The Talking Machine Forum — For All Antique Phonographs & Recordings

It is currently Sat Dec 15, 2018 7:20 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 9 posts ] 
Author Message
 Post subject: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 6:49 am 
Offline
Victor IV
Buyer of broken things
Joined: Sat Feb 11, 2012 4:10 pm
Posts: 1018
Location: Alston, UK
I recently bought some parts to repair my columbia AT, including a nice cast bedplate restored by Gregg Cline to replace the pot metal one that had disintegrated, but now I'm met with a problem, these old machines would have had some variance over the production run, and seemingly the earlier cast iron and later pot metal bedplates must have had slightly varying dimensions, nothing noticable, but it just means that only 1 of the screw holes on the bed plate are lining up, as photos show.

I'm lucky enough to have good tools to do the work, but the best way I can think of repairing this is to plug the three original holes that dont line up, done by screwing and cementing short lengths of threaded rod into them then drilling and tapping three new holes to match this bedplate with new screws, does this sound like a plan?

The alternative I could think of would be altering holes in the bedplate which would be visible and most likely risky as the holes have a good chance of reaching beyond the bedplate

Attachment:
DSC02028.JPG
DSC02028.JPG [ 6.64 MiB | Viewed 459 times ]

Attachment:
DSC02029.JPG
DSC02029.JPG [ 5.19 MiB | Viewed 459 times ]

Attachment:
DSC02031.JPG
DSC02031.JPG [ 5.24 MiB | Viewed 459 times ]

Attachment:
DSC02032.JPG
DSC02032.JPG [ 6.17 MiB | Viewed 459 times ]


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 9:33 am 
Offline
Victor VI
User avatar
Needle Tins are Addictive
Joined: Fri Jul 09, 2010 8:32 pm
Posts: 3616
Location: Belmont, North Carolina
First, let's settle on the correct terminology. The part you had restored by Gregg is the upper works, I am assuming. The bedplate is the nickel plated flat steel piece underneath it. If we are on the same page, then your idea of drilling the bedplate to match the holes in the upper works is a good one. Your idea of tapping the old holes and filling them with threaded rod, then re-drilling the filled holes and re-tapping them should work just fine... Make sure that the one hole you leave as original allows the upper works to align correctly and then fasten it before marking your new holes...

Good luck...
"The phonograph† is not of any commercial value."
Thomas Alva Edison - Comment to his assistant, Samuel Insull.

"No one needs a Victrola XX, a Perfected Graphophone Type G, or whatever you call those noisy things."
My Wife


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 9:50 am 
Offline
Victor IV
Buyer of broken things
Joined: Sat Feb 11, 2012 4:10 pm
Posts: 1018
Location: Alston, UK
Curt A wrote:
First, let's settle on the correct terminology. The part you had restored by Gregg is the upper works, I am assuming. The bedplate is the nickel plated flat steel piece underneath it. If we are on the same page, then your idea of drilling the bedplate to match the holes in the upper works is a good one. Your idea of tapping the old holes and filling them with threaded rod, then re-drilling the filled holes and re-tapping them should work just fine... Make sure that the one hole you leave as original allows the upper works to align correctly and then fasten it before marking your new holes...

Good luck...


Can I blame autocorrect? :lol:

I'll give it a go


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 2:27 pm 
Offline
Victor III
I've got both kinds of music--classical & rag-time.
Joined: Fri Oct 06, 2017 11:39 am
Posts: 635
Location: South Carolina
Kirtley--nice machine. Very "Steampunk" in design--kind of nifty, it looks super modern and Victorian at the same time!


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 4:31 pm 
Offline
Victor IV
Joined: Mon Aug 24, 2009 3:08 pm
Posts: 1964
Location: Harrison Township, MI
Kirtley,

If you're only off by approximatly ½ a hole, you may find it troublesome to plug a hole, as you suggest, then re-drill on the new location. The problem may be, that your plug will fall out once you've essentially drilled half of it away. Is it possible to simply elongate the "bad" holes till the bolts will pass through, then put a nut on the backside? I realize this is not as "proper" and invisible a fix as you propose, but maybe a second choice, if need be.


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 5:43 pm 
Offline
Victor VI
User avatar
Needle Tins are Addictive
Joined: Fri Jul 09, 2010 8:32 pm
Posts: 3616
Location: Belmont, North Carolina
Jerry is probably right about the half hole problem, but my thought was to enlarge the new hole to encompass the half hole, then a larger piece of threaded rod could be inserted and tapped. I actually used this method on a reproducer that didn't match the holes on the tonearm I was using and it worked fine...
"The phonograph† is not of any commercial value."
Thomas Alva Edison - Comment to his assistant, Samuel Insull.

"No one needs a Victrola XX, a Perfected Graphophone Type G, or whatever you call those noisy things."
My Wife


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 7:14 pm 
Offline
Victor IV
Buyer of broken things
Joined: Sat Feb 11, 2012 4:10 pm
Posts: 1018
Location: Alston, UK
It didn't prove to be a problem, I plugged the original holes using screws from the destroyed pot metal trunnion, the newly drilled holes didn't cross over to the original holes, came close, but didn't touch, so I tapped the holes and put my new lathe to work on it's first proper project making new brass screws for it

Attachment:
DSC02045.JPG
DSC02045.JPG [ 3.34 MiB | Viewed 385 times ]


Attachment:
File comment: Back together
DSC02048.JPG
DSC02048.JPG [ 6.3 MiB | Viewed 385 times ]


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 7:40 pm 
Offline
Victor IV
Joined: Mon Aug 24, 2009 3:08 pm
Posts: 1964
Location: Harrison Township, MI
Made your own screws, wow. Proud of you!


Top
 Profile  
 
 Post subject: Re: Columbia AT repair, how should I go about this?
PostPosted: Sun Nov 04, 2018 11:23 pm 
Offline
Victor VI
User avatar
Needle Tins are Addictive
Joined: Fri Jul 09, 2010 8:32 pm
Posts: 3616
Location: Belmont, North Carolina
Great... glad it worked...
"The phonograph† is not of any commercial value."
Thomas Alva Edison - Comment to his assistant, Samuel Insull.

"No one needs a Victrola XX, a Perfected Graphophone Type G, or whatever you call those noisy things."
My Wife


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 9 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Americanized by Maël Soucaze.