Putting and LED into an host intended for Incandescent - worth it?

Flashlight Modding and DIY Parts
1

So i have a couple hosts in the form of the pistol-grip style spotlight. It's a really useful form factor, big reflector, lots of room for batteries, but the trouble is two of them have incandescent bulbs in them and are about as bright as convoy S2 stock. I found this thread in which Old Lumens does a hell of a lot better job than I ever could, and his host and led choice are nearly identical to mine. My host is a different brand, but nearly identical reflector and shabby aluminum body with lots of plastic. I was about dremel off the bottom of the reflector when I found OL's thread and started to second guess:

https://budgetlightforum.com/t/-/18778

Sorry, I made that entire paragraph a link to OL's thread and can't figure out how to change it back.

To the point, is putting an MT-g2, XHP 50 or 70 worth it and/or doable in a reflector made for incandescent bulbs? From talking to some other members, I am hoping that making the opening in the bottom of the reflector ~20mm so that the mcpcb can be raised or lowered on some aluminum or copper bar stock in order to get a better beam shape might be possible. OL seems to always post that the best beam's from his mt-g2 mods come when the reflector is about level with the mcpcb or the substrate of the led. And in the previous post the led looked a little lower than usual in the images, but what do I know? And usually he's got reflectors meant for LED's so I don't know if this applies, and unfortunately, I did not know the man, so I can't tell if the above post was on of his first mt-g2 efforts before he figured out how to get them focussed properly.

But from another option I have as a host, this Q-beam max million rechargeable, obviously the incandescent bulb sits high in the reflector opening and the beam angle must be over 300 degrees?

Is there any reason to think this can be easily remidied by putting the emitter higher in the reflector, or is it likely a waste of time and a host made for LED's is a much better choice?

2

Pictures are too big

If you go out in the sunlight you can see where the reflectr focuses the light in one spot, the LED has to be near it for best throw and a uniform hotspot without beam artifacts

For this one it should be where the tungsten filament is

You likely need to get the LED that high
As the reflector behind the LED hight is useless its better to cut it

If you mount a good heatsink inside the light you can probably up to 20-30W LED power

3

Fixed the pics for ya!

4

The reflector should probably work fine with an LED, but as Lexel said, the LED has to be at the focal point which is where the filament currently is. This means some of the inner area of the reflector will be behind the LED and so won’t be illuminated by the LED. But it would still make a powerful beam with an XHP70.

Making an adequate thermal path for heat dissipation in a light like this is the hard part. So whether it’s worth it depends on how much work you want to put into it. If you like this form factor I say go ahead and do it, but I think it will require some custom made parts and modification of the plastic body for proper heat sinking. It is a large reflector so the result would be very impressive.

5

Thanks, gotta figure out how to shrink the pics next time. Also, cutting the reflector would allow more space for heatsinking without having to raise led just straight into the reflector on a piece of barstock or something similar. I’ll give this some more thought, also considering a small cpu-type fan inside and obviously the most heatsinking I can get in there and still reach the air outside. Probably better off just buying a better host, but this also could be an interesting learning experience. Definitely a lot of hours in building the battery pack, making a custom thermal path, and getting the led in the reflector at the focal point. This could wind up a learning experience with no real result, but I’ll post more as I find out more. Thanks for the help

6

When you put in the URL, there’s a “relative width” percentile field right below. 100 sets it to the width of your post.

7

i retrofired few of those rechargeable search lights, and almost none of them had reflector that worked with led.
than you got heat transfer issue, in some lights i had to use fans inside, but then you can forget about it being waterproof, others i had to do quite a bit of work to get heatsink to move heat into outside radiators. in every case it would be cheaper to buy ready made led searchlight,
a lot easier to use automotive hid kit, or led kit. it seems like you have h3 bulb there, there are hid and led kits with that type of bulb.

8

Thanks, after going through the lights a few times I definitely agree with your conclusions, for anyone else considering this in the future. With the plastic housing and incandescent reflector, either upgrading to a HID or higher power bulb in the same form factor seems the way to go unless you are just looking for a difficult project to try and overcome. I’ll probably end up making a li-ion battery pack and trying some HIDs or more powerful 12v H3 bulb in there and see if it makes a big difference. Appreciate the tip alpg88, saved me a lot of time and effort but I’m glad at least somebody was successful in converting these to LED, even if it didn’t turn out as expected.