It's a lot like regular new-product development. Steps forward, and a step back (or two). Forward was that printing the strip with DLP resin technology gave incredibly crisp letters on the strip.
Whereas the filament-printed strips still show the layering, on the scale of typewriter-characters the resin-printed strip is absolutely crisp. In actual typing, it does show that the resin-printed shuttle is better quality. Because the actual typing goes on paper and through a ribbon, the difference on paper is not as large as the difference when comparing the strips.
The ribbon was a hand-inked 'home-made' narrow one. To check the impact of this home-inked ribbon, the Hammond Multiplex was temporarily fitted with a new, commercially bought half-inch ribbon.
That changed the whole look of the machine - it didn't however improve the typing much. (It actually made it worse - so back to one of the narrow home-made ribbons!)
The DLP resin-printed strips were unfortunately also less firm. They really need the metal flange to stay in shape. That lack of stiffness probably is the cause of these new crisp strips again binding in the wheel and jamming the machine. That problem had been completely solved for the FDM-prints, so that's clearly a step back again.
With all the 'mucking-about' and exchanging ribbons, the relatively weak aluminum type-shield broke and lost a small section. This is the cause of the 'echoing' under the characters in the above image. More new shields to be made.
From the experience so far, it may turn out that for simpler typefaces (low-cost) FDM technology is the best compromise to create a working Hammond type-shuttle that produces acceptable text. However for more complex typefaces (e.g. Attic), the crisp detail of a DLP resin printer is needed - the added problems of resin-printed parts yet to be solved.
It's definitely product-development - and continue to be impressed with the fine balance of parts and process-parameters that Hammond achieved in the 1880s!
Keep at it! You're doing important work for Hammond lovers.
ReplyDeleteSmall steps and slow going. Teaming-up with Leonard - joint efforts we'll surely get there :-)
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