Safe removal of aluminium pulleys with key

I have a 3 phase motor from a Meddings Pillar drill which is fitted with a light alloy step pulley which is keyed with an L shaped key
(it looks a bit like the gib keys used to hold flywheels on stationary engines). They key is fitted with the short leg of the L over the motor shaft rather than over the attached pulley (i.e. the opposite way round from a flywheel key).
The pulley needs to be removed from said motor and I've had previous experience that it is all too easy to break these pulleys and they are expensive to replace and/or difficult to source.
Do I need to remove the key before trying to pull off the pulley? Is there a trick? Most of the methods in books on stationary engines involve placing most of the strain on the flywheel and they don't appear to translate well to the light alloy pulley.
Any suggestions would be greatly appreciated!
Alan Bain
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes remove the key first. Try inserting an old screwdriver or chisel between the end of the motor shaft and the underside of the key and tapping this in to lift the key out of it's seat.
John S.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If I might add to Lord John of Bridgeport's answer, quite often if the key has not been removed for yonks, there might be corrosion between the steel key and the alloy pulley. If the key does not come out easily, don't strain but heat the pulley with a hot air gun or similar, Boiling water temperature or a bit more should expand the pulley enough to ease things. T.W.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Tue, 24 Mar 2009 15:37:19 -0700 (PDT), John S

If you cannot get under the key then try gripping with a Mole Wrench and lever on that.
Richard
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Alan Bain wrote:

==Try tapping the pulley a little further onto the shaft. JW ==
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 24 Mar 2009 21:44:31 +0000 (GMT), Alan Bain

From my experience in removing the pulley from a Pacera (predecessor to Meddings) drill:- When you have got the key out and need to pull the pulley off, turn up a out of two pieces of steel clamped together. Turn the inside face of the ring to the same angle and size as one of the pulley flanges so that the ring can spread the load around the weak pulley casting. Then use the puller against the ring to get the pulley off. Even with heat, shock etc. the pulley may take a lot of effort to get moving. Only difficulty with the motor pulley, if it's a single belt drill, is that the ring needs to be large enough that you can get the puller to it past the biggest pulley flanges at the top. But you can weld/bolt bits of steel onto the ring to give something to grab if you can't turn al large enough ring directly.
Hope that made sense.
Mark Rand RTFM
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes; that was very clear and makes sense; my previous experience with 3 jaw pullers is that it is easy to break a piece out of the pulley when used directly.
The drill is a single belt with the largest pulley at the top and presumably the ring is arranged to fit one of the middle pulleys, as this has a stronger flange than the largest one.
I should be able to turn up a suitable ring on the faceplate -- the only prerequisite is some suitable raw material! Up till now most of my work has been pretty small (clocks/watches, but I'm developing an alarming interest in larger work!
Thanks for the advice,
Alan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes; that was very clear and makes sense; my previous experience with 3 jaw pullers is that it is easy to break a piece out of the pulley when used directly.
The drill is a single belt model and on the motor shaft, the largest pulley is at the bottom (i.e. closest to motor) and presumably the ring is arranged to fit one of the middle pulleys, as this has a stronger flange than the smallest one.
I should be able to turn up a suitable ring on the faceplate -- the only prerequisite is some suitable raw material! Up till now most of my work has been pretty small (clocks/watches, but I'm developing an alarming interest in larger work!
Thanks for the advice,
Alan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Once the key and any other fasteners are out, it sometimes helps to carefully drive the pulley further onto the shaft to free it.
Don Young (USA)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
In article

[cut]
It does indeed. Thanks for all the suggestions; the most difficult part turned out to be removal of the key. A combination of heat and a series of wedges filed up out of scrap steel started it and then a piece of 1/8" steel pivoted on a peice of steel round resting on the spindle removed the key.
After this, driving the pulley on further broke the lock and then I was able to remove it by careful use of a puller and hammer.
Alan
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.