Lathe belt splicig

Discussion in 'Horological Tools' started by bkerr, Jul 21, 2012.

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  1. bkerr

    bkerr Registered User
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    Nov 29, 2007
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    I am finishing up my new (new to me) Levin 8mm lathe. Things are comming together well and it is now mounted on a bench and the motor is in place.

    I need to get a belt and I tried those green belts that you use a hot razor blade to make the splice. The belt material works well but I don't have three hands so here is what I came up with to make a good (easy) splice job.

    The concept is that the belt is held on the left side (clamped) and positioned half way in the slot. The right side is snug but the belt can slide with a little pressure applied. Center the ends in the slot, get the hot blade ready and while the blade is in position slight pressure can be applied to the splice and can be continued when the blade is out and the material is still soft until it firms up. Remove the four screws, trim the flashing from the splice and now the belt is ready to use. Well, that is the concept and I'll let you know how well it works later today.

    If this is not the right place to post please fell free to move to the proper place. Thanks
     

    Attached Files:

  2. bkerr

    bkerr Registered User
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    Well the belt is now on the lathe. Tool worked good but, I found out that I need to make the slot a little deeper to allow the heated blade to pass all the way thru the belting material. I still ended up putting the tool in a bench vise as well.
     
  3. Ron P

    Ron P Registered User

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    Nice method.
     
  4. Max Phillips

    Max Phillips Registered User

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    Very nice, thanks for sharing! What material did you use for that tool?
     
  5. cazboy

    cazboy Registered User

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    #5 cazboy, Jul 22, 2012
    Last edited: Jul 22, 2012
    Well done sir! Your shop-made tool seems well made and the principle seems sound. If I may share, I use a simpler but very effective method in my shop. I use one of those "third hand" things that has a base and two alligator clips articulated with adjustable linkages. I place the already-cut green belting in the clips and adjust until the two cut ends meet perfectly. Then I tighten down on one of the clip's linkage so it won't move (or resists moving), and loosen the other one so that it's firm but moveable. Then I double check the belting to make sure the ends meet. Then I just spread the loose arm so the belt's tips are about 5/8" or 3/4" apart - and I just hold a Bic lighter between the tips. If the tips are too close together, they'll catch fire, but if they're just right they will heat up and begin to melt without igniting. Once I can see both tips begin to melt, I remove the lighter and move the loose arm back where it was - and the tips usually still meet in the middle. You have a few moments before the belting cools so you can adjust up/down or back/forth, but once you're happy with the joint just walk away and come back later to razor the excess away. It works great for me.

    EDIT: I forgot to mention I keep a fire extinguisher and smoke alarm in my shop at all times, but I've never had any problems because I'm pretty careful - more like paranoid! :cyclops:
     
  6. bkerr

    bkerr Registered User
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    The material is aluminum (6061 T6) that is very common and easy to source. I have been reading about engine turning or jeweling recently and have another project that I posted that I would like to jewel it. The authorities all state that the material to be jeweled shold have no defects. This piece was sanded with 800 grit wet / dry (wet w/ soap) and then buffed on a cotton wheel. It really came out like a chrome finish. To get a sense of scale th length is 3" and the screws are 3 -56. It was all machined from one block of material. I did cut the material in half withmy bandsaw and then on the mill with a fly cutter. While I had things set up I idecided to make a duplicate. Below is a picture of the jeweled and finished product.

    Doug, your method sounds like a very good one too. I have thought about using a soldering iron with a thin flat iron to melt he material. I think I have seen them so I'll be looking. I don't like a flame in the shop but I do use a alcohol burner from time to time (I work on watches too so the the burner comes in handy for setting jewels).

    IMG_1877.jpg

    Now if I could just get the spell checker to work!
     
  7. wefalck

    wefalck Registered User

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    As an add-on: once the the two ends of the belt have been pushed together a sort of doughnut of molten material develops at the joint. I first clip this off with a pair of round scissors and use a coarse grinding wheel to smooth down the joint.

    wefalck
     
  8. bkerr

    bkerr Registered User
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    I used a razor blade to trim up the excess but, thinking about your scissors idea maybe fingernail clippers would work also?

    Thanks!
     
  9. wefalck

    wefalck Registered User

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    Anything that cuts closely would work. Using a coarse grinding wheel afterwards really makes the joint almost invisible, which eliminates vibrations.

