Calibrating without 1-2-3 blocks

[ThLDQ]

Hi,
I've not got any 1-2-3 block and I wondered a lot to calibrate my scales.
This is how I did :
I placed a dial indicator in the X axis referring an edge of my wise, then chose an arbitrary CPI (2550) for the X axis, and displaced my X axis 1mm (checked on the dial).
I then noted the displacement counted by TouchhDRO.
I changed the CPI (+10), moved back to 0 on the dial indicator (after having removed the backlash), displaced the X axis 1mm (checked on the dial), noted the displacement counted by TouchDRO.
Then I just had to adjust the CPI +/- in order to have the maximum accuracy between the dial and TouchDRO.
All this measurements were made in 00.000 mode and in MM.
After that I checked in the 00.00 mode and adjusted once again if needed.

BUT I'm not sure this procedure is good and accurate.
Maybe it's better to buy 1-2-3 blocks.
Please tell me.
Regards
Thierry

[Tweinke]

I think you could use the indicator in place of the blocks but I am pretty sure you will want to set the cup to 10000 to do the calibration. There is a tube video on calibration also there is the same info listed under setup on the main site.

[ThLDQ]

Hi Tweinke,
I've not been able to find the video nor the infos.
Could you give me the links, please.
Regards
Thierry

[Briney Eye]

The complete process with 1-2-3 blocks: https://www.youtube.com/watch?v=s4Aa1Q9zOc0

Alternatively:

1. Set the CPI to 2540 (for Shahe scales), move the axis to one end of its travel, zero the dial and zero the axis in TouchDRO.
2. Crank the axis some whole number of inches, even to the other end of its travel if you want.
3. Perform the following calculation: CPI * Display_Inches / Dial_Inches = New_CPI
4. Plug the new value into CPI (it takes fractional values).
5. Repeat the previous three steps for the other direction.

For instance, you move the axis three inches and TouchDRO displays 3.028"

2540 * 3.028 / 3 = 2563.7

Make sure you take the backlash out before commencing the move. When your dials agree with TouchDRO you're done.

If you're in metric mode I'll leave the calculation to you.

[ThLDQ]

Thank you for your help.
I finally bought 1-2-3 blocks which will be usefull for my constructions.
Regards
Thierry