Reamer bit guide

[SkinnyWire]

Ahhhh, sounds like you need a more powerful drill press I bet. That would explain alot...

Bingo.

[Zhangliqun]

It sounds to me like his drill is too underpowered and losing power or is too low speed? Change your gear belt to the highest speed, put a little oil on the piece you're widening. I have a Delta drill press and do what you're doing all the time with an old drill bit and not having any problems, its just a cheapie from Lowe's. Go to Harbor Freight they're not expensive:
- Harbor Freight Tools - Quality Tools at the Lowest Prices

Looks all but identical to the one I have. The motor swivels out slightly in the back with a screw clamp to hold it in position -- I assume that's the means of tightening the belt. I have the gear belt already set at the highest speed per the chart under the lid.

[David Schwab]

Looks all but identical to the one I have. The motor swivels out slightly in the back with a screw clamp to hold it in position -- I assume that's the means of tightening the belt. I have the gear belt already set at the highest speed per the chart under the lid.

That's the same press I have too, only mine was from Homier.

You might want to try a slower speed then.

I haven't changed mine since I got it. I know it's not on the fastest speed, since it's better to drill metal slower and wood faster, and I use this for both, it seems like a good speed.

[Possum]

...

Good point, slower speed will have more torque, I forget what mine's set on....

[David King]

A range of 600-1000 rpm is good for drilling small holes in soft steel. The top speed on most of these smaller drill presses is 3000. Way too fast.

[Joe Gwinn]

That tearing and chipping is what I'm running into. And yes, I'm using a drill press and a clamp. Nothing moves but the bit.

I do not force it in there, my little drill press just doesn't have near enough torque to try anything like that, it would stop dead while the belts continue rub against the shaft. So I just lower the bit with light gentle jabs into the hole to avoid abusing either the bit or the keeper, or the press itself for that matter.

And still I get this tearing/chipping so I think you must be right, Joe.

I think the chucking reamer is the answer.

PS, in case it wasn't clear, I am widening existing holes, I am not drilling new holes. Original size of hole is 1/8". I like the keeper holes just a shade wider in case the bobbins, baseplate, and/or keeper are slightly off in spacing relative to each other.

Interesting that the 1/8" bit I have cuts the steel like butter when making my own keepers but because my press doesn't have much torque, it will stop dead with the 9/64" bit, so I have to make the 1/8" holes, then widen them.

As others have said, arrange the belts so the bit goes slower, and make sure the belts are tight. Even with a pipsqueak drill press, you should not have any problem drilling a 9/64" hole in mild steel.

Using a reamer to go from 1/8" to 9/64" in one pass won't likely work, but a unibit step drill will do just fine. But don't forget the black sulfur oil.

[David Schwab]

But don't forget the black sulfur oil.

That's the stuff I was trying to remember...

[Zhangliqun]

I tightened the belt and that definitely beefed up the torque. Guess it was unduly loose. There was even bit of "belt dust" in there from the rubbing. Will see if that prevents the tearing/chipping now...

[Possum]

....

Another thing, push the drill bit WAY up into the chuck so you have the minimum amount of drill bit sticking out, this will make the bit effectively shorter and more stable. If you just have a small grip on it and the bit is allowed to be long and not well gripped that would cause problems too. When I drill my keepers on my mill I always use the minimum amount sticking out to get the job done....

[Zhangliqun]

Keeps it from wobbling and wandering as much, I'm hip to that trick at least.

[Mystic]

Maybe you should try an end mill bit.

[Possum]

...

I tried drilling with an 1/8" end mill, I didn't like it, it really stressed the machine alot, though it didn't wander much. Not really a good idea...

[Joe Gwinn]

I tried drilling with an 1/8" end mill, I didn't like it, it really stressed the machine alot, though it didn't wander much. Not really a good idea...

One can drill with an end mill, but it must be done in a mill (not a drill press) and one must rough the hole out with a twist drill first.

There are also end mills designed for drilling. The tip is pointed, not flat.

Be aware that drill chucks cannot get a very secure grip on end mills, which are too hard for the chuck jaws to dig into. The shanks of twist drills are made slightly soft, precisely so the chuck can grip them securely. Use end mill holders for end mills.

The other danger is that if one tries to mill moving sideways on a drill press, the side loads and pulling forces will often unseat the chuck and it will chase you around the shop as it spins.

[Bruce Johnson]

The bad part about having flying machine parts chasing you around the shop, is that they'll usually catch you. They're fast.

I agree with all of the above: To drill steel, your drill press should be on the slowest speed it will go, with the belt tight. A sharp bit, short length, cutting oil, and the part held in a drill press vise or clamped down. It takes horsepower to peel steel chips. That means more downforce on the quill arm, and more resultant twisting of the part.

[Joe Gwinn]

To drill steel, your drill press should be on the slowest speed it will go, with the belt tight. A sharp bit, short length, cutting oil, and the part held in a drill press vise or clamped down. It takes horsepower to peel steel chips. That means more downforce on the quill arm, and more resultant twisting of the part.

Well, one can also go too slow, so there is a happy medium. A little experimentation will quickly show the way.