stroker crank anyone

[waxhead]

this is a 6 mil stroker crank
its about to get made out of wood to make sure its all ok
its alot cheaper that way

The plan is to make a 5 and a 6 the rods are to hard to get for a 8 mil

i will post pictures of the wooden one when i get it finished

 

[3rid]

Looks already nice. Keep us informed wax.

 

[Powder]

The always important question....HOW MUCH?!?!?!? I got wood just thinking about it. :fest30:

 

[butti]

:Banane01: :Banane01: :Banane01: :Banane01: :Banane01:

 

[Superjet3]

You have my attention

 

[onesojourner]

this is a 6 mil stroker crank
its about to get made out of wood. its alot cheaper that way.

The plan is to make a 5 and a 6 the rods are to hard to get for a 8 mil

i will post pictures of the wooden one when i get it finished

just dont tell any one how many hours they will get with a wooden crank...:sneaky:




























:joke:

 

[Mile9c1]

How are you balancing it? Or are you just trying to copy someone else's?

 

[bad93blaster]

this is a 6 mil stroker crank
its about to get made out of wood to make sure its all ok
its alot cheaper that way

The plan is to make a 5 and a 6 the rods are to hard to get for a 8 mil

i will post pictures of the wooden one when i get it finished

why are the rods hard to get for a 8 mil stroke?
what do the rods have to do with the 8 mil stroke?

 

[waxhead]

you need longer rods for the 8 mil

mile i will get it balanced and see how far out it is
but yes its very similar to a rad crank

 

[Superjet3]

you need longer rods for the 8 mil

mile i will get it ballanced and see how far out it is
but yes its very similar to a rad crank

Hopefully the price wont be!

 

[Mile9c1]

Hopefully the price wont be!

Last I heard all RAD was selling was leftover 6mm units, for around $1,200 each.

 

[waxhead]

i am doing the exercise and seeing what the pricing will be when i have finished

I didnt think rad were making cranks at all anymore
i was hoping to make small stroke ones so they fit in the cases with out modification
but time will tell the mill is half way through making the first wooden web at the moment and i will see how it all shapes up after that
if it loosk ok then i will take it to the machine shop with the cad file and get one made
if thats works ok then its in production

 

[Mile9c1]

They are just selling leftovers (last I heard). All they have left are the 6's.

 

[waxhead]

i have a 6 here as well but i am not sure thats the best size
i thought the 5 was the best size as it requires little maching work as well being very reliable

the 8 is awesome but its on the edge as far as i can tell because your cases get so thin
i was going to look around and see if there was a rod the same length or longer that had a smaller little end so you dont have to machine the cases as much as you do now

i think my ski will get a 4-5 mill crank in it if they are reasonable to build

 

[SkiDaddy]

Wax, I think you'll find a significant power loss with that design due to windage in the cases at running speed. That's why almost everyone use full circle cranks.

If you want to reduce weight then you could mill out pockets & press a thin cap into the top of the pockets as on MX bikes.

 

[waxhead]

this is just a copy of a rad
my understanding was that every one had moved away from full sircle due to the better scavenging of the pipes we have now
and they wanted as much volume in the crankcase as possible to give a broader power band

 

[SkiDaddy]

That may be true, but my understanding was that a smaller crankcase volume yielded better low RPM response. Definately not a consideration for racers.

 

[Mile9c1]

In one of the case "finger filling" threads, Jr.magoo said that more case volume is better for low RPM power.

I don't know either way, but Rad cranks seem to work really well IME.

 

[SkiDaddy]

I think it depends upon displaement, porting, RPM range, etc. I'm thinking a stoke stroke ported 701.

 

[douglee25]

Wax,

I assume you're going to be using rapid prototyping to make your wooden model? What method of rapid prototyping do you use? Do those parts take about 24 hours to form? Thanks for your time.

Doug