Thread: Trying to figure out how to bore an odd shaped object (mac strut tube)

For starters do you have a lathe around 1200/1500 between centres.
Do you have a Fixes Steady that will accomadated the diameter of the strut plus 30mm.
Is the OD of the strut suitable for holding with a steady.
If the answer to the above question is yes not a problen,if no you will need to make a Cat Head to support the tube.The Cat Head can be made stepped if your steady will not accomadate it plus tube.
Is there any machined surface near the stub axle that you can use to set up to,you will also need to set the open end of the tube .
Is it possable to remove the Tube from the Stub Axle alltogether and replace the tube with a new piece machined to size.
Theres no problem in making your own boring bar.

Originally Posted by pipeclay

Is it possable to remove the Tube from the Stub Axle alltogether and replace the tube with a new piece machined to size.

Starting to think this might be a better option, as machining a 400mm long boring bar will be a tad flexy, even if i do use a 25mm solid bar to do it.

Thinking i could spin it up and remove the tube from the rest and machine a shoulder into the lower part. Then spin up a tube and machine to suit (would have to thread the gland nut at the top) and then press it together and weld it up.

Would probably be the less time consuming and possably easier way to go.

This isn't the answer to the flexing tool problem, but fixing the job to the cross slide and using a rotating boring bar between centres would avoid having to swing the job.

Jordan

Originally Posted by nadroj

This isn't the answer to the flexing tool problem, but fixing the job to the cross slide and using a rotating boring bar between centres would avoid having to swing the job.

Jordan

I doubt you could single point bore something that long with a small boring bar... You would need to make up a cutter with three or more cutting heads..