- Joined
- Jun 12, 2014
- Messages
- 4,817
One of the issues when adding a DRO scale to the cross slide is that it often blocks the ability to use the lock. On the PM1340GT, they use a 6mm Allen screw on the right side of the cross slide which is completely inaccessible with the mounted DRO scale. I considered various options, but I wanted something (simple) that would securely lock the cross slide with no movement while machining with the Y axis. I ended up using the mounting holes for the steady rest to mount a 1/4" steel plate to the left side of the carriage, and it extends up to just below the top of the cross slide as seen in the picture. The plate is mounted with two 8mm cap screws.
The friction lock has an overall length of 0.8", so it has very minimal interference and the lock arm can be located down out of the way. I cut the lock body from 3/4" high strength 544 bronze rod (will not damage the steel), with 0.50" turned down and threaded to 9/16-18. The lock arm is 0.200 steel rod with a 8-32 thread on one end, it protrudes 1.125" from the lock body (any longer and they will interfere with the steel plate mounting bolts). When mounting the lock, I use a rubber washer on either side of the plate to give some friction (holds the arm when not engaged) and prevents chips from getting between the lock and cross slide. Once locked down, the X axis DRO stays within +/- 0.0001", good enough for me.
The friction lock has an overall length of 0.8", so it has very minimal interference and the lock arm can be located down out of the way. I cut the lock body from 3/4" high strength 544 bronze rod (will not damage the steel), with 0.50" turned down and threaded to 9/16-18. The lock arm is 0.200 steel rod with a 8-32 thread on one end, it protrudes 1.125" from the lock body (any longer and they will interfere with the steel plate mounting bolts). When mounting the lock, I use a rubber washer on either side of the plate to give some friction (holds the arm when not engaged) and prevents chips from getting between the lock and cross slide. Once locked down, the X axis DRO stays within +/- 0.0001", good enough for me.