Modding the Mag - Some help please

[Lucien]

Well, I finally bought myself a 2D Mag to use as a mod base. Been meaning to do it for some time but kept putting it off to play around with the electronics to drive a LS first.

First thing I did was to take it apart, completely. Then put it back together and tested it to see if I reassembled it right - so far so good. /ubbthreads/images/graemlins/tongue.gif

My plan is to mod this to use a 5W HD - cut the "stalk" on the reflector and see if I can get a nice heatsink machined that would put the LS nicely into it.

Now the problem: I know the Mag reflector gets damaged easily when cleaning, so is there any good way to cut the stalk off it without getting it too dirty? /ubbthreads/images/graemlins/confused.gif I was going to clean it by blowing off the dust after, and if that isn't enough, to rinse it off with water. But I'm really worried about screwing this part up.

Also, I did some rough testing by sticking a lighted 1W LS up into the reflector to gauge where the ideal position would be for a nice tight spot. (Hopefully I didn't do too much damage to them by running them without a heat sink.) But I was unable to get even a half decent idea of how far in they have to be placed. Does anyone know? /ubbthreads/images/graemlins/confused.gif I hope to be using a 5W HD and still keep some degree of focusing ability.


Thanks in advance for any and all advice you guys can offer /ubbthreads/images/graemlins/smile.gif

 

[Ginseng]

I used a fine tooth hacksaw and just sawed away. I have a Dremel so the the next one I'll use a fine cutoff wheel.

I do not touch the silver surface. Simply run it under some water. It might help to immerse it in soapy water first. Works for me and no scratches.

Wilkey

 

[Slick]

Grind and file away with abandon... Just don't TOUCH the reflective surface.

When all filing is complete, I spray the reflector down with windex and flush in hot running water. Then I use "computer duster" to blow off any remaining water droplets.

As long as you don't touch any part of the reflective surface with a tool or your finger, it will still look like new.

 

[Rothrandir]

that's a good way to do it.

there are several ways to modify it, one is to create a bulb base, the other is to remove the bulb assembly altogether, and solder the wires directly from the switch. the latter is the method i prefer.

if you don't run the ls very hard or very long, you shouldn't have damaged it.

for a 1w ld, the bottom of the emitter should be pretty much even with the bottom of the reflecting surface...it is slightly different for different dome type, but all pretty much the same.

how do you plan on doing the heatsink?

 

[Shark]

I usually put masking tape on the reflective surface keeps it clean dry and free of scratches as for the heatsink check out the ones Wayne sells at electrolumens they do a nice job and all you have to do is drill the holes.

 

[Pellidon]

A cutoff wheel in a drill press lets you buzz off the tube evenly, something I can't do with my eyeballs and a hacksaw it seems /ubbthreads/images/graemlins/ooo.gif. Go with high RPM and feed slowly or you will have lots of broken cutoff wheel bits flying around unless you use the fiber wheels. Set the table to have a uniform cut height.

I turn my heat sinks with a slight stub in the center to make alignment of the emitter easier and to give it a little elevation into the reflector to insure a range of focus.

A good centered low dome will turn the reflector yellow when looked at it in the OFF condition. /ubbthreads/images/graemlins/grin.gif My high dome is at work but I think it goes all yellow as well.

 

[Burnt_Retinas]

The first one I did I hack sawed close to where I wanted it. I then played with the cut-off by cutting it with wire cutters. The plastic is soft-ish and didn't crack or splinter. The remainder of the part to be removed on the first lens, and the entire second one I did, I just trimmed the end off with wire cutters, slowly spiraling down like a screw thread. Worked a treat. It's the poor man's option as I don't have access to much machinery, let alone a dremmel.

Don't touch the reflective coating, not even with a tissue. I started to wipe mine with a tissue soaked in metho and it began to scratch. Go for the blow off or rinse option if required, but the preference is don't get it dirty in the first place ie don't touch it.

Re placement of LED. I had mine spaced 3mm off the heatsink, but in hindsight I'd go for 4-5mm to give even more flood if required.

I also removed the globe mounting assembly so I could have the heatsink about 9mm down into the neck of the mag tube to avoid a) the reflector crashing into the heatsink and b) be able to get both flood and tight focus without having the head go past the O ring at any point.

Chris

 

[Lucien]

Trimming the reflector off with the wire cutters sounds good. Alas, I'm a bit of a perfectionist, and probably will suffer using cut-off discs or sanding discs to cut it down to size.

I was thinking of cutting a circle out of tape or cardboard to plug up the base of the reflector, though cutting one and getting it into place just right may be a problem.


Rothrandir,

At the moment, from a project I'm doing for someone, I know another someone who said it should be pretty cheap to machine a one-off job of a simple slug to fit into the Mag body. (I explained to him it was for a personal project.) I'm thinking a disc about 10mm thick that press-fits into the Mag body, with a post to raise the LS into the reflector. The post would have an indentation to "auto" centre the LS.

Unfortunately, after this week, I start a *REAL* job and won't be able to see this guy at his office. (Getting a real job is fortunate, losing a chance to get a heatsink done is the part that isn't...) Either I'll have to liase through the person I'm currently doing a project for, or I'll have to find some other opportunity to get a heatsink made /ubbthreads/images/graemlins/frown.gif

I'm thinking of putting it in the freezer, to shrink it, then stuffing it in the Mag body so that when it warms up, it should fit tightly. Thermal compound applied to the mating surfaces of course. The anodization on the Mag body should electrically insulate it from the heatsink. As long as no other conductor contacts it, it should be fine.



