rotating)
if you ever think about doing this it would be interesting to see the final version!
https://www.sparkfun.com/products/9375
http://www.hobbyking.com/hobbyking/...og_Servo_1_4kg_0_09sec_10g_AU_Warehouse_.html (R$7.68 when you wait for a minute, but only one time offer. you could modify it to make it continuously rotating)
if you ever think about doing this it would be interesting to see the final version!
Hi S,
If the problem is with the drill running out, perhaps a quick tap with the drill before going through might help, this should make a centre dot, especially if the drill is sharpened as a lathe centre drill.
If the problem is board moving, and speed is essential, perhaps a 'say' thin wooden bar (With soft pad towards the board) across the board area, loosely connected at on end of the drill table (away from the board) connected at the other end to a string for a stirrup where you could pull it down with your foot.
Hope it helps, C.
You May Also Like
-
With an Eye on On-Device AI, Qualcomm Rolls Out New Snapdragon SoC
by Duane Benson
-
A Q&A With Renowned Neuromorphic Chip Designer Chiara Bartolozzi
-
You’ve Got the Power—Ensuring Interoperability for Power Over Ethernet Devices
-
AMD Launches Embedded+ Architecture Blending Ryzen and Versal
by Jake Hertz
