View Full Version : Building a small mill?

08-16-2004, 08:08 AM
Hi ya'll. I know this is probably an outrageous idea, but I would like to make my own mill. I have an old worn out small drill press that I would like to strip and use the shell of. The cast head base and table pehaps. I have a minilathe that I am getting tuned in and tooled up. I have motors, shafting and bearing sources, xy cross slide table. Rather than spend the money on a tiny mill, I was thinking that I have the stuff to make one nearly as good for smaller milling jobs in my shop. I have 3 other drill presses and I won't even attempt to use these for milling. They drill fine though. http://bbs.homeshopmachinist.net//smile.gif
If I was wanting to do this, what type of tool holder would be the easiest to fabricate? I don't necessarily want to use the spindle advanceing handle thingy thats on the DP. I would rather lower the head with an acme threaded rod and handle or something. This will eliminate a lot of the problem with the shafting mechanism and bearings.
Anyone done this or seen any plans for such an odd ball idea?
I figured this may be worth a shot since I'm pretty much having to rebuild the mini-lathe to make it do what it needs to. Definately a kit type purchase there.
Any thoughts as to just how lame I might be to even attempt this. http://bbs.homeshopmachinist.net//smile.gif Thanks.


08-16-2004, 08:45 AM
I built a similar type project. I used a cross slide from HF and mounted stepper motors on it.

It chattered on anything I tried to make on it. It would have been a excellent engraver or a pcb driller.

It was too small for anything I wanted to do, so I bought a larger lathe/drill..

It was a excellent learning tool.

David Cofer, Of:
Tunnel Hill, North Georgia

08-16-2004, 10:33 AM
Look in past threads, Evan has posted some elegant pictures/work on a similar project.


Forrest Addy
08-16-2004, 10:55 AM
Drill presses were designed to puch a drill through the work not restrain a mill cutting on its side. You'll find a drill press spindle is pretty limber for milling work.

Otherwise you seem to have many of the bases covered.

08-16-2004, 12:12 PM
I do not see it as an oddball idea. How practical, well, I would tend to agree with Forrest. I see that your desire is to make one for "small" milling jobs. "Small" covers quite a range of tasks, anything from drilling a 1/8" hole, or milling a 1/2"x1/4" wide slot 3" long. Both are "small" tasks, however a drill press "transformed" into a milling machine would most likely perform only one of those "small" tasks very well. Unless it has a sizeable, solidly cast base and quill housing, a drill press "frame" may not be up to the rigors of becoming a mill, regardless of how lightly it would be used as one. If you are considering using the quill that is in the drill press, most drill press quills are not very large in O.D., thus the casting may not have the mass to support a larger, more suitable quill. The internal taper, or lack thereof, will also restrict what you can do or obtain as far as tooling. If the quill in your drill press is of a standard internal taper, say M2, and fairly large, you may have an advantage there. However, the quill in a drill press is probably not "fitted" as well, meaning with the same tolerances as in a mill, or supported by the same class and type of bearings you would find in a mill. Thus, I do not beleive you would be able to hold close tolerances, should you need to, with such a set-up. You would also want to be able to prevent ANY movement on any axis, except the axes you want to move, when you are milling. I do not know how securely a drill press can prevent against un-intended movement, especially in the Z axis. I'm not saying it cannot be done. As Scott has mentioned, Evan has "transformed" a drill press into a light duty mill. How well it works as a mill, only he would know better than I.

[This message has been edited by ERBenoit (edited 08-16-2004).]

G.A. Ewen
08-16-2004, 12:19 PM
These are not very good photos but the may be of some help to you. This attempt at making a mill out of a small P.O.S drill press was very educational. The quill lock system worked very well but the spindle shaft was to light and would flex with anything over a .015 cut.



Your idea to raise and lower the head is a good one.

Keep use informed as to how your project goes.

08-16-2004, 03:59 PM
Actually I have been working on a small milling machine off and on for about a year. I am moldmaker by trade and have acess to quite a bit of machinery including a CNC that you could park a ford f150 truck on. I however chose to make a small knee mill with a quill feed head similar to the Grizzly 6"x26" mill. My machine is know where near completed but I do have quite abit done. My table is 5"x22", it has 11" of vertical knee travel with 6" in the Y and 13 1/2" in the X. The head is going to be powered by a tread mill motor at this point with a 2 or 3 step pulley for power at slow speeds, my knee for the machine was patterned by me from a set of photos from a guy on the Chaski board, it was from one of the old Cataract/Hardinge millers of the 30' and 40's I am having it cast at a local foundry in a month or so, the knee is 3/4" -10 Acme lead screew and the table is powered by a 1/2-10 acme lead screw and a 12 volt cordless drill motor for power feed if I can get the motor to hold up and run ok. I have the (3) screws finished along with the nuts the handles the table the saddle and the base and hav started the column using a piece of 6"x8" structural tubing that has a 1/2" wall on it and a dovetail bolted to it that will be ground and then scraped (maybe). It will probably be finished in about a year at the rate I am going.

