Belt Tension Adjustment on SO3 using Neil Ferreri's Tension block design

CNC Brands Carbide3d
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I use Neil Ferreri’s design of tension adjustment block. The 3D printing files can be found on Thingiverse under the heading “Shapeoko 3 Belt Tensioning system”

I have made a very short video clip demonstrating how I use the tensioning block designed by Neil Ferreri. The clip is unsophisticated but it will demonstrate how easy and useful is the Neil Ferreri design of tensioning block.

I created index marks on the 600mm long rail. I measure and adjust the tension of the central 280mm length of the 9mm wide Gates GT2 belt by suspending it 1/4" above the rail. Plucking the belt and observing the tuner, with the addition of playing the note on a digital keyboard to assist with honing in on the note.

I use a vibration detecting guitar tuner attached to the endplates of my SO3. The tuner is set to 440 cycles (concert pitch A) and I adjust the belt so that the 130Hz note C3 (130.8) is in the centre of the scale and is illuminating the green triangular index. In music it is possible to be very slightly out of tune and I do not consider the belt tuned until I see see the index mark illuminated without any additional plus or minus cents (one cent is 1/100th of a semitone). Any and all comments are welcome.

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Wow… this is a really great way to very accurately tension your belts.
Love this idea.

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I have found C3 to be ideal and the belts remain in tune for about 9 months at a time. There are some really helpful ideas at Carbide 3D forums. Here is the belt tuning/calibration guidefrom Liam Newcombe - Measuring belt tension, squaring and calibration - Shapeoko - Carbide 3D Community Site

The tensioning blocks are a design by Neil Ferreri over at Carbide 3D and here are the files on Thingiverse.

Now my spindle is working well, I intend to machine the blocks in metal… I fancy bronze or aluminium. My PwnCNC spindle upgrade write-up is here.