Bill Dunlap Posted November 24, 2022 Share Posted November 24, 2022 Here's a Jandus C frame I've almost completed. Just waiting on wire and plug to assemble, and an itty bitty GE lil' ripper. Cute, eh? Cheers, Bill 11 Quote Link to comment Share on other sites More sharing options...
Steve Butler Posted November 27, 2022 Share Posted November 27, 2022 Looking great so far. I think a video of the c-frame would be in order when you get it finished. 👍 Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted November 27, 2022 Author Share Posted November 27, 2022 (edited) OK, here's a short video. I have the blade from my Verity's Junior on it and no cage. If it didn't have different watt readings between speeds, I couldn't tell the difference. So I used my Variac to adjust speed just for demonstration. It runs fine on standard voltage. Very smooth. This is the first C frame I've had in my shop. The gearbox is pure genius. For those who haven't seen them, there are only two gears, one inside the other, an eccentric mounted on the shaft with no fixed connection between the rotor shaft and gears. The center gear orbits inside the outer gear and processes one tooth per revolution dramatically reducing the rpm. A cross shaped piece connects the inner gear to the rotating arm with an oval cut out in the center. This oval serves also to control the motion of the eccentric. Just genius. The pin that connects the rotating arm to the C frame is actually a spring, which acts to prevent damage to the mechanism should it encounter an obstacle. It will just pop out of the groove. VID_20221125_141850758.mp4 Edited November 27, 2022 by Bill Dunlap 3 Quote Link to comment Share on other sites More sharing options...
David Kilnapp Posted November 27, 2022 Share Posted November 27, 2022 Wow, that paint job looks fabulous Bill. Did you make that cord holder on the front cover? I have the same fan and I get very good separation between the two speeds so I'm wondering if there is an issue with the speed coil in your fan. Quote Link to comment Share on other sites More sharing options...
Anthony Lindsey Posted November 27, 2022 Share Posted November 27, 2022 I have a C Frame and had the speed coil rewound. Same scenario, almost zero difference in speed but there is a difference in readings. Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 27, 2022 Share Posted November 27, 2022 9 hours ago, Bill Dunlap said: OK, here's a short video. I have the blade from my Verity's Junior on it and no cage. If it didn't have different watt readings between speeds, I couldn't tell the difference. So I used my Variac to adjust speed just for demonstration. It runs fine on standard voltage. Very smooth. This is the first C frame I've had in my shop. The gearbox is pure genius. For those who haven't seen them, there are only two gears, one inside the other, an eccentric mounted on the shaft with no fixed connection between the rotor shaft and gears. The center gear orbits inside the outer gear and processes one tooth per revolution dramatically reducing the rpm. A cross shaped piece connects the inner gear to the rotating arm with an oval cut out in the center. This oval serves also to control the motion of the eccentric. Just genius. The pin that connects the rotating arm to the C frame is actually a spring, which acts to prevent damage to the mechanism should it encounter an obstacle. It will just pop out of the groove. VID_20221125_141850758.mp4 152.8 MB · 0 downloads Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 27, 2022 Share Posted November 27, 2022 1908 Introduction. Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 27, 2022 Share Posted November 27, 2022 1909 introduction. Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 27, 2022 Share Posted November 27, 2022 1910 introduction Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 27, 2022 Share Posted November 27, 2022 Shedd 1911(?) Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 27, 2022 Share Posted November 27, 2022 Did Bernie(Jandus) borrow/buy/lease from Becker(Diehl) Quote Link to comment Share on other sites More sharing options...
Bill Dunlap Posted November 27, 2022 Author Share Posted November 27, 2022 I've been looking for the name of this particular gear application and the closet I've found is called the Tusi couple. However, that design is really intended to act as a crank and rod converting rotating motion into linear motion. But it does feature an internal gear on an eccentric rotating inside another gear with internal teeth, so the principle is the same. Tusi Couple...it's the best I've come up with. Quote Link to comment Share on other sites More sharing options...
Russ Huber Posted November 27, 2022 Share Posted November 27, 2022 Becker and Stowe use the words concentric and eccentric in patent descriptions relating to the gear arrangement. There may be other references there. I just breezed over the descriptions. 1498392801247396921-00867914 (storage.googleapis.com) 1498409628279048311-00924601 (storage.googleapis.com) 1498385094272078276-01012110 (storage.googleapis.com) Quote Link to comment Share on other sites More sharing options...
Bobby Gaines Posted November 29, 2022 Share Posted November 29, 2022 That's amazing Bill! Very nice. Looking forward to seeing it completed. Quote Link to comment Share on other sites More sharing options...
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