indicator fixture for cross slide

[PeterT]

I needed a high degree of accuracy on my cross slide for a recent job so made this clamp fixture for my 1.5" dial tenths indicator. There isn't a great spot to mount dials anywhere on the cross slide assembly without drilling holes or brackets. But this worked out pretty good. I re-mounted the dial back plate 90-deg so the mounting lug is perpendicular to the plunger vs. aligned. The plunger ball rests on the end of the cross slide casting so it sees absolute displacement. If the cross slide needs to be positioned more inward, I have screw-on plunger posts to extend the reach. If it needs to be positioned more outward I can screw in a spacer post between the mount & the lug. This particular indicator range is only 0.250" but was fine for this particular application.

 

[Dabbler]

Nice to see! Great way to double check movements!

 

[Hruul]

Thanks PeterT. Looks like another project to add to my project list.

 

[Tom Kitta]

Looks great - I just used my magnet to measure my cross slide when threading - this widget would be used instead as it would be faster to setup - if I had one.

However, I think a DRO is a better option for long term use - I have to measure my little lathe and order one on aliexpress. I still make accurate parts with just the dials but DRO on my mill has proven that it is far faster to use then dials. Also greatly reduces errors.

 

[PeterT]

Yes DRO is perfect for 99% of applications. I was doing some tool post grinding that needed finer resolution. (It’s a tenths indicator.) Attaching a dial with a mag block or whatever is still a good method in the absence of DRO but harder to do on the cross axis. I might be able to adapt a mini mag block with a special rail but it seemed a bit clunkier & no real advantage over the clamp.

 

[PeterT]

If you ever want to see whats REALLY happening when you tighten the carriage lock, just install an accurate dial. When I first installed the DRO I was shocked to see 3-4 thou movement displayed on the DRO yet my dial was stationary. Then I modified the slide locking screws so it has a bearing ball on the end. That pushes brass foot which is angled like the gib so its more pure lateral force. The stock design torques on the gib strip which a) moves things b) makes bite marks down the gib strip. I still think there is a better system but that mod got it to within a thou pretty reliably, but it still moves slightly. No wonder creeping up on final diameters can be challenging. The nice thing about a DRO or dial is it takes the backlash & clamping out of the equation. They cost money but makes machining so much more enjoyable. Respect to old school machinists that worked around it with various tricks & could count backwards & do mental math on the fly.

 

[Kelly McLaughlin]

Thats a nice elegant solution! Nicely made! Food for thought : )