    Actually, I think your tool isn't a bad idea, because aligning the two ends carefully also helps to reduce vibrations. However, most of my joints lasted for years, so one doesn't need it that often.

    wefalck
     
  10. bytes2doc

    bytes2doc Registered User
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    I forget what book I found this technique in but one just secures a knife in a vice which serves as your third hand, heat it. Next touch each side of the knife with the belt and d slide the two ends off each side of the knife simultaneously so the the two end meet together. Works like a charm but you may need to trim off the excess melt. Your design may give more consistent results. Nice work.
     
  11. wefalck

    wefalck Registered User

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    I believe there is a respective illustration in Carlè's book on lathes. Incidentally, not having such a nifty tool, I always used a soldering iron with a Teflon-coated cutting-knife for styrofoam mounted in it. I push the ends onto knife and slide them off when well melted, trying to 'make ends meet' precisely. Trimming off the excess as indicated above.

    wefalck
     
  12. bkerr

    bkerr Registered User
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    I think I am going to get one of these tips for my soldering gun. It makes sense to be able get away from the potential fire hazards. That being said I may not splice another belt for several years but, if I do I will have the tool to do the job. LOL

    pd_6110_100 weller tip.jpg
     
  13. KurtinSA

    KurtinSA Registered User
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    Figured I'd open an old thread!! I've had to repair my belt now 4-5 times in the past month or so. I found out about the process of heating a piece of metal (putty knife) and sliding the butt ends together. I seem to have done it OK in my book, but each time after only 5 minutes of use, the butt joint slowly opens up. I can't keep using it given that it will open up and who knows what will happen.

    I seem to be missing something. I've been trimming the old ends to get new surfaces. My belt is beginning to shorten and I just noticed that the motor on my Levin lathe is not adjustable. I might have to remove things and open up some slots in order to allow for some adjustment.

    Thanks...Kurt
     
  14. wefalck

    wefalck Registered User

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    What kind of belt material are you using ? I found that the Chinese Polycord imitations aren't as good as the original one (surprise !). While butt-weld on Polycord may have lasted for years, the Chinese stuff seems to come apart every few months and sometime doesn't even weld very well in the first place.
    Make sure you degrease the belt around the joint. The welding works best, if it is really hot, the belt material must be almost running.
     
  15. KurtinSA

    KurtinSA Registered User
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    The belt is a clear/yellow piece of rubber band. I haven't been trimming back the old butt joint much...just enough to square things up. If I do much more trimming, the belt will get shorter and I have discovered that the motor is fixed in place, so it can't be moved closer to the bed. I'll need to do some surgery to see if I can correct that. :banghead:

    Kurt
     
  16. wefalck

    wefalck Registered User

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    Wouldn't it be simpler to get some new belting ...
     
  17. KurtinSA

    KurtinSA Registered User
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    I suppose. But won't the headstock of the lathe have to be torn down? I don't have that much experience working on these. This is a used setup I bought last year. The motor has been sort of kludged to fit on the base.

    The downside of all this is that I was three pivots away from finishing a clock and I could start putting it back together. I need to fix something and/or order a new belt. All which shuts me down on this. Kinda bummed...

    Kurt
     
  18. wefalck

    wefalck Registered User

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    Unless you buy an endless belt, you don't need to tear-down the headstock. That's why there are these fusible belts.
     
  19. KurtinSA

    KurtinSA Registered User
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    Well my fusing attempts are not working. And since my lathe stand needs some major surgery, I'm back at square 0.

    Kurt
     
  20. Dave Coatsworth

    Dave Coatsworth Super Moderator
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    You might consider using O-rings. Yes, you do need to disassemble the headstock to install one but, by the time one breaks, it's probably time to tear down and clean the headstock anyway. Sort of serves as a reminder.

    If you are using a lathe that you bought last year and have never cleaned the headstock, I would encourage you to do so. Who knows how long since it has been properly cleaned.
     
  21. dAz57

    dAz57 Registered User

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  22. KurtinSA

    KurtinSA Registered User
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    What are sources for o-rings of that size?

    Kurt
     
  23. Dave Coatsworth

    Dave Coatsworth Super Moderator
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    McMaster-Carr www.mcmaster.com

    I've been using "Buna 70" with good long-lasting results.
     

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