Improving drill press use, no more off-center holes

[Debriefer]

I have a floor drill press which I believe is of reasonable quality (Ridgid R1500).

I also have a cheap 3" 'drill vise' from a local tool store, and a thick piece of scrap aluminum that I use as a base when things don't fit well in the vise.

I've had lots of issues with drilling large diameter holes where the workpiece shifts while drilling, which I think can be attributed to a few things:

- Bent drill bits that "find their center" on some small angle, which eventually causes them to walk.

- Poor clamping of the workpiece to the vise or metal plate.

- Poor clamping of the vise or metal plate to the drill press' table.

I'd like to know how to effectively use a drill press to ensure I always get perfect holes, especially when it comes to clamping. Is there a premium drill vise I can buy? What about some sort of toggle clamp arrangement for large workpieces?

I'd also like to know how to reduce or eliminate "exit wounds" when drilling metal.

Lastly, how can I discern good drill bits from bad? I believe my bent ones were sold that way.

TIA for any insight.

Drill press: https://www.ridgid.com/us/en/15-in-drill-press-with-led-r1500

Vise style simlar to mine: https://www.amazon.com/dp/B0001LQY4O/?tag=atomicindus08-20

 

[lilredex]

If concerned about exit wounds, you can drill through with a smaller bit, then drill from both sides with the final one.

Might be some help here...

https://www.instructables.com/id/DIY-Drill-Press-Accessories/

 

[PugetDude]

A twist drill will never yield a perfectly round hole. That's what you use a reamer for. I doubt your brand-new drill bits are "bent". You're probably looking at a stack-up of manufacturing tolerances and spindle run-out. Larger bits in a homeowner drill press want to grab; with larger holes in steel you're operating at or near the capability of the machine and there isn't enough torque to power through at speed-so the bit grabs, your vise or drill press table shifts and you get obround holes.
The only way to eliminate an exit wound when drilling from one side is to back up the piece being drilled. (a sacrificial plate, clamped tightly to the workpiece.
For 99% of what you're doing, a homeowner drill press dies an adequate job- if you use quality bits, plenty of lubrication, the right feed/speed combination and securely clamp your workpiece.
Good luck.

 

[MattT]

- Poor clamping of the workpiece to the vise or metal plate.

Heavier/better vise would definitely help.

- Poor clamping of the vise or metal plate to the drill press' table.

That's probably part of your problem. Unless you get the spindle lined up perfectly with your punch mark it'll pull the bit off center. It's normal to let the vise, or workpiece, float so the bit can center it.

If you must clamp to the table one of these will help get things accurately centered.

https://www.starrett.com/metrology/product-detail/827b

 

[matt_i]

Clamp everything up solid like you'd use in a mill, like the arm clamped solidly to the column, the vise bolted to the table and the workpiece clamped in the vise. Leave space at the bottom on parallels or a sacrificial spacer to avoid drilling the vise.

Make sure the pilot hole or center punch is on-location.

I'm not sure that the edgefinder even with the center cone is going to be of any use in a drill press because there aren't really defined axes to move into position.

I'm a fan of drilling a 1/8 or 5/32 pilot hole for everything, then stepping up. If the drill bit is over 1/2" then I'll drill a 1/4" pilot. Hopefully you are running your drill press at the lowest RPM you can, most models can't go below 300 rpms which I still regard as too-fast for holes over 1/2". Of course it will work but the heat and potential impact shortens the life of the edge tool.

I've been using C-L (chicago latrobe) drill bits for a long time with success. I don't like the 135 degree split points, I always use the 118 degree versions if I have a choice. In a mill I would use a 120deg included solid carbide spot drill bit not worth the chance it would break in a drill press.

Triumph, Precision Twist Drill and Cleveland are also drill bits I've used and would trust. I'll probably take some flames but if you bought them at a green, blue or orange box store then they aren't of high quality.

The exit wound is always going to be there, use a countersink at about 10 rpm to clean it up. Melin tools makes my favorite countersinks. Use a cordless drill on the "low gear" setting. If the burrs are really nasty you can knock them off with a rat-tail file.

 

[Bigblue&Goldie]

I have a floor drill press which I believe is of reasonable quality (Ridgid R1500).

I also have a cheap 3" 'drill vise' from a local tool store, and a thick piece of scrap aluminum that I use as a base when things don't fit well in the vise.

