RGS 20 Driver Spokes
| January 23, 2009 11:53AM |
|
We just finished repairing one driver spoke. First the spoke was pinned with a steel bar and then the spoke was brazed. The pin will add some strength and form a backup for the braze. The braze seemed to knit well to the iron.
When the wheel is turned prior to applying the tires, there will be even compression on all the spokes and the pin in the repaired spokes. This should effectively increase the braze strength by placing it in compression to some extent.
Repairing iron driver centers is always a crap shoot. I have never seen a successful weld repair but I have seen successful brazing jobs. I have seen weld repairs that looked good at first glance but closer examination showed cracking that blossomed in service. The brazing process seems to be more compatible with a lot of the older iron centers which can be of dubious quality.
The cracks in the short crank hub spoke appear to have started as shrinkage cracks when the wheel was made new. If chills were not used in the hubs, the difference in the cooling rate between the hub and the spokes would be significant and the slow cooling hub would have attempted to pull cooler and partly solidified iron from the spoke thereby creating voids and tension in the spoke.
Spoke showing hole for pin.
Spoke with pin in place ready for brazing.
Repaired spoke.
Other wheel from #1 axle showing all three defective spokes. The one on the right is cracked half way and will not be pinned - only brazed.
When the wheel is turned prior to applying the tires, there will be even compression on all the spokes and the pin in the repaired spokes. This should effectively increase the braze strength by placing it in compression to some extent.
Repairing iron driver centers is always a crap shoot. I have never seen a successful weld repair but I have seen successful brazing jobs. I have seen weld repairs that looked good at first glance but closer examination showed cracking that blossomed in service. The brazing process seems to be more compatible with a lot of the older iron centers which can be of dubious quality.
The cracks in the short crank hub spoke appear to have started as shrinkage cracks when the wheel was made new. If chills were not used in the hubs, the difference in the cooling rate between the hub and the spokes would be significant and the slow cooling hub would have attempted to pull cooler and partly solidified iron from the spoke thereby creating voids and tension in the spoke.
Spoke showing hole for pin.
Spoke with pin in place ready for brazing.
Repaired spoke.
Other wheel from #1 axle showing all three defective spokes. The one on the right is cracked half way and will not be pinned - only brazed.
| Subject | Author | Posted |
|---|---|---|
|
Linn W. Moedinger | January 23, 2009 11:53AM |
|
FordCVP71 | January 23, 2009 12:09PM |
|
Tom Moungovan | January 23, 2009 02:11PM |
|
Linn W. Moedinger | January 23, 2009 08:50PM |
|
stuart olson | January 23, 2009 02:14PM |
|
Linn W. Moedinger | January 23, 2009 08:53PM |
|
jd johnson | January 23, 2009 03:20PM |
|
Linn W. Moedinger | January 23, 2009 08:54PM |
|
Russo Loco | January 23, 2009 06:49PM |
Sorry, only registered users may post in this forum.
488 stops for water at Los Pinos tank on closing day Oct. 1979. Photo courtesy Don Richter
The NGDF was started by Don Richter and is currently operated in his memory by Nathan Holmes and others. Others who have contributed to the upkeep of this board are (in no particular order): Charles McCandless, Everett Lueck, Ted Wilton, Cole Adams, James Bane, John Moellmer, Jon Bentz, Linn Moedinger, lloyd lehrer, Rod Jensen, John Craft, Steven Forney, Herb Kelsey, Bill Ramaley, Russ Sperry (El Russo Loco), Josh McNeal, John West, Jim Armstrong, Bob Bergstrom, Greg Scholl, Blake Forbes Doug van Veelen and Mark Fuller.