# My first finned Mag heads! & the mandrels I made.



## Mirage_Man (Nov 4, 2006)

Well I spent the last few hours of spare time I had making a couple mandrels/arbors for finning Mag C&D heads. They work fantastic and make the process very easy. I can swap out the C&D in a matter of seconds and have great repeatability.

Here's a couple pictures..






















MM


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## jwl (Nov 4, 2006)

Looks nice. Don't suppose you will ever fin heads that aren't part of a group buy???

Hope you do another HAIII group buy, I missed the first two because I spent my light 'allowance' prior to the buys.:sigh:


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## Mirage_Man (Nov 4, 2006)

jwl said:


> Looks nice. Don't suppose you will ever fin heads that aren't part of a group buy???
> 
> Hope you do another HAIII group buy, I missed the first two because I spent my light 'allowance' prior to the buys.:sigh:



The answer is yes, I most certainly will to both your questions. 

MM


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## wquiles (Nov 4, 2006)

Very good idea and excellent job in the execution !!!

Will
(now trying to figure out to make my own set !!!)


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## will (Nov 4, 2006)

Mandrels are definately the way to go. One item with the Maglites, keep in mind they have a + or - tolerance in their machine work. not every one is exactly the same size. If you get any that wobble, loosen it up and turn it 1/8 turn or so on the mandrel. From all my work with the minis, it looks like maglite does the inside boring and threading, then they do the outside work.


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## Mirage_Man (Nov 4, 2006)

From now on I'll be doing my own finning heads and grooving bodies! :naughty: Now that I have the appropriate tools and set-up I'm ready to go. All I really need now is a grinder/s to sharpen my tooling.

MM


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## cmacclel (Nov 4, 2006)

Good job on the mandrels. I just use a Mag "D" body and screw the head on. The I come from the other side with a live center.

If you plung a little too hard that head mayl spin on the mandrel and may damage the threads and mandrel.


Mac


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## cmacclel (Nov 4, 2006)

will said:


> Mandrels are definately the way to go. One item with the Maglites, keep in mind they have a + or - tolerance in their machine work. not every one is exactly the same size. If you get any that wobble, loosen it up and turn it 1/8 turn or so on the mandrel. From all my work with the minis, it looks like maglite does the inside boring and threading, then they do the outside work.




Yes Maglites tolerences are sometimes.....pathetic. I've seen some of centering that I would have tossed in the recycle bin.


Mac


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## Mirage_Man (Nov 4, 2006)

cmacclel said:


> Good job on the mandrels. I just use a Mag "D" body and screw the head on. The I come from the other side with a live center.
> 
> If you plung a little too hard that head mayl spin on the mandrel and may damage the threads and mandrel.
> 
> Mac



Thanks Mac. I can't take credit for the design. A machinist friend of mine made ones like these to do some other heads for me. I just copied his design.

No worries about them spinning. I've already plunged too hard. The lathe belt just slipped and I backed out the tool. I think the design also makes the screw cinch tighter with the turning force. Regardless it seems to work great. 

MM


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## wquiles (Nov 5, 2006)

cmacclel said:


> I just use a Mag "D" body and screw the head on. The I come from the other side with a live center.


Yep, that is what I have been doing so far. The mandrel looks like something fun to try as well 

Will


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## Mirage_Man (Nov 5, 2006)

wquiles said:


> Yep, that is what I have been doing so far. The mandrel looks like something fun to try as well
> 
> Will



I too have an old body I cut in half to use as an arbor. It just seems so much nicer to use the mandrels. 

The nice thing about this setup is I am using a collet. So I don't have to mess with a chuck. I have no idea whether or not it makes much of a difference. But it was a great learning experiece to make them.

MM


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## will (Nov 5, 2006)

The collets tend to run truer and are more repeatable than a 3 jaw chuck. 

I tried with the minis to screw the head on a chucked body and work them that way. more often than not, the head would not run concentric to the body. I ended up using the inside of the front to hold them. that works great all the time. 

I use tool steel lathe tools for most of my work. A grinder would probably be the best to sharpen tools. I have a large belt sander 4" x 36" that I picked up some 'blue' belts - zirconium I use that to make my tools . If you use carbide bits, then you have to with a diamond wheel...


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## Mirage_Man (Nov 5, 2006)

> I tried with the minis to screw the head on a chucked body and work them that way. more often than not, the head would not run concentric to the body. I ended up using the inside of the front to hold them. that works great all the time.



