Rek-O-Kut Rondine Jnr L-34 rebuild

Discussion in 'Turntables' started by penfoldvr6, May 14, 2017.

  1. penfoldvr6

    penfoldvr6 New Member

    Messages:
    23
    Hi all.

    My name is Carl and in from Leicester in the UK.

    I have a liking for US broadcast and vintage turntables/tonearms.

    Not long ago I came across a ROK on eBay USA. So I took the plunge and ended up buying it. I got it shipped to a friend in Oregon and I personally shipped it back to the UK.

    I can't wait to get it all up and running with a few improvements. It was an estate find and needs a full going over
     

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  2. penfoldvr6

    penfoldvr6 New Member

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    23
    The build has come on quite a bit since I first received it.

    I'm wanting to improve on the fidelity of the ROK, so it will have a new heavy weight solid hardwood plinth. More support under the plate, more fixing points to cut down the chance of any flexing of the plate.

    I was thinking of improvements to the bearing also, including a bearing brace.

    I purchased some oak blockwood countertop for making my plinth from, this will be five layers of 27mm making a total of 135mm. The plinth will be 500 x 600mm.

    Tonearm will be a Gray research 108 clone.


    I made a lexan template and routered the aperture for the motor and workings. I designed my own isolation feet that are internally damped and fully adjustable for height, these can be locked too.


    More to come soon :rockon:
     

    Attached Files:

    Last edited: May 16, 2017
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  3. MCM_Fan

    MCM_Fan AK Subscriber

    Messages:
    1,101
    Location:
    Oregon
    Carl,

    Great work so far. I look forward to future installments.

    Where are you getting the Gray Research 108 clone. Is it a new product or one of the many clones Gray made for other turntable manufacturers.

    What cartridge are you planning on running? Are you going to wore it for mono or stereo?
     
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  4. JFRACE

    JFRACE AK Subscriber Subscriber

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    460
    Location:
    New Jersey
    Not to hijack his thread, but there's a guy on Facebook who's under the https://www.facebook.com/groups/transcriptionturntables/ page who does those arms, as well as his own design. Sergey Rogozyanski I think.
     
  5. penfoldvr6

    penfoldvr6 New Member

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    23
    The Gray 108 clone is a new product. It's a 100% accurate copy of the original. It's milled from billet magnesium alloy.

    I have a choice of three cartridges I can use on the arm.
    Denon DL-103r (rebodied)
    Stanton 500 broadcast cart
    Shure SCSC-35C (rebodied)

    I have two of these clones and the modern design arm.


    http://www.karmadon.net/
     

    Attached Files:

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  6. JFRACE

    JFRACE AK Subscriber Subscriber

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    Location:
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    That is the arm I was talking about. They run about $350.00-ish if I'm not mistaken.
     
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  7. penfoldvr6

    penfoldvr6 New Member

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    23
    You are most correct.
    It's a great arm
     
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  8. penfoldvr6

    penfoldvr6 New Member

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    23
    Time for some more build updates.....well, as I've said it's come some way since I purchased it.

    He goes:

    I wasn't happy with the way the original plate mounted to the original plinth, so I made a much more sound absorbing plinth, added isolation feet etc. The feet run in at 1.1kg each, so not light by any means. I enjoyed designing them (some parts shown)

    The thing is to make it play stereo well, with as little rumble what so ever.
    Hence the plinth being made with just enough clearance for all the workings underneath. The original was suspended by its perimeter and I thought this was a bad thing.
    I'm going for maximum support, fixings and bracing.
    I want the plate to be rigid and firmly fixed to it's plinth, without any flex at all.
    The original only has minimal fixing points (six in total)

    I set about stripping the plate/motor down. As I was to be fully refinishing everything.

    I found a guy in Peru that would make me some custom water slide decals as the originals. I sent him enough pictures and measurements.
    Eduardo did a great job I must say.

    I made a template from craft board and allowed for clearance on the moving parts etc. I used this template to help me create the lexan plinth cutting template. Although in the picture it needed to be flipped to be the right way.
    I marked out on the plate the outline of this to help me determine extra fixing positions. These were all centre punched and drilled.
    In total there are now sixteen fixing points now.
    All these will be fixed to threaded wood inserts which will be in the plinth.
     

