Another Matrix Holder Issue

[Dave Hughes]

I have been contacted by @John Cornelisse who asked me to post these two pictures:





Says John: Here are two photos of a holder for American flat matrices the only problem with is its small size...

It does not fit in any bridge

Does anyone know how this can be used on a composition caster?"

[John Cornelisse]

The width of the holder is 2 5/8 inch,

while the normal die-cases are 3 3/8 inch wide.

[KPMartin]

This is the usual (i.e. most common) 41A holder for using Lanston flat matrices in the Composition Caster and its ilk using Lanston type T and U display moulds. There is an outer frame this slides into, the outside being shaped like a normal cellular composition matrix diecase.

Like a regular diecase, the outer frame has the hook which engages into the slider on the rear pin block, so it is necessary to position the rear pinblock properly, either by always having the correct lettered airpin channel active, or by manually positioning the rear rack and setting the caster so the racks do not unlock and move.

The scars on the matrix holder in the original post indicate having run it frequently with the wrong rear airpin position.

Because the outer frame hooks to the rear pinblock mechanism, removing this frame requires using the carrying frame lifter arm, and often reaching around behind the bridge to engage or disengage the hook. This is a pain to do every time you want to change the matrix, so this insert is made to come out easily by pressing down the small button next to the handle.

Although the Lanston matrices are aligned to two different vertical bearings, to automatically match the type T and U moulds, this holder allows replacement of the three parts 41A5, 41A6, and 41A17 visible in the second photo to give three alternative matrix positions, lowered from the normal position by about 0.050, 0.100, or 0.150 inches.  These alternative inserts have numbers like a41A25/a41A26/a41A27 for 0.150". I don't know what the original intended purpose was for these, although I can see using them to cast a caps-only font on a type body smaller than the font's nominal size. The choice of insert set would get you close to the desired vertical alignment, and the bridge's alignment adjustment would do the rest. These inserts are alas not generally suitable for casting 24 and 30 point Lanston matrices on English display moulds since this requires raising the matrix, not lowering it.