View Full Version : What have you done to your mill / drill ??
08-17-2001, 05:36 AM
Nobody has mentioned using Fenner link belts instead of the original equipment. It's worth it! I made a ten inch long bar with T-bolt cross section that fits snugly in the table slots so I can square up work or a vise pretty accurately and quickly. Added neoprene levelers and leveled the table with a master precision level so nothing rolls off. Wrote "1/4 inch per turn" near the head crank, and the idler bolt size near the drive shroud (perpetual senior moment). Replaced the x-motion stop with a vertical rod mounted in a split clamp so I can remove and replace it accurately during a machining operation. Made a square, split clamp out of 1/2" aluminum plate that clamps onto the bottom of the quill. Screw holes in the edge hold a fixture with a short, horizontal rod that accepts dial indicator clamps. Handy when you don't want to disturb the tool in the collet to hold an indicator.
Thanks to all for all the good ideas! I'd especially like to add a dial caliper to the z-motion.
09-30-2004, 02:04 PM
To increase the rigidity of the column, reduce vibration or generally make it feel more like a Bridgeport http://bbs.homeshopmachinist.net//wink.gif
How about success with a VFD if you're using one?
09-30-2004, 02:10 PM
Painted it gold metalflake in clearcoat over a glossy black paint.. Pinstriping to come soon. Maybe a lil airbrushing, some mirror polished stainless.
Fanciest drill press in Tunnel Hill Georgia.
David Cofer, Of:
Tunnel Hill, North Georgia
09-30-2004, 02:30 PM
Ok, so maybe "Bridgeport" was just a little bit optimistic.
09-30-2004, 02:49 PM
Sorry, I couldn't resist.
I put a toshiba single phase in, 3 phase out 2hp inverter in it. That way my old bridgeport would run on single phase and have speed control. I put a ten turn speed pot on the head, inverter is started by the opto-22 control boards, they work off the parallel port and isolate the 5vdc ttl control computer voltage via ODC5 opto modules.
Actually I gutted it like a fish, sold all the old junk on ebay and made myself a mill. It is more David Cofer than Bridgeport nowadays.
David Cofer, Of:
Tunnel Hill, North Georgia
[This message has been edited by ibewgypsie (edited 09-30-2004).]
09-30-2004, 03:14 PM
The application isn't to a mill (how I wish!), but I recently installed a VFD on my 20" bandsaw. It works like a charm. The outfit I went through also has an ebay store (http://stores.ebay.com/Friesen-Electric-Inc_AC-Motor-Control_W0QQcolZ2QQdirZQ2d1QQsclZallQQsotimedispla yZ2QQtZkm).
I found AC Tech to be very clear in their manual, which is the main reason I selected the brand. (Usual disclaimers, no connection etc.).
09-30-2004, 03:15 PM
I use the smaller (~ 300 lb) Grizzly mill-drill. To increase rigidity, and in general get the most out of it for heavy work, I:
(1) clamp work directly to the table, instead of in a vise,
(2) use a collet instead of an end mill holder,
(3) use short, fine-tooth roughing end mills (3/4" dia), they chatter less than regular end mills, and
(4) retract the quill and lower the head as far as possible for the setup.
This allows setting the head flat on the base of the column for most work, it is a whole different machine than with the head a foot up the column.
It is no Bridgeport, but after 10 years the more I use it the more I like it. Darn handy for general metal and wood work.
09-30-2004, 06:52 PM
Starting with a Taiwanese round column mill-drill on a heavy stand of my own construction . . .
1) Replace the column clamp bolts with grade 8 -- the old ones stretched, these don't. Head doesn't rotate any more under heavy cuts.
2) Fiddle with the gibs, to get them evenly tight. Helps a bit.
3) Use roughing mills for heavier cuts. Helps a good bit more.
4) Add a laser for repositioning. Didn't help with vibration, but made me feel better about the mill.
5) Buy a square column mill drill -- which is truly a bit more rigid. Keep the old mill drill with a rotary table on it.
09-30-2004, 08:03 PM
I agree with some of what Toolbert and Pete has done, I haven't done the laser things yet. I use rougher a lot on my mill/drill, where on my knee mill, I seldom need them.
I bought one of those 3/8 inch clamp sets and use them more than the mill vise. I do suggest that if you use this method, buy or make extra cross bars, T Nuts, hold down bolts, etc. You never seem to have enough for some projects.
09-30-2004, 08:27 PM
I added a 6in.dial caliper to the front of the spindle casting and depth bracket.Drilled a hole in each jaw and mounted it vertically. Wish it had been my idea. Need to do something with those sharp inside jaws! Works great for accurate depth machining.
09-30-2004, 08:39 PM
I like using a vise quite a bit but one thing PeteM mentioned has me thinking. I have noticed what appears to be bolt stretch on the jaws of the Kurt clone. Replacing them may stiffen that up a bit.
Has anyone attempted to dampen the column by filling it? This has been discussed a bit in the past but I was wondering if anyone has seen results from it.
A caliper on the quill seems to be an essential for precision work. It's pretty hard to determine depth without it unless you keep the quill lock under some slight pressure and feed against it, reading the micrometer dial on the downfeed. Some of the downfeeds are not accurate though.
09-30-2004, 09:11 PM
You can fill the column with oiled sand to dampen vibrations. Another idea involves drilling holes in the column, inserting interior cross bracing (lengthwise), welding through the holes then remachining it. A better idea might be to have a "big" shop machine a new solid post.
09-30-2004, 09:34 PM
I think a bridgeport could turn my mill into confetti in a single pass. All I have is a harbor freight micro mill. Better than nothing though.
09-30-2004, 10:38 PM
High spindle speed + sharp cutters + tight gibs = small, precision work.
