I have some largish parts that I had been profiling out of plate, with attendant finishing problems. I detailed the issues in this thread. The goal was to eliminate the coupons (tabs) left to hold the parts in the plate which had to be removed and finished by hand; also to reduce setup time. The parts are between 8" and 14" in longest dimension. They have round overs on both sides, so I was concerned about how much grip I could get on the rounded edge. Consensus was I wouldn't need much, but I might distort the part unless I used some sort of vacuum fixture.
I have two Orange double station vises I originally reviewed here. Sol at Orange vise suggested I could use some of his Size Large machinable jaws and sent me some to try. These are 10" wide, and big enough to contain nearly the whole part. With the matching center jaw, I was able to get two parts on one vise. Like the normal jaws on the Orange, they can be set up as moving or fixed, but in addition these can be reversed so you can use both ends (there are clamping wedge features at both ends, so you turn them 180 and use them again). I put 1" parallels between the jaws and machined the shape into them. There is enough metal left to recut them for a refresh in this use probably 100 times.
Here are the longest parts, first side has been machined, the waste removed, and clamped in the soft jaws. You can see how wide the jaws are compared to the 6" vise base. One part is done, the other raw:
The jaws and part overhang enough I had to move the vises closer together to get within the work envelope. They grip about 0.400 of the edge, but the 0.25 round over on one side makes the grip only 0.15, leaving about 0.015 tool clearance for the second side round over. One of the issues on these things is the round over bit causing chatter. This was not a problem with these jaws, because the part is very well supported and damped:
Second part is more triangular, but grip on the thinner (moving jaw) side pretty skinny. I engraved the part name on each jaw, if you can read them they are in the right way around:
Parts finished. On these I could space the vises and get four in the machine if needed. The thin part of these is 0.2" with some stiffening ribs underneath. They do distort about 0.002, bowing up in the middle. That is acceptable in that area, and I get some relaxation distortion anyway due to the amount of metal removed. I interpolated 2 holes near the edge of the center jaw, these are used for electronic probing for datum and rotation. (I back bored them after this picture was taken, otherwise chips would pile into the hole and interfere with the probe). If the center jaw is removed and replaced, it repeats within about 0.0003 position typically (within the thermal drift of the DMG), and rotation less than 0.002 deg. I probe before each finishing pass, after 4 or 5 parts are run and thermal stability is achieved, the errors are down to 0.0001 or less, and features on the part probe within about 0.0003 true position:
The result has been pretty much all positive. I can use a much smaller blank because no perimeter is needed for vise grip on either the first or second side: I machine above the vise jaws on the first, and grip only the machined surface on the second. That reduces cost and allows room for two parts in the machine. The registration and repeatability is good enough I probably don't even have to probe once the machine is warmed up. The part is supported over about 80% of its edge and 80% of its underside so there have been no chatter or vibration problems. I can swap from the step jaws to the soft jaws to different soft jaws in about 5 minutes (could be much faster it I was in a hurry, but I'm not - spend some time cleaning the vises, etc.). Even if the datum has been reset or vises moved, I can just eyeball zero over the tooling hole and then run automatic probing for setup, which takes about a minute.
I'm still quite happy with Orange Vise and I really like the big jaws. I have ordered more.
I have two Orange double station vises I originally reviewed here. Sol at Orange vise suggested I could use some of his Size Large machinable jaws and sent me some to try. These are 10" wide, and big enough to contain nearly the whole part. With the matching center jaw, I was able to get two parts on one vise. Like the normal jaws on the Orange, they can be set up as moving or fixed, but in addition these can be reversed so you can use both ends (there are clamping wedge features at both ends, so you turn them 180 and use them again). I put 1" parallels between the jaws and machined the shape into them. There is enough metal left to recut them for a refresh in this use probably 100 times.
Here are the longest parts, first side has been machined, the waste removed, and clamped in the soft jaws. You can see how wide the jaws are compared to the 6" vise base. One part is done, the other raw:
The jaws and part overhang enough I had to move the vises closer together to get within the work envelope. They grip about 0.400 of the edge, but the 0.25 round over on one side makes the grip only 0.15, leaving about 0.015 tool clearance for the second side round over. One of the issues on these things is the round over bit causing chatter. This was not a problem with these jaws, because the part is very well supported and damped:
Second part is more triangular, but grip on the thinner (moving jaw) side pretty skinny. I engraved the part name on each jaw, if you can read them they are in the right way around:
Parts finished. On these I could space the vises and get four in the machine if needed. The thin part of these is 0.2" with some stiffening ribs underneath. They do distort about 0.002, bowing up in the middle. That is acceptable in that area, and I get some relaxation distortion anyway due to the amount of metal removed. I interpolated 2 holes near the edge of the center jaw, these are used for electronic probing for datum and rotation. (I back bored them after this picture was taken, otherwise chips would pile into the hole and interfere with the probe). If the center jaw is removed and replaced, it repeats within about 0.0003 position typically (within the thermal drift of the DMG), and rotation less than 0.002 deg. I probe before each finishing pass, after 4 or 5 parts are run and thermal stability is achieved, the errors are down to 0.0001 or less, and features on the part probe within about 0.0003 true position:
The result has been pretty much all positive. I can use a much smaller blank because no perimeter is needed for vise grip on either the first or second side: I machine above the vise jaws on the first, and grip only the machined surface on the second. That reduces cost and allows room for two parts in the machine. The registration and repeatability is good enough I probably don't even have to probe once the machine is warmed up. The part is supported over about 80% of its edge and 80% of its underside so there have been no chatter or vibration problems. I can swap from the step jaws to the soft jaws to different soft jaws in about 5 minutes (could be much faster it I was in a hurry, but I'm not - spend some time cleaning the vises, etc.). Even if the datum has been reset or vises moved, I can just eyeball zero over the tooling hole and then run automatic probing for setup, which takes about a minute.
I'm still quite happy with Orange Vise and I really like the big jaws. I have ordered more.
