- Joined
- Jan 20, 2016
- Messages
- 173
Had a MSC 8x30 mini knee mill for past 10 years while waiting for a decent Bridgeport at a decent price nearby; some of the 8x30 mods/upgrades have been shared/shown on here. After 10 years for constant searching, I recently picked up a 1973 Bridgeport Series I 9x42 with Step Pulley head at a local auction with minimal wear for a good price. Despite being a Bidspotter auction, it even had a reasonable rigging fee to move it the 4 miles to my house and place in my garage. Because it was a Bidspotter auction, you could not power it up during the pre-auction inspection; could only tell that it was in nice shape with minimal backlash everywhere. Had a Bridgeport feed but no DRO, so couldn't tell if feed worked (owner said it did). Didn't realize till after it was delivered that it had a single phase motor, so saved the VFD I was planning to buy.
Spend the first couple of weeks building the moveable base for it. Found some 3/8 x 4 x 4 angle drops at a steel yard in Delaware, so worked on building the base. While building the base I placed adds for the MSC 8x30 knee mill on FB Markeplace, Craig's List, and here (it was seriously in the way). Sold in 1 week of FB for full price, so that was nice to get it out of the way. I got the same as I paid for it 10 years ago, so the Bridgeport & rigging was an even swap for the smaller MSC mill.
Was able to pick it up with my 1 ton chain hoist and place it into the base (had to rotate the head 180° and place weights on back of ram to make it hang level). Could finally get the machine out of the way and near its final resting place to begin working on it. Got it powered up, motor/spindle is quiet in both high/low ranges. Table feed didn't work initially, but that is another topic/post for another day.
As I went to use the mill, I noticed that the boss on the quill housing to side of the quill lock did not have the vertical hole drilled thru it, and it did not have a cross lock screw. I have seen some really old Bridgeports that didn't have this boss at all, but I never saw one with a boss that was not factory drilled. Not exactly sure what the purpose of the hole in the boss is for, but when I was a tool & die maker I mostly used them to place a chip shield or dial indicator stem into; same as I wanted to do with this mill.
So first question is: What is the true purpose of the vertical hole & cross lock screw that factory typically placed in this boss?
What size diameter is the factory hole - can anyone measure theirs? The stem on my chip shield is Ø 1/4, but I seem to remember that my stem was pretty loose in the factory hole.
Any thoughts about best way to drill this hole? Don't think it is a critical featur that would require a drill strapped to the table somehow. I am tempted to rotate the head 90° and drill it by hand (probably with 3 drills, small-medium-final size, or maybe a final ream). Anyone see any issues with that?
Ted
Spend the first couple of weeks building the moveable base for it. Found some 3/8 x 4 x 4 angle drops at a steel yard in Delaware, so worked on building the base. While building the base I placed adds for the MSC 8x30 knee mill on FB Markeplace, Craig's List, and here (it was seriously in the way). Sold in 1 week of FB for full price, so that was nice to get it out of the way. I got the same as I paid for it 10 years ago, so the Bridgeport & rigging was an even swap for the smaller MSC mill.
Was able to pick it up with my 1 ton chain hoist and place it into the base (had to rotate the head 180° and place weights on back of ram to make it hang level). Could finally get the machine out of the way and near its final resting place to begin working on it. Got it powered up, motor/spindle is quiet in both high/low ranges. Table feed didn't work initially, but that is another topic/post for another day.
As I went to use the mill, I noticed that the boss on the quill housing to side of the quill lock did not have the vertical hole drilled thru it, and it did not have a cross lock screw. I have seen some really old Bridgeports that didn't have this boss at all, but I never saw one with a boss that was not factory drilled. Not exactly sure what the purpose of the hole in the boss is for, but when I was a tool & die maker I mostly used them to place a chip shield or dial indicator stem into; same as I wanted to do with this mill.
So first question is: What is the true purpose of the vertical hole & cross lock screw that factory typically placed in this boss?
What size diameter is the factory hole - can anyone measure theirs? The stem on my chip shield is Ø 1/4, but I seem to remember that my stem was pretty loose in the factory hole.
Any thoughts about best way to drill this hole? Don't think it is a critical featur that would require a drill strapped to the table somehow. I am tempted to rotate the head 90° and drill it by hand (probably with 3 drills, small-medium-final size, or maybe a final ream). Anyone see any issues with that?
Ted
