Wixey questions & tolerances

[Rob Lindquist]

After seeing the Wixey equipment on this site I bought through Amazon so SMC would get a cut.

I bought the decimal/fraction calipers and the DRO for the RC-33 planer I bought for $200:D.

Install was fairly easy. The only problem is the calipers and the DRO do not measure the same piece of wood the same. The DRO seems calibrated fine .750 comes out as close to .750 as I can tell with a scale, but the calipers always shows about .006 less than the DRO. Putting the wood under the DRO shows .000, taking it back out it returns to .750. I tried measuring other pieces and the same results. Tonight I will bring home another dial calipers (Starett) and see what I get. Also I will bring home some of my micrometers and use the calibration pieces that come with them so I know exactly how thick the piece is I am measuring.

I'm not too concerned yet, but how close is close enough with wood?

[Myk Rian]

Check the caliper faces for a burr. A fine stone or diamond hone will clean them up.
I have my doubts sometimes about the Wixey DRO on my DW735 planer. The bottom zeroing plate isn't exactly a truly flat reference point.

[Glen Butler]

A decent set of calipers are typically good to .0005 resolution. Basically they will tell you if youare to the high side or low side of the next one thousandth. The wixey digital readouts are only good to .005 resolution. So they will tell you if you are to the high side or low side of the next one hundredth. Remember learning rounding in elementary school? So seeing a difference of .006 is not unreasonable, and you can trust your calipers more, but any miniscule piece of dust and the way you pinch the calipers together can change it a couple thou.

[glenn bradley]

+1 on the zeroing plate issue. I fooled with mine a bit and ditched the double-stick foam in favor of bolting the unit to the planer. Much better. I will still get reading discrepancies between the DRO and another device now and then but realized something. I get different readings in the low .00X" values across the planed board with the same calipers because . . . let's all say it together . . . wood moves.

[Larry Frank]

I put the DRO on my DW735 recently and had the same issue with different readings with it and the calipers. At best, the DRO on the planer is an approximation due to the bottom plate as mentioned by others in this thread. I checked and found the Wixey calipers to be very close to calibration blocks and more than good enough for a piece of wood.

I use the planer DRO mainly for lowering the head a fixed amount rather than a good measurement of the wood thickness.

[Rob Lindquist]

I found last night it was much better if I calibrated it to thicker wood, I had done it on a 3/8" piece. I did it with 1.25" and it is and stays exactly the same as the calipers. Obviously with the tappered bottom plate you need to be very sure you find the "sweet Spot" when calibrating. All in all it is a good tool for the price, better than the rivetted on tape and pointer.