First drill press ive ever bought.

Worked decent plugn away at bumper brackets. I did buy the replacement just incase I happen to burn it up


Figured ill do another bumper completely my own design

 

My buddy gave me one of their 12 speed ones.
They still sell it. Cost like $140. Before coupons and whatnot.
He had a floor one and did not want it anymore.
Really haven't had a chance to play with it yet.
But have a couple up coming projects that I am hoping it will be useful.
You using cutting oil there?

 

Cutting oil is for the weak, if my bit explodes it's doing its job lol

 

Wd40 pushing a dull 9/16 through a very small pilot.

Much much faster then the hand drill and 3 bit process


This is the 12 speed one. I have it set at 630rpm

 

This other friend I have used to be a machinist. Retired now.
I have been meaning to pick his brain about the speeds on the drill press.
What speed to use and when. Etc.
I am betting different speeds for different applications.
I just hope there is some sort of guidelines for what speed to use and when.
Other wise I figure pick a speed in the middle and just use it for everything. LOL.

 

Bigger the bit the slower you spin it.

 

Slow and steady wins the race.

 

The proper RPM for drilling is driven by surface speed at the OD of the drill bit. The optimum surface speed, measured in surface feet per minute (SFM), is a value that has been determined empirically and is driven by metallurgical properties of the material being cut and the material of the drill bit. Using the surface speed value with the diameter of the drill bit, the most efficient RPM can be calculated. For example, mild steel with a HSS drill bit wants a 110-120 SFM surface speed (from the chart pinned to the wall in my cube). Using 115 SFM and a 9/16 diameter drill, I calculate that 781 RPM is the most efficient speed to run at.

But that's only half of the equation;

In machining, the term "speeds and feeds" is used to describe how hard and fast to push a tool through a workpiece. The surface speed allows us to find our speed, but we still need to find the feed. The desired aggressiveness of feeding the drill bit is again driven by metallurgical properties of the material being cut and the material of the drill bit. Some materials are gummy and tend to clog up the flutes of the drill whereas others break into easy to manage chips more readily. Furthermore, larger drill bits have deeper flutes and can move more material up and out of the hole. The chart on my wall shows a graph giving a light, medium, and heavy feed rate for a range of drill bit sizes. Certain materials cut better at heavy feed rates, others not so much. Continuing with the example of mild steel and a 9/16 HSS drill bit, the chart calls for a heavy feed which equates to approximately 0.012" of feed per rev (that's a lot!).

When I program CNC machines, I use these two values to tell the machine how hard to push, but there are many more variables at play here. I typically have coolant flooding the drill bit and the hole to keep everything cool and flush chips out of the hole, and the setups are very rigid. But more than that, I often find the horse power limit of the machine is the most limiting factor. Following through with this example and my typical procedure, I calculate it would take a 5 hp motor to push a 9/16 HSS drill bit through mild steel at 0.012 IPR at 781 RPM requiring 340 in-lb of torque from the motor.

I can tell you that you're not going to get that from your drill press. HF rates that at 3.85 amp draw which equates to about 1/2 HP, or 10 times less power than required to push that to its most efficient limit.

Point of this rant: speeds and feeds are not set in stone. Yes, there are charts, calculators, and "optimum" values, but they typically do not translate to real world usage, especially for what we do. My advice: Slow for big drill bits, fast for small drill bits, keep it well oiled to keep the heat down and lubricated to help clear chips, and push moderately hard without breaking the drill bit or bogging the motor.

 

Sweet reply.

So on the week harbor freight motor what speed would you recommend. Ill mostly be doing 9/16 holes in 1/4" plate.

I meant to get a new 9/16. Guess I'll sharpn it with my grinder

 

Oh, please no. Get a bit sharpener or buy a new bit.

 

Haha.
I've made it work in a pinch also use a belt sander

when you have 4 that won't cut you get crafty late in the night.

 

I’ve sharpened hundreds of drill bits by hand on a grinder. I wouldn’t put them in a mill after or expect a super straight hole but it works well when done properly

 

My buddy has one of those Drill Doctor things. Got it for a present.
Says they work pretty good.
My other buddy, the machinist, says he can sharpen by hand no problem.
Of course that was when his eyesight was better. LOL.

 

Yeah, you can get it sharper than a rounded bit, but you also destroy the temper.

 

I've made a few realy pull some chips.

I only do the big bits ive never tried to sharpen small like 1/8"