Evan Atkinson Posted April 16 Share Posted April 16 Was reassembling this Signal pedestal osc gearbox with a number of 1536 on it (the typical "minimal" cast metal gearbox found on most Signal fans of the 1930's), and came to realize the threads for the large slotted 'plug' are a mess: someone did a real number on it. This plug cap acts as the support end for the main transmission worm and phenolic drive gear. So I need to fix it, if possible. Uncertain if a bottoming or standard tap was used to create this bore, but might anyone happen to know the size? Threads on the plug appear to be NF 32, but the diameter of the bore is measuring out .78. I'm not finding any taps even remotely close to this size and spec...wondering if a 3/4 tap was used..? Quote Link to comment Share on other sites More sharing options...
Jerry Van Posted April 16 Share Posted April 16 What is the overall diameter of the cap threads? Quote Link to comment Share on other sites More sharing options...
Evan Atkinson Posted April 16 Author Share Posted April 16 (edited) Sorry, I measured the bore, not the cap threads 🤦🏼♂️. Edited April 16 by Evan Atkinson Quote Link to comment Share on other sites More sharing options...
Jerry Van Posted April 17 Share Posted April 17 (edited) 13/16"-32 apparently. There is at least one tap on eBay right now. The cheapest I saw was $18. Edited April 17 by Jerry Van 1 Quote Link to comment Share on other sites More sharing options...
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