How To Handle Down CMMs?

Fire up the surface plate and sine plates! 
Ask your local Hexagon office if they have a loaner Romer arm to at least measure something. 
3d print some contour templets on a $150 Ender 3 and hope for the best. 
Walk to the shop next door and trade with them, maybe you have machine time and they have CMM time, work out a deal.

My CMM is currently down for Refit. But we have a Leica, and 2 large Romers, and 3 old Red Romers as mothballed backups, and technically a Pocketgage Romer (it's so cute).  So, they just expect us to "get by" even if it takes 5x the time. 

This is interesting.  We have five CMM's at our facility, so usually when one is down, we have others that we can run parts on.  With one exception.  We have two jobs of similar parts that are very long and we stand up vertically to run on our big DEA CMM (15-20-14).  So if that goes down and we have those parts, we're kinda screwed.  But I like the idea of having a Romer arm (or similar) as a backup.  I have been interested in getting a used one just as a backup for our lab and other stuff.  Any idea of which brands are any good?  I've never used one.  I have no idea what a used one costs, but I would need that for my boss to justify buying one.

CMM to Romer arm? Wouldn't accuracy be an issue?

That's a good question.  I have no idea how the accuracy of one compared to the other is, in numbers.  I know that Romer arms are less accurate, but how much less, I don't know.

dcoss said:

That's a good question.  I have no idea how the accuracy of one compared to the other is, in numbers.  I know that Romer arms are less accurate, but how much less, I don't know.

Most portable arms are approximately 10 times less accurate than stationary CMM's (30µm to 50µm as opposed to 3µm)

We have you use the Leica laser tracker to even maybe be in the outskirts of the vast parking lot for the CMM's ballpark.

Leapfrogging an arm that many times leads to some "compounding issues with accuracy."

Sadly Leica's are prohibitively expensive, but do open you up to some impressive measurement volumes. Pending line of sight, I could easily measure any surface in my 60'x40'x30' lab. 

We have you use the Leica laser tracker to even maybe be in the outskirts of the vast parking lot for the CMM's ballpark.

Leapfrogging an arm that many times leads to some "compounding issues with accuracy."

Sadly Leica's are prohibitively expensive, but do open you up to some impressive measurement volumes. Pending line of sight, I could easily measure any surface in my 60'x40'x30' lab.