Hi Steve Errors in the tram would reduce the accuracy of the Z axis I did check this prior to testing . I also used a plunger type DTI which was held in a collet setting the plunger on centre line.

@@enotsengineering If you look back at your video you are altering the Z axis in all your measurements. But if you've tramed the head before starting then everything will be fine. 😉

Thanks, will do!

Hi John Yes the gauge blocks are correct at 20c but the scale and machine is under 20c that's why I put the gauge blocks on the machine bed so the temp would be the same as the machine. So if the gauge blocks contract with the temp the machine should contract the same.

@@enotsengineering thanks Alan :-)

Hi The latest DRO from Banggood is better than the older ones see my review kzfaq.info/get/bejne/aqygZZamspbdk2Q.html see link with 15% off in video description

Hi Dave the correction data is In mm on my unit I would think that as most scales are metric you need the deviation in mm. You can convert inch to mm then input the correction result in mm.

Hi Ram. 1.50918 was the calculated correction over a metre to correct the error in the scale

@@enotsengineering I have sino product do you have any idea

It should tell you how to make a correction factor in your scale instruction book

@@enotsengineering thank you can you upload end mill milling in manual milling machine

@@enotsengineering I have doubt in side milling because expert says it affects screw rod and cause backlash

This is to remove angular measuring. Picture a tape measure cooked on an angle vs straight. The scales when installed are leveled and straightened off of the aluminum extrusion. Often quite long. And to build a length that Long that is rigid enough to not flex appreciably would require extream mass. Which is inconvenient for linear scales. So we compensate for the angular miss match of the scale to the machine ways. With the invisible magic of computors doing triangle maths