Actually, you have an advantage (over the M/Ds) with the dovetailed column ... but you'll still be shredded http://bbs.homeshopmachinist.net//wink.gif
10-01-2004, 12:07 AM
I bought two clamp sets and some extra clamps. Bought and made a lot of studs in short lengths. I do a lot of panel work for electronics.
Changed out the lock screws on the cross slide with SHCS with plastic snap on thumb screw heads. Much easier to use.
Made a table in Excel to calculate actual spindle feeds vs handwheel markings.
Of course I tramed and shimed the column to square it to the table.
Made a pair of blocks to quickly align flat panels to the table slots.
Now if I could figure a way to make it self cleaning...
10-01-2004, 06:39 AM
I was gonna remake the column out of 1 inch flat stock, but I think I'll get some 1 1/2 inch chrome cylinder rod and make some brackets so the head doesn't move when it goes up and down. I don't swing it from side to side anyway.
10-01-2004, 11:18 AM
http://www.industrialhobbies.com/Merchant2/merchant.mvc?Sc reen=PROD&Store_Code=IH&Product_Code=SQR3A&Category_Code=R (http://www.industrialhobbies.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=IH&Product_Code=SQR3A&Category_Code=R)
Makes a "nice" CNC. Mill ordered yesterday. Will wait for it to actually be here then order the servo kit. JRouche
[This message has been edited by JRouche (edited 10-01-2004).]
10-01-2004, 12:39 PM
** drool **
These things started to come out just a few months after I bought the M/D http://bbs.homeshopmachinist.net//frown.gif
10-01-2004, 12:43 PM
i couldn't resist this...........
i gave mine to my kid and bought a knee mill.
10-01-2004, 01:18 PM
<font face="Verdana, Arial" size="2">Originally posted by billr:
i couldn't resist this...........
i gave mine to my kid and bought a knee mill. peace.
That's the best thing a person could do if they have the room. I would suggest buying the knee mill before the bench top. They are so inexpensive now.
If you are looking for CNC the price would be about the same. I also have a Bridgeport CNC and it cost me about the same as this bench top is gonna be.
Also the link above has some nice mods you can do to the small mills. It is under "tips and how to". JRouche
10-02-2004, 06:12 AM
I bolted the stand to a concrete pad I cast mainly because the floor was not level. I filled the stand with as many bags of sand as I could fit. This certainly dampened the stand vibration. Next I braced the top of the column against the concrete block wall using a piece of angle iron and against the ceiling joists with 1" diameter steel tubing. This stiffens the column to a noticeable degree. I can take heavier cuts without the machine complaining. I have definitely given some consideration to a VFD and new 3 phase motor. This combo I am sure would make the mill easier to use and I suspect it would deal with the remaining issue of a slight vibration that comes with the stock motor.
I have taken the table off the machine two different times, the last time was to add ball bearings on the ends of the leadscrew. They are sealed bearings (6003) so I don't have to remember to oil them as before. I replaced the stock taper roller bearings and adjusted them so the machine can run at top speed without getting hot.
Besides the normal tweaking to the machine I have added digital calipers for the X,Y and Z axes using Roland Friestad's plans in HSM and just in the past month I added Scott Shumate's DRO. This addition has been the best thing I have added to the mill since I got the X axis power feed. Scott's design is great and not that expensive (<$150). The difference it makes to have a real DRO is hard to measure (is that a pun?).
10-02-2004, 07:45 AM
I replaced it with a Bridgeport!!!
10-02-2004, 09:04 PM
Cut a 2 1/2" post...slid it in the column so about 5 inches hangs out the bottom. Sealed the bottom with breadbags...filled the whole column with cement. Have 1/2" bolts in the bottom that bear up against the post that hangs out the bottom. These can move and stiffen the column. Also made a very heavy stand...filled the legs with sand before welding it together. Attached a Fowler 6" digital caliper to the quill...works great for depth control/measurements. Also replaced clamp bolt with Gr8 bolt.
10-03-2004, 12:39 AM
My mill-drill came with a heavy, but still inadequate stand. Not much more than a beefy endtable sort of thing. I built a heavy duty table for it, using reclaimed drill casing (heavy-wall pipe used in well drilling- that's oil wells, not water wells.)
4" diameter legs, 3/8" plate top, lots of cross-bracing, and most importantly, I ran two 2.5" diameter pipes all the way up to the top. They straddle the head, with clearance for the head and controls, and has an A-frame clamp that attaches to the top of the column.
Unfortunately I did this before learning that even a mill-drill cam be 'trammed', and pretty much locked it into a few thou off.
The frame added much-needed rigidity, but did nothing for the loss of zero when moving the head, or any of the other drawbacks. I replaced it a year or two ago with a Grizzly full-size knee mill, which I'm very happy with. Haven't looked back.
Last spring I yanked the MD apart and started working on it (slowly) with the idea of converting it into a homebrew CNC. I have some of the parts collected, but haven't yet sprung for ballscrews or steppers.
What I'll probably do first is finish the general rebuild (new C5 spindle bearings, all-new drivetrain to get rid of the old vari-drive crap, which is badly worn) and replace the motor, get it all spiffed up as a normal manual mill. Once I have it back in service, then I'll go back and work on the CNC conversion.
10-05-2004, 03:23 PM
Thought I'd try to restore this one since it disappeared on my watch.
10-05-2004, 03:34 PM
Herb, Thanks for making it re-appear.
Does the link belt have a significant impact on vibration or noise on these machines?
10-05-2004, 10:43 PM
Den - The link belts worked so well that I bought an accelerometer to measure the difference in vibration on my RF 30 mill/drill, but haven't done it yet.