Feed Rate Question - Small Hole

Whatever that is.

Only have values for carbide drills that small. HSS starts at 2mm. For carbide in Al (diam 0.1 ... 0.9mm):

HTH, Nick

I've done a lot of circuit board drilling, and a little bit using circuit board drills in aluminum, etc. Yes, .0005"/rev sounds fairly good. You need to peck often to allow the chips to clear. What is the total depth of the hole? You will be using solid carbide drills? What spindle speed can you get up to? I do most of this at 24000 RPM. I do .00125"/rev on circuit board material.

Jon

Not bad... 0.020" thickness total.

Surface is a tube - convex - so he will be using drill bushings - hopefully ground to the contour of the tube.

His choice, but I'm not sure what else there is available to him without a very special order.

Well... Probably very slow. 3000-3500 RPM. Simply too many gears inside that head to run any faster safely...

Regards, Joe Agro, Jr. (800) 871-5022

Is it worth fitting an air turbine, high speed motor based unit or geared speed increaser to the quill to get a better speed for this job?

Don't know who makes them, But I know that they have been added to jig borers in days gone by.

Mark Rand RTFM

Mark Rand wrote in news: snipped-for-privacy@4ax.com:

NSK -

They also make high speed spindles that can be belt driven. I wonder if you could make a drill head with a serpintine belt driving all of the spindles.

Here is a video of some 50,000 rpm drill spindles in action. The largest tool is 1/8" the smallest is .006". Once we dialed the process in, it ran in about half the cycle time shown in the video.

innews: snipped-for-privacy@4ax.com:

Try TPS Intl. They import OMG which makes speeders for a quite a wide range of equipment.

It's not the drill press limitation that is holding the speed down, but the RPM limitations of the multiple spindle head I'm selling the guy. It has a single input, many outputs and many intermediate gears to keep rotation the same. All packed closely together.

Although the housing is aluminum and will transfer heat well, the hardened helical gears (more surface area for shear strength, etc.) and the grease inside can only take so much.

The drilling load is very low, but at some point is not even figured into the equation as the overall speed causes problems for the bearings, gears, grease, etc. In this particular case, I feel comforable that they could run at 4000-4500 RPM but will always tell them to run slower as "cheap insurance." The cost of a line that goes down is higher than the head and the cycle time is not critical to the customer.

Regards, Joe Agro, Jr. (800) 871-5022

Why don't you use oil? It would run cooler.

Nick

Not designed to accept liquid. The seals keep liquid out as long as it's not pressurized, but would not keep it in... It would simply run right out past the spindles. To make a head that could be oil filled would bring my prices WAY up and at least close to the insanely high cost all my competitors charge. :)

Sorry, I was thinking about just one spindle on the head rather than the drive to the head. 'course, if all the spindles are drilling tiny holes then that idea does out the window and if a speed increaser on an individual spindle took up more than bugger all depth, that idea gets defenestrated as well. Ah well, the idea was worth what it cost :-)

Mark Rand RTFM