Upcoming SST-90 build, thoughts?

Mr_man · Jun 4, 2014

Hi gents.
Firstly, just joined after finding this forum so thought I'd introduce myself.
While I am, what I would consider a "noob" in the world of DIY flashlight builds, I'm hoping experience with machining and quite a few laser builds might help me contribute in some way for others in the future.

This is not so much of a questions thread, but I was hoping it might end up as an informative one for anyone searching for the type of flashlight I'm after, and also for a place to search with updates to links as manufacturers improve on products.

Hopefully for myself included, a sort of "what not to do" thread to avoid in making costly mistakes.
While I've probably played around with a few builds from spare emitters and hosts, its only in the last few days that I've specifically purchased parts for a full build.

Here is what I have planned...

Host: http://www.fasttech.com/products/1618/10002463/1277302-convoy-c8-diy-led-flashlight-host

LED: https://www.fasttech.com/p/1664000

Driver: https://www.fasttech.com/p/1424817

Then I stumbled across this driver and am thinking it might be a better option, just have to go with 2 cells though.
(Btw, using AW IMR 18350 cells)..http://www.kaidomain.com/product/Details.S020148

Heatsink: won't start on that until I have the host.

Anything I might be missing, or isn't obvious to me that might not work out that can be spotted by vets?
Any links to cheaper parts or ideas would also be appreciated for other members or future builds.

Hopefully, if it works out well I'll post a build thread, with beam pics of course to what I would consider close to the best $50 or so you could spend for a torch of this power.

Or, a "How to avoid spending $50 for no result" thread.

Thoughts?

Cheers.

monkeyboy · Jun 4, 2014

Hello and welcome to CPF

There are a couple of issues I can see with this build.
1) The LED won't fit that reflector opening, need at least a 10mm opening for the dome or 16mm for the whole emitter to go through.
2) I don't think either of those drivers will fit into that host.
3) I doubt you'll get anywhere near maximum output current of those drivers with just 2 cells (probably need to use upper end of the voltage range), so 3 or 4 cells.
4) The host is too small so won't provide enough heatsinking for the SST-90, so should be used in short bursts only.

Rod911 · Jun 4, 2014

What kind of light do you want to build? Do you want throw or flood? The size of the light itself, small or large? Is the host that you indicated in your OP, the C8, the size you are looking for?

First up, that's an ok host. However, you probably wouldn't want to be pushing anything more than 5A to power up the LED. 5A would be the limit, no matter which LED you choose. Any advise going forward will be based on using this host.

Second, throw or flood?
- MT-G2 will provide the floodiest option. More efficient than SST-90. I would recommend up to 4.5A
- XM-L2 is a good mix of flood and throw. At 5A, depending on the tint and bin of the LED, you're looking at 1500 lumens. Note that, if you are after throw with ok spill, removing the dome on this LED will increase throw (lux) by around double. However, removing the dome of any LED will reduce lumen output by up to 30% and making them warmer (ie. a cool white LED will become neutral, a neutral LED will become somewhat in the warm colour spectrum)
- XP-G2 is for throw. This can be driven at 5A, but the lumens wise, it's more like 900 lumens, again, depending on the tint and bin. Remove dome for the best throw option

Now, if you are powering up your LEDs at greater than 3A, you should head over at intl-outdoor.com and look at their LED section, specifically, the Noctigons. These can withstand the high amperage abuse. If not, your standard aluminium star is ok. Just remember to select a 16mm sized star/MCPCB.

Next are the driver options. If you want the MT-G2, go to mtnelectronics.com and search for "zener" for a ready made driver for this LED. If XM-L2 or XP-G2, any 7135 based driver is fine. I would suggest a Qlite. These things, by default are 3.04A. Buy yourself some more 7135 chips, read about stacking, and stack away to your hearts content. What ever driver you want, it has to be 17mm in diameter as they are the only ones that will fit this host.

The last steps you could be taking is to read up on copper braiding the springs, along with possibly changing wires in your driver to something thicker (at least 22AWG if possible) to help reduce resistance, and therefore, increase the efficiency of getting power from your batteries, to the driver, and thus, the LED.

monkeyboy · Jun 4, 2014

Rod911 said:
- XP-G2 is for throw. This can be driven at 5A, but the lumens wise, it's more like 900 lumens, again, depending on the tint and bin. Remove dome for the best throw option

XP-G2 cannot be driven that high. The limit is about 2A with a regular PCB and about 3A with a direct copper PCB. Beyond these limits, no more light is produced, only extra heat. It will never produce 900 lumens.

