Cool Trick to slightly enlarge bore.

[amphibious drew]

I got a hub and sprocket from tractor supply to replace a rear sprocket on my machine. I had the set screw drilled out and for a sheer bolt and got the axle welded on. I went was messing around with it trying to get it on a new axle I was making and realized that the hole in the sprocket hub was a little too small to slide over the axle. I was going to use my die grinder to grind it to size, but decided to call a machinist buddy of mine first. He informed me that using the old die grinder would egg out the hole no mater how careful you are. I was told to get a piece of emery cloth and attach it to a drill bit. Then just stick the hillbilly tool in the hub and run the drill. He said it would conform to the original shape of the whole keeping the shape true. I took his advise. I grabbed a bit (5/16th I think), wrapped the end of emery cloth around it overlapping 1 full wrap, and put 2 small binder clips on it (one on top and one on bottom ends of the bit/cloth setup). Of course I took the finger press things off the binder clips. Then stuck the bit in the drill, wrapped the cloth up tightly, and slid it through the hub. Wouldn't you know it worked perfectly. I just let it run in the hub for a few minutes at a time, and kept checking to see if it would slide over the axle till it worked.

He said this is what they did at work when something needed slightly bored out. Hope someone else finds his advice useful.

[Jeff t-boss]

Another trick with the same concept is to take a 1/4 X 2 inch bolt (Fits in most die grinders) and cut the head off. Then take a hack saw or whatever you choose and cut the shank right down the middle about the width of your emery cloth or more. Then take whatever length of emery cloth you choose and fold it in 1/2 lengthwise. Slide that in the cut on the cut on the shank and just wind the rest around the shank. (Same rotation as your drill/die grinder) Works best in a drill as it doesnt remove as much as fast, and doesn't eat the emery cloth as fast. Plus, with a drill, you can use a bolt/shank up to the max size your chuck will accept. Been doin it for years, and havn't had a complaint or error yet.

[jwiereng]

jeff t-boss, I have done the exact same thing said in the past but for large holes approx 1 inch I have used a piece of 1/2 inch wooden doweling for the shank instead of the bolt like you said. Seems a bit easier to slice down a dowel than a bolt. 1/4 bolt sliced would allow one to enlargen a smaller hole or course, a 1/4 wooden dowel will surely break easily.

[wfo]

brake cyl hone works best

[jwiereng]

I did consider using a brake cyc hone, but the hole I was working on had a keyway in it. I was thinking that the stones might hang on the keyway, so I did not try it.

[wfo]

the one i used years ago was this ball hone..i guess i should have said that..it
worked good enough for just taking it down a couple .001
http://http://www.smallparts.com/res...qid=1298257272

[Jeff t-boss]

I've even used larger (1/2-1 1/2inch) pipe nipples with reducers to drive in a drill. All worked great. Also, if you get into these bigger things; useing this concept; drill a 5/16 inch hole in the opposite end of the pipe. Get your hands on a 16 inch belt sander (New or used medium grit) belt and turn it inside out. Slide it in the slot you cut in the pipe and you have yourself a great oil filter/strap wrench. The 5/16 inch hole is so you can stick a #3 screwdriver through and use for torque.

[Jeff t-boss]

wfo, your link don't work.

[wfo]

THANKS..i dont know what happened..its just a link to a 1.250 ball hone