Fox .35 Modifications

What I see with regularity is two places where a Fox .35 stunt shaft breaks. The first and most common is the cutout on the shaft. It either cracks or fully departs. I think this is generally assisted by backfires. This is also Fox metallurgy and poor machining practices. The cutout needs to have a radius in the corners to prevent stress risers. Some I know will use 15% nitro and this will also shorten the lifespan of the shaft. The other area where the shaft breaks is where the crankpin is on the web. Seeing how the crank is ground, this is weakening that area even further due to the heat generated by grinding and the lack of material surrounding it.

Myself and many of my club members use the Fox .35 more than any other engine available to us. There's no need to try and balance the shaft. There's far too many other issues with the engine to do so. If one build the motor crutch properly, this is all that's needed to insure consistent smooth runs. The larger and bigger problem is the runout of the shaft from Fox even when it's brand new. Randy Smith made the Hi-Zoot shaft which was really the finest shaft you could have for the Fox .35 stunt. It wasn't hand hammered with stone tools and ground to size on the concrete. Randy's shaft was balanced, it also had no runout issues and it was properly hardened. The cutout in the shaft was also done precisely with the proper radius in the corners. It had a price tag which was a $60. Not too many were interested in purchasing and a limited amount were made.

What is the motor crutch? Sorry for my lack of experience Ken.

Never mind your talking engine Mount so trouble have the least vibration

Never mind your talking engine Mount so trouble have the least vibration

Ken, does anyone run the Fox 35 Speed event over there? I saw Henry Nelson fly two old F2C wings this weekend here. I didn't ask about the engines, but people were saying in typical Henry Nelson fashion, the only Fox part left was the case. They did go, but he was working out fueling issues on launch.

The biggest problem faced with any speed event is the aging members who participate. Not only is the control line arena losing attendance due to age, there's just not enough interest overall. Henry is also correct in terms of the only thing left is the case. Brodak just dropped Fox speed from the events. I'm pretty certain Henry has participated in that event at Brodak's. The Jersey crowd still utilizes Foxberg which means box stock .35 but they also have a event that is more or less anything goes in terms of mods with the Fox .35. In Philly , we have non official events using the Fox .35. We tend to utilize Brodak rules mainly because no one has to think them out and the judges are the same judges who judge Brodak speed events.