I guess you need the I.D. for heatsinks? A while back I saved this post from wquiles talking about a driver. He measured several Mag-D bodies I.D. to come up with the "smallest" I.D. measurement of 1.3481" (34.242mm). I think that's changed in recent Mag builds. I measured the O.D. of an H22A heatsink as 34.26mm in keeping with Will's size estimate. In fact I had 3*H22A heatsinks, all the same. The I.D. of the MagLite I wanted to put it in was only 34.19mm. Nothing a little sandpaper couldn't fix.
As Will mentioned in the post I linked to, there are variations between bodies. I'm suggesting since you have a friend making the heatsink for you, that you just give him the light so he can custom fit it. The thinner the layer of Arctic Alumina compound between heatsink and battery tube the better.
Actually that's not what I meant. The older MagLite is more than a little bit bigger. I have a pre-2001 Mag-D and its battery tube I.D. is 37.02mm. But if you want it made to a number instead of to fit, 34.26mm would be it.Thanks for the reply and i did read the older maglite bodies was slightly larger on the ID than the newer type but it is the newer type i will be using.
Like Al Combes said, give the machinist the Mag body so he can make a heatsink that fits perfectly
The 0.23 seconds is how long Google took to get results on "Mag diameter"
BTW care to share some details of what your planning with these copper heatsinks ?
Just so you know, Luminus apparently revised their binning codes recently. The new top bin SST-90 is WP3, with a range of 1,130-1,200 lumens @ 3.15 amps.I would like the SST-90 but finding it hard to find the WN bin at the moment and the price is putting me off a little also