I've had lots of issues with drilling large diameter holes where the workpiece shifts while drilling, which I think can be attributed to a few things:

- Bent drill bits that "find their center" on some small angle, which eventually causes them to walk.
Likely not bent. You're likely using 118° bits which tend to wander without a pilot hole. Try 135° bits with a center punch or pilot hole. Pilot hole shouldn't exceed the thickness of the web of your larger bit. Also. Use the shortest bits you can. My preference is "stub" length aka "screw machine bits".
- Poor clamping of the workpiece to the vise or metal plate.
Needs to be rigid
- Poor clamping of the vise or metal plate to the drill press' table.
Needs to be rigid
I'd like to know how to effectively use a drill press to ensure I always get perfect holes, especially when it comes to clamping. Is there a premium drill vise I can buy? What about some sort of toggle clamp arrangement for large workpieces?
Anything from vise grips to Teco clamps work great. It all depends on what you're working on.
I'd also like to know how to reduce or eliminate "exit wounds" when drilling metal.
You will most likely always have a burr upon exit. Get a chamfer tool to clean these up.
Lastly, how can I discern good drill bits from bad? I believe my bent ones were sold that way.
If you're buying your bits from a big box store or chain hardware store there is a 99% chance they are ****. Buy your bits from McMaster Carr, MSC, Sun Coast Precision, or one of the other industrial suppliers. You get what you pay for. Made in USA, Germany, Japan, or even Korea (on a budget).
TIA for any insight.

Drill press: https://www.ridgid.com/us/en/15-in-drill-press-with-led-r1500

Vise style simlar to mine: https://www.amazon.com/dp/B0001LQY4O/?tag=atomicindus08-20

Also, lubrication and RPM is key. I use WD40 for aluminum and Tap Magic or some other industrial cutting fluid for steel. Look up speed and feed charts to calculate your RPM's. I used to hate drilling holes, but machining 101 class changed my life. I'll never forget my instructor (a 30 year journeyman) leaning on a drill press handle and saying "if everything is proper, you can lean pretty hard on it. 8 thought he was crazy and about to destroy the bit, but he was spot on. Understanding tooling makes life easier. There are great resources online.

FWIW, I have a garbage vise on my drill press, but 99% of the time I'm clamping my work directly to the table.

 

[Kev In]

The advice above is great. For me, I do a lot of drilling and use various bits depending on the thickness and depth, etc. Buy a good cam vice that will keep your work secure, you get what you pay for. I have a few different vices, but love my Heinrich cam vice for drilling. You must firmly clamp these to your table! Make sure your table is level, especially if you are drilling deep holes. Proper coolant and rpm are key.

 

[fiftyv8]

I agree, very level table is your foundation for all other issues.
If that is level then other things will follow.
Clamping is probably the next box to tick.
Accurate center popping helps.
Learn to be good at sharpening your own drill bits and know what you are trying to achieve.
Pilot holes are a must in most cases.
Use a lubricant/coolant and choose your rpm wisely...

 

[Gotcha640]

I've seen a lot of flex in those style tables. If you're having to bear down at all on the arm, you're probably flexing the table, making the part move and the bit will cut an odd hole.

If you can't get speed and feed right (and a sharper bit) a bumper/hi lift/off road jack can help stiffen things up.

I put a bottle jack under my table top drill press and it helps a lot.

 

[slowtwitch73]

Yeah, you need to get out an indicator and a square and check some things. Is the table level and flat? Does it flex when drilling? As stated above, the table can flex a ton. Use a section of drill rod.. not dead nuts straight but good enough for this task.. the thickset you can chuck up.. and see what kind of runout you get. The spindles out of printers are also a good choice. Excessive runout could be spindle, could be chuck. Use the drill rod to check for square in regards to table.

If you have bad table flex, your kinda stuck with what you have.

There's more after that, some of it already mentioned above.

 

[fiftyv8]

Yeah, I got two drill presses.
One is just a belt driven old unit that does OK on most days, the other is an old Swedish geared unit which is great, but I did a dumb thing a few years back and purchased a cheap two way cross slide vice that has never been any good and will one day upgrade to something worth a damn.
I spent more time shimming and adjusting it than it is worth.
That is what happens every once in a while when you mail order stuff, never has good as it looks in the pic's...

 

[Downwindtracker 2]

First off, there is no such thing as good drill press. They just don't make them anymore. At least the ones we can afford new. The common drill press design is Japanese but are now make in Taiwan and China. The head has no adjustment for the quill, to make it work easy, it's broached sloppy. Even the best of them. Next the table itself will flex away. When you put a prop under the table, you the discover the exhaust pipe column flexes . On my made in Taiwan Jet, the spindle has a .010 runout.

It's not you.

A round column mill/drill makes a good drill press.

 

[slowtwitch73]

First off, there is no such thing as good drill press. They just don't make them anymore.

I agree. Like doing good work on a clapped out lathe, it can be educational. I bet the op could make his situation significantly better. Inputs of time, money and fussing around.

 

[harley jim]

Sometimes I will just dimple my steel with the drill bit before final clamping this will allow the bit to center with my center punch mark. Doesn't work well with heavy items but works well with most things I put on the drill press.

Sent from my SM-A102U using Tapatalk

 

[Lassen Forge]

Center punch, pilot hole, drill, ream.

 

[sanddan]

I have a Rigid drill press and I'm sorry to say it's just ****. Many good suggestions here on doing the best hole that drill press can do. A decent mill/drill is a good solution, I use my big mill for 90% of the holes I have to drill. The drill press is good when I need the extra clearance, either due to height or oversize work piece.

