Pedal rod for Pilgrim 41


  • Participant
    tenthousandclowns on #210708

    I have a pilgrim progress 41 string pedal harp, and broke the G pedal rod on sunday night… I have been emailing pilgrim all week and heard nothing back.. All the harp places I have emailed don’t know how to get them, nor have I found any specifications I can give to a machinist…

    Any advice/direction appreciated.


    Participant
    charles-nix on #210710

    If it is broken, and if you plan on replacing it yourself, why don’t you just remove the old rod (both pieces) and give that to a machine shop for a sample. Would probably take 15 minutes for them to make one from a steel rod with a threading die. They might want the rod coupling from the pedal as well to be sure they get the threading tolerance tight enough to have no slop, but not too tight to move by hand.


    Participant
    Alison on #210711

    I am sure they will be able to supply another so give them 1 to 14 days to respond they might be out on the road or on the isle of wight.


    Participant
    patricia-jaeger on #210737

    Hello tenthousandclowns

    Have you used the e-mail: info@pilgrimharps.co.uk ? That might connect you with John Hoare, head engineer there. You could also ask whether Pilgrim now has a USA or Canadian dealer, quite possible. Pilgrim is a cooperative run by the owner-workers who years ago bought out Wilfred Smith Harps Co. for which I was the U.S. dealer at the time.


    Participant
    tenthousandclowns on #210752

    yes, that is the email I was using…
    I wasn’t able to find any evidence of Pilgrim dealers in the US.
    Yes, I think i will go to a machinist…. i was talking to a friend who works in a machine shop, but his shop only does larger stuff like ship driveshafts… so I will find a smaller shop.
    It seems the rod is 34 gauge music wire, 0.094 inches in diameter. The threads seem to be 2.5mm by 0.45 thread pitch, but this is really what I want to check for sure.. they are so small and hard to measure. I have a retired bicycle mechanic friend, and looked pretty closely at it and it seemed right, but a pro machinist would probably be more confident.


    Participant
    charles-nix on #210756

    I can’t say they didn’t use it, but music wire would seem an odd choice to me. First, it would be undersize for M2.5 threads. Second, it is very hard tempered, which would make it brittle, and subject to breaking with repetitive stress, and which also makes it “challenging” to thread. Are you sure it isn’t just 2.5mm cold rolled low-carbon rod? A micrometer is necessary to tell size for sure, though cold-rolled isn’t particularly accurate. Any machine shop will have a thread gauge, so you can find out for sure. M2.5 x 0.45 is a standard thread, but I wouldn’t assume it is standard. You can also lay a M2.5 x 0.45 bolt beside the threaded end: if the threads line up (nest with each other) then they are the same pitch. A grinder spark test on the original will give some idea of the hardness/temper/carbon content, as will the visual appearance and the feel of the rod’s stiffness. Also, 0.0045″ below size for the thread major diameter is a _lot_ of slop in the rod coupling, assuming the coupling is threaded M2.5 x 0.45.

    The thread tolerance needs to be closely fitted. Standard tolerance M2.5 x 0.45 may be too loose. The adjustable threading die, or lathe, if they do it that way, will need to be set to make it just loose enough to turn by hand when threaded into the rod coupling, but with no looseness in the threads, or you will have lost motion at the beginning of the pedal action chain. Too tight, and you won’t be able to screw it in by hand.

    Once you find the exact thread, you can always have it made slightly oversize and use an adjustable die to shave a little off until it fits exactly right in your harp, if you don’t want to take your harp to the machine shop to test.

    Charles Nix


    Participant
    tenthousandclowns on #210797

    I mentioned music wire not because it seems right, but because that is what I was able to find for sale… Probably you are right about the metallurgy. I sure wish I would hear back from Pilgrim. I still haven’t had time to go to a proper machinist but that is the plan. Thank you so much Charles for your detailed thoughts.


    Participant
    Tacye on #210819

    That is most unlike Pilgrim, I rather suspect rogue spam filters on the email. Can you give them a phone call?


    Participant
    tenthousandclowns on #211147

    the 2.5×0.45 threads thread in, but then get tight too soon.. my die is adjustable but I need to take it to a machinist who has the proper thingy to adjust it with.


    Participant
    tenthousandclowns on #211841

    with more practice and tightening the die up i was able to get some good threads that went in smoothly.. i welded on a nub at the base end and ground it down to about the right shape… so i have that installed and so far so good.

    I did hear back from Pilgrim, so that was good news finally. they say the welded nub may be more brittle than a soldered one.

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