First, I'm back. I'll take my warning points for swearing in the public forums and move on (provided I'm still welcome). I'm sorry if I made anyone mad by purposely messing up the signature images I was hosting. That was childish. They are back as they were. If anyone is still mad at me, that's fine -- my ignore list will just have to include a few more names.
Anyway, onto the r/c stuff.
I bought this old Nitro Hawk for my son. The pull start was on it's last leg when I got it. After a time or two of taking it out, it looked like this:
I figured I'd replace the pull start. Wrong! This thing is as old as dirt. The one way bearing, that is normally outside the crankcase on a modern engine is inside the crankcase on this "IMAGE 12". This makes adapting a normal pull start impossible. Calling R/C museums and asking if I could borrow the pull start off their vintage displays was also out of the question. I could have just bought a new engine with a pull start. I would have done that if I didn't have the spare parts to rebuild this engine twice. Also, having the cabage to pay for a new egine might have also helped. (I could have also bought a bump start or a starter box for that matter.)
Anyway, this is what I did:
The shaft from the pull start (the part that basically turns the engine over) was held inplace by the pull start housing. The pull start housing, however, was now in a million pieces. I was not completely up a creek; the one way bearing and the shaft still worked together. Turn the shaft one way, the engine turns over. Turn it the other way, the shaft just spins (this is a good thing).
The only thing keeping me from using a cordless drill to start the engine was the simple fact that the ever-so-important shaft freely slid in and out of the crankcase. Basically, if I ever took a turn to sharp it would throw the shaft out on the ground, leaving a hole where you can look in to see the crank shaft.
My goal was to keep the shaft in the engine and to make sure it still spun freely.
This is what I did:
I call it "Frankin Crank". You might call it "Jerry Rigged", but it really isn't. I took the spool off the old shaft and removed one of the lips. This made it more of a hat than a spool. I bought a ball bearing that was the exact size to be mounted to the shaft (it's tapered and makes life easy). The outside diameter of the ball bearing fit loosely inside the hat-shaped remains of the spool. I then drilled four holes in the rim of the hat which coresponded to the four allen screws just behind it. I replaced the allen screws with compatible longer screws and screwed what once was the spool for the pull cord to the engine. The ball bearing was inside the hat but it wasn't a good tight fit. I had to drill and tap four holes in which I put four screws. The screws you see poking in all four directions act as set screws and as guides to keep the shaft and bearing straight.
The end product is the shaft from the old pull start hanging out side of the crankcase. The shaft is supported with a nice ball bearing and spins with ease. Because the bearing is pressed onto the shaft, the shaft no longer moves in or out.
Now I can use a drill to start the car. Because the one way bearing is inside the engine already, I dont have to worry about a oneway bearing on the outside (like the Yank Eliminator has).
I've tested it and I'm pleased to anounce that it works great! A very solid solution that should last my son for a few years.
The best part is that it cost me $9.40 to do it.
-rob (no spell check here sorry)
Anyway, onto the r/c stuff.
I bought this old Nitro Hawk for my son. The pull start was on it's last leg when I got it. After a time or two of taking it out, it looked like this:
I figured I'd replace the pull start. Wrong! This thing is as old as dirt. The one way bearing, that is normally outside the crankcase on a modern engine is inside the crankcase on this "IMAGE 12". This makes adapting a normal pull start impossible. Calling R/C museums and asking if I could borrow the pull start off their vintage displays was also out of the question. I could have just bought a new engine with a pull start. I would have done that if I didn't have the spare parts to rebuild this engine twice. Also, having the cabage to pay for a new egine might have also helped. (I could have also bought a bump start or a starter box for that matter.)
Anyway, this is what I did:
The shaft from the pull start (the part that basically turns the engine over) was held inplace by the pull start housing. The pull start housing, however, was now in a million pieces. I was not completely up a creek; the one way bearing and the shaft still worked together. Turn the shaft one way, the engine turns over. Turn it the other way, the shaft just spins (this is a good thing).
The only thing keeping me from using a cordless drill to start the engine was the simple fact that the ever-so-important shaft freely slid in and out of the crankcase. Basically, if I ever took a turn to sharp it would throw the shaft out on the ground, leaving a hole where you can look in to see the crank shaft.
My goal was to keep the shaft in the engine and to make sure it still spun freely.
This is what I did:
I call it "Frankin Crank". You might call it "Jerry Rigged", but it really isn't. I took the spool off the old shaft and removed one of the lips. This made it more of a hat than a spool. I bought a ball bearing that was the exact size to be mounted to the shaft (it's tapered and makes life easy). The outside diameter of the ball bearing fit loosely inside the hat-shaped remains of the spool. I then drilled four holes in the rim of the hat which coresponded to the four allen screws just behind it. I replaced the allen screws with compatible longer screws and screwed what once was the spool for the pull cord to the engine. The ball bearing was inside the hat but it wasn't a good tight fit. I had to drill and tap four holes in which I put four screws. The screws you see poking in all four directions act as set screws and as guides to keep the shaft and bearing straight.
The end product is the shaft from the old pull start hanging out side of the crankcase. The shaft is supported with a nice ball bearing and spins with ease. Because the bearing is pressed onto the shaft, the shaft no longer moves in or out.
Now I can use a drill to start the car. Because the one way bearing is inside the engine already, I dont have to worry about a oneway bearing on the outside (like the Yank Eliminator has).
I've tested it and I'm pleased to anounce that it works great! A very solid solution that should last my son for a few years.
The best part is that it cost me $9.40 to do it.
-rob (no spell check here sorry)