    Attached Files:

    Last edited: May 16, 2017
  9. penfoldvr6

    penfoldvr6 New Member

    Messages:
    23
    Extra mounting points drilled in the plate. I chemically stripped it after removing the serial number sticker so I could re-apply it when I painted again.
    The area where the Lord rubbers go need to be
    back with wire wool.
    The original mounting points that were too near the outer edge will be filled with epoxy bridging compound prior to filling and etch priming. (These are marked in red)

    I have to be careful using the wood inserts, as if they are too near the edges they will show. They are quite large in comparison to the 4mm internal threaded section I am using.
     

    Attached Files:

    Last edited: May 16, 2017
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  10. penfoldvr6

    penfoldvr6 New Member

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    23
    Next pictures jumps a bit in time, but it shows the plate after it has been filled with bridging compound, sanded back, etch primed and has a thin coat of filler.

    This was sanded back again and primed ready for paint.
    Before paint I used 2500 grit wet and dry to totally level.
     

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  11. Ohighway

    Ohighway AK Subscriber Subscriber

    Nice,....... enjoying your pictures and updates !
     
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  12. penfoldvr6

    penfoldvr6 New Member

    Messages:
    23
    While all this was drying I turned my attention to the problem of getting it spinning at the correct speed, as it was to be used in the UK with its 50hz 240v supply.

    I couldn't just buy a step down transformer to supply the 110v, as it still wouldn't spin at the correct speed. It still required 60hz or it would spin too slow at 110v 50hz.

    So I found a place in Italy that sold a two speed conversion capstan that was built for 50hz, but span at the correct 60hz rpm.....it's all getting confusing o_O.
    I had to remove the original plastic capstan and measure the motor shaft.
    The machinist in Italy wanted to know, as these things are made bespoke for every motor apparently.

    I then found a suitable toroidal step down transformer, one that was of high quality. I went with one that was designed for studio music work
     

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  13. penfoldvr6

    penfoldvr6 New Member

    Messages:
    23
    I checked the original idler wheels to see if they were good.
    Fortunately they were and not too worn.

    The place in Italy makes replacement idlers too. It was the same process of measuring as these are bespoke too.
    I gave them a go in a bid to cut rumble.
    I ordered some Teflon and PTFE self lubricating washers to replace the originals too.......so nice and slippery
     

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    Last edited: May 16, 2017
  14. Todd Dodds

    Todd Dodds AK Subscriber Subscriber

    Messages:
    454
    Carl, could you comment on the design and performance of the new idlers new? I'm curious about the pros and cons of the new design vs having old ones reworked.
     
  15. penfoldvr6

    penfoldvr6 New Member

    Messages:
    23
    Last edited: May 16, 2017
  16. penfoldvr6

    penfoldvr6 New Member

    Messages:
    23
    The plate was ready for painting. I went with the original silver in metallic.
    I spent quite a while on the paint to get it looking good.

    Once painted and cured for a while.
    I tack ragged the surface and clear coated. I put quite a few layers on it.

    I then wet sanded with 2500 grit and used a body shop buffer with cutting compound to get a nice glass like finish.

    It was time to get out the water slide decals that I had made and apply them. I hope I made a good job ;)

    As far as it all goes your all up to date with my progress so far.
    I have to clear coat the decals in and wet sand/polish again.

    Then it's mounting time. I will mount it to the top layer of the plinth and then work out my spindle to pivot, so I can mount my tonarm and cut out all the necessary areas underneath with a router.

    Once done I can finish gluing my plinth
     

    Attached Files:

    Last edited: May 16, 2017
  17. JFRACE

    JFRACE AK Subscriber Subscriber

    Messages:
    460
    Location:
    New Jersey
    Absolutely great work so far. I can't wait to see the finished product. As well as hear your feedback.
     
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  18. Nat

    Nat AK Subscriber Subscriber

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    12,126
    I think you might suggest to your decal guy Eduardo that others might be interested in buying.
     
  19. b brian

    b brian Well-Known Member

    Messages:
    513
    Location:
    Seattle
    I would be interested. It could put an extra shine on my table
     
  20. Todd Dodds

    Todd Dodds AK Subscriber Subscriber

    Messages:
    454
    Eduardo (I assume it's Eduardo) is on the big auction site if you search Rek O Kut.
     

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