You spin me right round

[mattsk8]

Opposing magnets... brilliant .

I'm not being a neigh-sayer, I think your project is awesome! But, if you look at all the turntables out there, especially the high dollar ones, they use a composite or alloy plinth of some sort, whether it's MDF or plastic or aluminum. I'm not sure how much experience you have with cartridge alignment, but it's a finicky process. I don't see azimuth being much of an issue, the plinth would actually have to warp before that would be a problem. But, with a thick piece of hardwood like you have, cartridge alignment from a wet spring to a dry winter could definitely change. It would be a lot of work, but if (down the road) that's an issue, maybe consider hollowing out the beautiful plinth you made and inserting a composite or alloy of some sort for the tonearm to mount to. Just a thought, and please don't let me sound like I'm taking away from what you're doing, I think it's really cool.

[jjgoertz]

Opposing magnets... brilliant .

I'm not being a neigh-sayer, I think your project is awesome! But, if you look at all the turntables out there, especially the high dollar ones, they use a composite or alloy plinth of some sort, whether it's MDF or plastic or aluminum. I'm not sure how much experience you have with cartridge alignment, but it's a finicky process. I don't see azimuth being much of an issue, the plinth would actually have to warp before that would be a problem. But, with a thick piece of hardwood like you have, cartridge alignment from a wet spring to a dry winter could definitely change. It would be a lot of work, but if (down the road) that's an issue, maybe consider hollowing out the beautiful plinth you made and inserting a composite or alloy of some sort for the tonearm to mount to. Just a thought, and please don't let me sound like I'm taking away from what you're doing, I think it's really cool.

I could potentially end up with something on the order of 1/4" change in width on this board, but with the way I'm just setting this tonearm assembly on the plinth I'll have to not fiddle with the turntable for months for it to be much of an issue. If the linear arm doesn't work and I end up with a conventional tonearm I'll probably bring the mount forwards to the center of the plinth. Then there will be no cross grain between the platter and the tonearm and expansion will be basically a non issue.

[Kevin K.]

Beautiful Craftsmanship! I have just one complaint. Every time I see the title to your thread that song gets stuck in my head for hours. I look at the forum several times a day and review any new updates or new threads, you're killing me man!

[jjgoertz]

Beautiful Craftsmanship! I have just one complaint. Every time I see the title to your thread that song gets stuck in my head for hours. I look at the forum several times a day and review any new updates or new threads, you're killing me man!

Just give in to the song. Get yourself some shoulder pads, some hairspray, and an eye patch and live it.

[Kevin K.]

Just give in to the song. Get yourself some shoulder pads, some hairspray, and an eye patch and live it.

Lmao! Will do!

[jjgoertz]

Got the flanged shaft in from Misumi that I'm using for the platter's pivot.



Counter-bored the bottom of the spindle hole to align everything and attached the shaft with wood screws, making sure to tension everything evenly to get it square. It's not perfect, ended up with about 10 thou of run-out on the spindle, but I think it will be okay for now.

I don't have the magnets in yet, but with just the teflon bushings and giving the platter a flick it spins for about fifty seconds.



Mounted a AT95E cartridge to my little carriage, and this piece of sticky tack is all I ended up needing as a counterbalance to get a 2 gram tracking force.



And here is where I am tonight. Using a literal rubber band to drive it, and a motor and motor controller that won't be the final ones I use. Until the real controller gets here it's the only drive combination I have on hand that can hit the right speed. All I need to do tomorrow before I can play something with it is make a bracket to hold the RCA jacks, run wires to the cartridge, and make a little arm to hold those wires freely up in the air.

[WernerM]

Nice. I also keep getting that song stuck in my head too...

"like a record baby right round, round, round..."

Lol

[Navy Guy]

Really amazing work!

[r-carpenter]

Very inspirational! Great work and lots of patience.

[jjgoertz]

Picked up some nylon hardware for the bearings to ride on. That saved 17 grams, which of a 38 gram total weight of the carriage before-hand, that's pretty huge.



Then I made this little bracket to elevate my wires and hold the RCA jacks.



And I finally got to play something! My rubber band is slipping so I'm getting a warbly 32.5rpm, but essentially everything works. The arm tracks fine, no skipping, and the stylus seems to stay nice and vertical.

The real motor controller will get here next week, then it's just a motor mount and a pulley for the o-ring belt that I still have to make.

[daryl]

Twisting your wire pairs should reduce noise considerably.

[Æ]

Oh Brother Where Art Thou OST and I have some SoA OST clear vinyl, too.

"O Brother, Where Art Thou?" is one of my favorite movies. I have both the movie (DVD) and the soundtrack (CD).

[Æ]

I wonder how much force it takes to move the tonearm? How far does the cantilever deflect before the tonearm actually moves? How much lateral force is required to move the tonearm? After it is all set up and accomplished, you might want to play a test record and check that you are getting equal performance from both channels of the pickup/cartridge.
I really don't know very much about linear tonearms, but all the commercial versions that I've seen have some sort of driving mechanism to help the tonearm more laterally.

[jjgoertz]

Took Daryl's suggestion and twisted up the wire pairs. The wire hanger thing was a little top heavy so I swapped out the brass tube for a smaller and lighter tube, and then filled the base block with some more lead shot.

Finally I made a little queueing arm. It's some 90 thou music wire covered in heat shrink for that nice soft touch.

[filmslayer]

in the 2.5 years i've been here this is probably the coolest thread i've seen . good work