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Can someone confirm I have a RO transitional slide

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colreed View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote colreed Quote  Post ReplyReply Direct Link To This Post Topic: Can someone confirm I have a RO transitional slide
    Posted: Feb 15 2023 at 5:04pm
Mine is the one in the middle. I've never seen one like it. 
It has a 1/4" (precisely) arm joint AND a semi-circle cut in the back.
It doesn't conform to any other slide in the slide chart.
Per the data sheet, it would be labled a E269.

CCNL 119-3 states:
"A transition slide from E169 to E279 exists. it has a 3/16 arm joint and a "squared off round box". In other words, it is a flat box slide with a curved cut remaining on the inside of the arm. This type slide has only been reported with the Rock-Ola name on the inside or outside of the box."

Let me know if a different photo angle would help.






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Dan Pinto, Photo Editor

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Post Options Post Options   Thanks (0) Thanks(0)   Quote New2brass Quote  Post ReplyReply Direct Link To This Post Posted: Feb 15 2023 at 7:20pm
Hmm, any sign of rework and refinish?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote colreed Quote  Post ReplyReply Direct Link To This Post Posted: Feb 16 2023 at 12:59pm
I am glad you asked the question, Dan
On closer observation, it appears as if some of the semi-circular feature may have been illed off. See arrows. 
That being the case, and if true, this was an ordinary type 1 to begin with.
Why would anyone do that? Or could Rock-Ola have done this on the line for some reason?  The milling mark design appears to match closely other milling marks on the slide. Could the slide have been mis-forged during mfg and this was done to 'clean it up'? So many questions.
Thoughts?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jackp1028 Quote  Post ReplyReply Direct Link To This Post Posted: Feb 16 2023 at 1:21pm
It looks like someone added the radius to a Type II arm joint like you see on the Type III, reducing the thickness to 1/4". Maybe it's a Type II and a half. Reed, would you post a side view of the arm joint with a scale in the picture to show the 1/4"width of the arm joint.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote colreed Quote  Post ReplyReply Direct Link To This Post Posted: Feb 16 2023 at 5:45pm
sure. Does this one work?



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Post Options Post Options   Thanks (0) Thanks(0)   Quote New2brass Quote  Post ReplyReply Direct Link To This Post Posted: Feb 16 2023 at 6:33pm
Ok, had a little time to go over.
The reason for the arm joint to go from 3/8 to 3/16 was it was the same forging from 169 to the 279 slides. The bevel was cut with a step as pointed out below. Being the joint was so thin they went to a new forging for a longer joint with more strength.


CCNL 119-3 goes on to say the Rockola name on the inside is earlier and outside on the later. The transitional slide had been reported marked inside, presumed earlier, and marked outside presumed later.

I have one somewhere which I will pull when I can, but nothing is suspect about yours from what I can see. The 1/4 inch is because they did not machine the step back as far.
They evidently found a benefit by putting in the step, which would give an extra 3/16 play for the spring at compression.

From a machining perspective, imagine how long the cutter had to be to cut that round section out being it had to clear the arm.
With the advent of the new vertical mill the slat cut could be made easier, less horsepower and far less overhang, which could lead to errors due to flex or runout. 



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Post Options Post Options   Thanks (0) Thanks(0)   Quote jackp1028 Quote  Post ReplyReply Direct Link To This Post Posted: Feb 16 2023 at 8:27pm
Thanks for posting the additional picture. It looks like the arm of a Type II was modified to add a radius to the intersection of the arm and inertial block like you see in a Type III. I believe this undocumented change might have been made to eliminate the stress riser in the sharp corner that could lead to breakage. This unfortunately had the effect of reducing the thickness of the arm joint which was corrected in the Type IV where it was increased to 9/16".
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Post Options Post Options   Thanks (0) Thanks(0)   Quote GotSnlB28 Quote  Post ReplyReply Direct Link To This Post Posted: Feb 18 2023 at 9:59am
Here's one that I have with the same characteristics, though it has the early mfg marking inside the box. No evidence that it's been altered, refinished, etc. One interesting thing about this one is the hole for the slide stop. It seems when manufactured the top hole was mistakenly drilled through with the larger diameter hole from the bottom. I have examined the hole and its edges closely and there is no evidence this was done post manufacture.








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Post Options Post Options   Thanks (0) Thanks(0)   Quote colreed Quote  Post ReplyReply Direct Link To This Post Posted: Feb 18 2023 at 10:59am
Yep, looks the same except for logo location. Thanks for posting.
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