Turning a SAiK SA-305 into a Fat Boy-T6 -Photo & Video intensive

I love AA flashlights, but most of all I love to have something to do. Modding lights is something to pass the time. I only use hand tools, no drill presses, no lathes or any other large shop tools. It takes time to hand fit stuff, but that's what I have plenty of- (time to burn).

Most 3AA lights are 3 single cells inline (like the Mag-Lite 3AA), which makes the light long & skinny. I like 'em fat (flashlights I mean). 3 cells side by side making short a "1D cell Mag-Lite" sized barrel... But there's not many out there that can be had. I like the looks of the SA-305, so I decided to mod one with an XM-L T6 emitter.

I thought I would start a thread and show the build as it develops. Of course since the DX stuff "just shipped", I'm looking at a good 14 days till it gets here, but I'm starting the thread anyhow, to build up a little suspense...

I ordered an SA-305 from DX and along with it I ordered an aluminum MOP reflector and a glass lens. Now the reflector and lens will NOT fit as drop ins, so I will have to MOD either the light itself or the parts to fit.
I also ordered an 8X7135 driver, extra AMC7135 chips and a T6 emitter from Illumination Supply(IS). I have to thank them, as the items shipped Priority and they were packaged well beyond what I expected. (Small flat rate box with plenty of bubble wrap!). Hats off to Illumination Supply!

Here is a photo of what came:

The Driver is a NANJG 105C and I plan to remove the diode for surge protection/reverse flow and piggyback 1 more AMC7135 to up the amperage to 3100mah (roughly). I may not even use the driver, but that will be decided when I test the emitter direct on 3AA NiMHs.

The main reason for me doing this build is to fill up the empty hours with something that lets me use my hands to complete. I will be doing mods here that no one in their right mind would do, but it's all just for fun and for the learning experience, for me. Things such as modding the stock battery holder contacts to all copper (including making copper springs), making a heat sink out of copper water pipe fittings and replacing the tail cap spring with a handmade copper one will all be shown here.

When I am done with the build, I will list all the components I used and where I got them, as well as the other supplies like copper, thermal compounds, tools, etc.

This thread may get long and it will be done in stages, so I will reserve the next few posts for the build.

SAiK SA-305

It came today! - 14 days from there to here. Not bad time really, normal amount of time for Hong Kong orders.

Here's some Specs and Info:

Brand: SAiK
Model: SA-305
Casing Color: Black
Emitter Brand/Type: Cree
Emitter BIN: Q2 WC
Color BIN: White
Total Emitters: 1
Battery Configurations: 3 x AA battery (not included)
Voltage Input: 0.9~4.5V, 4.5V Max.
Switch Type: Clicky/Clickie
Switch Location: Tail-cap
Modes: 3
Mode Memory: - No
Mode Arrangement: Hi > Lo > Fast Strobe
Circuitry: Digital Regulated 700mA Current Output
Brightness: 140 lumens maximum brightness (manufacturer rated)
Runtime: 35 minutes (manufacturer rated)
Lens: Plastic Lens
Reflector: Aluminum Smooth/SMO Reflector (It is Plastic!)
Carrying Strap: No
Dimensions: 5.16 in x 2.09 in x 2.09 in (13.1 cm x 5.3 cm x 5.3 cm)
Weight: 8.89 oz (252 g)

Here are some Dimensions:
OAL- 130mm
Body OD- 41.5mm
Head OD- 53mm
Body Length- 70mm
Head Length- 47.5mm (with bezel)
Head Length- 41mm (w/o bezel)
Lens OD- 46mm
Lens opening in bezel- 48mm
Reflector OD- 46mm (ID 40mm)
Reflector Length- 31mm
Head major ID- 43mm
Head minor ID- 31mm (threaded for body end)
Head depth from reflector lip to step for inner (to body) threads- 24.5mm
Head depth (length of threaded ID) - 31mm (these are the body attachment threads)
Head Inner Height from reflector lip to face of pill (with body screwed on) - 25.5mm
Tail cap threaded ID- 31mm
Tail cap length- 21mm

Here is a VIDEO!! It's the very first one I ever made, so Be Nice! ;-)


So you know what I want from this build. I want an XM-L T6 light when I get done with it.

