Need drilling help

Gotta start somewhere, like all of us. :)

I have some HF stuff I keep mostly so I can heat and beat it into weird shapes when I get a forge running. I think it will make me feel better, and I get some artwork. The cobalt drill bits are supposed to be ok, for HF anyway, but I haven't used them.

Does the mill have a back gear or pulleys? On mine, I set the pulleys/gear to get close, then VFD to fine adjust. Every machine is different though.
 
I do this all day long in different materials, for a living.
For a 1/2" HSS twist drill in 1018/A36 steel I would begin at 50 FPM cut speed, around 375 RPM's and NO LESS then .004" per revolution feed rate, if using water soluble flood coolant, if using flood cutting oil start faster.

Do not pilot drill, spot the hole and drill to size in one shot. HSS twist drills are the least expensive tooling that you will ever buy, if one lasts 50 parts buy 5 if 200 parts are needed.

Do not baby the feed rate as mentioned above, force the tool to cut at all times, if a through hole most of the damage will occur when it passes through the far side of the hole, this is mostly unavoidable but there are strategies to make this less of an issue.

This is a 1 5/16" twist drill through 3" of 1018 round stock, no spot, no pilot hole, straight through with no pecks.
If you listen to the audio the sound of the drill passing through the far side is obvious, this causes the drill bit all manner of problems.

32 parts drilled at less then 4 minutes each using 1 used unsharpened drill bit.
180 RPM's (62 FPM) and a .008 per revolution feed rate. If I had 320 parts I would have used a carbide insert spade drill.

 
Great info. I had always learned the "let the tool do the work" and not to use too much pressure. Seems like its the opposite in these cases.
 
I have a Drill Doctor...not impressed. Hard to get the geometry right with a device made from flexible plastic.
Robert
 
Great info. I had always learned the "let the tool do the work" and not to use too much pressure. Seems like its the opposite in these cases.
If you baby the feed you will simply rub the tool on the work, doing so will over heat it and cause rapid tool failure, the tool must cut at all times.
When a twist drill passes through the far side the chip becomes very thin because there is no material left, the dimple produced will often turn blue from the heat unless there is excellent coolant flow at the bottom of the hole. Coolant through drills help with this.

Drilling through holes in certain stainless alloys will make this abundantly clear.
 
I do this all day long in different materials, for a living.
For a 1/2" HSS twist drill in 1018/A36 steel I would begin at 50 FPM cut speed, around 375 RPM's and NO LESS then .004" per revolution feed rate, if using water soluble flood coolant, if using flood cutting oil start faster.

Do not pilot drill, spot the hole and drill to size in one shot. HSS twist drills are the least expensive tooling that you will ever buy, if one lasts 50 parts buy 5 if 200 parts are needed.

Do not baby the feed rate as mentioned above, force the tool to cut at all times, if a through hole most of the damage will occur when it passes through the far side of the hole, this is mostly unavoidable but there are strategies to make this less of an issue.

This is a 1 5/16" twist drill through 3" of 1018 round stock, no spot, no pilot hole, straight through with no pecks.
If you listen to the audio the sound of the drill passing through the far side is obvious, this causes the drill bit all manner of problems.

32 parts drilled at less then 4 minutes each using 1 used unsharpened drill bit.
180 RPM's (62 FPM) and a .008 per revolution feed rate. If I had 320 parts I would have used a carbide insert spade drill.

I dont think this would work on a garden variety 13x40 chinese lathe. :)I think the tailstock nut would strip.Nothing nicer than some serious rigidity in a machine.What capstan is that .? Looks like a russian tank
 
I believe that's a Warner and Swasey lathe, possibly a Number 3.
 
I dont think this would work on a garden variety 13x40 chinese lathe. :)I think the tailstock nut would strip.Nothing nicer than some serious rigidity in a machine.What capstan is that .? Looks like a russian tank
Warner & Swasey #5 turret lathe of 1950's vintage, a very powerful machine.
This is my version of humor, I realize that most hobby machines will not do this but the principles remain the same.
 
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