View Full Version : homemade mill knee problem
10-11-2002, 09:04 PM
I am attempting to make a mill out af a benctop drillpress. But I have no accurate vertical adjustment,like a knee. Has anyone else done this? How did you do it? Any suggestions, anything at all?
10-11-2002, 10:12 PM
I think that you could use a long range dial indicator and a magnetic base to accurately gage your vertical adjustment. Set the magnet on the head with the indicator plunger touching the table and set it to zero. Then you would just lock your spindle quill, devise some sort of mechanism to lift the table (i.e. Cut some square threads on a rod, put a handle on one end a C-clamp "foot" on the other, weld a 1.500 inch long nut to the column. Just the start of a rough idea) and you would know how far the table moved by the indicator. Let me know how it works out for ya!!!
<font face="Verdana, Arial" size="2">Originally posted by David Hafnorske:
I am attempting to make a mill out af a benctop drillpress. But I have no accurate vertical adjustment,like a knee. Has anyone else done this? How did you do it? Any suggestions, anything at all?</font>
You're fighting an uphill battle on this one, because drill press bearings aren't designed to take side loads, only axial loads. The bearings may give up on you rather quickly, or become unacceptably loose, but if you're using small end mills and light cuts you may be okay.
CNCPhoenix has some good thoughts. I guess I'd just buy a section of Acme-threaded rod and a nut (it's pretty cheap), rather than bother with making my own, though.
You may want to put some kind of keyway along the column to keep the table from turning as it's raised and lowered. You could cut a square notch in the table clamp ring around the column and drill/tap the column for a piece of square keyway stock. There would be some slop, the best you could do, but with careful work it might be okay.
10-12-2002, 11:09 AM
Thanks guys. Good ideas. I knew about the bearing problem, but decided it is worth the risk if I stay with small endmills and light cuts. Replace bearings often. My drillpress has a sort of rack and pinion mechanism on it for vertical adjustment now. But it swivels side to side and is to sloppy. I figured I could weld or bolt the rack to the column, and maybe make a gib to take up some of the slop. Not exactly sure how to make the gib though. If i get this figured out, I may think about putting a hand dial on it . Until then I would have to use a dial indicator.
10-12-2002, 02:58 PM
Harbor Freight has a low cost mill for about $350 that looks like a drill press with a x-y table. You might be able to download the manual from their web site to see haw it is made.
Does your drill press have a morse taper?
I tried to use my Taiwan made drill press using the jacob chuck (it only had a jacob taper) and an x-y vice. when the chuck came lose with a 1/2" end mill and flew across the room I decided to not try that again. If you have a morse taper you may be able to make a draw bar and hold an end mill holder or collet in the spindle.
Good luck and be safe:
10-12-2002, 04:17 PM
DICK, this is the machine I am modeling mine after. I must have seen it in harbor freight once years ago, ( after I purchased my drill and table, otherwise I would have just purchased this machine ) but have not seen it in a catalog recently so I was begining to wonder if I dreamed it. It looks like they move the head up and down rather than the table. I printed the picture for reference. No, my drill does not have a morse taper, just a jacob taper. I removed the jacobs chuck and filed a little bit of a reverse flat on the jacobs taper and made an endmill holder with a set screw so it hasn't come off yet. I intend to make a drawbar since it is the only realy safe way. THANKS for the info!! P.S. when I downloaded it from harbor freight the one I found was $389.99. Does anyone out ther use a machine identical to this? If so, how do you like it? I would like any input good or bad.
[This message has been edited by David Hafnorske (edited 10-12-2002).]
Iv'e done some light end milling on my 17" delta DP. The results are never what you want. A DP is not designed with the stiffness necessary for milling. My DP has a heavy column (over 4") and a heavy production table, but the spindle is just not stiff enough and there is just too much give between the column, head and spindle, that the milling cutter either grabs or pushes itself away from the cut. Incidently
I have a setscrew on the spindle to keep morse tapers from coming loose, and my chucks are bolted axially to the morse tapers. I now have a horizontal mill and there is even some give that I can detect when taking heavy cuts. (There is no machine or anything for that matter, that doesn't yield, somewhat, under pressure) The question is how much yield is acceptable. On a DP the only way to mill is light cuts, high speed and sharp cutters, its very frustrating. The best thing would be to get a mill or a milling slide for the lathe. You're trying to do something beyond the capacity of the little machine (if its the one I think it is, the 5 speed benchtop with 2" spindle stroke)Iv'e got 2 of them and they are great for drilling small holes, I've even drilled to 1" by stepping up, before I got my big DP, but milling is pushing it too far. The column is only about 1 5/8" od and like I said even my Delta with the 4" column, gives under pressure.
I've been pretty resourcefull and have done jobs that I was told couldn't be done with the equipment I had. Mabey you could do the jobs you think you need to mill in another way ie; chain drilling, chiseling, filing, grinding etc. Sometimes hand methods end up being faster. I've found, now that I have a mill that its often faster and more accurate to file a job, rather than set it up in the mill. With hand work you have very prcise control and there is no chance of a cutter digging in too deep. Most work I do with a machine, I will finish with a file, because it allows very small amounts of material to be removed and removes tool marks and helps me avoid overcutting and ruining an almost finished piece.
I'm not trying to discourage you from experimenting with your equipment. I'm just giving you the advice that I wish someone had told me, before I learned it the hard way, after I had spent time and money and still couldn't do the operation I wanted to.
Hope this helps