Wednesday, April 12, 2017

Mill: Vises

While prefer clamping directly to the table, I like vises because they're already trammed, so anything I clamp with it I know is already aligned. I primarily use two: a screwless precision vise and an angle drill press vise.

The 3" screwless precision vise fits beautifully on the mini mill and has more than enough clamping power for the machine. Be sure buy one with slots on the sides instead of just holes, since it makes clamping the vise at angles much easier. I purchased mine from Shars and paid about $54 shipped.

As soon as it arrived I made two modifications. I removed the holder the bolt threads into, and removed the cross piece from it which hooks into the grooves on the bottom of the vise. I then turned a new cross piece on the lathe whose length just fits. This keeps the assembly from rotating when tightening or loosening the vise. Second, I put a spring the bolt. This keeps tension on the bolt at all times, making it much easier to move and hook the cross piece. 

One of the biggest annoyances using the precision screwless vise was loosening the jaw and accidentally unscrewing it from the T bracket which holds the cross bar that hooks into the base. After having it happen it again in the middle of a project I took the screw which connects the jaw to the T and turned it smooth starting 5 threads from the end.

Middle section of screw turned smooth.

I then ground a flat on the T right where it threads onto the screw. I then assembled the vise, threaded the screw into the T, and peened the flat to capture the screw. Now, no more accidentally unscrewing it.

Another reason I like the screwless vise is because I don't need a swivel base to rotate it. I can just loosen the clamps, rotate the vise on the table, check it with my protractor, and tighten the clamps back down. This provides more rigidity and more space between the head and table. Making the clamps is a good project for the mill.

The angle drill press vise isn't a milling vise, and has a whole set of issues because of it. The moving jaw will always want to lift when tightening, so I need to tap it with a hammer once it's tight and also make sure the work didn't move, thought using parallels helps since I can carefully tap the work back down until it's resting fully in the parallels. The vise also isn't super stiff, but for the power the X2 has it's adequate. Finally, it can be a bit of a chore setting the angle on it, and usually requires a bit of tapping it back and forth with a hammer. However, the angle adjustment is dovetailed, hardly has any play, can be locked very solidly, and has basic angles preset with the use of a pin. To set a precise angle I just zero my Wixy digital angle gauge on the table and then stick it on the vise and set my angle. Some operations on the mill would be pretty difficult to set up without an angle vise, so I'm happy to deal with its shortcomings, especially since it only cost me $43 brand new from Sears.

My preferred vises.


I also ended up getting a 3" Kurt-style milling vise. The Kurt-style vise forces the moving jaw downward as it's tightened, which keeps the part from lifting. While it's not quite as precise as the screwless vise, it's faster to use. It did need a lot of cleanup work. The Casting for the jaw where it meets was the nut was deformed with extra material in the jaw, so I Dremeled away the extra. Also with the Dremel I smoothed out the location where the hemisphere rides in the jaw. After this I lubed it up and reassembled it.

Ultimately, the precision screwless vise is what I prefer over the Kurt-style vise. It's very easy to set up and square up, it's high capacity is really nice, and with my modifications it's not much slower than the Kurt-style.


No comments:

Post a Comment