Posted by Sherman in Idaho [72.47.153.112] on Tuesday, February 25, 2014 at 16:40:41 :
Any of you machinsts out there have any clever ideas for how to pull out a pin that's driven flush to the surface and goes into a blind hole?
I'm trying to disassemble a lathe to clean it and de-rust it, and I find that the carriage is attached to the apron with pins, and the block holding all lead screw and 3 other horizontal bars is attached to the bed with pins. It's like they nailed the thing together. I understand the point of using them for alignment, but it seems like it was designed to never be disassembled. I can't get the carriage off the bed because there are screws underneath holding the lower guides on which I can't get to with the apron in the way. I can't move the carriage to the side of the apron because of the pins. I can't drop the apron down because its various gears collide with the various bars. I can't slide it off the end without removing the bed from the base. If I could just get two taper pins out of the carriage I'd be set. They are loose in the apron but I can only separate the parts about 1/16th of an inch, which isn't enough to get any tool in there. I could theoretically drill and tap the pins and pull them out, but taper pins are hard and this seems like an exercise in frustration and broken taps. Plus, they're probably in tight and I can't get much pull on what would probably be a 10/32 screw at most. All I can think of is to slip a hacksaw blade in the gap and try to saw them off, if they're not too hard, which they probably are. Then I'd need to find some metric taper pins. I had a hard enough time finding American ones some years ago. If the casting that they go into wasn't so thick, I'd drill up from the bottom and drive them out, but I'd have to drill a hole about 8" deep in cast iron, and hit the end of the pin exactly, and do it with no access to the bottom side of the apron.
So, is there some magic trick I'm not thinking of? Did they really nail this lathe together so it can't be disassembled?
Follow Ups: