rek o kut model V with model M5 cutter assy. help

[flashbk13]

Not sure this is the proper forum for this topic as I am new to cutters, but not this forum (it's been awhile since I have been in here), so mods, feel free to move this thread.
Hi all,
I just won this lathe on ebay and have some questions (it's one ROK I have never seen before). I know its missing the feed screw, the spring loaded record pin (from the platter), platter mat, and the crystal (brush development rc-20) cutter head is dead. Is this worth fixing and can I find the parts/ fix or replace the cutter head? I only want to cut 45's, so I will need the proper idler and feed screw. Any info. on this lathe would be great (need to know what all of the controls on the cutter arm/ assy. are for). A manual would be great. As you can see from the pics, the base is pretty beat up, but I have a friend that can make a new one with a lid, but want to see if the rest can be salvaged without breaking the bank before I do that.
So, if this is worth it, does anyone here have a fine groove feed screw (outside in) that is good for 45's; a record locking pin for the platter; a 45rpm idler wheel; a platter mat; and can advise on the cutter head? Thank you, Rick.

[piaptk]

ROK feedscrews are VERY hard to come by. And crystal cutter heads SUCK, and as far as I know, nobody fixes them. You may be able to replace the head with a magnetic head with the appropriate adapter, but the adapting bar will have to be made at a machine shop.

That’s a nice turntable though. Does it spin at 45?

[flashbk13]

Hi Piaptk,
thanks for the reply. Yah, I know it will be work converting the cutter arm to receive a different head. It is a very stout table (huge 15 1/2" platter!). It runs normally 33/78, but can run 45 with a different idler, not sure what is in there now as I can't read the numbers on the idlers. I will assume it's stock 33/78 (have not plugged it in yet as as I need to reconnect the motor wires to test it). Rick

[concretecowboy71]

Lead screws are almost impossible to find. Some body had larger sized ones on Ebay a few months ago. I think they were for a 16" diameter unit.

Terry's Rubber Rollers can make you a 45 roller. He has a database of sizes. He re-did a 45rpm roller for my ROK.

That lathe by the way, cannot cut lead-in or lead out grooves. Not sure if you knew that or not, but there is no wheel on the side to "spiral."

This might be the part you need to fabricate to mount a cutterhead:

[flashbk13]

Lead screws are almost impossible to find. Some body had larger sized ones on Ebay a few months ago. I think they were for a 16" diameter unit.

Terry's Rubber Rollers can make you a 45 roller. He has a database of sizes. He re-did a 45rpm roller for my ROK.

That lathe by the way, cannot cut lead-in or lead out grooves. Not sure if you knew that or not, but there is no wheel on the side to "spiral."

This might be the part you need to fabricate to mount a cutterhead:

Thank you concretecowboy71 for the info. I did notice ROM made two types of master pro 5 cutter assy., but didn't think about the lead in/ out groove. Since this does not cut the lead in/out groove, what was this type of lathe used for? I did notice no crank, but it has several other knobs on it, so i thought one of thos might do the spiral (like on the challenger or imperial assys., they have a pinch type control at the back to do the spiral. So it seems this late will be useless for cutting my own 45's for the jukebox (even with a new 45 idler made by Terry

[piaptk]

Without a crank, you can't get a reliable lead in/lead out groove.


It is not necessarily useless for cutting for your jukebox. It just means that you have to cut a fair amount of dead space on the record at the beginning and the end in order to give the needle some space at the beginning for the dropping needle to find it's purchase, and at the end for the auto-return mechanism to trip.

Certainly not ideal, because it's going to cause there to be a good amount of silence but, at least you can start experimenting.

But the feedscrew is your REAL problem. those things are super hard to find... ESPECIALLY a 16" ROK. Deroy Wood had one on ebay a while back, but it's gone. I texted him and asked if he had any others and he is going to check, but if he doesn't have them, you are sort of S.O.L. If you DO find one, make SURE it has the matching halfnut (but also check your machine to see if it already has a halfnut installed on the bottom of the overhead. Each pitch of feedscrew has a matching halfnut, and the threads have to match in order to work... for example a 120 lpi halfnut won't work with a 180 lpi feedscrew.

[flashbk13]

Hi Piaptk,
Looking at the cutter assy (m5), this is the standard model, the M5S is the deluxe with the crank. It seems to make the start and end spiral grooves with the standard M5 (according to the instruction manual I found online), you have to hold up the "carriage saddle" so the 1/2 nut is disengaged from the feedscrew and manually slide the saddle/cutter head by hand (this will take some practice to get right) then lower the saddle back onto the feedscrew to cut the record, then repeat at the end. This was how my Challenger did it (m12 without the crank feature), but used those pinch paddles at the back to disengage the 1/2 nut and and to also be pushed manually at the start and end of the record and release those pinch paddles to reengage the 1/2 nut for the recording. So mine is the cheaper manual spiral assy.
Thank you for asking Deroy, hope he has one suitable to cut microgroove 45's (but at this point, any LPI would be great so I can at least practice cutting (manual spirals) and will fit a 16" cutter without the spiral drive gear at the end. There is no 1/2 nut in my machine, the holder is empty. I will worry about a 45 idler after I get a feedscrew and replacement head. Thank you, Rick

[timinbovey]

I think what you need is not a 45 idler wheel, but a 45 shaft, or capstan for the motor. The mechanics/science of it has been discussed extensively elsewhere on this forum, but the size of the idler does not determine the speed.

To change the unit for 45 operation you need to either locate of have made the proper diameter shaft for the motor. Whether these exist as a replacement part of if you need to have one made, I don't know. But someone out there
knows the correct diameter for the motor shaft.

Tim in Bovey

[flashbk13]

Thanks Tim for the info. ROK did offer a 45rpm idler that replaces the 33 idler and Terry (mentioned in a reply above) can make me a new one. I have to reconnect the power wires to the motor to see what I have in there now (can't read the numbers on my idlers), I may already have the 45 idler. Thanks, Rick

[jesusfwrl]

We can make almost any part for any make/model of disk recording lathe, as a one-off or in quantity. We can also make custom parts where needed.
So, technically, it would be possible to make a leadscrew and half-nut for your machine, if you cannot find the original parts anywhere. In most cases, finding an original part in considerably cheaper than the custom machining of a one-off precision part, but if the parts in question seem to be made of unobtanium, then you have no other option if you really want to get this lathe up and running.

I have experience with ROK lathes, good machines, capable of very decent results, within their limitations.

For 45 rpm, a different roller will do the trick, no need to mess with the motor shaft.

[flashbk13]

Thank you jesusfwrl for the great info. I will save it in case I need to go that route, Rick

[EposLab]

Recently i bought the V model too with a B-5 carriage which look identical with your M-5!

[EposLab]

Jesus of AgnewAnalog is the man!
He is doing really a great and precise job!
Here is what he did for me:

https://agnewanalog.com/blog/rek-o-kut-model-v-repair-and-50-hz-conversion.html

https://agnewanalog.com/blog/rek-o-kut-master-pro-system-with-modified-presto-1d-cutter-head.html