Is it possible to buy hollow bar with a keyway cut in it?

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Avocet

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I need to put a pulley on to a 1" diameter shaft which has a 1/4" key in it. The pulley is off a car and will need some sort of adapter, as it is supposed to just bolt to a flat face with a spigot in the middle to centralise it. I'm therefore looking for a bit of 2 1/2" (or bigger) bar with a 1" hole through it and a 1/4" keyway. It would only have to be an inch or two long. Can such stuff be bought? The closest I've found so far are Taperlock bushes:

http://www.bearingshopuk.co.uk/belts/taperlock-bushes/?bush_bore=24303

and I did wonder about turning one so that it had a spigot on one end for my pulley and then drilling and tapping it to bolt the pulley to it. Trouble is, I don't think I'd be able to miss the four holes and two slots (my pulley has three holes, just to be awkward)!
 
Assuming you have a lathe, you can machine a keyway by using a bit of hss ground to the thickness of the keyway and with the chuck locked and the tool centred in the toolpost push it along taking very small cuts. Before I had a slotting machine I did them like this.
 
Avocet said:
I need to put a pulley on to a 1" diameter shaft which has a 1/4" key in it. The pulley is off a car and will need some sort of adapter, as it is supposed to just bolt to a flat face with a spigot in the middle to centralise it. I'm therefore looking for a bit of 2 1/2" (or bigger) bar with a 1" hole through it and a 1/4" keyway. It would only have to be an inch or two long. Can such stuff be bought? The closest I've found so far are Taperlock bushes:

http://www.bearingshopuk.co.uk/belts/taperlock-bushes/?bush_bore=24303

and I did wonder about turning one so that it had a spigot on one end for my pulley and then drilling and tapping it to bolt the pulley to it. Trouble is, I don't think I'd be able to miss the four holes and two slots (my pulley has three holes, just to be awkward)!
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I still do not understand that bit. :confused:
 
colhel said:
I based my assumption on the fact he said about turning a spiggot. :cool:
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You assumed right! Yes, I have a lathe (albeit rather an old one)! After you posted, I did, indeed, find a Youtube clip from someone who did exactly that - just used the saddle as a sort of broaching machine! Might give it a try.... thanks!
 
PuffTheMagicDragon said:
I still do not understand that bit. :confused:
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The Taperlock bushes have four holes (well, half holes) round their perimeter at 90 degrees to each other and two slots in them so that they can be pinched up on to the shaft. If I was drilling into the thickness of the bush to bolt my pulley to it, I'd have to miss all those (which I think would be unlikely as my pulley has three holes in it at 12 degrees to each other). I'm pretty certain that no matter which way round I put it, one of the three holes will hit (or be very close) either to one of the drilling or one of the slots.
 
Avocet said:
You assumed right! Yes, I have a lathe (albeit rather an old one)! After you posted, I did, indeed, find a Youtube clip from someone who did exactly that - just used the saddle as a sort of broaching machine! Might give it a try.... thanks!
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I'm sure Col has the right answer really. But would there be any mileage in putting an end mill in the chuck and somehow clamping the work to the cross-slide, then winding it across the bed so that the mill passes along the bar?

Pete, who hasn't used a lathe since school :)
 
Avocet said:
The Taperlock bushes have four holes (well, half holes) round their perimeter at 90 degrees to each other and two slots in them so that they can be pinched up on to the shaft. If I was drilling into the thickness of the bush to bolt my pulley to it, I'd have to miss all those (which I think would be unlikely as my pulley has three holes in it at 12 degrees to each other). I'm pretty certain that no matter which way round I put it, one of the three holes will hit (or be very close) either to one of the drilling or one of the slots.
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So, if I am understanding correctly, your only reason for buying the taperlock bushes is the fact that they have an internal keyway?

I think that since you already have a lathe you could easily turn an adapter from scratch and then cut the keyway as has already been described, thus avoiding the slots and the half-holes, which you don't need anyway. Once you have set up a tool and locked the chuck it shouldn't take long. If there is an engineering workshop near you I am sure that they'll cut you a piece off of a bar that has the right diameter. One source that I use for such projects is the internal disk that remains when pipe flanges are flame-cut; these I can get for free. Other sources for 'raw material' are scrap yards. Think hard about what you have in your vicinity. I have also used risers from a cast iron foundry as a source.
 
colhel said:
Assuming you have a lathe, you can machine a keyway by using a bit of hss ground to the thickness of the keyway and with the chuck locked and the tool centred in the toolpost push it along taking very small cuts. Before I had a slotting machine I did them like this.
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Just an update and a big "thank you"! Tried it last night. As luck would have it, I had a brand new piece of 1/4" tool steel so I just clamped it to the tool post at what looked like an "appropriate" angle and had a go. Worked like a charm! It was a fairly soft bit of aluminium bar that I was using, so that probably helped, but just winding the saddle backwards and forwards scraped me out a lovely keyway and it fits perfectly!
 
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