Bridgeport slotter head
Start here - I couldn't find the operator's manual for the Bridgeport E shaping and slotting head on line. The link I did find shows you the guts. Careful reading will give you an idea of how to adjust the stroke, set the gibs on the ram, lubrication etc. Page 46 on the PDF; 42 on the manual page:
http://neme-s.org/Shaper Books/Bridgeport Manuals/Bport Series 1 Install Operate and Maintain.pdf
Browse the auctions here. Some are educational:
http://www.ebay.com/sch/i.html?_odk...aping+.TRS0&_nkw=bridgeport+shaping+&_sacat=0
There's also dubious stuff on YouTube.
Maybe I'm lucky.
My BP E head has a cleverly designed little clapper box with adjustable spring tension, index detents, and a relief stop and has a 5/8" tool hole with a single set screw.
Factory BP 5/8 slotter tools in a set are expensive: I've seen them on eBay for $400 and up for a partial set of seven tools and the link below offers a new full set for nearly $700. That's $70 per tool. You can make them easy enough from 5/8" dia x 6" round HSS cut to length but be careful of the as-ground shank dia. The HSS round can run a bit oversize. It should fit snug but if it's too snug it may be hard to extract.
Here's an eBay auction that has several very informative photos:
http://www.ebay.com/itm/NEW-BRIDGEP...ultDomain_0&hash=item461decae79#ht_3694wt_629
BP Type E heads are beautifully designed but while they are robust for their scale that doesn't put them in the same league as a Pratt & Whitney 12" vertical shaper or even a slotter attachment for a horizontal knee mill. OTH you won’t break off the ram unless you do something Darwinian dumb.
When using a Bridgeport E head, you have to limit not only the amount of material removed per stroke but the actual width of material the cutting edge engages. When you buy a turret mill you buy versatility not cutting capacity. Don't sneer at it for not being a 15 HP K&T.
A 1/8 keyway tool in mild steel is about the limit for a BP E head in plunge cutting. If you have to cut a wider keyway, better start with 1/8" and, using a succession of wider tools, cut the width in symmetrical stages. YMMV but start conservatively.
If you have to enlarge a round hole to square, make the hole about 2% larger than the finished square to reduce the amount of material you have to remove and to greatly simplify the finishing.
Make a double corner cutting tool whose side reliefs and clearances are 5 degrees. The tool should start out looking like a keyway tool and the width should be a bit less than the width of half the square. Relieve the center between the corners leaving narrow lands at the corners. Naturally the tool has to clear the hole: you may be in for a LOT of grinding. Cheer up. Once you've labored through grinding a few nicely made shaper tools they can be used for many other things.
Orient the clapperbox to solidly seat the ball detent and tighten the clamping screws. Incidentally the clapperbox is retained by bevel ended pins (pc E28) matching an angle groove in the ram pilot much like the compound swivel clamp on a South Bend lathe. If you have to remove the clapperbox for any reason, be sure to back off the set screws (pc E80) far enough for the pins to fully retract. Also on re-assembly, make sure the bevel on the ends of the pins mesh with the bevel in the ram’s retaining groove.
Dial in the ram stroke square with the table in X and Y. Note the machined reference edges in the E head’s lower front cover.
Indexing: Rotary table, super spacer, or use the detents in the clapper box. Your choice.
Install the tool and dial in the lands before tightening the set-screw.
Check the oil level and add worm or hypoid oil as needed.
Set the stroke to the feature length plus 1/2" or so.
Position the tool at the bottom of its stroke. Adjust the knee so the tool just emerges from the bottom of the work. Allow clearance for chip accumulation.
You need positive support to keep the tool from pushing the work from the thrust of the cut.
Monitor the clearance under the work so the tool doesn't run into a parallel as cutting progresses.
Check the width of the tool, find the center of the hole and work out the X and Y of the hole corners with respect to the tool corners.
Make a sketch to help you keep track of your moves.
Center the hole under the tool and crank the tool through its stroke by hand-turning the step pulley. This ensures you don't start the motor with something solid in the tool path.
Jump the belt to the top pulley step for minimum strokes per minute and snug the motor clamp. You can speed up as you gain confidence. Go no faster than the palest straw chip color on steel.
Start the motor and hope for no surprises. Nibble away at the corners of the square until you get used to what you are doing. A 0.008 depth of cut by 0.005 incremental feed is a good starting point. Increase from there. Be careful. You will have enough time to dial 0.040" in a single return stroke but don't do it.
Watch what you’re doing and how the machine responds to your control inputs. Listen to how it cuts. Try to develop a general cutting strategy as you work.
Follow your sketch.
One very important point: in-bore shaper tools are springy and the whole E head is dainty. The tool, unless perfectly ground, tends to deflect on entry leaving a bell-mouthed hole. You will have to be careful of end rake and side relief, tool wear, minimum cut, and to an extent coolant. You may have to "spark -out" the cut. Sneak up on sizes at first depending on the work hardening characteristics of the material.
This is new stuff. Don't be a fool. Practice on scrap before you move on to the part you may have some hours in.