Mr_man · Jun 4, 2014

monkeyboy said:
Hello and welcome to CPF

There are a couple of issues I can see with this build.
1) The LED won't fit that reflector opening, need at least a 10mm opening for the dome or 16mm for the whole emitter to go through.
2) I don't think either of those drivers will fit into that host.
3) I doubt you'll get anywhere near maximum output current of those drivers with just 2 cells (probably need to use upper end of the voltage range), so 3 or 4 cells.
4) The host is too small so won't provide enough heatsinking for the SST-90, so should be used in short bursts only.

Rod911 said:
What kind of light do you want to build? Do you want throw or flood? The size of the light itself, small or large? Is the host that you indicated in your OP, the C8, the size you are looking for?

First up, that's an ok host. However, you probably wouldn't want to be pushing anything more than 5A to power up the LED. 5A would be the limit, no matter which LED you choose. Any advise going forward will be based on using this host.

Second, throw or flood?
- MT-G2 will provide the floodiest option. More efficient than SST-90. I would recommend up to 4.5A
- XM-L2 is a good mix of flood and throw. At 5A, depending on the tint and bin of the LED, you're looking at 1500 lumens. Note that, if you are after throw with ok spill, removing the dome on this LED will increase throw (lux) by around double. However, removing the dome of any LED will reduce lumen output by up to 30% and making them warmer (ie. a cool white LED will become neutral, a neutral LED will become somewhat in the warm colour spectrum)
- XP-G2 is for throw. This can be driven at 5A, but the lumens wise, it's more like 900 lumens, again, depending on the tint and bin. Remove dome for the best throw option

Now, if you are powering up your LEDs at greater than 3A, you should head over at intl-outdoor.com and look at their LED section, specifically, the Noctigons. These can withstand the high amperage abuse. If not, your standard aluminium star is ok. Just remember to select a 16mm sized star/MCPCB.

Next are the driver options. If you want the MT-G2, go to mtnelectronics.com and search for "zener" for a ready made driver for this LED. If XM-L2 or XP-G2, any 7135 based driver is fine. I would suggest a Qlite. These things, by default are 3.04A. Buy yourself some more 7135 chips, read about stacking, and stack away to your hearts content. What ever driver you want, it has to be 17mm in diameter as they are the only ones that will fit this host.

The last steps you could be taking is to read up on copper braiding the springs, along with possibly changing wires in your driver to something thicker (at least 22AWG if possible) to help reduce resistance, and therefore, increase the efficiency of getting power from your batteries, to the driver, and thus, the LED.

Thanks for the welcome.

This is exactly what I was after, some good advice from a couple of guys that show me as little as I thought I knew about flashlight mods, I actually know less.

Luckily, the host is the only thing I haven't purchased yet, thankfully.
The LED and first driver shown are the only 2 parts I've comitted to yet.

The size of reflector hole isn't much of an issue as I can open that up a bit with a lathe etc.
I'm after maximum throw, trying to run the LED at full capasity, but in the smallest host I can manage to squeeze it into.
I'm not concerned about long run times as I know I'd be asking to much from any of the sized hosts I'm after.

Another host I thought I might try is from a Sunwayman D40A, it has a nice deep reflector from what I can remember, and it would also allow me to power it off 4X14500 as 2 cells was mentioned might not be enough.
Or am I just asking too much from hosts of this size?

Thanks for the input gents, I've got lots to learn.

monkeyboy · Jun 4, 2014

@rod911, OK fair enough maybe Vinh can achieve those numbers with his custom copper heatsink, but it's not something you can do with a store bought PCB. See this link:
http://www.candlepowerforums.com/vb...B-Sinkpad-VS-Direct-bonded-Copper-PCB-sinkpad

@Mr_man, The SST-90 has a relatively large die area, so won't give you much throw unless you have a huge reflector. XM-L2 or XP-G2 would be better for throw. You could try modding a ready built light, but bear in mind that all the parts tend to be thread locked and/or glued together and are difficult to open up without damaging. If you want crazy levels of overdrive, it might be better to buy something from Vinh or Oveready instead.

