Aligning Spin Indexer using dial test indicator and pin

[coolgoose]

Hi Everyone!

I have recently purchased a spin indexer and have been going through the below posts http://www.homemodelenginemachinist.com/index.php?topic=5766.75

http://www.homemodelenginemachinist.com/index.php?topic=2681.0

These are very informative posts for a beginner like me. Before I make changes to the spin indexer as mentioned in the above posts, I want to try aligning the spin indexer using a dial test indicator. The setup I am using is shown in the attached picture. The procedure I followed is same as the one used for aligning the vise. I have preloaded the dial test indicator and moved it across the pin in collet in the spin indexer. When I reached the end of the pin, I split the difference into half on dial indicator reading, by slowly tapping the spin indexer with a rubber hammer. Now the problem is, when I start the reading again from the start position of the pin, I still end up having the same reading on the dial indicator that I get before tapping the spin indexer with rubber hammer.

Can someone please describe the correct procedure? I must be doing something wrong here.

 

[coopertje]

When the angle is not changing the only conclusion I can draw is that the indexer did not rotate related to your table...... It can be that when the indexer is fixed to tight to your milling table that with the tapping of your hammer you move the milling table by a few hundreds. See if you can lock your table (just as test) and try again. Also I would try to loosen the clamps a little and add a clamp to the front side of the indexer. The change is big that when adding this clamp after having the indexer straight it will move slightly off again...

Hope this helps, Regards Jeroen

 

[coolgoose]

Thank you Jeroen. I will try your suggestions and report back with the observations.

Sri

 

[MachineTom]

I don't know if you have the height on the mill, such that the indexer can be mounted in the mill vise. That is where I use mine 99% of the time. Of course to do that the sides need to be milled paralell to the spindle of the indexer.

Another thing you can do is use a precision square to line off the edge of the table, and the front of the indexer, again only in you know that the front edge is square to the spindle, or you make it so.

 

[hobby]

Another problem could be, depending how it is clamped to the table that when you tap the unit, it is not pivoting from back to front, but semi parrallel, to the point where the indicator is indicating a sideways movement of the workpiece from its start position, rather than an arc.

Ive had that problem several times, when my clamping was not in ine with eachother, one clamp would be very offset from the other, and when I tapped the fixture, the clamps caused the fixture to move in a awkward fashion, giving false readings, to remedy it, I loosened the clamps, and manually lined up the workpiece in the fisture by eye to the indicator tip, while running the table back and forth, when I had a fairly even gap along the workpiece, than I preloaded the indictor against the work, and tapped for final tuning.

 

[Omnimill]

It may be easier if you had a longer piece of rod extending from the collet. Be aware as well that folks have found that some of the cheaper collets are not as accurate as they should be and that there may be some run out on the spindle. Once you're happy with your setup rotate the rod and check again to be sure! Keep at it you're get there! ;D

Vic.

 

[coolgoose]

Thanks a lot for all the advice guys. When ever I get stuck I always turn to this forum and get great advice :bow:

I finally found the problem. There are multiple problems:

• As hobby mentioned in his response, the clamping is one reason. When I tap the unit, it moves semi parallel rather than pivoting from back to front
  
  As Omnimill mentioned, the pin I am using in the collect is not long enough

My mill is SX3 model and has enough height for using the indexer in the mill vise. As MachineTom mentioned, I plan to mill the sides of the indexer parallel to the spindle of the indexer and use it in the vise. I guess this is easy rather aligning the indexer itself.

Thanks a lot for your time and suggestions guys!
Sri