Sumiko Premier MMT template
- Thread starter SJH
- Start date
Register to hide this ad
markd51
Nyuk Nyuk
Hello,
I looked, and yes, I seen that, but unsure why you would need such, when all specs and mounting instructions are provided at Vinyl Engine for this Arm?
All you really need is an accurate Metric Ruler to measure the correct Spindle-Pivot Measurement.
Then drill the prerequisite hole for the Mounting Base, and for the Screw Holes. It's all written-explained there.
It states drilling a 3/4" Hole, which it appears there's then a little "wiggle room" for precise positioning. One of the critical things will be, where exactly will the hole need to be drilled, and where the Arm will be positioned so that the Arm can travel through its full travel upon a record without interfering with things like a Dust Cover.
I looked, and yes, I seen that, but unsure why you would need such, when all specs and mounting instructions are provided at Vinyl Engine for this Arm?
All you really need is an accurate Metric Ruler to measure the correct Spindle-Pivot Measurement.
Then drill the prerequisite hole for the Mounting Base, and for the Screw Holes. It's all written-explained there.
It states drilling a 3/4" Hole, which it appears there's then a little "wiggle room" for precise positioning. One of the critical things will be, where exactly will the hole need to be drilled, and where the Arm will be positioned so that the Arm can travel through its full travel upon a record without interfering with things like a Dust Cover.
markd51
Nyuk Nyuk
Admittedly, I once let a master machinist friend mount and drill a brand new replacement Armboard he made for my Denon DP-2550. Since it was impossible to locate a blank factory Armboard for the Denon, I had him make the new custom fit Armboard from 1" thick Black Acrylic.
He made that Armboard with NASA-like precision, absolutely flawless fit and snug. And absolutely flush with the top of the deck, the material needed to be slightly milled to about slightly under .900" thick.
He had a very long Dial Caliper in his shop that was surely more accurate than a ruler.
What he then did, was he fabricated a "Locating Pin", the exact diameter of the Tonearm Mounting Shaft to fit inside of the Arm Base, and was long enough so that it could be adjusted in height to be of exact equal height to the Platter Spindle.
This Locating Pin he then turned one end of it on a Lathe to a pinpoint at one end. This then would aid measuring the exact precise distance for the Audioquest PT-8 Arm I was going to use on that Table.
He said he achieved precise Spindle to Pivot Distance at +- .03mm!
One probably doesn't need that high a degree of precision, as that's why I believe Tonearm Manufacturers commonly place Cartridge Mounting Slots on a Headshell, so there is some plus-minus travel of adjustment of the Cartridge to achieve correct distance-overhang.
What I would likely then do in your instance, and without the need of spending too much money, would be to print to scale one of Grover Hoffman's Arc Protractors for your Arm's Specs.
That this would likely be much better than relying on Universal Sight Line Protractors, or any means of trying to measure Overhang at the Headshell.
Hope my comments have helped some.
He made that Armboard with NASA-like precision, absolutely flawless fit and snug. And absolutely flush with the top of the deck, the material needed to be slightly milled to about slightly under .900" thick.
He had a very long Dial Caliper in his shop that was surely more accurate than a ruler.
What he then did, was he fabricated a "Locating Pin", the exact diameter of the Tonearm Mounting Shaft to fit inside of the Arm Base, and was long enough so that it could be adjusted in height to be of exact equal height to the Platter Spindle.
This Locating Pin he then turned one end of it on a Lathe to a pinpoint at one end. This then would aid measuring the exact precise distance for the Audioquest PT-8 Arm I was going to use on that Table.
He said he achieved precise Spindle to Pivot Distance at +- .03mm!
One probably doesn't need that high a degree of precision, as that's why I believe Tonearm Manufacturers commonly place Cartridge Mounting Slots on a Headshell, so there is some plus-minus travel of adjustment of the Cartridge to achieve correct distance-overhang.
What I would likely then do in your instance, and without the need of spending too much money, would be to print to scale one of Grover Hoffman's Arc Protractors for your Arm's Specs.
That this would likely be much better than relying on Universal Sight Line Protractors, or any means of trying to measure Overhang at the Headshell.
Hope my comments have helped some.
Last edited:
markd51
Nyuk Nyuk
Yeah, I'd say 222mm would be safe. How much is .3mm? The thickness of a Credit Card or two?
As I said previously, measure and check as many times as need be, because once you drill holes, that's it!
One can simply mark the center point where the hole for Arm Base will sit with a pencil. Then as close as you can, hold the Arm in vertical position above and on that exact spot (without Cartridge)
Rotate the Arm full travel, and note where that rear counterweight is going to travel. Think, and think again.
Because I know there's many folks who like to spin vinyl, and have the Dustcover in the down position. I do often. I know some don't like Dustcovers at all, and they can be a source of resonance.
That 221.7mm or 222mm "Arc" is of course a circle from the Center of Spindle that goes entirely around the table at any point. You folks have of course seen tables with 2, or 3 Tonearms Mounted?
Without regards of a Dustcover, then it doesn't matter where.
But myself, I am a real stickler for aesthetics. I want my tables working right, and looking right.
markd51
Nyuk Nyuk
Here's one of mine.
What you're seeing here, was once a simple HW-19 Jr Table that I bought new in 1996.
That's a 1.00" Thick Sheet of solid Black Acrylic as the Plinth, and under that Sheet is a 10lb SS Sub Chassis Plate bonded to it. The Acrylic Sheet was only slightly routed for clearance of the SAMA Motor and Motor Pulley.
And yep, there's a SAMA as well (Stand Alone Motor Assembly) underneath in its 10lb case.
16lb MK-IV Platter, a custom made Arm Mount Base for the AQ PT-9 Arm got rid of that egg shaped hole in the Stock AQ Arm Base Mount, and the custom made one is highly precise, 1/2" taller-thicker than stock, no wobble, holds the arm precisely vertical, and has a Nylon Tipped Allen Locking Screw to allow for VTA Adjustment.
Platter Clamp is 2-part custom, coaster is a BDR Carbon Fiber part, with a custom Stainless Low Profile Puck on top so there was enough clearance with the Dustcover in the down position.
All that weight rests upon 4 Herbies Tall Firm Tenderfeet within the wood base, and the SAMA sits on 4 standard height Tenderfeet. The Table is "Herbie-ized" to death, with grungebuster washers, and discs everywhere throughout. Table sits on 4 Audiopoint Brass Cone Feet and Decoupler Discs. and also are Herbi-Ized" with DB Neuralizer Discs.
Isolation Base the Table sits upon is a Silent Running Audio Iso-Base V-3.0 custom made-tailored specifically for the HW-19 MK-IV Table. While it doesn't look like it from this particular picture, the SRA Iso Base has the exact same length-width dimensions as the Wood Base.
Platter speed is precisely handled by the VPI SDS.
Last edited:
SJH
Active Member
Thanks,
I do know a machinist
sounds like you got all the bells and whistles
Punk_oldie
Active Member
Also don't forget that as long as you have an accurate measurement of the actual pivot to spindle distance that you mount your arm at, then if you use an arc alignment template generated using your actual P to S measurement your null points will be good for your chosen alignment (Baerwald, Loefgren B, Stevenson), so I'd say for that arm as long as you have the P to S within 2-3mm of the recommended 222mm you should be fine.
SJH
Active Member
Good info. Thanks!
Similar threads
