Hub Conversion

[kartjockey]

So.. I decided to take a shot at converting a rear hub into a front hub. It has been said that the parts are the same. And for the most part they are.  I did notice a small difference in the depth of the inner bearing in relationship to the edge of the break drum. I am not sure if this will impact anything but decided to hold the dimension from bearing race to bearing race. If for some reason it doesn't fit I would just need to pop it back in the lathe and move the outer race a bit further in. I have yet to completely record my dimensions but I think the offset of the races from hub to hub was about .100".

These pictures give you an idea of how it was done.  From some quick dimension drawings to programming the mill. What I see on the screen. The 'star' wheel is a view of the path the cutter travels. Programming works off of the Cartesian scale.  X and Y coordinates. It may seem complicated but it actually is pretty easy.

[kartjockey]

A few more pictures.  Last pictures are proof ....'It can be Done!"

[Ricks]

Sweet Tom.  It's easy only when you know what you are doing! 

[kartjockey]

The original front hub had the slotted flange welded some. Not sure if this is factory or if someone did it along the way.  The flange on the rear hub was only pressed on. once I cut the tube off I put the flange in the lathe and then bored the tube paper thin until I was able to just pick it out with a small pick. Sometimes those kinds of things are induction welded and it is hard to tell.  So I pressed it back on as it was originally on that hub.

[Mike Sal]

Very good project.....my only comment is that this belongs in the "wheels & tires" section!
Mike Sal

[Ricks]

How much time did I take to do it?  Is it economically feasible?

[kartjockey]

5 hours or so.  So what ever shop rate you would want to go by. If you needed one I guess  it would be worth it.

[Stafford]

Thanks RickS,
He lost me at "So..............."

[kartjockey]

Take a look at this and maybe you will recall it.  The red  dot X= +8   Y= +13,  yellow dot X= +6  Y= -5, green dot X= -5  Y= -9,  black dot is X= -3   Y= +4    The center is called the datum point or absolute zero. This is shown in the photo where the cutter is in the center of the hub and the picture above it shows X=0 and Y=0. The datum can be any where you put it and in this case the center of the hub makes the most sense. 

[butch27]

OK if you say so. I don't think many of us here could do that but very nice.

[kartjockey]

I think after doing one of these and if slotting the flange was all I had to did I could probably do one in about two hours. Once you have the set-up the actual  machine work goes fast.

Through time the question comes up about upgrading the wheel bearings. I am not sure there is much to gain from it other than the new bearings being sealed.  Despite all of that it can easily be done in a lathe. I found some 1.250 od bearings however they have a 1/2in. ID so you would have to change the shaft also. I searched for quite awhile but did not find any with a 7/16in bore with a 1 1/4 OD. Who knows, they might be out there. The original outer race measures 1.240 so you just have to skin .010 out and you are golden!

[Ricks]

Tom, I spoke to Wayne about a sealed bearing conversion, and his thoughts were the same as yours.  It seems it would be a change for the sake of change without much real world improvement.

[kartjockey]

Just been going through some old drawings and thought I would post these up with the rest of the posts on this topic.