Jeff, I am not familiar with your lathe but assuming it has a screw on chuck and is a standard type drive with back gear etc, one way would be to engage the back gear to "lock" the spindle then use a piece of flat bar gripped in the chuck jaws to use as a lever you can loosen the chuck, remove the bar and unscrew. Good idea to put a piece of plywood or similar on the bed to protect it in case the chuck was to slip off.

Take care with this method so not to damage the back gear — you would have to be a bit ham fisted to do so but I have seen it done !

Backlash well I'm sure someone with one of these M/C,s will have already worked out how to do this.

Cheers John

Jeff,

Picking-up on Keith's observation

Please look at this Parts List

MichaelG.

Hi Jeff,

If this is the first time and you have removed the three chuck securing nuts from behind the mounting plate, it is probably stuck with the protective grease that was originally used to protect these components. I had the same problem and used a rubber mallet to knock the chuck off. You need to rotate the chuck a little after each blow. It will release suddenly so be prepared as Jens said by protecting the bed with ply, I have a specially shaped softwood cradle which protects the bed and is used to store the chuck, I'll take a picture later. You may also like use a large wad of cloth, both to cushion the possible landing and to prevent it rolling off the bed if the chuck releases unexpectedly. A rubber mallet will not damage the chuck.

Tips:

Switch OFF the power to your lathe, do NOT put your free hand under the chuck to catch it, you WILL cause yourself an injury, Also be sure to REMOVE any fabric before turning the lathe on again. Clean off the protective grease with white spirit and lubricate chuck locating spigot with a dry grease, I use PTFE spray – it doesn't attract swarf or grit – to prevent sticking in future.

Regards

Terry

P.S. I Forgot ,  do not remove the nuts completely from the securing studs, screw them to the end of the stud then use the mallet.  This will prevent the chuck dropping unexpectedly when it releases.

T

Edited By Terryd on 07/10/2012 07:56:20

Terry is right, unless its like a combination lathe/ mill a friend has, the chuck on that is held in place with cap screws, and they are that close to the head that you can't get a standard Allen key in, so you have to cut a good bit off, then as you unscrew the screws, you pull the chuck out. If it were mine, I'd fit studs, and use nuts. Ian S C

Sounds similar to my machine. if it has the three cap screws you most likely will need a cut down hex key, replace with short studs and spacers and nuts when convenient. With a wood plate on the bed, put a short piece of wood in the chuck and use that to wiggle about or hit if the chuck is tight. No need to touch the chuck backplates.

If it is a screw on try warming up the chuck with an air gun to expand the joint and soften the grease. To come back to your starting question the spindle has to be secured by using the concept of the jam jar lid remover pulling a belt (old fan belt?) tight around the pulley to grip it. Tricky job. As you have probably picked up elsewhere the chuck key is not to be used as a lever. Best is a large piece of hex held in the jaws and a spanner. Teh shock force of a tap with a hammer is often required.

When refitting make sure the chuck is not hotter than the spindle or you get a shrink fit. Terry's wood block is good but pack it up to chuck height to make refitting easier especially if a bolt fitting.

The photos on the web of the 4 jaw and faceplate do make it look like a screw fitting though they could be stock photos and it could be you have the wrong chuck. If you have found studs etc on the 3 jaw no harm in taking it off to get a better look at the backplate joint. If it is a non screw fitting it may be like the hobbymat where the fixed spindle plate has additional holes from new for fitting the 4 jaw which will be a clue.

Sealey do seem to charge way over the odds for general parts not specific to the lathe, eg morse taper fittings. It seems they are exploiting the car/bike repair market of people who don't know much about other tool sources.