Here's what I see already:

A glass lens
An Aluminum Reflector
A big Heat sink
A different regulator board
T6 emitter

Remake the battery holder with all copper
Remake the Clicky with all copper, or replace the switch
Fill the 1/4x20 hole in the body
Smooth all the threads
Replace "O" rings
Paint with a special paint I want to try out
Add a FatBoy Logo

Issues I see right now:
I ordered stuff before I had good measurements, so the new reflector will have to have a ring made for it, to fit tightly in the head ID.
The heat sink I have is a piece of Aluminum rod stock in 1-5/8", so it will have to be "made to fit" with a sleeve, so the fit to head ID is tight.
The difference between the step in the head and the height of the pill, when screwed together, is 2mm, so I will have to figure out the gap from my Heat sink, to the pill (which will still hold the new regulator board & positive spring contact). I am figuring now that I will remove the threads from the pill and attach it to the bottom of the Heat sink I make, so it's all one piece.

Other than that, the rest is fairly straight forward.

I will post again, as I work on this mod and I may do more videos along the way.

I got a couple hours to work on this today, so here is the info and pics. I decided to start with the reflector. The original plastic one was 46mm Dia. and I had ordered a smaller diameter one, not knowing the size.


I will make do. I have to make a ring that will fit tight around the new reflector, so that it fits in the head. I first thought about using the old reflector, but it's too brittle to work with. I finally decided on a cap off a spray can. It's Polyethylene and it's easier to work with. I cut the center out with an exacto knife and used emery cloth to get it to the final inner diameter. I made it so it would snap over the edge of the reflector like this.


Now I have to get the 46mm OD, so I used a pair of scissors and then the emery cloth to shape the OD. Here's the final ring, ready to go.


Now I put it all together and see how it works.


I also decided to do the lens too. I removed the lens (camera filter) from the housing by unscrewing the locking ring and lifting the lens out.


and here is the finished head with all the components in it.


Since I still had a little time, I decided to tackle the heat sink. The stock one is tiny and I am replacing it. I used a shallow reflector to give me some more room for a heat sink. Now I have to cut it. It's 1-5/8" Aluminum rod stock and I sure don't want to do this again. I need a young guy to "assist".


I'm already tired!


10 minutes later... Seroiusly?? I'm so glad it's not steel!


About 20 minutes with breaks to slow the heart rate down and to breathe.


I still have to cut the step in it, but not today! I need to go rest...

More coming later...

After a little rest, I did the tailcap mod this morning. The stock clicky switch is rated at 1amp @ 250VAC, which means 2amp @ 125VAC and "DC rule of thumb" says it would be 2amp at 12vdc. Well I will be at 3amp @ 3vdc, so it might not work.

Once I opened up the switch and saw the parts, I would say it would take 3amp with no problem, especially in a light like this with a short run time.

But... I have it apart now, so I might as well put copper parts back inWink. The photo shows the stock parts and the copper replacements.


Here's the switch put back together with the copper replacement spring I made.


and here's the finished tailcap.


We are going to have a "Cold Snap" here in TX,Surprised temps below freezing for the next few days. (So the weather people say)Undecided. If that happens, I probably will not finish the build till it warms up. Garages in TX aren't insulated!

As the cold front comes in I decided to get the battery holder "copperized". I just took out the stock metal parts and copied them in copper, springs included.


and here is the finished holder.



Have Fun, I'll be back sooner or later...

Heat Sink Time!

As you have seen already, heatsinks will kill me sooner or later. Now that this one has been chopped off to length, I have to put a step in it, so that it clears the inner body ID.

I have scribed the ID on the heatsink and I have taped off how far down I need to go.



At first I was foolish enough to think I could use a file. - Wrong! I had to break out the Hacksaw Cry again. Oh man, I was hoping I wouldn't have to do this!


I ended up making 8 cuts around the center ring


and then I cut around the side till the pieces all came off.


Now I can do pretty good by eye, when shaping something into a round, but I cheated here and I will show you.


Using magic marker helps a lot when taking material off. You can see what you have removed and need to still remove. I did this more than once as I rounded the heatsink.

Here is the final shape


and a couple shots of the heatsink in place.


This is at the battery end and it does not touch inside, because I need to be able to take the body off once in a while.


Here's the business end and I have used a copper shim around the heatsink to make the fit tight. It's tight enough that I have to tap it in with a hammer.

