Homebuilt CNC Hole Drilling Machine

[nitrosaturn]

I am planning to build a 3 axis hole drill based on the same principle as a cnc wood router. It is to continusly drill a 1000 hole pattern in fiberglass and I need some help figuring out what kind of drive setup i would need to to be able to drill 1 hole every 2 seconds. the pattern would be 5 holes in a row step over 3/8" then 5 holes in a row again. The z axis only needs to move 5" the y2" and x60"

Thanks in advance

[Guldberg]

As you say yourself, the same principals as a cnc wood router, so i guess that a standard stepper system will do. If you are not going to do any routing, you can go with quite small steppers since they only have to overcome the system itself

[Oldmanandhistoy]

Hi,

Did you just want information on type of system as in stepper motor or servo; or are you asking for recommendations of a particular set up to work to your 1 hole every 2 seconds?

John

[Guldberg]

You could of cause argue for that with larger steppers you have more power to overcome the constant acceleration/deacceleration. But my hornest guess is that a 200oz hobbycnc kit would do. What size of holes are we talking about? A pneumatic drill might do the job for you. Check the shopbot page of such a tool in action

[nitrosaturn]

I quess i'm not really fussy as to which system servo or stepper my big thing will be speed and reliability as at a 1000 holes per part and 8000 parts thats 8,000,000 holes so what ever i use for the z and you axis need to have long term wear resistanceas these are to 2 that will be moving on a continous based , also does anyone know a link to or a forumula to figure out ipm of acme thead's compaired to motor rpm

[nitrosaturn]

they are .210 holes

[Guldberg]

Pitch x rpm = speed, A motor running at 100 rpm with a pitch of 4mm = 400mm/min.
In imperial i think its given in TPI (turns per inch), so it would be RPM/TPI = speed. A motor running at 100 rpm with a 5TPI leadscrew = 20inch(min

[Bowman]

To what depth do you have to drill these holes? You say your Z will need to move 5" and the Y 2". Five inches in Z seems like your drilling a deep hole and two inches in Y would seem to make them close together.

So you want to drill 1 hole every 2 seconds or 30 holes a minute. You need to know how deep the drill will go in inches then multiply that by 2 for the retract, then add the step over distance to the next hole 3/8". See how far your drill bit will actually have to travel in a minute to make 30 holes and you will know what type of speed you will need.

IE- At a feed of 30 IPM if you drilled Z-.5" and retracted to Z .6" that would be over one inch of travel for drilling that one hole not including the step over to the next hole (or any extra peck drilling or dwell time you may need to add for each hole). I hope this gives you some idea of how to calculate how fast your setup needs to be to get the results your hoping for, good luck.

Bowman

[Guldberg]

Mach has a hole drilling wizard built-in, you could use that to experiment with speed. Once you find a total time for the whole pattern you know what speed to aim for. Thats how i would do it:-)