Possible mods (inc.) for a 4C Mag

[Spypro]

Hi !
I would like to mod my 4C Maglite.
But I don't know where to look at.

I don't care about runtime... but 30 mins would be ok for me.
Incandescent.
I want a lumens monster.

I'm a newbee to modifications... so this is why I've wanted to ask the experts here.
What are the possible mods that I can apply to my 4C ? Is it better to buy something like the WF-500 for 30$ ?

Thanks !

 

[DonShock]

A Mag85 version using three 18650 li-ion cells fits nicely in a Mag4C. The length is nearly perfect, you just need a spacer for diameter. I made one from 3/4" grey PVC electrical conduit. It's still a little too large, but a simple saw cut along the length and a little sanding made a perfect fit. And then of course you need the metal reflector, glass lens, bipin bulb holder, and 1185 bulbs.

 

[Spypro]

Thanks for the advices !
How much lumen from thr 1185 bulb with 3 x 18650 ?

 

[Spypro]

What do you think of this setup ?
- Light-edge Mag Reflectors reflector - Mirror Finish (for maximum throw)
- 52.1mm Borofloat or UCL lense (what is the better ? is there something better on the market ?)
- WA1185 potted bulb (is there better (powerful) that this bulb ?)
- 4 x AW protected LiIon C cells or (economical) 3 x AW Protected 18650 cells
- Bipin bulb holder (where can I get it ?)
- AW regulator... I'm not sure of the name... but this thing with 3 level of brightness + soft start

I'm looking for a maximum of lumens from my little 4C Mag

 

[mudman cj]

I recommend the Borofloat lens instead of the UCL. The UCL will transmit about 3% more light, but is much more likely to crack from thermal stress as well.

You should use the bi-pin version of the 1185 with this bi-pin bulb holder for better results than the potted version. Also consider installing the KIU socket for lowest resistance and best heat tolerance. Of course, if you go with the AW regulator then you don't need either the PR to bi-pin adapter or the KIU socket. The AW regulator already comes ready to accept bi-pin bulbs.

If you really want a much brighter light then you will have to go with a bigger light. 5 Li-ion C cells can power lamps such as 25W or 35W IRC for a lot more light than the 1185. But 5 C Li-ion cells would require a light even longer than a 5C size due to the length of AW's cells. There are people that have built these lights, it would be best to ask them if you are interested. I will look for the posts discussing this and post a link when I get a chance.

Other options of course tend to use D size Mags with many Nimh cells in series to get voltages high enough to overdrive the high powered bulbs.

Edit: Here is an example of someone using AW C cells to power IRC bulbs.

 

[DonShock]

Another point to mention: the AW li-ion C cells are slightly longer (about 3mm IIRC) than a normal C cell so 4 cells won't fit in a Mag4C. Plus the voltage would be wrong for an 1185 bulb.

 

[Spypro]

Thank you all for the advices !
I think I will start with a 1185 bulb because it will be my first mod... so I'll start with something simple.

So it will look like that:
- Light-edge Mag Reflectors reflector - Mirror Finish (for maximum throw)
- 52.1mm Borofloat
- WA1185 bi-pin bulbs
- 3 x AW Protected 18650 cells
- AW regulator

What is the best reflector for throw ? This one "Light-edge Mag Reflectors reflector - Mirror Finish" looks like the best for the purpose. What do you think ?
Is it ok if I use rechargeable AW 18650 ?

 

[mudman cj]

The "best" reflector for throw would be smooth, but there are other options besides the one you reference that would provide more throw because of being longer and/or larger diameter. There are 2.5" and 3" diameter head and reflector assemblies available as well as a deep reflector with special bezel. These options add to the cost, especially the 2.5" and 3" head assemblies. They are also more difficult to acquire. What you have in mind will still provide a lot of throw, so I recommend starting there.

AW's protected 18650s work well with the 1185. I have built a 4C mag using three of them with the 1185 and I am very pleased with the result. This is a great first mod. Also look into the resistance fix for the tailcap spring - it will make the bulb run slightly whiter and brighter.

I'm glad DonShock mentioned the problems with using 4 AW C cells with the 1185 - I glanced right past that!

 

[Spypro]

Thank you for the advices. I'll start with the setup I've mentioned.

Can you tell me more about this "resistance fix" please ?

Thanks !

 

[mudman cj]

The steel spring has enough resistance to drop a fraction of a volt under operating current levels. This reduces the voltage available at the bulb. Reduce this resistance by running some braided copper solder wick or wire from the battery contact to the bottom of the spring where it makes contact with the flashlight body. The wick may be soldered with a high power iron or even a blowtorch from a distance, or some just wedge it between the tight upper coils of the spring and between the spring and body at the bottom. Try to have the battery contact the wick instead of the steel spring for lowest resistance. Similarly, you want the wick to touch the aluminum body at the bottom. You can also use Pro-Gold to treat all electrical contact surfaces for best results.

 

[Spypro]

I'm not sure if I understand clearly:
All I have to do is solder the top of the spring with a wire (and let it touch the battery) and then solder the other end of the wire to the bottom of the spring where it is making contact with the body.

l would like to build something like the powerful Borealis.

 

[mudman cj]

It sounds like you understand how to reduce the spring resistance. Wrap the wire around the spring a few turns so the solder doesn't have to hold the wire onto the spring all by itself.

