aluminium machining

[drumsticksplinter]

Thanks for the replies and advice guys!

I wasn't really sure the best way to machine this piece, I do actually have a lathe, but I wouldn't really know where to start with getting the piece center....

It looks like you've chosen 7208 bearings, which are bigger than you need for a 25mm ballscrew - I'd use 7207 instead to reduce the moment of inertia and cost. Have you drawn the rest of it?

Thanks for that advice Jonathan, I was just allowing a little more clearance for the screw, but I think the 7207 would be better like you say.

[Jonathan]

I wasn't really sure the best way to machine this piece, I do actually have a lathe, but I wouldn't really know where to start with getting the piece center...

Presumably your lathe is big enough and you've got a 4-jaw chuck and dial indicator? If so then you can just do what m_c said, as that's how I'd do it (or I might line bore it). If you buy the bearings first then you can use them to help with the machining - when it's close take very small cuts and keep trying the bearing to see if it fits. If you set the compound slide to an acute angle you can use it to advance the tool in small increments more accuratel than using the cross slide.

Edit: This thread has more information: http://www.mycncuk.com/forums/steppe...-steppers.html