mon Posted March 31, 2015 Report Share Posted March 31, 2015 John, This is the close cut lines that shows the "H" that I was talking about. I know Chad had posted a nice example but I can't find it! OOPS, Pedidoll, I meant to put your name in the title but stuttered on Peltier! http://marbleconnection.com/topic/20358-crazy-little-guy/ Link to comment Share on other sites More sharing options...
Shamrock Marbles Posted March 31, 2015 Report Share Posted March 31, 2015 Mon, I see two cut-lines and one butt-crack (fold).The fold is in the middle of the white section.Like a Jabo.If you look at the Peltier patent, it is easy to see how one side can have a color and the other side not.The "bi-furcation" is because ribbon colors are added from the "left" and the "right" of the machine.Looks like the red hasn't made it down to the nozzle, yet.Steph is alluding to it with her comment about being white underneath.The red has bled over on one side. Here is a marble that I made a long time ago to describe the Jabo Butt-Crack (fold). Think of an inchworm. The gob extrudes out from the nozzle between shearing actions. When it hits and lands on the delivery chute, it folds up onto itself creating a faux third cut-line. Does that help? Sincerely, John McCormick "Shamrock Marbles" Link to comment Share on other sites More sharing options...
mibstified Posted March 31, 2015 Report Share Posted March 31, 2015 John, nice to get a visual as to how a butt-crack between cut lines might occur. Here is (what I belive to be) a clear based example of a Pelt that folded in on itself between cut lines. Interesting to "visualize" how much the gob must have elongated between shearing actions, before it hit the pan, as evidenced by the depth within the marble that the yellow ribbons traverse. Guessing that the elongation factor would be more pronounced if feeding more flowable, lower viscosity (higher temperature) glass. Link to comment Share on other sites More sharing options...
Shamrock Marbles Posted March 31, 2015 Report Share Posted March 31, 2015 What size is that marble? Here is why I ask. The marble machine is running at a fixed speed. The shearing device is synchronized with the machine speed. The nozzle diameter at the bottom of the fore-hearth is fixed. (I don't think Pelt used a gate plate to alter flow, because it would have altered the pattern. Especially for NLR marbles.) If the temperature rises in the tank, then the viscosity of the glass drops (gets thinner). A longer but thinner stream extrudes from the nozzle. Because the time is fixed between shearing actions, actually a little bit more glass comes out than if the glass was thicker. So, sometimes I find these folded up marbles larger than intended. Say 11/16ths versus the target 5/8ths diameter. I could be wrong. Sincerely, John McCormick "Shamrock Marbles" Link to comment Share on other sites More sharing options...
mibstified Posted March 31, 2015 Report Share Posted March 31, 2015 It measures 0.614" or just a littel under 5/8". If the melt is thinner than target viscosity, couldn't the mass be consistant but in the form of a thinner, longer stream? Is the shear syncrinization adjustable so they could zero-in on making the desired marble diameter, for a given glass (properties) run? Have no idea of how the machine mechanics work together but just woindering. Link to comment Share on other sites More sharing options...
Shamrock Marbles Posted March 31, 2015 Report Share Posted March 31, 2015 LOL! I said I could be wrong! Tank levels also come into play (head pressure at the nozzle). Adjustments to machine speed could have been made. Typically the shear is synchronized mechanical with the auger. Guess the marble could have hit and folded the other way and made a yellow ring around the marble! This stuff is fun. No two marbles alike due to system variability. Sincerely, John McCormick "Shamrock Marbles" Link to comment Share on other sites More sharing options...
I'llhavethat1 Posted April 1, 2015 Report Share Posted April 1, 2015 It measures 0.614" or just a littel under 5/8". If the melt is thinner than target viscosity, couldn't the mass be consistant but in the form of a thinner, longer stream? Is the shear syncrinization adjustable so they could zero-in on making the desired marble diameter, for a given glass (properties) run? Have no idea of how the machine mechanics work together but just woindering. If the shear device was mechanically driven, a thinner longer stream would be cycled/sheared either way based on timing and not mass... So it was probably based more on a (somewhat crude) volumetric flow more than a mass flow. I like the results either way Link to comment Share on other sites More sharing options...
lstmmrbls Posted April 1, 2015 Report Share Posted April 1, 2015 You can also find 2 seam CACc with the fold. Gives them that 3 seam look Link to comment Share on other sites More sharing options...
pedidoll Posted April 2, 2015 Report Share Posted April 2, 2015 :D Link to comment Share on other sites More sharing options...
Shamrock Marbles Posted April 2, 2015 Report Share Posted April 2, 2015 You can also find 2 seam CACc with the fold. Gives them that 3 seam look Below could be an example of a CA marble that Galen eludes to if you were to believe he meant that, IMHO. (Photo from MarbleAlan Ebay auction. For educational purposes only.) I think Galen is quite familiar with this one. Sincerely, John McCormick "Shamrock Marbles" Link to comment Share on other sites More sharing options...
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