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I have a 100# Fairbanks/Dupont Hammer and want to remove the drive pulley. It is keyed with 4 set screws (2 on inside and 2 on outside). I have loosened them all and made a puller with a porta power. I expected it to come off easily and ended up cracking a piece of the pulley lip off and did not budge the pulley at all. i cannot see anything holding the pulley in place. it is a well used and oiled machine.

am I missing something and does anyone have a replacement pulley, just in case....

Any suggestions?

Thanks,

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I think the pulley is cast so I was concerned that heating in the middle might crack it, of course I cracked the rim anyway but I can still use it. I can try to bring the whole piece up to heat together. Would I want to pull when it is hot or will it break the connection when hot and then pull easier when it cools off?

Thanks for the response

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I've pressed off the crank plate off a 50 LG and a 100lb Bradley, they both took all of a 20 ton press. I had to drill holes around the perimeter of the shaft and use heat before they came. I'm not surprised you broke the flange, although I would think the belt pulley would come off easier than a crank plate.

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I took apart a 75 lb fairbanks hammer to replace the main shaft a few years ago. The drive pulley came off with little trouble. It was only held on by a couple of set screws If I remember correctly. Check that it has not been messed with in some way. Some one could have welded it to the shaft or there could be a set screw with the head sheared off flush to the casting covered under grime and grease. Look for perhaps a dowel pin. It also could be that it is seized to the shaft try a penetrating oil of some sort. It often takes days before it works it self in all the way. There is a parts diagram on the New England blacksmiths site http://www.newenglandblacksmiths.org/power_hammer_info.htm Worst case cut the shaft, its just cold rolled steel and not super inexpensive to replace. You can even use a torch because it wont cut cast iron but will cut steel.

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I was a little hasty with my response, I forgot you don't have split bearings, so you have to pull or push the pulley off with the shaft still mounted on the machine. I agree with southshore's advice, keep cleaning and looking. It seems like it had to originally be a slip fit for the builder to be able to assemble it.

Here's a link to guy who striped and reassembled his Dupont/Fairbanks, there is a photo of the bare shaft on this page
http://www.bladeforu...manual.../page4

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thanks for all of the help. I need to pull the pulley because the internal brake, which sits inside of the pulley, has worn and i wanted to fix it. I made a mechanical brake to go around the fly wheel so i could keep working while I fix the brake.

I thought there might be a hidden pin holding it in place. don't see anything. I think I might drill and tap two holes on the hub so I can attach a puller directly to the hub, heat and maybe it will go then.

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Steve B.- Seems like there should be a way to pull out the brake without removing the pulley? It's been a while since I looked at that end of our hammer but I'll give it a look at work tomorrow, maybe I'm remembering the mechanism wrong. Seems like you could run some bolts into the ends of the brake and squeeze the brake smaller by pulling the bolts together?

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There is an easy way to fix the brake without taking the hammer apart. Where the ring is split you can add shims, basically a cap on either end of the split ring. The shim can be a piece of steel bent at 90 deg with a hole for a screw. Drill and tap a hole on the face of the split ring and bolt on the shim. My hammer was fixed in this way it worked like a champ. Alternately you could build up the end of the cam that pushes the split ring apart to give it more throw.

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Tim,

I have the shims and added material to the cam. The face of the brake itself has gotten worn enough that I am worried about it breaking. I did think about leaving it in place and building up the face of the brake with braze but thought it would be too hard to true up in place. I didn't expect it to be so hard to remove the pulley. I am still thinking I should persevere, and build up the brake off the machine so I can turn it back to round. Maybe ginding it back to round would not be so hard while still on the machine.

Does that make sense. Hi to Rachel.

Steve Bronstein
Blackthorne Forge.

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