How does one use the WallyTools tractor if the tonearm effective length isn’t equal to one of the gradations on the disc? My Durand Tosca effective length is 258.5mm. The gradations are 258 and 259.8. Would I just choose the closer one (258)? Does that mean my alignment would be slightly off or is the difference negligible?
I think you have to go on his site and look at a chart that has the effective length and it tells you the arc to use. I messed it up the first time myself. JR came to my house and went through it all. It was not obvious to me how to get the correct arc.
How does one use the WallyTools tractor if the tonearm effective length isn’t equal to one of the gradations on the disc? My Durand Tosca effective length is 258.5mm. The gradations are 258 and 259.8. Would I just choose the closer one (258)? Does that mean my alignment would be slightly off or is the difference negligible?
You can use either one. Small changes on effective length is not important because when you align overhang conforming to the arc on Wally Tractor, it compensates effective length while setting overhang correct.
The most important thing is setting up overhang correct. Effective length varies depending on pivot to spindle distance because P2S distance is not precisely achievable during tonearm mounting. The difference on overhang between effective lengths of 258 and 258.5 is small enough to be neglected. So using the closest effective length on the tool to your tonearm’s will yield perfect overhang alignment.
It’s very obvious from your sentence “I cannot reach either arc” that your tonearm is not correctly mounted to specified 258mm P2S distance. Small differences are not important but in your case it should be big. I recommend you to use 258mm arc after you set your tonearm’s P2S distance correct.
Because it is using the wrong effective length. I checked the alignment with my Mint Tractor (specifically for the Tosca) and it was spot on. With WallyTools it would have needed an adjustment.
I am no expert here but if the effective length is 258.5 how can it be properly aligned with an arc developed for another length?
You can use either one. Small changes on effective length is not important because when you align overhang conforming to the arc on Wally Tractor, it compensates effective length while setting overhang correct.
The most important thing is setting up overhang correct. Effective length varies depending on pivot to spindle distance because P2S distance is not precisely achievable during tonearm mounting. The difference on overhang between effective lengths of 258 and 258.5 is small enough to neglect.
It’s very obvious from your sentence “I cannot reach either arc” that your tonearm is not correctly mounted to specified 258mm P2S distance. Small differences are not important but in your case it should be big. I recommend you to use 258mm arc after you set your tonearm’s P2S distance correct.
Effective length doesn’t have to be precise as indicated in the specs because you most certainly already made a big enough (0.5mm) mistake on P2S distance while mounting the arm which directly affects effective length.
Effective length doesn’t have to be precise as indicated in the specs because you most certainly already made a big enough (0.5mm) mistake on P2S distance while mounting the arm which directly affects effective length.
There is no tool to enable that level of precision. It can show 258.5mm but drilling armboard, mounting tonearm is impossible in 0.1mm precision let alone locating pin of Dr. Feickert or Smartractor kind of ruler precisely on pivot point on the tonearm due to parallax errors. And even if you can do all those there is the question of whether the dot coinciding with real pivot point of the tonearm or not. That’s why it’s practically impossible to mount a tonearm on the armboard in 0.1mm or 0.5 mm precision.
More importantly all these are not important. Just choose the closest effective length and concentrate on adjusting the stylus following the arc precisely because as I explained above you think your tonearm is mounted at 258.5mm P2S distance but it isn’t. None of ours.
There is no tool to enable that level of precision. It can show 258.5mm but drilling armboard, mounting tonearm is impossible in 0.1mm precision let alone locating pin of Dr. Feickert or Smartractor kind of ruler precisely on pivot point on the tonearm due to parallax errors. And even if you can do all those there is the question of whether the dot coinciding with real pivot point of the tonearm. That’s why it’s practically impossible to mount a tonearm on the armboard in 0.1mm or 0.5 mm precision.
More importantly all these are not important. Just choose the closest effective length and concentrate on adjusting the stylus following the arc precisely because as I explained above you think your tonearm is mounted at 258.5mm P2S distance but it isn’t. None of ours.
I see. Makes sense. I guess what is important is that I follow the arc which is as close as possible to my effective length. Thanks for the explanation.
I see. Makes sense. I guess what is important is that I follow the arc which is as close as possible to my effective length. Thanks for the explanation.
Because it is using the wrong effective length. I checked the alignment with my Mint Tractor (specifically for the Tosca) and it was spot on. With WallyTools it would have needed an adjustment.
I am no expert here but if the effective length is 258.5 how can it be properly aligned with an arc developed for another length?
Your arm’s effective length is variable because you have a slotted headshell. So if your P2S was off you’re already compensating for it by moving the cartridge in the headshell. No different than aligning to an arc that’s slightly different than 258.5.
Your arm’s effective length is variable because you have a slotted headshell. So if your P2S was off you’re already compensating for it by moving the cartridge in the headshell. No different than aligning to an arc that’s slightly different than 258.5.
The reason for small differences like that you are referring to is because WHICH alignment pattern you choose (Loefgren, Baerwald, etc.) has not been standardized. On the WallyTractor, the nominal dimensions of the arcs are MOSTLY quoted in Baerwald, but each arc is a SET of two options - Baerwald or Loefgren. Depending upon the total radius, the difference between the two can be anywhere from 0.6mm to 0.22mm.
So...your Tosca arc is on the WallyTractor but they may have called out the Loefgren arc when I named the Baerwald arc. They are concentric with each other so when you look closely, you'll see the dual arcs. Whichever one you choose, the IMPORTANT part is to ensure you use the proper null points for the cantilever alignment.
By the way, why not simply reach out to me via the website? I am available 7 days a week to support WallyTools owners for all manner of analog related issues.
By the way, why not simply reach out to me via the website? I am available 7 days a week to support WallyTools owners for all manner of analog related issues.
