Pearl No. 1 Roller, Core, & Wheel Data

Golding Parts Nos. 161 & 162

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In this Notebook I'll present the surviving data for Pearl No. 1 Rollers, Roller Cores, and Form Roller Wheels (i.e., Trucks).

Thanks are due to Stephen O. Saxe for having preserved the original Golding & Co. drawings and tables from which these data come.

For a modern compatible design, see the Pearl No. 1 Compatible Form Roller Wheel Design Notebook.

N.B., The use of the term "truck" or "roller truck" with regard to a Pearl is a modern convention. The Golding & Co. name for them was "Form Roller Wheels."

1. Roller and Roller Core Data

The Roller Core for a Pearl No. 1 was Golding part no. 161. It was described in a Golding & Co. combined drawing/table "Cast Roller & Roller Core Data," which presents data for many models of Golding Jobber, Pearl, and Official presses. This undated document has been preserved by Stephen O. Saxe.

In the drawing below, I've re-drawn the Roller Core and Roller from this document (drawing it/them to correct relative scale) and added the dimensional data from the table in the original. It is all rearranged from the original, but all of (and only) the original information is present; nothing has been added.

The Roller diameter specified in the original table is 1 1/2 inches. Discussions online have suggested that this is indeed the correct diameter for composition rollers for this press using 1 3/8 inch Form Roller Wheels; the softer composition rollers are indeed of greater diameter than the trucks. The consensus online is that rubber rollers, being harder, should be the same diameter as the wheels. However, I've also spoken with a very experienced retired printer who insisted that roller diameter should in general be 0.020 inch less than the trucks - and indeed the rail height for the one Pearl No. 1 that I have examined is lower than the type height. You will have to draw your own conclusions.

The pin 'G' in the drawing is specified in the table as "#10", but the gauging system for this number is not indicated. There are at least eight different wire or sheet gauges which could have been used. The most common modern gauge (American Wire Gauge, formerly Brown & Sharpe) No. 10 is about 0.102, but it was not commonly used with ferrous wire. The gauge most commonly used for steel wire at the time, Stubs Steel Wire Gauge, is 0.191 for No. 10, but this is larger than the size of the corresponding slot for this pin in the Golding Form Roller Wheel specifications. If this gauge is based on a screw standard, I'm not sure which one it could be. The former Unified National (formerly Sellers) machine screw nominal diameter for No. 10 is 0.190 (only similar to Stubs' by coincidence), which won't work. I can find no dowel pin standards for the period. It can't be a Brown & Sharpe taper pin (for which No. 10 is too big). One cannot scale from the original drawing, since it is only a schematic drawing intended to represent 19 different Roller Cores. An examination of existing pins on (replacement, not known-original) Roller Cores reveals dimensions from 0.096 to 0.130. So I'm puzzled. In the absence of further information, all that can be said is that 'G' must be less than 3/16 inch. The height of this pin is not even indicated as a dimension (but the truck drawing indicates a maximum of 3/16 for this as well).

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CircuitousRoot Drawing No. CRD-4. The image above links to a PDF created from the CAD drawing. Here is the DXF-format CAD source: crd-4-pearl-no-1-roller-original-data.dxf In my experience the PDF prints well enough, but if you have the ability to read and print a DXF file that will be slightly crisper and more likely to be the size as drawn.

2. Form Roller Wheel Data

The Form Roller Wheel (i.e., Truck) for a Pearl No. 1 was Golding part no. 162. It was described in a Golding & Co. engineering drawing and table "Form Roller Wheels" originally dated Oct. 1898 with revisions on 1906-04-11 and 1911-06-25. This document has been preserved by Stephen O. Saxe. His original, an ozalid/diazo copy of a previous original, was in damaged condition as acquired. He has done some fine digital restoration of it, and it does not appear as if any information pertaining to the No. 1 Pearl has been lost.

Still, the drawing is not without ambiguity. It was a drawing intended for use by someone who already knew what they were making.

The drawing specifies the diameter of the bore through the wheel as "5/16 R". The 'R' cannot, however, indicate radius as "5/16" is the correct diameter of the Pearl No. 11 Roller Core end. I have omitted the 'R' in the drawing below.

The radius of the fillet between the two diameters of the Wheel is not specified. It is not a functional aspect of the part, though, so it probably doesn't matter (but it was specified on some Wheels for other models as shown in the original drawing).

The Form Roller Wheel has an annular recess cut (or cast?) into the large inner side facing the Roller. The original drawing is drawn showing the material remaining at the sides and the bottom as being of the same thickness. But the dimensions indicate a sidewall thickness of 1/8 inch and a bottom thickness of 1/16 inch. In the drawing below, I have followed the dimensions.

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image link-to-crd-3-pearl-no-1-truck-original-data-sf0.jpg

CircuitousRoot Drawing No. CRD-3. The image above links to a PDF created from the CAD drawing. Here is the DXF-format CAD source: crd-3-pearl-no-1-truck-original-data.dxf In my experience the PDF prints well enough, but if you have the ability to read and print a DXF file that will be slightly crisper and more likely to be the size as drawn.


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