Next time is making the cavity fot the board and attaching the emitter.


Another day, Another Video


The video shows putting the T6 emitter on, wiring it and checking to get proper reflector height for a good beam.

Tomorrow is painting day.

Ok, I have painted and clearcoated the light. I have a photo of the finished light and I will describe the paint I used.


The paint is Rustoleum Textured Metallic paint and it has Copper flecks in it. It leaves the finish textured and the black with copper in it is fantastic looking!

The Clear is Krylon Crystal Clear. It's the best clearcoat paint I have ever used. I use it for doing an OP finish on reflectors and as a top coat on just about everything, from flashlights to knife scales. It's a great paint.

Here's a closeup of the finish.


The photo does not do it justice. The light feels good in the hands now, like you could never drop it and the copper in it just looks great!

Hopefully this week-end I can do the final assembly and beam shots.

So, here's the video with the final assembly and beam shots.


Now, here's the runtime test:
Starting at 7:20PM using a set of AA Eneloops that were fully charged almost 2 weeks ago.

(Note: By saying "no change in brightness" I mean no noticeable change to my eyes. Obviously it changes from the moment it is turned on, but my eyes did not notice enough change to note it.)

7:20 turn on
7:30 no change in the brightness - slightly warm to the touch at the base of the head where the heatsink is.
7:40 no change in the brightness - warm at the head and on the top of the body near the head.
7:50 no change in the brightness - warm all over from top to tailcap.
8:00 no change in the brightness - noticeably warmer to the touch, but still ok to hold, sort of like a hand warmer on a cold day.
8:05 slight change in the brightness - heat is the same
8:10 more noticeable change in brightness (estimate 30% less than when first turned on) - heat is the same or less.
8:20 down to 50% estimated light from turn on, still useable for a sidewalk or bright room light - body is cooling off
8:25 very dim, estimated 25% of light from turn on - heat is no longer an issue, it's cooling off fast.
8:30 it's a night light now
8:35 I shut it off. I don't want to drain the eneloops to nothing, but the light left would be about like a keychain light.

Conclusion: Amazing!! 1 Hour to get down to 50% from start up! Over 1 hour of continuous useable light! Heat was never any real issue and it could be handheld all during the run! Although at 15-20 minutes I might switch hands, but never hot enough to make me want to let go or worry about it.

What mods did I realy end up doing?
1.- Replaced the plastic lens with a glass one.
2. - Replaced the plastic reflector with an OP aluminum one.
3.- Made a new Heat Sink.
4.- Added the Cree XM-L T6 emitter
5.- Painted the light

That's really it, since I am not counting the mods to the tail cap switch, the battery holder or the circuit board. I had to undo all of that when the board turned out bad. Lot's of work that didn't need to be done. In fact most of it didn't have to be done. It was for the enjoyment of doing something and now it's up for sale.

I would say I easily sunk $60 into this project and if I were really to add it up, it would be more like $75.00
Not a budget light!

Conclusion: Overall the mod came out well, but I would not recommend this light for someone who just wants a drop in. The dimensions of the light fall into the "either too small or too big" category and you probably will not find the proper size Lens, Reflector or Heatsink. Those parts have to be modded to fit. Also, for all it's hype, the T6 isn't really spectacular. It's in the same range as the P7 and MCE. It's just newer and has less Vf and better efficiency. If you own a P7 you won't notice the difference, if the T6 were in the same exact light.

What I was very happy about was the runtime! The best runtime I have seen in a high powered 3AA light. Emitter efficiency has something to do with that, as well as how well the heatsink is taking care of the heat and of course the Eneloops are a big plus factor. Gotta love those Eneloops.

Parts List

SAiK SA-305 -DX - $14.99 free shipping

41.5mmx18mm OP Reflector -DX - $3.99 free shipping

46mm UV Lens -Ebay $1.99 free shipping

1-5/8"x1" Aluminum Round Bar for heatsink -Local - $5.00

8X7135 Selectable Mode Driver -Illumination Supply - $6.75 shipping additional

Spare 7135 Chips -Illumination Supply - $0.50@ shipping additional

Cree XM-L, 12.8mm Round MCPCB, T6, 1C tint -Illumination Supply - $9.00 shipping additional

Other Supplies
Arctic Alumina Adhesive -NewEgg
Arctic Silver Ceramique Paste -NewEgg
Loctite Anti Seize Compound, Silver -Drillspot

Copper Wire -Local
Copper Sheet (Small Pieces) - $5.00 to $8.00 with shipping in price

Teflon Wire -Ebay

Paint - Local Hardware Store
Krylon Crystal Clear
Rustoleum Textured Metal Paint

I love the idea!

