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.
What have you done to your mill / drill ??
To increase the rigidity of the column, reduce vibration or generally make it feel more like a Bridgeport
How about success with a VFD if you're using one?
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
Ok, so maybe "Bridgeport" was just a little bit optimistic.
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).]
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-Elect...isplayZ2QQtZkm).
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.).
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.
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.
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.
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.