Why does welding tabs to an axle, then bolting the sprocket to the tabs not work?

[Jacka$$withawrench]

I understand that the sprocket need to be concentric to the live axle on a kart. I previously posted this idea and was told it would not work because the sprocket would not be concentric. If I welded tabs to either side, then measured out the holes radial from the center of the axle, it should be concentric. Can anyone think of a simple way this doesn't work? Thank you.

 

[Functional Artist]

The sprocket would not be adjustable
...& welding to an axle weakens it

Something like this the usual method for mounting a sprocket (or brake drum) to an axle

Steel Multi-Patterned Sprocket / Brake Hub (1" Bore)​

https://www.bmikarts.com/Steel-Multi-Patterned-Sprocket-Brake-Hub-1-Bore-_p_1404.html

 

[Denny]

Not to mention welding on the sprocket would warp it. So many good reasons not to do a bad thing.

 

[Master Hack]

No way you could make that concentric, within .100 Yer talking about sumpthin the HAS to be as close as possible, preferably within .005 to .010, though few are. I used to make a livin making round things. I can tell ya making concentric, round things is not as easy as one might imagine.

 

[Jacka$$withawrench]

I meant welding tabs on, then drilling holes and bolting the sprocket to the holes. I can control concentricity by changing where I drill the holes, and by not welding the sprocket, I don't warp it. I could then make the tabs identical to lessen the vibration from oscillation. Im using a 1 and 5/8 axle which is why im not using a hub

 

[Master Hack]

I can control concentricity by changing where I drill the holes, and by not welding the sprocket,

Thats tougher than you might think. The theory is great but I don't think ya can do it and have satisfactory results. I would however, love to be proven wrong.
Another idea:
Buy a 1 inch thick slug of steel bar stock, 3 or 4 inch in diameter. (whatever OD ya need to fit the hardware you want attach)
Have a machine shop bore a center hole to fit the axle and a step to fit the sprocket ID then face it. then take it home and drill the sprocket pattern in it. Then you will have a custom hub that you can weld if you wish. Maybe a few bux, but it will be concentric, and yer chain will stay on.

 

[panchothedog]

Anyone who thinks that they can drill multiple holes into steel tabs welded onto an axle AND KEEP THEM WITHIN .005" of each other is either dreaming, or smoking something real strong. Impossible. Ain't gonna happen.

 

[Jacka$$withawrench]

thank you all for the advice. I put a model through AutoCad and realized my welds would need to be orders (3) off magnitude better to conduct the horsepower I want to throw at it. Im gonna go with the custom hub idea from Master Hack

 

[Master Hack]

Here's one very similar. It was drilled for a key and set screws. It has not been drilled for the sprocket in this pic. Concentric within .003

 

[Jacka$$withawrench]

and cut a key way

 

[Master Hack]

and cut a key way

Optional, I suppose ya could weld it, but thats kinda permanent...

What kinda equipment/tools ya have available?