Here's how to show it who's boss.... with an electric drill and a custom-made cutting 'slug': no torch or chemicals .... it even works with carbon fibre frames .... sorry no pictures of the tool because a Fitter & Turner mate showed me this method he devised 20 years ago, and I still just drop in to use his and say hello ... Phil DeGruchy of Lightfoot Engineering here in Melbourne ... Phil's the Aussie spoked wire wheel (car and motorbike) guru here in Australia.....so old school he doesn't have a website .... ... he still has the custom MTB frame of Prestige tubing that he ordered from me in '93 when I was only 25 ....
You should be able to work this tool design out from the detail below :-) I use this for 27.2mm seatposts ... another suitably lathed-up slug will fix other seatpost sizes
my website page for this technique ...
Gellie Custom - Stuck seatpost removal
you need to lathe up a 4 to 5 inch long steel 'slug' that will fit down the I.D of common 27.2mm seatposts..... drill a 1/4" hole through its side 3/4" up from one end ... and grind a 1/4" drill bit as you would an old-school lathe cutting tool .... and drill another hole from the bottom of the slug for a grub screw or bolt to lock your 'cutting tool' in place, and finally weld on a length of 1/2" rod welded at the other end of the slug to make a long extension shaft, to hold in the drill. A bit of mucking around to set the cutting tool in just the right spot to leave 0.5mm of seatpost and off you go. Chop the top off the seatpost, insert the slug, and go slowly with the drill machining out the seatpost. The limiting part of this process is pulling the slug in and out multiple times to get the swarf out.... and the slug will rattle around if you have to do a 2nd pass ... so set the cutting tool right early on ... I do the final cut through with a file (at 2 o'clock on the pic below)
An adjustably-expanding slug would make this a breeze to do multiple passes with, as would a swarf removal channel or similar ...
Make one yourself if you reckon its worthwhile, and post your pics here to show and let us improve our work.........
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