 

[Downwindtracker 2]

Tubal Cain on YouTube did a series on locating, which was surprisingly difficult, using various methods. And Drilling. It's worth watching.

First you pick up your lines with a ***** punch. It's sharp enough that you don't want to just grab it in the drawer . 60 degree point

Next you use the ***** punch mark to locate the center punch. The center punch should be meaty for good transfer. Mine is a J.H. Williams, It must be made of 5/8 stock. 90 degree point

Using a smaller drill with a deep center point hole you will see the drill deflect if your set up is off.

Use the small drill , the drill doesn't have to be any bigger than the flat non drilling section on your main drill.

An offering to drilling gods would help.

 

[MFolks]

What condition is the drill press chuck in? Most are ****,unable to grip drill bits straight,see if a better one can be installed. The Jacobs brand were good years ago,not sure of the quality today.

 

[Bigblue&Goldie]

What condition is the drill press chuck in? Most are ****,unable to grip drill bits straight,see if a better one can be installed. The Jacobs brand were good years ago,not sure of the quality today.

That's a good point. When I bought my 15" JET I installed and removed the chuck 3 times, but I was able to reduce my runout significantly.

 

[Shadowdog500]

Get a mill hold down set that fit the t slots in that table.

See mine in use drilling a big hole beginning at 5:00 In this video.

You can also use the slots and t nuts to hold down a new (less crappy) drill press vise. You don’t need a mill vise that are a lot heavier and bulky than they look. The $20 Irwin drill press vise that you are using should be all that you need.

 

[mowkep]

No mention of using center drills. It's always a good place to start.

 

[Downwindtracker 2]

Center drills are fine for solid and precise set up like on a mill, a small drill will allow you to see your set-up mistake and self align a small amount if you miss.

 

[Debriefer]

Thanks everyone. I've ordered a new vise, and am going to look into table flex to see how much it's deflecting, and then see about propping it up.

I'm also going to look into getting a mill.

 

[cmandp]

Most of the time it really is best to let the work float on the drill press table, even drilling large holes in steel. I will usually hold the work in a drill press vice and make sure it is braced against the column or a clamp so it cannot spin if the bit catches.

Your drills really must be sharp and the cutting lips ground reasonably centered. If the lips are not symmetrical the drill bit will want to pull itself off center causing chatter and an oversize out of round hole. Good drill bits will help with that. I've seen a lot if drill bit sets at Home Depot and Lowe's poorly ground brand new to want to use any cheap ones anymore.

If you must clamp the work piece to the table, spinning the drill bit backwarks against your punch mark or pilot hole can get you lined up and then you can clamp.

Even that Ridgid drill press you have is probably near it's limit drilling 1/2" holes in steel so keep that in mind.

 

[bradpac]

I see mentioned in this thread using 118 degree bits over 135 degree bits. What instances would the 135 degree be a better choice? For wood or materials other than steel? Just curious why 135 is so common if 118 is recommended in this case.

 

[QwikKotaTx]

When it comes to the drill press I have always found that clamping everything down can lead to things being off or the bit wanting to go at an angle. At the very least it is good to use a center punch and lower the bit to it with the work piece loose. With downward pressure on the spindle, clamp the work piece and the location should stay set. Remember it's not a mill. Accuracy is relevant and spindle run-out on drill presses is nicht zo gut.

Sent from my VS987 using Tapatalk

 

[slowtwitch73]

I agree with not clamping but it means everything else needs to be done well... table, punch, drill bits, feed etc

I like to use a milling vise that just lays on the table. If it's a hole.. like to an edge or something that is likely to really want to move the part,vise, I will clamp the vise down.

 

[cmandp]

I see mentioned in this thread using 118 degree bits over 135 degree bits. What instances would the 135 degree be a better choice? For wood or materials other than steel? Just curious why 135 is so common if 118 is recommended in this case.

135° (or 150°, etc). Are going to be better for harder or tougher metals. Think titanium alloys, stainless steel, alloy steels, tool steels. They will wander more since the point angle is flatter, thus you need a more ridgid setup. The thrust needed for them to penetrate material is usually less too but I think that comes more from the fact that they usually have split points or other fancy point grinds. They will also drill a rounder hole in thinner materials than say a 118° drill bit (the larger point angle is fully supported in the work for longer).

Generally the softer the material the smaller the bit included angle should be. They make 90° point drills for plastics for example.

Ideally for wood a brad point bit or forestner bit that scores the wood fibers first will make the cleanest most round hole.

 

[Downwindtracker 2]

The degree isn't as important as the thinning of the web. Out in the field , the drill can be started with out a small hole being drilled first. A lot of the time a 135 is a high cobalt HSS, over a even high quality plain HSS, they stay sharp at least 10x as long. This is in the field, in the shop the it's not so important. Drill presses are easier on drills than drill motors. Or more to the point , it's easier to use more force.