Its starting to look like cutting the post on the switch unit will also be a must. The head of the Mag has 8mm of travel between the fully screwed down position and before the O-ring starts to show. And when fully screwed down, I calculate the space between the base of the reflector and the top of the plastic of the switch unit to be 1 to 4 mm, not enough for a decent heat sink IMHO.

With cutting, I'm looking at 24mm of space - much better /ubbthreads/images/graemlins/wink.gif


Whats puzzling me is where the LS should be in the reflector for a tight hotspot. Granted right now I only have 1W emitters to test with, and I plan to use a 5W. But it seemed like the emmitter roughtly needs to be 5mm into the reflector for that. Seemed to be that is - a shortage of hands and a makeshift setup meant that I was tried to look at the LS position when it was on - NOT a smart thing to to /ubbthreads/images/graemlins/crazy.gif

 

[Rothrandir]

the reason i asked about the heatsinks, is because i have a lathe, and have made some premium heatsinks for cpfers in the past /ubbthreads/images/graemlins/wink.gif
i did just notice that you are in singapore though /ubbthreads/images/graemlins/frown.gif so it would probably be to cost prohibitive and troublesome anyway...customs might even think it's a bomb part! /ubbthreads/images/graemlins/eek.gif /ubbthreads/images/graemlins/grin.gif

cutting down the assembly is the best option /ubbthreads/images/graemlins/grin.gif it reduces electrical joints...reducing resistance and increasing reliability /ubbthreads/images/graemlins/grin.gif plus, it allows room for larger hetsinks /ubbthreads/images/graemlins/grin.gif

electrical isolation from the slug isn't really necessary for a single 5w luxeons...it only really matters for the ingan type luxeons (red, red/orange, amber) and they are all 1w as it is.

here is a picture of two heatsinks i made for another cpfer...the lambda heatsink is in the middle:

the heatsink on the left slides right in without adjusting the bulb post. it looks taller than the lambda heatsink, but isn't...it is recessed on the bottom /ubbthreads/images/graemlins/grin.gif also, it is a solid slug, and you will notice a small round area on top...this is to perfectly center the luxeon /ubbthreads/images/graemlins/grin.gif
the heatsink on the right is a special heatsink, it was made to be easly dropped in and removed from the mag house...no trimmage is necessary no this either. of course, if you choose to trim the bulb post, these types would still work /ubbthreads/images/graemlins/grin.gif
both of my heatsinks allow are fully focuasble, so you wouldn't need to worry about specific placment.

if you choose to have heatsinks made by someone...either of the two i showed above would be ideal /ubbthreads/images/graemlins/grin.gif

 

[moraino]

The right one is what I was waiting for. Any plan for mass production?

Henry

 

[lambda]

Yes, I too vote for the one on the right. Great work Roth!

 

[Rothrandir]

thanks guys /ubbthreads/images/graemlins/grin.gif

i'm afraid i'm not able to do mass production, but if anyone else would like to do so, please feel free /ubbthreads/images/graemlins/grin.gif

i do have a little spare time, so if anyone would like a custom heatsink, such as the one seen above, please feel free to contact me. there is a lot of work involved, so the price would be prohibitive for some. /ubbthreads/images/graemlins/frown.gif

 

[Lucien]

Rothrandir,

Nice work there, and thanks for showing them off. /ubbthreads/images/graemlins/grin.gif Having a lip on the top of the heatsink is a good idea, it doesn't restrict how far down you can screw the Mag head does it?

I might actually just look you up if I can't get one done here, and brave customs myself. /ubbthreads/images/graemlins/tongue.gif

How do they fit in to the Mag body? A tight press-fit, or do you have to epoxy them into place?

 

[Rothrandir]

the lip doesn't go out as far as the threads, so it doesn't affect how far it screws down.

it doesn't require any epoxy, but if you want a more permanent solution, you can certainly use it.

it should allow enough mass and contact area that it doesn't require thermal goo either...but thermal goo is always a good idea /ubbthreads/images/graemlins/grin.gif

i plan on picking up a mag soon ( i don't currently have any un-modded ones /ubbthreads/images/graemlins/grin.gif ), because i have a great idea for a dropin module /ubbthreads/images/graemlins/grin.gif

feel free to look me up if you need to /ubbthreads/images/graemlins/grin.gif

 

[MR Bulk]

Hey Roth,

Very nice. If you would be willing to show it to a local CNC shop, you could have them crank these out and I believe it would create its own very, very large and healthy market (myself included, I'd be good for at least fifty)...

 

[Rothrandir]

50?! /ubbthreads/images/graemlins/eek.gif

well...it sounds as if there could be some demand for these. i highly doubt i will ever be able to find a cnc shop, or especially fund the project, but thanks for the interest /ubbthreads/images/graemlins/smile.gif

if someone else would like to take up this design, feel free. /ubbthreads/images/graemlins/smile.gif

 

[souyou]

The one on right is what I've thought of, wanted to make and been unable to make (no lathe).
You did make it! Glad to see it.

But no mass production... /ubbthreads/images/graemlins/mecry.gif

 

[shiftd]

Roth, Can you at least put a (estimated) price for both? How prohibitive is the price? /ubbthreads/images/graemlins/smile.gif

 

[Rothrandir]

hmmm....$12 and $16 respectively?

 

[shiftd]

Hmmm, reasonable.
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