Feickert Protractor - anyone use one?

I humbly disagree with Stiltskin and Doug.
Alignment is only one of the functions possible with the Feickert. For me the greatest benefit is setting the spindle to tonearm distance accurately which allows the absolute effective tonearm length and overhang as specified by the tonearm designer.
Only those with adjustable (swinging) armboards (as on the Ravens), will appreciate this function but with the Feickert it is possible to get these accurate to 0.2mm.
I have the DaVinci 12"Ref Grandezza tonearm which comes with the Feickert complete with the set-up platter with one side dedicated to the DaVinci and the other side applicable to all arms.
I also have the Continuum Copperhead tonearm which comes complete with a dedicated Wally Tractor.
When I set up the Copperhead using the Feickert, I obtain 99% accuracy when I then test it against the Wally Tractor.
However when I try to set it solely using the Wally, I can achieve little better than 90%?

Halcro, sorry I don't quite understand your last paragraph, are you talking about measured pivot to spindle accuracy?
An arc protractor such as your Wally that inscribes a specific arc your cartridge stylus follows and if set up is done correct you will know the stylus is where it should be.
The proof is heard in the play back.

I didn't get this with Grahams ingenious set up jigs for the Phantom, nor did I get this with the Feikert.

Sorry Stiltskin if I was unclear.
If I try to set up the Copperhead by adjusting the cartridge to follow the arc of the WallyTractor which (correct me if I'm wrong) has the same mirrored base and inscribed arcs as the Mint, I can't seem to achieve a perfect match without taking hours and hours.
However if I adjust the Copperhead using the Feickert and THEN run it over the WallyTractor arc, Le Voila!!!

And yes you are right......the proof is definitely heard in the playback.

Henry Yes using an arc protractor for some can wear patience fast,for me,by the third attempt every step became a whole lot easier.
Setting up your Copperhead with the Feikert are you saying your stylus follows the inscribed arc of the Wally?

One major feature of a mirrored arc tractor its designed to allow the ability to align the cantilever and stylus tip to a extreme degree of accuracy which further reduces distortion.

And yes the MintLp and Wally tractors are similar as far as design goals are.
However the Wally as far as I know right now is next to impossible to get.

Yes Stiltskin, when I set up the Copperhead with the Feickert (20 minutes), it then follows the arc of the Wally Tractor (Baerwald)....perfectly!
Regards
Henry