The Making of a Full Circle Crank in a Homeshop

[awol]

Why not a press fit on the weights/rings?

I was afraid the rings would just distort to the shape of crank, and no longer be perfectly round. Now if we machined more material from the crank, and made the rings thicker, that may work well.

 

[Deets066]

If a guy was to sweat em on, how much undersized would you want the rings

 

[awol]

On that size of ring, about .003

 

[Nitroman]

If you want to make the epoxy nice and smooth...use a pair of large veterinary syringes, about 60-80ml. Cut about half of the end off one, but not all, you want a hole about 3/8" in end where needle would have gone. Now mix epoxy. When done, suck up as much as you can with modified syringe, the inject contents into unmodified syringe. When you squirt out the epoxy, there will be no bubbles.

To keep everything in place, use clear packing tape.

 

[Deets066]

If you want to make the epoxy nice and smooth...use a pair of large veterinary syringes, about 60-80ml. Cut about half of the end off one, but not all, you want a hole about 3/8" in end where needle would have gone. Now mix epoxy. When done, suck up as much as you can with modified syringe, the inject contents into unmodified syringe. When you squirt out the epoxy, there will be no bubbles.

To keep everything in place, use clear packing tape.

That would take a long time, but I see the benefit to it

 

[Moparmyway]

Saran wrap is the easiest thing to pick JB Weld off of .......... it just falls off when you pick it up after it cures

 

[Nitroman]

That would take a long time, but I see the benefit to it

I do this same thing when bedding a stock, or a large repair like on my lathe table. I cut the end of the syringe with a scalpel. Gotta be real careful!

 

[bikemike]

Those look like what we did for rc nitro engines makes a difference in performance and centrifugal force help sling the air n fuel to transfer ports

 

[Nitroman]

Now that is a mod I would like to see dyno'ed. I had mentioned this previously to a builder before.

 

[jmssaws]

I'm building a circle crank 660 that I'd happily send to run on a dyno.
If someone wants to do it let me know and I'll send it out when it's finished.

 

[bikemike]

machining ur own crank halves could come in handy stroke it out if the case has a Lil extra room torque would go through the roof

 

[Deets066]

machining ur own crank halves could come in handy stroke it out if the case has a Lil extra room torque would go through the roof

It wouldn't take much more stroke to make a big difference either

 

[Nitroman]

Faliconcranks.com is your friend if you want a stroker. Might be challenging for a home builder as they (Falicon), told me they'll weld up the off side, then grind down the pin for the correct stroke.

They'll make a crank for you too if that's what you want. You know how the saying goes: horsepower costs money.

 

[Ozarker]

To paraphrase an old adage: If it makes your saw go faster, then it either won't fit, or is illegal, or is damned expensive.

 

[Warped5]

Alan, I'm just thinking out loud here ... but JB is plastic and any time plastic is subjected to temperature changes and stress it will fail.

Very interested, but not crazy wild about this ...

 

[Deets066]

Alan, I'm just thinking out loud here ... but JB is plastic and any time plastic is subjected to temperature changes and stress it will fail.

Very interested, but not crazy wild about this ...

Be interesting to see how long it will last

 

[Cut4fun]

Nice awol.

Reminds me of the 5000 full circle crank I bought from SB that MVP did.

 

[Stihlbro]

C4f, how did the crank that you bought from sb made by mvp work? Was there a improvement in power? Did you have to change the porting? Did you use the same piston? Did your cylinder have the modification where the transfers feed from the bottom on the full circle crank you tried?

 

[Magic_Man]

Interesting stuff

 

[Cut4fun]

SB, traded it off since after doing some long talking on it at racesaws. Came to conclusion it wouldnt have been good for a COLD start saw, but good for a over the wood hotstart saw for its size.

It ended up in one of Frank's 5000's.