I´ve been looking at that exact model many times because it uses the 3*AA in series. A perfect thing to mod and then give to non flashaholics (sleepers I call them). But I´m not home for cristmas this year and all the people in the family goes " lets drop the gifts this year shall we" so I´ve let it pass.

When I see how your progress goes I´ll know for sure if its something I´ll do another time. I´ve got family that I´m sure would love such a light :-) Its got a nice format ( I think) for something you have next to the door or in the window sill and just pick it up when you need to locate the dog/dropped keys/where the dog dropped the keys :-)

Looking forward to your posts


SA-305, Thought you had the 305 already , must come back and see what you think of the SAIK ...

I was thinking along the same lines , but dropped coin on a factory AA XML

What factory AA XML is that if I may inquire??

I look forward to seeing the progress. There are quite few people who have build XML Ultrafire MCU-C88s (3xAA) but I've never even seen this light. I like it.

Good choice for a mod. Waiting&watching!

i too have considered modding this light, or the c88. i'll be watching w/ much interest!

I wanted and never did buy this flashlight to mod it, but my idea was to use a single 26650 instead of 3*AA.

I will look close to this thread as I still like the idea of modding this light a lot.

I have to agree that I like the 3AA "fat" format as well. I'm not keen on the long & skinny. I also would like to see 3 AA's instead of the more commonly seen 3 AAA's. Now just make it capable to run on 3 AA NiMh's or 1 32600 lithium ion (or sleeved 26650 or 32650) and that would be great! Watching with anticipation! Definitely want to see the parts list /

I too have an order coming from DX, as well as one from KD. The DX parts will be for my very first mod and I'm excited!


BTW - Is that manufacturer rating of "35 minutes" runtime on the stock light for real??? That seems rediculous! Is that emitter that inefficient?

Don't trust any specs on Chinese budget lights.... is a good rule of thumb. I am interested in these experiments, because I also own the Saik SA-305. I have never gotten around to install the warm white XM-L T3 20 mm star, that lies around here somewhere. I think that the hollow aluminum pill is not suited for hi-amp drivers. You will have to pot it, or something like that.

I understand not to trust specs on the Chinese budget lights, but it's usually the other way around, right? Usually overstated, not understated! (Sorry if I'm pulling this thread off topic.)


I have one of those Saik, well I did, my wife has decided it's I nice light and told me to order another for myself.

I looked at the Saik for modding, a couple of point you will have to cover.

1- As you said, you'll have to make a good heatsink, the std one is crap, has a hole under the LED.

2 - The std driver is a large diameter, so you need to make a mount for the new driver.

3 - Not sure how long the switch will last with 3 amps

But I you can work it out I'm sure, then you'll have a great little fat light!

@ Vectrex - Yes, the stock parts are junk and not suited to high amp drivers or LEDs. Part of the solution will be the reflector change. The stock reflector is somewhere around 30mm in length (I am guessing), so the replacement will have to be signifigantly shorter, to give room for a much larger (deeper) Heat Sink. I am really hoping that I can just go direct instead of using the driver. Direct is so much simpler and if it was a P7 I wouldn't even be concerned about Vf.

@ Essexman - I may have to replace the stock switch. I don't really like those chinese clicky switches, but I will have to look at it some. There are some viable replacements that would work.

Yikes - Jetbeam PA-40 actually - Not very budget , but was made an offer I could not refuse [ dont ask - cant tell ]

Glad you're working out the details for me because I wasn't thinking it'd need a shorter reflector. Before/after beamshots would be great;)

I'm interested in lens dimensions too. I can see myself camping w/ one of these in each back pocket - one floody, the other w/ http://www.dealextreme.com/p/50mm-18mm-2-80-degree-glass-optics-12834

edit:i suspect the emitter would be closer than focal length:(

Good luck, I want to see how this turns out!

Another model being still a budget more or less is the Ultrafire C88 you can find it in ebay for US$39.99.