Precision turntable

[GiroDyno]

Trying to design a measuring fixture for some of our products which are basically 5<10" ID x 10<16" OD rings. We need to rest each part flat on a fixture and spin it 1 full revolution while we measure the runout/flatness/parallelism(?) at the periphery on both top and bottom. Our goal for these is <0.001" max deviation and I would be measuring with some 0.0001" indicators, so the runout of the rotary fixture needs to be (at mimimum) just as tight as my measuring equipment.

The measuring function of the fixture is only part of the battle as we have 300 different parts and will need to make it universal/self centering, and preferably somewhat automated... so before I get too into the weeds I want to make a homebrew proof of concept, any ideas what to use for a precision turntable?

I've looked into air bearing spindles and such but they are quite expensive, thinking maybe a milling rotary table since they are easy to come by and operate, but I'm not sure how much runout they have IRL.
Any other ideas?

 

[Homeshopblob]

Is a Talyrond not suitable for these parts?

 

[GiroDyno]

Is a Talyrond not suitable for these parts?

Never seen or heard of that before in my life, but that's pretty close to what I'm looking for
Thanks!

 

[specfab]

FYI, the Talyrond systems are air-bearing spindles; they will have the accuracy you are looking for with a lot to spare, assuming a given unit is not totally clapped out as a used machine. A used air bearing rotary table will likely work if you can get one from a reputable source and you are able to test it before buying. Decent air bearing tables are typically tested for accuracy in the single-digit micro-inch ballpark.

As far as mechanical rotary tables meant for machining or inspection, you will need to be on the high end of the scale for that level of as-built accuracy. Maybe Moore, SIP, or Ultradex would be places to look if you want to get close to your desired tolerance to start.

 

[ballen]

Buy this and use the table and bearings. Quite a deal for 250 Euro:

Heimwerken. Heimwerkerbedarf gebraucht kaufen | eBay Kleinanzeigen ist jetzt Kleinanzeigen

Kleinanzeigen: Heimwerken. Heimwerkerbedarf gebraucht kaufen - Jetzt in St. Johann finden oder inserieren! eBay Kleinanzeigen ist jetzt Kleinanzeigen.

www.kleinanzeigen.de

 

[mattthemuppet]

here's another air bearing table, got this in an auction lot a couple of years ago. I don't know how much they are new, but the buyer was very happy with spending a grand on a used one

 

[fobyellow]

Buy this and use the table and bearings. Quite a deal for 250 Euro:

Heimwerken. Heimwerkerbedarf gebraucht kaufen | eBay Kleinanzeigen ist jetzt Kleinanzeigen

Kleinanzeigen: Heimwerken. Heimwerkerbedarf gebraucht kaufen - Jetzt in St. Johann finden oder inserieren! eBay Kleinanzeigen ist jetzt Kleinanzeigen.

www.kleinanzeigen.de

i would like to pay 200 euro for the probe and the signal condition box, if you buy it

 

[jccaclimber]

I recently bought a Moore 11" to do this. I'm not yet convinced it has runout that meet the factory specs, but then again it is 52 years old. For the experiment I'm running that's fine.
If I could have gotten a 350 euro Talyrond I would have done that, though I'm not sure what it would take to control the spindle if not used with the rest of their software. Does anyone know if the much older ones are also air spindles?

 

[specfab]

I bought a Talyrond 150 (whatever that means) maybe 15 years ago at a local govt.surplus sale. It has an 8" air bearing with 10" tilt/centering table, and that stuff is mounted in a cast-iron base that also contains "simple" motor drive electronics and some airplumbing, as well as being outfitted with a t-slot rail (hand-scraped) on the back side to mount up indicator stands that came with it. I disconnected and removed all the motor drive stuff so I could use it by hand. It would have been relatively easy to swap in a different motor and external drive.This system was likely a 1980's vintage. It's labout 220 lbs. The Taylor-Hobson and earlier Pneumo Precision 8" rotary air bearing tables are right at 90 lbs by themselves. I can't imagine that there is a Talyrond roundness instrument that isn't based on an air bearing.

 

[ballen]

i would like to pay 200 euro for the probe and the signal condition box, if you buy it

Just realized that this was meant for me... where are you located?