Are most rotary tables like this?

[WobblyHand]

I’m not 100% sure but is this what your talking about , around the 7 minute mark

. I have the same one as Joe Pi and fixed mine too

Something like that. Ok, that is an extended pointer - a nicer version of what @682bear mentioned. Not skilled enough to make that just yet, but sure would be nice to make.

 

[WobblyHand]

Loosen the "tee" handle and rotate the whole crank assembly clockwise to disengage.

Will try that tomorrow.

 

[RJSakowski]

My 12" Enco RT lines up perfectly with the index mark when the slots are parallel with the vertical mounting surface. The 6" Tormach 4th axis which appears to be built on a Phase II RT is about 30º off.

 

[woodchucker]

I have just put a piece of tape on the table and used an ink pen to make a mark at zero...

That is pretty standard practice on the 30 inch rotary table we use at work.

-Bear

that's pretty much what I did see this: https://www.hobby-machinist.com/threads/steady-rest.97516/page-2#post-923124 #19

 

[Manual Mac]

I’m not sure if this is what you are talking about, but on my 6” four slot RT I removed the rivited-on degree pointer (it was off a number of degrees when the slots were 90º (or lined up) to the mill table. and would put a silver verithin line on the RT body when the slots were 90º or lined up with the slots on the mill table.
i finally made A zero pointer plate and drilled & tapped for the (now) adjustable zero pointer.
much easier for me to use.
not sure how this would work on a 3 slot RT, but 1 slot would be able to be zero’d out.
or I may be full of shirt.
As always, YMMV

 

[Flyinfool]

It has always been my opinion that those slots are not precision machined, they are just there for clamping things down. I have never tried to index anything off of the T slots.

But now you did get me thinking of making a sacrificial plate for my RT......
I have had some pretty crazy setups just to get things clamped down. It would be nice to just drill and tap a hole as needed where needed.

 

[WobblyHand]

I’m not sure if this is what you are talking about, but on my 6” four slot RT I removed the rivited-on degree pointer (it was off a number of degrees when the slots were 90º (or lined up) to the mill table. and would put a silver verithin line on the RT body when the slots were 90º or lined up with the slots on the mill table.
i finally made A zero pointer plate and drilled & tapped for the (now) adjustable zero pointer.
much easier for me to use.
not sure how this would work on a 3 slot RT, but 1 slot would be able to be zero’d out.
or I may be full of shirt.
As always, YMMV

I have a four slot RT. Seems that the angle offset is not abnormal. My pointer is fixed with screws, so I could make an offset pointer. Seems even a Vertex RT is a kit. Oh well, I'll mod the pointer. Have some 0.010" brass I could use, if I can cut it without distortion.

 

[woodchucker]

I have a four slot RT. Seems that the angle offset is not abnormal. My pointer is fixed with screws, so I could make an offset pointer. Seems even a Vertex RT is a kit. Oh well, I'll mod the pointer. Have some 0.010" brass I could use, if I can cut it without distortion.

10 thou use a scissor, then re-flatten.
That does not make it a kit. That makes it different than you think it should be.
Add another pointer like Manual Mike.. A valid thing.

 

[WobblyHand]

That does not make it a kit. That makes it different than you think it should be.

Guess it is a matter of expectation management. Seems strange to me that stuff sold to do relatively precise stuff may be manufactured with oddball offsets, or require calibration, which require some degree of knowledge and talent to fix. For this example, it is an easy fix.

Since entering this strange world of machining and precision, I have experienced more of this than I had anticipated. Perhaps it is all due manufacturing to a price point, but it continually surprises me nonetheless. Just my perspective. YMMV.

 

[woodchucker]

Guess it is a matter of expectation management. Seems strange to me that stuff sold to do relatively precise stuff may be manufactured with oddball offsets, or require calibration, which require some degree of knowledge and talent to fix. For this example, it is an easy fix.

Since entering this strange world of machining and precision, I have experienced more of this than I had anticipated. Perhaps it is all due manufacturing to a price point, but it continually surprises me nonetheless. Just my perspective. YMMV.

well, then we need to see what was going on in the 30s to the 70s here in the USA.. were they all as you think, or did they vary? I'm not sure.
Maybe we can ask some guys out there with some old equip what it looks like.