Rek-o-Kut lathe

[Davevr]

Hi everyone,

A few years back I bought this Rek-o-Kut Challenger cutting lathe. I had the machine completely overhauled by a technician, and it now, at least, plays 78 records with the integrated tone arm.

The machine spins on both 33 and 78rpm, and my idea always was to cut an 78 record every once in a while.

Although it has been completely refurbished, I haven’t been able to test the cutting function, as I have no blank discs. I did have some small 7” blanks, but when
cutting on them, only a very small sound is heard and mostly noise. The cutting head is working, as I put a paper sheet on the stylus to test if any signal is passing through the cutting head. Of course, i don’t know if the stylus still works.


Does anyone have an idea where to get a couple of 10” 78rpm blanks? I searched the internet, but haven’t been able to find any useful info on where to get them, or which ones are suitable to get along with this ancient machine.



Thanks in advance,
Dave

[timinbovey]

I also have a Red-O-Kut lathe, which I was just preparing to put to use after a complete restoration about two years ago, right after the fire at the Apollo plant in California. Your machine (as is mine) was meant to cut lacquer record blanks, the 10" blanks you're thinking of would no doubt be lacquer coated aluminum blanks. These are nearly impossible to obtain for hobbyist or small studio use, as the last place I'm aware of making them is in Japan, and they provide them for the major record companies who consume them in mass quantities for use making lacquer masters used in making stampers for pressing today's records (yes, even a brand new modern record at the store starts out as a cut lacquer disc). Even before this, first grade quality 10" blanks were about $20 each from Apollo/Transco, and you could get "seconds" that only promised one perfect side for about $10 each. Now, it's nearly impossible to get them in smaller quantities and they would be ungodly expensive for our uses. If you really want to try it, you need to keep your eyes glued to eBay and see if anyone has any NOS vintage blanks listed (although they're getting expensive too). Then you have to wonder if they'll cut properly. There are some tips that help, like using various treatments to prepare the surface, and using a heat lamp or bulb near the blank on the machine to warm and thus soften the lacquer for cutting. Results will vary at best, and will be different from disc to disc depending on which discs and their age. Apollo/Transco was also the only source for cutting styli for many of the older consumer and prosumer machines.

What many of use are doing is setting up our machines to emboss polycarbonate blanks. The blanks are much cheaper, you use a different stylus that lasts much longer, and results can be very good. You can find advice for setting up for this here in the forums. I purchased my embossing stylus and blanks from https://www.recordlatheparts.com the owner of which is here in the forums. I'm happy with the blanks and the stylus, and he gave me good advice in getting set up. There are of course others here and online that offer blanks, etc. Just so happened that his website and offerings seemed to click for me but I don't want to rule out the many others out there who are offering good service and products too. I recently posted a test run with my Rek-O-Kut here in the forum - you can hear what a "non-expert" embossed disc of a Chuck Berry tune sounds like. I was quite pleased with the results. See if you can find my recent post here in the forum. Of course, I had done about half a dozen prior recordings that were awful before I got everything tweaked right. https://www.recordlatheparts.com has the blanks in 7, 10 and 12 inch sizes, in clear, white and black. Just taking a look at the website is educational, as are those from many other suppliers many of who advertise here on the lathe trolls page, so poke around! Good luck!

Tim in Bovey

[piaptk]

Thanks for the plug Tim!

Hi Dave, yes, you can use our embossing blanks on polycarbonate. If you really want 78, though, you will have to experiment to get grooves deep enough to play back on an acoustic phonograph. It can be done, and we have done it, but it took a fair amount of testing to get the weight just right. I also sell 10" polycarb blanks as well.

I do have some standard groove cutting styli and 10" lacquers that I could potentially sell you. But because of their rarity, they aren't cheap and I doubt that the lacquer would withstand many plays under a heavily weighted acoustic reproducer.

But feel free to DM me if you want to give our styli and blanks a try.

Mike.

[Davevr]

Hi Tim, hi Mike,

Thanks for your replies and advice, you both! Really helpful.

Of course that’s a great idea. My first intention was to cut 45s anyway, because those are the records I mostly spin myself. The only thing is that the machine doesn’t have a 45rpm setting on it. Only 33 and 78. Or is there a way to get it on 45? I do have two different feedscrews with it, though I don’t know which one is for 33, 78, or even maybe 45.

What would be a good way to start? which parts do I have to order? Do I have to customize the cutter head in any way? Or would it be simply installing a different stylus? If you could give me some advice, that would be great.

Regards from The Netherlands,

Dave

[timinbovey]

I do believe that you can get an adapter sleeve for the motor shaft to create 45 speed, but I've never done that. When I make 45's I "cheat" a little bit, using a computer as my sound source. Using my laptop and free Audacity software is take a recording that I want to cut at 45 and load it into Audacity. in th effects menu there is a selection to change the speed of what you are playing. You can change speed by percent, run time, etc and there is also a choice to choose record speeds, e.g. you can change the playback act 33, 45, 78 etc. I just select to playback 45 to 78 and the program plays the audio back at the speed it would be if you were playing a 45 at 78 on a record player. I feed the audio into the lathe at that increased speed. When done the disc I cut at 78 on the lathe (with the audio playing too fast from the computer) plays back correctly when played back at 45. My embossing test video here: https://www.youtube.com/watch?v=BfB18tXMCk0 was cut in this fashion. That's a Chuck Berry song played back at "45 to 78" out to Audacity into my Rek-O-Kut running at 78, and shown in my video playing back at 45. That is actually a clear 7" blank from www.recordlatheparts.com but it looks white as I had not yet removed the protective paper from the other side so the white is showing through. Also was made with one of their embossing styli.

