I have designed a new universal D mag heatsink but could use some input. :bigsmile:
If you have calipers, bore gages, etc., please provide a measurement of the inside diameter of the body (on the head end) and the serial #. With calipers, be sure to use light pressure and wiggle them in the tube until you get the largest reading.
SN: D2027482257 = 1.347” diameter [34.214mm]
SN: DL203086984 = 1.344” diameter [34.15mm]
I have others to measure and will post later
1.345", 1.344". You may be pressing more that me. I have never found more that an 0.003" difference in tubes over the years, but I don't know about the really new stuff.
Need to pick up new batteries… Seems I’ve left them in my caliper. I’ll measure mines real old though
34.23mm for both of mine.
D6002921386
D2014969732
I have a hand full of neck end cut offs in my leftovers bin I measured.
1.349
1.349
1.350
Its been my experience that at room temp of around 80 deg F typical is 1.348-1.349 according to my $10 set of calipers. The smallest ID I ever remember finding was 1.344 or 45 I think. Probly the largest would be 1.352.
Just my 2 cents. Looking forward to seeing your project.
Yeah, but what are we comparing here, Mag tubes or members calipers?
!.345” (3) place’s the same, # D6002480957 6D’s
I get 1) 1.345” and 2) 1.346” 3) 1.345” with no name Chinese calipers.
Well, You're comparing...
1. Mag Tubes
2. Calipers
3. TECHNIQUE..... and that one will bite you!!!
4. Temperature.... That one bites even harder! .001 to .003 change is easily caused by a warm hand...or cool room... or especially a work light on your lathe.
Dan.
Theres nothing wrong with my vernier g clamps Dan.
Hi.
That must be an "Aussie" invention! 
Being the "Knurling King" I suspect you are correct though.
Dan.
1.348” D3028264907
This is a great idea, though TexasLumens made a very good point.
Mitutoyo Calipers
Temp = 75F
Modern Mag- D4015342229 ID=1.347"... This is what I've measured on several Mags that I've modded.
Old School Mag- 33320978 ID=1.460-1.465...Not round
Ok, so when do we get to see some pictures?
Measured with my high precision Mitutoyo G Clamp calibrated to the nearest inch I get 1.348''. S/N 043231168. The age is unknown but it is old.
Thanks a lot everyone. Now I know to make the heatsink to fit a .01” range between 1.342” and 1.352” with a mean of 1.347.
Mag heatsinks are of course one part of a larger system of complimentary parts, and I do not have all of the components finished yet, so I think I should hold off with too many preemptive teasers. I will be releasing a “D” mag mod kit, essentially, though everything will be available individually. I am designing the heatsink to work pretty universally and it should require no sanding to fit any D mag. Two reflectors will be specifically suited/modified for the kit, one inexpensive, one high end. Glass/plastic lens choices. The configurable battery options should allow for direct drive / linear or buck configurations with lithium or nimh. Stacked parallel 26650’s feeding a linear driver, for instance. Yes, stacked parallel holders are coming. I have yet to finish the new switch housing which will allow for stacked 32650’s specifically to fit.(probably series only for the 32650’s, at least without a bored out tail cap) The new switch housing will be made to fit a few types of switches. Also there will be an adjustable tail cap spring insert which will allow 18650’s or 26650’s to extend into the tail cap a ways. I haven’t even gotten to C mag yet… but I think I will just finish the D mag stuff and then get some community feedback before selling them. I am laid off right now so I’m going at it pretty steady.
Sounds awesome! I would just stick with D mags for a while, I don't really like the formfactor of the C as much.
Thats awesome Hoop. I am a huge fan of Maglite mods. Thanks for the update.