I searched the lists of stock spur gears from international suppliers but I could not find a supplier of a 77 tooth, module 3 gear. 77 teeth is apparently unusual. Plenty of suppliers for 76 and 78 tooth gears, but none for 77.
I did find an Ebay seller who had some old new stock of rotary HSS gear cutters and I considered making a new gear.
But meanwhile, after airing the situation at a GSMEE meeting, I had a recommendation to try a local gear maker. Well, fairly local. He is 1 hour up the freeway. But the phone calls were unanswered, repeatedly. Another fellow GSMEE member also required a gear cut, for a telescope mount (a BIG telescope…. another story), and it was on his route home, so he called in, prepared to bang on the gear maker’s door. Despite the industrial turn down in Australian manufacturing, the gear maker is so flat out with work, that he has stopped answering the phone. But he received Frank very cordially, and was also very friendly and helpful to me when I turned up 2 hours later.
I took the broken gear and its shaft, and he is preparing a quote. His initial recommendation is that the gear be replaced entirely, rather than repaired, or a toothed ring shrunk on. So I am waiting for the quote. But frankly, the lathe is unusable the way it is, so I cannot imagine rejecting the quote, unless it is so high that I am pushed back to making a gear myself. I will post this when I get the quote. Meanwhile, a photo, and a plug for the gear making business.
Johnny proudly showed me around his factory, and we discussed the options for my job in detail. He has many (~40) gear hobbing machines, lathes, mills, and jobs in progress. He is just about to get his first CNC machine, a lathe. The machine in the photo was making a gear cluster of 6 or 7 different sized gears.
Sunshine Gears is at 14 First Avenue, Sunshine, Victoria. Telephone 0393117152. Probably best to just call in rather than telephone.
Post script. After considering the quotes I have asked Johnny to make me a gear which I will attach to the original hub. It should be ready for me to pick up when I return from my UK trip. It saves several hundred dollars to do it this way, rather than getting the entire gear with hub made from scratch.
By the time this post is published I should be in the air…..