Hi Thread, Trying to Get K-8 Up and Running

[alexdw5]

Hi all, very glad to find this forum. Just bought a K-8 off of Reverb and it seems to be in reasonably good condition. Am excited to get this thing up and running and I've got a barrel-ful of questions. This is my first record cutter and I am a complete noob here. I have a tiny amount of electronics experience – ie I've used a multimeter less than 10 times ever but I understand how to test resistors and do simple readings.

Questions:

Does anyone have a lead on a 33rpm worm gear for a K-8? I spoke to Steve E. today on the phone and sent him some pictures(posted here) and he said that it looks like I need a 33rpm worm gear. The platter spins fine with the brass chuck on the motor spindle(manual tells me this is 78rpm mode). Platter does not spin when chuck is out and toggle is switched to 33rpm, per manual's instructions. It actually kind of does if I give it a little push, but def not enough torque to cut a record, it seems.

Something seems up with the tubes. Here's a link: https://www.youtube.com/watch?v=pDHk5oefbc0. I guess my question here is, "what's the best way to test them?". My friend told me that's it's possible to test tubes by tapping them with the eraser on the end of a pencil but I'm wondering if there's a better way.

Third, what else do I need to do to get this thing functional? Am I missing anything? I saw Rsimms3 post here: https://www.lathetrolls.com/viewtopic.php?f=15&t=6504&p=41954&hilit=new+york#p41955 but stuck at removing the cover underneath the platter.

Fourth, is there a service manual for this thing? I made an attempt to remove the metal cover beneath the platter to get into the electronics but stopped when I couldn't figure out how to remove the playback and cutting arms.

Lastly, is there anyone out here in the Northeast(I'm about 45 min Southeast of Albany, NY – have car, will travel) that would take pity on a noob and possibly even help me get this thing up and running? By no means am I a rich man, but I'm willing to pay for your time.

Thanks, you guys. I know it's a lot of questions, I'm just very stoked to possibly cut some records on this thing in the near future.

worm gear?:

[piaptk]

Is your worm gear not in that white box that says “pinion”?

[piaptk]

I would recommend using a solid state Pa amplifier and skipping the amplifier section of the lathe all together.

And if that 5c cutter head is farm fresh, there is a 75% chance that the rubber armature shield that keeps it from rubbing against the pole pieces of the magnet are dried up and crusty and it is either gonna sound really bad or it is going to rattle with bass frequencies. They almost always have problems if they haven’t been tuned up.

[piaptk]

Here are some videos i made a few years ago for someone who bought a k8 from me. I have no idea whats in them or how useful they are because i havent seen them in years, but my guess is that they will be worth your time to watch at least once.

https://www.dropbox.com/s/e6qus6oe8s1tzu6/k8%20Vids.zip?dl=0

[alexdw5]

Hey piaptk, thanks for the feedback. I'll check the pinion boxes when I get home, and I appreciate the videos man, thank you.

[rsimms3]

You must have the pinion for anything to work. Hopefully it's in the box marked "pinion". They made them for outside-in and inside-out cutting. Chances are yours is for outside-in cutting.

There is no 33rpm worm gear for this machine. The K8 uses only 1 worm gear on the platter shaft, the size of the capstan (metal part that engage the edge of the platter transferring motion from the motor to the platter) determines the speed. You can run 78/45/33, 33 is standard speed with the bare capstan and you can add adapters for 45 and 78. Capstan for 78 was originally included with this machine new and a 45 was available later as a separate add-on.

The K8 only cuts 1 LPI (116 I think) at each of the 3 speeds. So, the smaller the disc you record to and the higher the RPM the less time you get on a disc. The K10 that you linked to above cuts 2 LPIs and will cut inside-out and outside-in by changing the platter worm gears instead of using two different pinions.

Be careful when removing and reinstalling the platter, the worm gear on the platter shaft is typically brittle and can be damaged easily. It rests against the pinion once installed and if you simply drop it into place you'll destroy the worm gear and no one makes those (at least that I am aware of).

Links to auctions for newly produced 78 and 45 adaptersn (not mine or associated):
https://www.ebay.com/itm/Presto-K8-K10-Record-Lathe-Cutter-78-rpm-motor-capstan-adapter/153643918601?hash=item23c5e42509:g:HSIAAOSwTnVdfonz
https://www.ebay.com/itm/Presto-K8-K10-Record-Lathe-Cutter-45rpm-motor-capstan-adapter/153635531983?hash=item23c5642ccf:g:mIAAAOSwajpdc~oO

Link to K8 manual (good for 2 days):
https://app.box.com/s/94aeujjllbkq1cxs2c5n

[alexdw5]

Updates:

- The taped-together boxes marked "pinion 2" contained my pinions/feedscrews. I am very happy about this. The previous owner had applied some sort of wax/grease to either end. Will need to clean these. Mounted one and it works. The teeth of the fan lock in perfectly.

- After watching piaptk's videos, I was able to get the motor capstan to make contact with the rubber tire on the platter. It's weird though – to do this I have to back the capstan out, start the motor, and then bring it into contact with the tire, and then tighten down the thumbscrew that sets the capstan in place.

Working on sourcing a PA amplifier today!

[New2Lathe]

Alexdw5-

Here are a few photos of a K8 ‘opened up’ as you were considering...

No need to remove the playback arm or the cutting arm; they should stay affixed to the metal ‘table’.




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[New2Lathe]

Looks like 8 screws to be removed and then a gentle pry to raise the table from the casing.

Thanks!


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[Jesus H Chrysler]

I'm guessing your tubes are OK. The 45 triodes are pretty robust. Its more likely the capacitors are shot. They're pretty easy to replace if you can solder. I did my k-10 in an afternoon. It was doing the same thing yours is. Haven't had a problem since. There's a k-8 manual and schematic in that section on the site if you don't have one.

[alexdw5]

Thanks, New2Lathe for the pictures of K-8 guts, and everyone else for the feedback. Turns out the lathe works just fine and I've cut a couple of blanks so far. Thanks, everyone!