Indicating in an indexing head

[GunsOfNavarone]

So, i purchased an indexing head some many months ago. Spend a lot of time reading learning about them. One thing I haven't come across, how to square it up on the mill. It does have a pivoting head, but using a machinist square seems like a quick way to do that, i don't think the dead out is dead on...splitting hairs, but not exact. How to indicate it along the Z axis? The surface of the unit isn't smooth, probably not straight either. The actual chuck? Why do I not think that is a good idea either?
just a little back story, I was just experimenting with it, no harm no fowl. I drilled a hole halfway through a piece of 1" sq bar , rotated 180° and drilled the other side. They were off. Not 10's thousandths, but 100's (along the Y axis) so that brings me to possible issues. Being square and I need to check for fun out on that chuck. Seriously doubt it's that, but just throwing it into the mix.
Happy Friday Gentlemen!

 

[MontanaLon]

Pull the chuck off and put an indicator in the mill spindle to see if the spindle in the indexing head is true. If that is good put the chuck back on and use a piece of drill rod in the chuck to see if it is true. It shouldn't really matter if the indexer is square to the mill as rotating it shouldn't change the relationship of the piece to the spindle of the mill.

It sounds to me like you weren't actually on center of the work. try using a round piece, it will be easier to find the center of it and get your hole located exactly. Make sure you center drill both sides to eliminate bit wandering.

 

[benmychree]

Best way to align is with a test bar, but if the dividing head is of good quality, I just set it to the zero degree mark, and have close fitting keys to fit the dividing head and table slots, also, a precision square against the face of the chuck should put it on accurate alignment. To accurately center stock for cross drilling as you stated, use the test bar in the spindle taper, or a piece of drill rod in the chuck if it centers well, or indicate it and rotate until the high or low spot is either on the top or bottom, then using a wiggler, pick up the edge of the test bar or piece, and move over half the diameter of the wiggler and half the diameter of the test bar, that should put you quite close to center.

 

[Illinoyance]

For those indexers that can be used ether horizontal or vertical, I indicate across the back of the indexer when using it vertical. Some of my indexers and thee RT can be keyed to the mill table. My Kalamazoo indexer and my spin index have been modified by milling the sides of the base parallel with the centerline of the indexer. That allows me to clamp them in the mill vise.

 

[mmcmdl]

My Kalamazoo indexer and my spin index have been modified by milling the sides of the base parallel with the centerline of the indexer. That allows me to clamp them in the mill vise.

My Hardinge heads have been slotted to match the BP table slots , and also ground on sides to center line of this slot . Makes for an easy set-up and usage in vise .

 

[darkzero]

I use a piece of Thomson shaft. Good enough for me.

 

[GunsOfNavarone]

Holy crap DarkZero...Is that your shop or a Dr's office??. Clean, well lit....I'd eat off that mill table!

 

[GunsOfNavarone]

Thanks guys! I guess I should have added, I'm fairly new to the home shop machine shop. I'll admit a bit of what you guys were talking about lost me.
Anyway MMCMDL AND ILLINYONCE and I think even more than that, you guys mentioned slotting your heads of keying them for quick indicating. I'd really like to see a picture of what you've done or at least a layman's explanation of it.
No worries if that's a bit much, I'll find some time to research that.
Much appreciated all, I really just want to jump in and get to it, I have to find so much time for cleaning and calibrating..that time consuming on its own.

 

[darkzero]

Holy crap DarkZero...Is that your shop or a Dr's office??. Clean, well lit....I'd eat off that mill table!

That's my kitchen. I don't know how you do it but I always clean my table off before bolting an accessory to the table.

I don't normally have both my super spacer & vise on the table at the same time. My SS was already trammed in & I needed to use the vise for something quick but I still needed the SS afterwards. It ended up that what I needed to use the SS for just barely cleared the vise so I just left it on there.

 

[darkzero]

you guys mentioned slotting your heads of keying them for quick indicating.

Like many vises, dividing heads, rotary tables, super spacers, etc usually have slots on the bottom for keys. I don't use them on my vise or rotary table (personal preference) but I do use them on my super spacer & tailstocks.