I'm no expert but I'll bet one feedscrew is for spacing the larger standard size grooves in 78's and the other is for the microgroove spacing for 33, which would also apply for 45's, although you could use either for 33/45 it would just affect running time. Can't really use the 33 feed for 78's as with the thicker groove the grooves would be too close, unless of course you're cutting microgroove 78's (which wouldn't work on a vintage player as the grooves are too small). Feedscrews don't really affect the speed as much as running time. More lines per inch = great playing time but a more delicate operation as the grooves are closer together. If I try to explain it more it will just sound more complicated, LOL.

You should be able to just install the embossing stylus, get some polycarbonate blanks and have at it. One thing I'll tell you is read the sheet that comes with the embossing stylus where he recommends 35 grams force on the stylus while embossing. I missed this and had it set pretty heave (possibly even heavier than my normal lacquer cutting weight) and it was WAY too much. It recorded but a ton of surface noise and hard to find the right groove on playback as the heavy embossing left ridges that would catch the needle on playback rather than the recorded groove. 1000% better once the proper weight was set. Also my machine isn't a Challenger so yours might be different, but I needed to drill a second hole for the drive pin in my blanks or they slip while cutting. Some machines need this, some don't. Old school lacquer blanks came with at least one drive hole drilled for the second pin. No biggie. If you need to do this just be aware that you'll have to remove the flash (or burr) from the backside of the hole you drill or the ridge from drilling will prevent your blank from laying flat.

Also, your feedscreews should be marked on the ends with a number, which means lines per inch. Bigger number means more LPI, longer playing time, but grooves closer together, which can mean you need a lower recording level and watch for too much bass or the grooves will get to close together or even cross. Depends on what LPI and other variables, but something to be aware of.

Tim

[piaptk]

With ROK lathes, there is no capstan adapter, changing the speed was done with different sized idlers. If your lathe motor plate in front of the turntable says 33/45/78 then somewhere along the way your 45 idler got lost. But that's good because you can have another one made. If it doesn't say 45, then you are sorely outta luck, because the way the idlers fit under there will not accommodate any modified sized idlers. And you will have to just slow down your audio to cut at 33 and playback at 45 in audacity (which is very easy, but takes 50% longer to cut).

[Davevr]

Okay, all clear (or at least a little bit).

Think the right thing to do now is order an embossing stylus from Mike’s website. I’ll take a look on the page.

Indeed there’s no indication of a 45 speed on the machine. So 45 is impossible i guess. I could make 10” 78s which can be played back with a normal record player stylus, if that’s possible. Or else I try the Audacity trick; I do have Audacity and I know how it works, so that won’t be a problem. The Chuck Berry track sounds awesome!

Dave

[timinbovey]

I do just the opposite. I speed up the playback to 78 and cut at 78, then slow down to 45 on playback. Works perfect (that's how that Chuck Berry test was made).

Tim

With ROK lathes, there is no capstan adapter, changing the speed was done with different sized idlers. If your lathe motor plate in front of the turntable says 33/45/78 then somewhere along the way your 45 idler got lost. But that's good because you can have another one made. If it doesn't say 45, then you are sorely outta luck, because the way the idlers fit under there will not accommodate any modified sized idlers. And you will have to just slow down your audio to cut at 33 and playback at 45 in audacity (which is very easy, but takes 50% longer to cut).

[mrd]

Okay, all clear (or at least a little bit).

Think the right thing to do now is order an embossing stylus from Mike’s website. I’ll take a look on the page.

Indeed there’s no indication of a 45 speed on the machine. So 45 is impossible i guess. I could make 10” 78s which can be played back with a normal record player stylus, if that’s possible. Or else I try the Audacity trick; I do have Audacity and I know how it works, so that won’t be a problem. The Chuck Berry track sounds awesome!

Dave

Another option here could be to explore Jed's belt drive solution which is reversible but does not use the original motor or capstan/idlers - there's a few ROK users out there doing that. I've got one but not used it enough to comment on it properly yet. Pretty simple to setup and focused around 33/45RPM

[Davevr]

I just ordered a new cutting stylus at Mike’s webstore, also some blank 78s. As soon as they arrive here in the Netherlands, I will begin to experiment with this. Of course I will keep you guys updated through here (as well as asking questions I guess, ).

Thanks,

Dave

[Davevr]

Here’s a little video of just the “playing part” of my Challenger.

https://youtu.be/msAH1uX9zKI

[Davevr]

And a video of my first ‘cut’, that failed completely… Using the original stylus and no experience here

https://youtu.be/7Lghf87QHrY

An audio signal is sent to the Rek-o-Kut and the cutting head is placed on the disc. As you can hear the stylus makes squeeking sounds and the groove that appears on the disc doesn’t look good; just and even “fading” grey line.

When played back there no music whatsoever. Just white noise.

So, just waiting for the new embossing needle and then start with the second attempt.