Would you trust a modified test bar? There may be residual strains from heat treatment that will be released by grinding off the material that is causing the problem. I think you would have to get the whole thing carefully checked after modification and it may need complete regrinding to get back to the original specifications if you want to keep the existing centres. If you abandoned keeping the end with its centre just cutting the end off should not cause the rest of the bar to distort. You may though have a problem in that the original specification was with the morse taper supported over its whole length. Removing part of the taper may change the setting of the bar in the socket.

These are just thoughts and the only way to find out if it is possible is to do the grinding and check the bar afterwards.

Martin

At the risk of causing a choking fit in the Myford camp, is there sufficient "meat" in the spindle to allow an enlargement of the bore at the back of the taper to allow the test bar to seat correctly in the morse taper. The spindle should be soft and a No4 taper large enough to get a boring bar to the back of it. As already said, cutting about a carefully machined test bar seems likely to introduce errors.

Paul

That seems entirely reasonable, Rod

MichaelG.