Fox. 35 Hi Zoot Crankshaft

[Dan McEntee]

   I have one of these, and not sure of when Randy started making these, before or after the availability of ABC set ups. This leads to the question, where these intended for stock pistons or for aluminum pistons. Just curious, as I can do either with it.
  Thanks in advance,
  DAn McEntee

[Steve Dwyer]

Dan,
Without my doing research what did these crankshafts do? I have a friend that sent an Anniversary Fox 35 to Randy years back for rework is this related?
Steve

[Dan McEntee]

Dan,
Without my doing research what did these crankshafts do? I have a friend that sent an Anniversary Fox 35 to Randy years back for rework is this related?
Steve

     The crank shaft makes the piston go up and down!! But if you have been running Foxes for any length of time, or read any good amount of information about them you know that the stock crank shaft is less than perfect. It's not balanced very well and this is the main cause of the vibration that Fox.35s are known for. Fox.35s have nee known to break crankshafts also. One of our club members has one on a Barnstormer, and to balance the model he put one of those brass heavy hubs on it and has been running it that way for quite a while. A few weeks ago, he was getting ready to put up a flight, I was holding the model with the engine running, and just before he gave the launch signal, the prop and bulk of the cranks shaft came flying out of the engine! It broke right where the main shaft meets the disc for the counter weights and crank pin. This is the main reason you should not use those heavy hubs on a Fox over an extended period!  Randy's shafts are more precise, better balanced and heat treated. What I would like to know is if he made these to accommodate the stock iron piston, or the aluminum piston of an ABC combination. It's almost impossible to get a perfect balance on any single cylinder engine, but helps to get as close as you can get it. A smoother running engine is a better engine. I have had this crank for quite a while and I think it's time to quit saving it and use it!
   Type at you later,
   Dan McEntee

[Steve Dwyer]

Thanks Dan, "the crankshaft makes the piston go up and down"...we learn something new everyday. LOL.

[Dennis Toth]

Dan,
I asked this same question a while back and Randy said it works with either.

Best,    DennisT

[Ken Culbertson]

Dan,
I asked this same question a while back and Randy said it works with either.

Best,    DennisT

Do you mean it will go down and up as well as up and down?

Ken

[Dan McEntee]

Dan,
I asked this same question a while back and Randy said it works with either.

Best,    DennisT

   I would almost accept that as an answer, but not until I get a chance to weigh both types of pistons. It's almost like saying a shoe will work with either foot, but it will most certainly fit one foot better than the other!  My guess is that he intended for it to be used as a replacement for stock cranks on stock engines. I would have to wonder if using it on an ABC set up would make the vibration pendulum swing the other way. The stock crank was too light on the counterweight for the iron piston, and if he addressed that, would it now be too heavy for the aluminum piston??? That is the question, I think It would certainly make the piston go up and down, but which one would it work best with??
   Type at you later,
   Dan McEntee

[Steve Helmick]

  Nah, it's the piston that makes the crank go round and round!  Steve

[Dennis Toth]

Dan,
There have been several discussions on this in the engine section. I never got the final answer about needing to reduce the counterweight with the ABC setup. The responses I got seemed to indicate that the strength of the crank and straightness were more important than the balance at stunt rpm. I did ask directly about the need to reduce it and we'll see if Randy or others anwser.

Best,    DennisT