So I suppose if you made a mandrel for them they would be easier to work with? I may make one for MM's myself. 



> I use tool steel lathe tools for most of my work. A grinder would probably be the best to sharpen tools. I have a large belt sander 4" x 36" that I picked up some 'blue' belts - zirconium I use that to make my tools . If you use carbide bits, then you have to with a diamond wheel...



I will be using both types. Aluminum Oxide for HSS and Silcone Carbide (Green wheel) for Carbide bits. A diamond wheel would be nice but wayyy out of my budget.

I actually bought a Harbor Frieght 8" grinder today. It is my very first grinder. Up until this point I've never really had a need for one. I brought it home and clamped it down to my work table. I turned it on and it shook and rattled like no tomorrow. The wheels are no where close to being concentric and wobble from side to side. I think I'm gonna return it and get something a little nicer. Unless someone tells me this is normal grinder behavior. 

MM


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## will (Nov 5, 2006)

Mirage_Man said:


> So I suppose if you made a mandrel for them they would be easier to work with? I may make one for MM's myself.




A mandrel may work for the minis. I just had the feeling that the multi start thread on the inside was not a good place to bank on. 



Mirage_Man said:


> I actually bought a Harbor Frieght 8" grinder today. It is my very first grinder. Up until this point I've never really had a need for one. I brought it home and clamped it down to my work table. I turned it on and it shook and rattled like no tomorrow. The wheels are no where close to being concentric and wobble from side to side. I think I'm gonna return it and get something a little nicer. Unless someone tells me this is normal grinder behavior.
> 
> MM




you sometimes have to dress the wheels, but they should be reasonably close to concentric. the weight of the grinder should hold it steady. 

then you have to learn how to sharpen drill bits on the grinder..


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## Rothrandir (Nov 5, 2006)

My first grinder was a $20 pos I bought years ago at a surplus/discount place. Wobbled like heck, any decent grinding would cause it to stall, it was just terrible.

About a year or so ago I bought a nice delta grinder for about $80, variable speed, powerful. A very worthwhile investment.

I don't buy *any* cheap tools anymore, but I would definitely say that a grinder is a tool that is worth paying for.


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## Mirage_Man (Nov 5, 2006)

> the weight of the grinder should hold it steady.



Not in this case. It starting walking around the table until I clamped it down with a couple bar clamps.

MM


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## nemul (Nov 5, 2006)

good work!


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## gadget_lover (Nov 6, 2006)

I've read of cases where the wheels were OK, but the stamped metal flange was not in alignment. A proper flange replacement cleans up those cases.

Daniel


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## will (Nov 6, 2006)

Mirage_Man said:


> Not in this case. It starting walking around the table until I clamped it down with a couple bar clamps.
> 
> MM



I should have said - It won't jump all over the place. You still need to hold it down in some way,


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## jar3ds (Nov 6, 2006)

very interesting...

Now before I say it... i mean no dis-respect... completely and simply curious of the acual usage of the finned heads...

I admit they look cool.... but from the heat tests done by a member of CPF who that the heat REALLY heats up a lot faster by having so much material removed... 

I have found similar findings when it comes to flutting when involved with barrels on rifles... that removing so much material acually henders rather than helps... It does lighten up the object... but it seems as far as heat goes... its not a good option? 

Any comments from you 'finners' would be greatly thanked!


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## Mirage_Man (Nov 6, 2006)

jar3ds said:


> very interesting...
> 
> Now before I say it... i mean no dis-respect... completely and simply curious of the acual usage of the finned heads...
> 
> ...



Jared,

For me it's strictly a visual thing. I am a visual guy and to me they look cool. Ahem, no punn intended .

However seems to me I remember someone doing some testing that showed when a finned head was in motion (fan blowing over it to simulate movement) it actually cooled quicker than a non-finned head. Now when the test was done with a static head the finned head heated up quicker like you said.

In any event most of my mods are with LED's anyway so this is all a moot point because they won't get hot enough to really make a difference one way or another. Besides did I say they look COOL?! :naughty:

MM


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## Mirage_Man (Nov 6, 2006)

Here's another one I just did. It was a part of a used light I got from another CPF member that had dings in it. Once I strip it and polish it it'll look like new. Even better than new once it's been anodized. Now I just have to decide whether to do it in HAIII or Camo?? Hmmm decisions, decisions.







