Just a side note to anybody who maybe interested while I wait for the mailman.
When it comes to cutting keyways in your shafts, I first thought I would need to go to a machine shop to get this kind of work done and had several keyways cut, but I found the prices for this work to be high considering how quick they can be done with the fancy machinery they have.
So when I managed to work out how my next lot of sprockets needed to work sometime into my project, when I discovered I found the need to add an additional level of drive to get my speed down even more.
I baulked at going back to the machine shop, so I decided to try and cut my own keyways and this is what I did.
Once my shaft and sprocket diameters matched, I set the sprocket in position on the shaft and tack welded the two components together.
I then mounted the pair with the shaft thru my drill press table center hole, center popped the contact line between the shaft and sprocket.
I have chosen to use a 3/16" or 4mm drill bit which when set up right you can drill down between the two components and ending up with half the drilled hole in the shaft and the other in the sprocket.
I used an electronic level to ensure that I was close to perfect alignment before drilling.
Drill slow and steady and pull the bit out to remove the metal cuttings.
If anything I made sure that any drill wander was biased toward the shaft.
The reason for this is I purchased from ebay a slightly used 3/16" keyway broche which will easily take care of any short coming in the sprocket internal bore later.
I figured for the cost of the broche and guide, I was at the end of the day going to be better off, since I would have cut keyways in both components, as my machine shop was not interested in cutting internal keyways with a broche and boy I am glad they were not as it would have cost me a bomb.
You can look on YouTube to see how to broche your sprockets etc, it is quite easy if you have a hydraulic press or similar equipment, again slow and easy is the way to proceed.
With respect to the drive shafts, I used a Dremel tool with a small grinding wheel and gradually squared up the half circle drilled hole to match the measurements I required for me keyway.
My keys are made from plain old mild steel and I just cut a piece off a flat bar scrap and use my grinder, belt sander and hand file to get it to size, it takes no time and to me for this kind of project keyway cutting is a myth, it is relatively simple and saves you decent $'s.
If I wasn't so keen to prove a point, I think I may have even just driven a round pin into the drilled hole and watched to see how well even that would hold up...
Sorry I don't have any pic's to offer right now, but will post some later, but if you have any questions please ask.
At the end of this build I will still own a broche and will be able to add keyways to any additional rollers I purchase or make for no extra cost.
My only other comment is, with your broche is treat it like glass, don't let if fall on the floor, make sure to get a guide to match your shaft diameter and be sure you have at least 1 shim included when you purchase it.
You won't use it much, but each time you do you will save decent money, plus gas, plus waiting time and still remain friends with the machine shop for those job you are unable to do at home.
Give it a go...
__________________
Russ.
https://www.youtube.com/watch?v=5GQ8Ujaq7MYThe more that you learn, the more your realise that you don't know...