With this and the AW regulator your light will be as bright as the Borealis, but with three brightness levels for extended runtime and strobe. And Li-ion cells are able to hold voltage better than Nimh as they continue to be discharged (only if the Li-ion cells are not being driven too close to 2C), so your light should be brighter at say 50% battery capacity than the Borealis, and definitely when closer to fully discharged. Also, the C sized maglites are more comfortable to hold for most folks and since you are using Li-ion batteries your light will not self discharge waiting to be used.

 

[Spypro]

Thanks
So... 2 x 18650 would be ok ? How much runtime can I expect on full power ?
The Borealis seem to operate at 12 volts to get 1050 lumens... so behind 12 volts will I get an instantflash ?

If I do not use the AW soft starter is it possible to achieve about the same power as the Borealis ? and which bi-pin socket could I use instead of the AW's ?

Thanks !

 

[mudman cj]

You will need 3 Li-ion cells to get the proper voltage for driving the 1185. Perhaps I threw you off when I mentioned 2C. That refers to twice the capacity of the cells. In the case of AW 18650s that is 2*2200mA=4400mA or 4.4A. The 1185 draws about 3.85A, so it pushes the batteries at 1.75C. 2C is the maximum rate for discharging Li-ion cells, and 1.5C or less is a preferred rate for extracting the most energy from the cells.

The Borealis does not operate at 12V. Batteries sag under load (higher loads cause more sag), so the actual voltage will be quite a bit less. The 1185 would instaflash off of 12V.

You can make your light as bright as the Borealis if you reduce the resistance of the switch assembly and use a KIU socket or bi-pin adapter along with best practices for reducing resistance. You want as many soldered connections and as few contacts as possible, and those should be treated with Pro-Gold for best results. Fivemega has sold PR to bi-pin adapters and I think he might still have some. And you can assemble the KIU socket for even lower resistance. Let me know if you want instructions for how to perform switch resistance fixes or KIU assembly.

If you don't want to assemble your own KIU switch assembly and you don't want to perform the switch fixes, I could sell you a C sized switch assembly I was using for my 5761 until I replaced it with AW's regulator. It uses a Fivemega Magcharger slug soldered directly to the upper switch contact with copper braid and another wire to connect the negative switch contact directly to the flashlight body without conducting through the hex screw. It should have slightly less resistance than using a PR to bi-pin adapter. To use my switch in a light you must remove anodizing where the screw tightens against the body because it pushes a contact against the body instead of piercing through the anodizing. I used this switch with a focusing reflector (Fivemega dual function focusing reflector) for nice results. Note that the KIU switch does away with the option of using a focusing reflector. I want to add that the magcharger slug is not the same height as the stock pedestal, so while it works without modification for focusing reflectors, I think it would not work with fixed focus reflectors because the bulb would sit too low.

 

[Spypro]

Thanks!
When it comes to the glass lens, 3x18650, reflector and the bulb it's ok !
Same for lowering the resistance on the spring.

But when it comes to the switch and the bi-pin holder I'm a little bit confused. Do I have to change the complete stock switch assembly or can I just put a bi-pin older on the stock switch ?

Thank !

 

[mudman cj]

You could get away with using the stock switch and a PR to bi-pin adapter, but due to resistance in the stock switch your light would not be as bright as a Borealis. The resistance will also heat the spring inside the switch assembly and can cause melting of the pedestal on long burns.

 

[Spypro]

So what would be the best options ?
What is the difference between the potted and bi-pin bulb ?
If I have to change the switch assembly in order to be able to use a bi-pin what would be the best switch ?
What about lowering the resistance elsewhere than the bottom spring ?
Is it possible to build something in the range of 1000 torch lumens ?

Thanks !

 

[mudman cj]

Realistically, you will not get more than about 775 torch lumens from the 1185 without using Nimh and a voltage regulator like the hotdriver to get over 10.8V provided by three Li-ion cells. However, the 1185 makes a very useful amount of light, and if you haven't seen one you will be impressed.

Potted bulbs are bi-pin bulbs that have been welded to a PR base and "potted" in with high temperature ceramic cement. Potted bulbs add another contact which adds resistance to the circuit.

Every source of resistance in the "circuit" of the flashlight drops a part of the total available battery voltage, and only what is left can be used by the bulb. Even a resistance as small as 0.1 Ohms will reduce output by about 12%. This is one of the reasons bi-pin construction is preferred. Another is the higher cost and restricted availability of potted bulbs.

In order to get the most out of the light and get it as bright as a Borealis you need to reduce resistance as much as possible. Here is a link to the switch resistance fixing instructions. In the link there is some data for what this fix did for the 1185 on 10.8V: 667 to 776 torch lumens - a 16% increase. So, you don't replace the switch with these methods - you improve it. The AW softstart regulator does replace the switch and comes with a KIU bi-pin socket for lowest resistance. Installing your own KIU socket replaces the PR bulb pedestal with a metal and ceramic version that also has very low resistance. This is the sales thread for the KIU socket which contains a link to installation instructions so you can see what it involves.

If you really need to get to 1000 torch lumens then something has to give - size or runtime (or both). I think the 1185 is a great value in hotwires and your build plan is a good one. Don't let the lumens number control your decision because the 1185 puts out a very nice and useful beam that can give heaps of throw. Some bulbs are much brighter but still don't exceed the lux (and therefore throw) of an 1185.

 

[Spypro]

Thanks for the infos I see much clearer now !
I know what to do and buy but I don't know yet what to buy between the AW softstart or the KIU socket. I think I'll go with the KIU because it is my first Mag85 mod.

 

[Spypro]

What is the best reflector for throw ?
Suggestions ?
Thanks !