MM


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## highorder (Nov 6, 2006)

finning and fluting ARE valuable methods of dissapating heat. in theory, without any air movement the reduced mass will heat up quicker, but that is NEVER the case. the greatly increased surface area in conjunction with even a meager amount of air movement provides a net gain in cooling.

in the case of rifle barrels, fluting also increases the stiffness of the barrel, theoreticaly increasing accuracy. ( you would need a machine rest in an underground test chamber to realize any benefit, though.)


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## jar3ds (Nov 6, 2006)

highorder said:


> finning and fluting ARE valuable methods of dissapating heat. in theory, without any air movement the reduced mass will heat up quicker, but that is NEVER the case. the greatly increased surface area in conjunction with even a meager amount of air movement provides a net gain in cooling.
> 
> in the case of rifle barrels, fluting also increases the stiffness of the barrel, theoreticaly increasing accuracy. ( you would need a machine rest in an underground test chamber to realize any benefit, though.)



they are in theory.... like a CPU heatsink with a fan on top... however, unless there is a STIFF wind I don't think theres enough natural movement of air to allow the object to cool... whenever you remove mass your making the object heat up faster... .its a give and take...

making a barrel stiffer doesn't increase accuracy.... having a consistant barrel is key... it can be like a noodle if everytime it fires it moves the same way... 

sorry to steal the thread MM


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## Mirage_Man (Nov 6, 2006)

> sorry to steal the thread MM



No worries Jared. Like I said it matters not to me one way or the other. 

MM


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## b2eze (Nov 6, 2006)

I use a cylinder of aluminum threaded the same pitch as the head as a mandrel for finning. (C and D) There is a flange (stop) to keep then head from turning. I made a similar mandrel to screw in the tailcap end of the battery tube to fin them as well. I use a 1/2' thick disk of UHMW plastic cut to fit inside the lens retainer (or the bulb end of the battery tube) with a live center for the other end. I use a dead MM body to fin MM heads and a similar setup as the "C" and "D" to fin the tubes (after removing the MM "switch")
Finning increases the available surface area , increasing heat transfer and provides a more secure grip than knurling alone on the tubes(IMHO) And, it looks cool! (Just don't fin the battery tube TOO deep!)


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## Anglepoise (Nov 6, 2006)

Like your mandrel set up. Good to have a solid way of holding items.
Its amazing what one can get away with in turning with ultra small feed and cut
but you had better have it all together on grooving or parting.


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## will (Nov 6, 2006)

b2eze said:


> I use a cylinder of aluminum threaded the same pitch as the head as a mandrel for finning. (C and D) There is a flange (stop) to keep then head from turning. I made a similar mandrel to screw in the tailcap end of the battery tube to fin them as well. I use a 1/2' thick disk of UHMW plastic cut to fit inside the lens retainer (or the bulb end of the battery tube) with a live center for the other end. I use a dead MM body to fin MM heads and a similar setup as the "C" and "D" to fin the tubes (after removing the MM "switch")
> Finning increases the available surface area , increasing heat transfer and provides a more secure grip than knurling alone on the tubes(IMHO) And, it looks cool! (Just don't fin the battery tube TOO deep!)



I tried to use a MM body to hold the head for grooves, in some cases the head would run true, in others it would not. the threading has 4 start points, I would try each one, sometimes that worked, sometimes not. I ended up using the 3 jaw chuck on the inside of the front of the head, tightening out ( like loosening ) then I put a live center on the other end. That holds the work rock solid and it runs as true as can be...


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## b2eze (Nov 6, 2006)

Try not screwing the MM head all the way down. Instead make a spacer (like a flat washer) that your MM tube will go through and let it stop the head. The spacer will be against your chuck jaws on the one side and the head on the other and the "slop" in the threads will allow the spacer to hold the head in line, if both halves of your spacer are parallel. Works for me!


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## will (Nov 6, 2006)

b2eze said:


> Try not screwing the MM head all the way down. Instead make a spacer (like a flat washer) that your MM tube will go through and let it stop the head. The spacer will be against your chuck jaws on the one side and the head on the other and the "slop" in the threads will allow the spacer to hold the head in line, if both halves of your spacer are parallel. Works for me!




I understand - That might be easier than what I am doing now..


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## cmacclel (Nov 6, 2006)

will said:


> I understand - That might be easier than what I am doing now..



For Mini Mags I use a dead center in my 3 jaw chuck and a live center in the tail stock.

Mac


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## b2eze (Nov 7, 2006)

Have to try that ! Thanks!


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## Ganp (Nov 8, 2006)

Hi MM...
It's nice to see that Southbend put to such good use...Great work :twothumbs 

Colin.


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