Dimensions of flywheel collet?

[Roog]

Hi RC car builders,

My next project will be an IC powered car, I have an Irvine .20 nitro engine but I need to make my own flywheel so that I can attach a specific bevel gear. I am going to fasten the flywheel using a tapered collet and buying these is no problem but none of the retailers say what the dimensions are. For instance the shaft dia of my engine is 1/4” is it safe to assume that all collets intended for .2 or .21 nitro engines have 1/4” fitting?

If I can be confident that such collets fit the shaft I cam measure the other dims to make my flywheel.

Many thanks

P.McD

 

[Greywolf74]

Hi RC car builders,

My next project will be an IC powered car, I have an Irvine .20 nitro engine but I need to make my own flywheel so that I can attach a specific bevel gear. I am going to fasten the flywheel using a tapered collet and buying these is no problem but none of the retailers say what the dimensions are. For instance the shaft dia of my engine is 1/4” is it safe to assume that all collets intended for .2 or .21 nitro engines have 1/4” fitting?

If I can be confident that such collets fit the shaft I cam measure the other dims to make my flywheel.

Many thanks

P.McD

I'm not sure if I can help you with this specific question, as I don't have any small block nitro motors currently. All I can tell you is the collets I have for big blocks have an ID of .274" and I can use any of these collets on my .26, .28 and .30 engines. If the small block motors have a smaller ID collet, I would assume they are all the same size like my BB collets.

 

[Roog]

I'm not sure if I can help you with this specific question, as I don't have any small block nitro motors currently. All I can tell you is the collets I have for big blocks have an ID of .274" and I can use any of these collets on my .26, .28 and .30 engines. If the small block motors have a smaller ID collet, I would assume they are all the same size like my BB collets.

Thanks @Greywolf74 0.274” does sound a little larger than than the plain shaft on my engine. It’s very frustrating because retailers state things like, “fits car ref xxxxx “ and actual dimensions aren’t necessary, I get it most people buy models and don’t need to know any other details weirdos like me are just trying to avoid having to make a part that I can buy reasonably cheaply. :0)

 

[Greywolf74]

Thanks @Greywolf74 0.274” does sound a little larger than than the plain shaft on my engine. It’s very frustrating because retailers state things like, “fits car ref xxxxx “ and actual dimensions aren’t necessary, I get it most people buy models and don’t need to know any other details weirdos like me are just trying to avoid having to make a part that I can buy reasonably cheaply. :0)

I totally understand. It likewise frustrates me to no end that manufacturers dont typically list things like battery tray size for electric RCs. They assume that you already have the kit and that you can measure it yourself, I guess? There are a couple/few other things like that I wish manufacturers would provide but I wont go in to detail.

 

[tudordewolf]

I ran into this issue doing some of my engine swaps, wound up accumulating a bunch of collets.

I'm pretty sure small block collets are 1/4" ID, but their "depth" can vary, so I've sanded the back of one to make a flywheel sit snugly.

 

[WickedFog]

Thanks @Greywolf74 0.274” does sound a little larger than than the plain shaft on my engine. It’s very frustrating because retailers state things like, “fits car ref xxxxx “ and actual dimensions aren’t necessary, I get it most people buy models and don’t need to know any other details weirdos like me are just trying to avoid having to make a part that I can buy reasonably cheaply. :0)

It is a collet, which crushes when tightened against the taper. So Grey's is probably a 1/4" I'm guessing. Just sprung open.

 

[Greywolf74]

It is a collet, which crushes when tightened against the taper. So Grey's is probably a 1/4" I'm guessing. Just sprung open.

Thats true, it does have a slight gap in it. I didnt even think about that the other day. What I should have done was grabbed my spare nitro engine and measure the shaft.