Printable View
All my tape measures are crap; the hook at the start is not fixed and has about 0.5mm play, so it is impossible to accurately measure things like lengths of steel for my CNC machine frame.
Can you guys recommend an accurate tape measure where the hook is fixed precisely, or another way to go about measuring longer items?
The movement of the hook is to have an accurate measurement of both ID and OD or length measurements. The movement is about the thickness of the hook.
Ahh I see, but still can anyone recommend an accurate item, rather than one where the movement is only about right?Quote:
Originally Posted by C_Bubba
How accurate ? How wide is your stick of chalk ? :friendly_wink:
I agree with John on this one. A "tap measure" is not a real accurate measuring device.
I would not even agree that the markings are real accurate! (precision)
Same.. it's the obvious solution.Quote:
Originally Posted by chip
Surely for a frame what's more important is to get repeatability since it's unlikely to make much difference if you measure 600mm and get 600.5mm as with the error you describe every piece will be 600.5mm. The frame will still be square etc, just negligibly off the size you wanted.
Tapes are for wood and rough material sizing, precision engineers rule is the minimum I would recommend and even then I'd double check every time.!
How would you accurately measure 1800mm, Jazz?
put two one metre rules end to end.
Tapes arent that accurate anyway and I think are only reasonable good at 20 degrees C. Since most tapes get wear and tear at the ends the best way as the others say is to measure from 100mm mark remembering to adjust for it at the other end. We used to get 15mtr tapes sent for calibration at one point, total waste of time in my opinion.