68 Spoke wheel help needed

[japat100]

theres another way you could try that may be easier ,,i did not do it this way but its worth a try,
,
take a 1 1/2 inch or 2 inch washer about 3/16 thick , fit it over the center of the hub make sure you fit it tight and even around the ridge of the hub ,, then you could go to a machine shop or someone with a lathe and tell him you want the washer tack welded on the center of the sprocket ,,tack welded to ovoid too much heat ,,this would cost you very little to do and would only take a few minutes ,

,note ,,tell the machine shop guy that the hole you put in the washer to be centered on the sprocket ,,not necessary that the outside of the washer be centered ,just in case your filing job when cockeyed

then place the sprocket over the hub with the washer ,the washer keeps it centered and also acts as a spacer to avoid the sprocket sitting on the ends of the spokes and then drill your 8 3/16 holes ,, should work fine
the hub seems plenty strong to bolt to ,and should have no problem but i would not go over 3/16 drill holes

worth a try
japat

 

[DutchDude]

the trick part is that the sprocket must fit over the ridge part of the hub to be centered ,,, thats why you need adapter plate about 1/4 inch thick .. even if you could make the hole in the sprocket the right size to fit the small ridge on the hub it would still not work ,, because the spokes are about 1/8 sticking out of the hub that would be enough to keep the sprocket from seating flat against the hub ,,,and then the sprocket would be pressing against the spoke ends instead of seating flat against the hub

The sprocket hole is about 1/8" larger then the ridge part of the hub. So accept for the spoke ends, it lays flat.

The original design has this conveyor belt stuff the gets wedged on either side of the spoke, and then compressed. If I were to cut some up and lay it on the hub before putting on the sprocket? Or, perhaps cut of the ends of automotive valve stems (thick rubber washer)?

 

[DutchDude]

theres another way you could try that may be easier ,,i did not do it this way but its worth a try,
,
take a 1 1/2 inch or 2 inch washer about 3/16 thick , fit it over the center of the hub make sure you fit it tight and even around the ridge of the hub ,, then you could go to a machine shop or someone with a lathe and tell him you want the washer tack welded on the center of the sprocket ,,tack welded to ovoid too much heat ,,this would cost you very little to do and would only take a few minutes ,

,note ,,tell the machine shop guy that the hole you put in the washer to be centered on the sprocket ,,not necessary that the outside of the washer be centered ,just in case your filing job when cockeyed

then place the sprocket over the hub with the washer ,the washer keeps it centered and also acts as a spacer to avoid the sprocket sitting on the ends of the spokes and then drill your 8 3/16 holes ,, should work fine
the hub seems plenty strong to bolt to ,and should have no problem but i would not go over 3/16 drill holes

worth a try
japat

I do own a mig welder, so I could do the tacks myself. But, unless the washer doesn't have a hole in it for starters, or if it fits just perfectly without any room on the sides before welding - it could still end up slightly off center. Might be worth a shot to see what size washer I could find though.

I would perhaps use it to make a three hole jig? Put a peg in the center of the sprocket, and the center of a scrap board. Drill through one of the nine holes of the sprocket into the board, put a bold in it. Then drill the first 3/16" new hole. Rotate around center and repeat?

Using the washer method for the hub drilling might be difficult. There is at least 3/8" of space to deal with because of the bearings and the oval shaped brake lever mount.

I like the way you think though - keep it coming

 

[japat100]

i am thinking back ,, that i also had to add "weld " a washer to the arm for the brake since i have coaster breaks ,,, i shaped the inside of the washer the same as the the hole in the arm ,, that allowed me to insert the arm on after i bolted the sprocket on ..the washer on acted as a spacer also so that the arm would clear the sprocket and since the washer had the same hole in it as the arm it held the cone in place ,,
you may get away with a 1/8 washer for the sprocket as long as the spokes don.t stick out to far ,,1/8 would be easy to file down so it fits perfect on the hub ,, you do have a dremel tool and power saw file would be handy ,,washer come in many different sizes with different size holes so the secret would be to save you a lot of work is to get one that close to the righ size hole
perfect center is important ,if you are out even a few thousands the chain will very back and forth from loose to thigh ,,

after you fit the washer you may get away with a wooden lathe ,take a piece of hardwood and make a axle
so it fits the sprocket and the washer ,,then tack the washer lightly with the mig until you have it on the money
once you have that down ,,then you can drill 8 holes " 8 holes works out good on the hub "" in the sprocket in the right place o fcourse """right diam."",, then place your sprocket in place held on by clamps ,then you can drill the hub holes using the sprocket pattern ,,i drill each hole then put in a bolt and nut in each hole as i went along tighten just snug ,,also drill holes criss cross from one side to the other so that the sprocket went on even ,,

hope this maybe some help
jaqpat