what makes a milling machine a milling machine?

Hi gang,

I’ve got a Clarke CDP 301B drill press and it drills nice vertical holes. If I wanted to introduce a sideward load on it and use it for milling, would converting the bearings to rollers be enough?


That leaves you with a drill press that can handle side loads. The tables on drill presses tend to not be very stiff to side loads and/or twisting. You would have to beef up the table, and then add and x/y movements

It's a toss-up as to whether it's worth the time/effort/money to try improving the drill press. At its best, it still won't be as rigid or repeatable as an entry level vertical mill. You can still get decent results as long as you can learn to work around its limitations.


As a machinist/fabricator by trade & job using them, Milling machines are machines capable of cutting loads on three axis. ( X, Y, Z) it will take quit a bit of modifications to a big Drill press to allow it to handle light & small milling jobs. ( been there & modded a Drill press once to a mill) Its almost more feasible to invest in a small used Mill if you want better accuracy and capabilities.

Depending on what you want to use a mill for you can actually build one. You won't be building a Bridgeport for heavy steel work but a very capable cnc machine with a flat bed and moving gantry. Again that depends on what the usage is. PM me if you want more information and I will be happy to share (with anyone).

That sounds very interesting bugsy36. That would be a great subject for a thread. It would get a lot of interest. Please consider doing so. I'll PM you soon if you don't make a thread on it.

Not to mention a vastly superior Drill Press!

I second this notion on a thread. Makes more sense than PMs IMO and generally a good thread for the forum.

Give me a couple of days and I will start getting all of the information together.

Thanks for the info and links folks, its given me quite a bit to think about.

The depth stop is on the handle like the drill you modified Comfy, so I think this will be the first mod to do on this drill, as even if I don’t progress to full-on milling conversion it will make the depth stop less sloppy.

A milling machine makes a better drill press than a drill press does a mill.

a DP as a mill isn't ideal, but if that's all you've got, it's better than not having one! Two things are important (although I'm sure Comfy will argue with me about one of them) 1) a secure way of holding an end mill and 2) some way of moving the work around in X and Y directions.

1) if your DP has a male spindle (bit sticking out that the drill chuck mounts to) you may be out of luck, unless it has a threaded retaining collar like my Walker Turner, which sounds unlikely if you mention a handle mounted depth stop. If it has a female spindle (like an MT3 taper) you may have better luck. The main problem is that the side loads from milling will want to make whatever chuck you use fall off that taper. You may have Comfy's luck and it never happens to you, in which case great. You may not, like many others, and your chuck falls off in the middle of a piece of work, which is irritating at best. Another thing is that drill chucks make crappy end mill holders as they only hold them on 3 points and generally just towards the tip, so that may cause other problems. Ideally some kind of collet chuck is the best bet - if you have an MT3 taper then an ER20>MT3 collet chuck would be a good investment.

2) drill press table, either a cheapy XY vise from Harbor Freight (expect it to need a lot of fettling) or a half decent XY table from Enco, Grizzly or the like. You're looking at $60 to $150, depending on which you choose.

You will suffer from chatter, be restricted to alu and plastics and forever curse the lack of fine feed on your quill, but you'll still be able to produce quite passable work if you're patient and it'll teach a lot of good skills for when you get a dedicated mill.

Here's the latest that I made

I've just finished putting digital readouts on the X and Y, just have to put one on the quill and it'll be pretty much done (using cheapo $7 plastic digital calipers off eBay)

The add-on depth limiter/quill stop I built is capable of adjusting the spindle down in tiny increments, .001" or less though it's not graduated so it's a thing that just has to be done by feel & experience. The load bolts that take all the slack out between the quill and headstock have to be backed off to just barely snug to use the limiter as a fine feed adjustment, but that's not really a problem since it doesn't need to be as tight when making fine cuts of only a few thou at a time.

I have a good keyed chuck, and clean the bore & spindle thoroughly with isopropyl before installing, and it's hammered in place much more than is probably considered normal, but if the fit is good and it's clean and dry it won't fall off.

I’m a bit concerned about the prospect of the chuck falling off, although I suppose it wont go flying across the room maiming all in its path!

Amazing work Mattthemuppet, is that a handlebar mount for a diy bike light?

Comfy, what was the thread of the bar you used for the depth-stop as I’ve found about 2’ of M10 stainless at work, do you think it will be ok?

Thread of the rod depends on what you're able to find for the adjusters. Grizzly has several different sizes, dunno what you'll be able to find in your part of the world. As I said in my drill press post, most common threaded rod available from the hardware store will be galvanized, and that's way too rough for this, the stainless was the only kind I could find that wasn't plated with something.

A lot of drill presses have a swivel table too- you’ll be mounting the cross vise onto that. The problem is it’s usually nothing more than a bolt holding that thing level. You will want to weld that into place. Other than that you should be able to do aluminum with a good set of bits. You will get vibrations you won’t get on a mill and you could reinforce it further by welding bars, but I’ve found if you take it slow and don’t shave more than .02 - .04” (if I remember right) a pass you can do it.

Use a rigged up caliper for the x axis. It’s limited for sure but I’ve built one a long time ago when I was poor and it actually worked. Cost around 400 bucks in the end.

Look on craigslist and you’ll find a mill every once in a while and people who have no idea how to use them = good deal. Usually someone passes away and his bastard kid inherits it. Do cartwheels if your the first one to call into that deal!