First milling machine project

[Buckshot]

http://www.fototime.com/C7B62885781C4F6/standard.jpghttp://www.fototime.com/A5F10F07ABFBF64/standard.jpg

I made myself a set of soft jaws! :-) Big whoopee deal eh!? Crap it took long enough. I probably could have filed one out faster, but I got to use all the 'Stuff'. Seems like all I was doing was cranking the knee up and down, and the table back and forth. First I took some 1/2-13 allthread and tuned a 60* point on each in the lathe. Took the steel jaws off and screwed in the pointy dealies.

Crank the vise out of the way. I oughta write that "CTVOOTW" because I did that a lot :veryconfu. Put in a collet and TI holder and TI, then Cranked the vise back and touched the TI back and forth across the tip to find 'it', and zeroed the DRO, then cranked over to the other one and entered it as a referance point. Then CTVOOTW, took out the pointy dealies slapped in a couple parallels and laid the pieces of aluminum in and tightened the jawless jaws.

The I CTKD (Cranked the Knee Down), took out the TI holder and put in the new (o-boy, I get to use it) new intregal shank Albreckt chuck and center drill. Then CTKU and move the table over to the 0.0000" place and center drill. Then CTKD and put in the 1/2" drill bit and CTKU drilled the hole. Then CTKD and put in a .520 reamer for clearance, CTKU and reamed the hole. CTKD and replace the reamer with a counterdrill. CTKU and counterdrill the hole.

Anyway, you get the idea [smilie=w: Of course I was using the quill to do the drilling, reaming etc. After the first was counterbored, the 2nd had to be done. The 1/2-13 sockethead screws fit perfectly just like this was the real deal, ha!

After the jaws were in and the vise closed up on them I touched off the endmill to zero the DRO so I could crank in on the Y axis to indicate .750" + .1875" for the width of a jaw plus half of the 3/8" endmill. So I cranked in .9375" and danged if that bloody endmill wasn't too far over the middle! I backed up and did it another couple times and boy this had me really stymied. Then I decided to check how thick the aluminum was. AHA, it's 5/8" and not 3/4". Yeesh!

After that it was smooth sailing. Ran the quill down to cut a .125" deep slot, hit the powerfeed and lit up a smoke, I deserved it :bigsmyl2:

...................Buckshot

[wonderwolf]

Gotta start somewhere :Fire:

looks good though

[scrapcan]

making chips in another direction (not everything makes chips that fall to the floor or the chip pan on the lathe, now you have to clear off your work piece also), good to see. Now the rest of us can come up with more projects for your enjoyment.

[Cap'n Morgan]

"CTKU"

Buckshot,
I remember what a pain in the rear it was cranking the knee up and down on a Bridgeport. One of the guys in the shop, where I worked as an apprentic, tried using a power drill with a simple clutch for the task, and it actually worked quite well.

This was before cordless, varispeed driver drills. Maybe there's a special project here, turning one the modern power beasts into a 'little helper' ?:-D

[grumpy one]

I'm missing something here. Why do you need to move the knee when you have 5" of quill movement? I seldom find any need to move the knee except for initial setup, i.e. making gross table height moves, unless the head is tilted. (You always get vertical movement from the knee, but not from the quill unless the head is vertical).

[Typecaster]

Chips ahoy!

Richard

[rusty marlin]

Looks good, but you forgot a very important detail. The inside corners should have a relief milled into them. This is for the odd burr, or small bit of swarf. I use a 45 dovetail cutter to mill in about .02" reliefe. A cutoff wheel in a Dremel held at 45 degrees works just as good, just not as neat and tidy.

[Buckshot]

manleyjt.....ah, chips! I'd bought some .125" thick polycarbonet in 1x4' sheets so I could cut it up and make up assorted chip guards. The first thing I did after making the soft jaws was to snap off a 6" x 12" piece. It needed 2 slots cut into it, so with it in the new jaws I made the slots and at the same time a bunch of fine fluffy plastic shavings.

Not to worry though. I grabbed the hose of the shop vac and turned the sucker on. When I pulled the hose around to get at the stuff the vac also turned and the exhast blew that stuff ALL OVER. Double CRAP!! It floated around forever it seemed. Nothing for me is EVER real simple it seems. I have dues to pay for some reason.

grumpy one , I was just trying to do everything as close to the quill as possible. Or rather, to not stick the quill out any further then possible. The whole rigidity issue. Add to that I'm new to this and don't know what I can get away with (again, rigidity). The collets don't take much room, but the drill chuck uses about 3", and then the center drill is short, the 1/2" drill was like 6" and the reamer is about 8".

rusty marlin , Rusty, you're exactly right. I didn't even think about that. O-BOY! Now I get to use one of the dovetail cutters :drinks:

.................Buckshot

[Willbird]

Buckshot you are dead right that ALL milling should be done with the quill all the way home. If you ponder on it a bit you will see that you can make a four sided soft jaw. They will be taller than what you have now, and will have counterbores in BOTH sides, so they need to be thicker too....but then you get more or less 4 sides to use as long as your milling is not too deep into the jaw.

One handy thing to machine into them is a pocket with a shallow 60 degree V(actually 30 degrees of the face of the jaw)...maybe 1/2" deep....this will allow you to quickly toss a batch of round items in there to do work on the ends of them. The shallower angle means that a slight dia. difference between parts does not equate nearly as much shift in the workpiece location as if it were a 45 degree V. You can also cut one set with a vee clear thru top to bottom, and another set with TWO vees, one on each end to hold two parts at once :-)

If I make up a set of soft jaws with milling done on both the fixed and mving jaw, if I put them back in later I just snug the jaws, then tighten the vise on a part, then really tighten the jaws...this lets them line themselves back up.

I have made them mostly from any kind of cold rolled steel.

You CAN undercut the corner with a hacksaw going in at 45 degrees if your careful :-)

Bill

[dragonrider]

Buckshot, here is my solution to cranking.
http://castboolits.gunloads.com/picture.php?albumid=29&pictureid=127
http://castboolits.gunloads.com/picture.php?albumid=29&pictureid=128

works slick.

[grumpy one]

grumpy one , I was just trying to do everything as close to the quill as possible. Or rather, to not stick the quill out any further then possible. The whole rigidity issue. Add to that I'm new to this and don't know what I can get away with (again, rigidity). The collets don't take much room, but the drill chuck uses about 3", and then the center drill is short, the 1/2" drill was like 6" and the reamer is about 8".
.................Buckshot

Rigidity is of primary importance - a serious toolroom machine like a full-sized Cincinatti transforms milling operations compared with any movable-head machine, and makes a joke of a Bridgeport which acts like a large leaf-spring by comparison. However it depends what kind of cutting, and cutter, is involved. Essentially quill rigidity is not an issue when you are cutting along the axis of the cutter (plunge cutting), but becomes important when you cut across the cutter. Cutting across a long cutter held in a drill chuck, will limit you to just a few thousandths per cut. The loss of rigidity associated with extending the quill somewhat is only important if you are trying for heavy cuts with extremely rigid cutters. Remember always to lock all movements (table and quill) firmly before you cut, except for the one you are actually cutting along.

I would use knee movements and retract the quill if I were cutting laterally using, say, at least a one inch cutter which was overhanging from the face of an extremely rigid toolholder by only an inch or so. Otherwise I'd be happy to have the quill extended by up to a couple of inches. I haven't seen any difference compared with a fully retracted quill, when cutting this way using a one inch end mill protruding from the toolholder by say 2.5 inches. The spring in the end mill is at least an order of magnitude greater than the spring in two inches of that huge-diameter quill support.