2min wax ribs.

[gramophoneshane]

I recently noticed that I have a couple 2min wax records that are smooth on the inside. Most of my others have the usual ribs.
Can anyone tell me when edison started putting the ribs inside the cylinders and why it was changed. Was it to strengthen them or just to cut down on costs?

[steve]

From my Ron D letter collection:

The smooth bore Edison 2-minute cylinders were produced around 1906
when Edison was having patent problems and had to stop reaming the
bores. Smooth bore cylinders usually have a problem fitting properly
on the mandrel. Edison soon went back to the ribbed bores which
somehow were easier to gauge.

[gramophoneshane]

Thanks once again Steve. You should write a book, or leave me your brain in your will! ;D

[steve]

My brain is worth a fortune, it is NOS and has never been used!

[edisonphonoworks]

I got one for you, I saw a few Edison Gold Moulded records that had spiral cores, like brown wax, I have only seen two of these in looking through bins and bins of Gold Moulded cylinders. They were title end, round ended kind, not the flat ends. Yes, I will back up the 1906 period for smooth bore cylinders. I do not understand this as Edison had patented the idea of spiral and annular projections on the interior of the cylinders in patent, 414,761 in 1889. So I am sure that once that was cleared up he went back to work. I use this information to make my own blanks.

[refseries]

Another problem with smooth bores is that they easily slide off the mandrel while playing. Naturally one doesn't want to push them on hard (particularly Grand Operas, of which a number are smooth bored) so I use a couple of paper strips between the mandrel and the cylinder to improve the grip without neeeding any undue force.

Keith