08-16-2004, 05:48 PM
Thanks for the help, pictures, explanations and realistic expectations. Some good things to think about here.
Here is a little more about the idea.
I was intending to completely remove the quill and shaft, pulleys motor and everything actually. Then I have a cast iron head on a steel pipe with a table and a base under it. I'm pretty sure that the hole for the pipe goes all the way through the head, but rests on stops. I was thinking about essentially cutting the pipe down the center and make a 3/8 inch slot about 6" or 8" down. This would be the track that the head would move up and down in. Now inside the pipe I would have a bearing that an acme threaded shaft would rest in at the bottom of this track. It would be acme threads about 5 to an inch. Inside the cast head would be the machined part that would be threaded with the acme thread. The top of the pipe would then have another bearing in the plug that would secure the shaft with a collar.
New bearings ad shaft would go where the quill was with another step pulley on top. A motor would then be mouted out back but off to one side so as not to interfere with the head movement.
I realize the little table is a weak point in my design idea, but I was thinking that since the head is the movement for the height setting, and the cross slide for the horozontal axis, then I could fasten some lathe jacks to the under side of the table to get a fairly solid mount for that. It would then have 3 points of a mount. I would most likely have to give it a bigger foot print on the base too. Especially with the motor off to one side.
I was thinking of using an r-8 for the tool holding, but that is flexable. I would use a drawbar as well. I have found a good source for the shafting, bearings and acme threaded rods and fittings.
Where can I find a shaft that already has a taper for tooling that I can use a drawbar with?
Thanks again.


G.A. Ewen
08-16-2004, 06:44 PM
<font face="Verdana, Arial" size="2">Originally
I was intending to completely remove the quill and shaft, pulleys motor and everything actually. Then I have a cast iron head on a steel pipe with a table and a base under it. I'm pretty sure that the hole for the pipe goes all the way through the head, but rests on stops. I was thinking about essentially cutting the pipe down the center and make a 3/8 inch slot about 6" or 8" down.

Good idea but instead of pipe how about mechanical tubing? It will be a lot more ridged that pipe.

08-16-2004, 08:39 PM
Hmmm. Well, I did go out and pull the belt guard off. The hole does go through the casting, but about half way up, instead of stops, it has a collar cast into it. The column seems to be milled or at least turned. The collar is a good machined fit. Now the conundrum is that I need a mill to finish milling the cast to the precise size of the shaft. I think what I really have here instead of the makings for a PITA tiny mill with 1/2" tolerances is a boat anchor. A small one at that. http://bbs.homeshopmachinist.net//wink.gif
I need to re examine purchasing one instead. Then maybe I can make something later. http://bbs.homeshopmachinist.net//smile.gif
Thanks for the help anyway, Guys.
Any suggestions from ya'll for a small bench top model? I'll do a search first and check them out. $700 for a Chinese mill that'll need the same tweakage as my mini lathe just seems like a lot of rice to me.


08-16-2004, 09:35 PM
If you want to do it for the fun of it then go ahead, it sounds like a cool project. But from a cost standpoint, I can guarantee when it’s all said and done you will be working for a buck an hour or so.


08-16-2004, 10:56 PM
Wow. Thats twice what I manage on some projects. http://bbs.homeshopmachinist.net//smile.gif
I will hang onto the DP and parts. It may turn into something one day. I have plenty of fun things to do already. LOML said to quit screwing around and buy the **** thing. http://bbs.homeshopmachinist.net//wink.gif I'm not going to pull any triggers just yet. My mini lathe is a small mill with the addition of an accessory. On down the road, then possibly aquire a decent mill. The things that I am wanting to mill, I would rather buy anyway. They are cam locks. The handle portion at least. Like the ones that fasten a clamp on a bicycle seat or front wheel.
I have looked for this part all over the net and the only ones I can find are too big. I bought a couple of these already. http://www.cambriabike.com/qr/rocky_mountain_seat_collar.htm
Any help locating these would be of even better assistance than advice on a mill right now.
I can R&D one or two parts, but I'll be needing a bunch of them if my design works like I imagine it will. Thanks again.