Pending any unexpected events I plan to have my (hobby) EZ-Trak running in the next week and am looking for a couple quick projects to make some chips. I'm also teaching a couple of the lab techs at work basic machining on an old Series 1 so I'm looking for a couple not too hard projects that use a variety of tools.
A split cotter quill lock seems like a good one, but I have a couple questions:
1) Do you need to index the threads or just trim down the brass piece in the front so the lock lever comes out at the right angle? I've seen lots of stock machines with washers in there and one of the online solutions uses a hex so they can get it oriented right. I'm not seeing any other obvious adjustment. How did they do this from the factory?
2) Is it better to slightly overshoot or slightly undershoot on diameter? I'd guess slightly under, but will a couple thou even matter? My only other experience is in clamps for round objects (bicycle stems and such) where slightly under was preferred and the mating part would deflect a bit.
3) Several people mention putting it in the back so that gravity opens it. I like the concept of gravity opening it, but not having it on the back. Other than the cost of a tap and die (or lathe work) is there a reason not to just use a left hand thread?
4) I'll be making these for two or three mills (all Series 1 heads). The gap for the bolt on mine is somewhere around 0.42" so I won't be able to get really close with a drill bit. There is a set of plug gages near only one of the mills. Is this dimension likely to be tightly held on all Bridgeports, or is it likely where ever it happened to end up?
5) Other than maybe sliding a cutter up into a collet is there anything that locking the quill more securely is likely to let a new person mess up?
One example:
Bridgeport Split Cotter Quill Lock | Dezign Shack Blog
A split cotter quill lock seems like a good one, but I have a couple questions:
1) Do you need to index the threads or just trim down the brass piece in the front so the lock lever comes out at the right angle? I've seen lots of stock machines with washers in there and one of the online solutions uses a hex so they can get it oriented right. I'm not seeing any other obvious adjustment. How did they do this from the factory?
2) Is it better to slightly overshoot or slightly undershoot on diameter? I'd guess slightly under, but will a couple thou even matter? My only other experience is in clamps for round objects (bicycle stems and such) where slightly under was preferred and the mating part would deflect a bit.
3) Several people mention putting it in the back so that gravity opens it. I like the concept of gravity opening it, but not having it on the back. Other than the cost of a tap and die (or lathe work) is there a reason not to just use a left hand thread?
4) I'll be making these for two or three mills (all Series 1 heads). The gap for the bolt on mine is somewhere around 0.42" so I won't be able to get really close with a drill bit. There is a set of plug gages near only one of the mills. Is this dimension likely to be tightly held on all Bridgeports, or is it likely where ever it happened to end up?
5) Other than maybe sliding a cutter up into a collet is there anything that locking the quill more securely is likely to let a new person mess up?
One example:
Bridgeport Split Cotter Quill Lock | Dezign Shack Blog