Rod911 · Jun 4, 2014

Mr_man said:
Thanks for the welcome.

This is exactly what I was after, some good advice from a couple of guys that show me as little as I thought I knew about flashlight mods, I actually know less.

Luckily, the host is the only thing I haven't purchased yet, thankfully.
The LED and first driver shown are the only 2 parts I've comitted to yet.

The size of reflector hole isn't much of an issue as I can open that up a bit with a lathe etc.
I'm after maximum throw, trying to run the LED at full capasity, but in the smallest host I can manage to squeeze it into.
I'm not concerned about long run times as I know I'd be asking to much from any of the sized hosts I'm after.

Another host I thought I might try is from a Sunwayman D40A, it has a nice deep reflector from what I can remember, and it would also allow me to power it off 4X14500 as 2 cells was mentioned might not be enough.
Or am I just asking too much from hosts of this size?

Thanks for the input gents, I've got lots to learn.

D40A? That will certainly blow out your budget!!

I suggest you should go with my XM-L2 build using the C8 host.

Or...

Search for "Lustefire K-08", guts it insides and use it as a host. It is essentially a Convoy L2 host which I have used before in a mod. If you want this to be a small thrower, this would be a pretty good bet.

I'd start off with an LD-29 driver and resistor mod that to around 4.4A. I have got it to 5A, but with limited success as it kept on burning up. Why this driver? It can be run on one cell. Then I would get myself an XM-L2 U2 1A LED on a Noctigon 20mm MCPCB and dedome it. Next step is to copper braid the springs. Finally, power it up with a 26650 King Kong ICR or INR.

There are also little things you can do whilst building it which includes using thermal paste, cleaning electrical contacts with deoxit, etc...

I also forgot, the next step is to try and mod/reprogram the drivers themselves. This, I haven't bothered to look into and I don't think I will.

You're guaranteed to lose a few LEDs, drivers and whatnot when modding. But that is all part of the process. Have fun.

Rod911 · Jun 4, 2014

monkeyboy said:
@rod911, OK fair enough maybe Vinh can achieve those numbers with his custom copper heatsink, but it's not something you can do with a store bought PCB. See this link:
http://www.candlepowerforums.com/vb...B-Sinkpad-VS-Direct-bonded-Copper-PCB-sinkpad

I am going by what I have done myself and others in the "other" forum. 5A on XP-G2 is doable on a copper PCB - either on sink pads or Noctigons. Again, I repeat myself, this is only really possible when the host has enough heatsinking to handle the heat generated by the XP-G2 at 5A. In something like a C8, it's definitely possible and has been done before, but it is always modder be wary.

monkeyboy · Jun 4, 2014

Saabluster's figures are quite different:

http://www.candlepowerforums.com/vb/showthread.php?340892-New-2nd-Generation-Cree-XP-G2-LED!/page3

With regular PCB, peak is around 2.4A and with direct copper PCB, peak is around 4.8A. (Ok maybe I was a bit off in post #4 but this test was with a chilled LED not a real flashlight situation).

Note to OP: sorry, we're going off on a tangent here.

Rod911 · Jun 4, 2014

I understand Saab's figures and influence here, but that is simply just one dude and his numbers. I go by personal experience.

I won't be back in Oz until start of August. I have been meaning to build a C8. Why not an XP-G2 at 5A? :thumbsup:

Conte · Jun 5, 2014

Honestly, I think you're attempting an experienced build.

You might want to start smaller.

Get something like an XML2 with a common qlite driver. Easy peasy, and get a feel for it.

It's not going to be your last build, so you might as well go for a walk before the marathon.

Conte · Jun 5, 2014

Oh, and if you're dead set on a big bruiser like the SST-90, consider using a maglite D as a host.

You'll find it easy to work with if you're going to custom fab a heatsink, especially something big enough to calm a large LED like that.
You'll also be able to use bigger batteries like 26650 IMR's so you can actually run it.

I'm taking that direction myself. Got parts on order to run an MT-G2 in a 2D mag.
I got the electrical aspects down, but I'm not quite sure what to expect in the heat department yet, but I know I'll be able to make it work in a Mag D.

Upcoming SST-90 build, thoughts?

Mr_man

Newly Enlightened

monkeyboy

Flashlight Enthusiast

Rod911

Enlightened

monkeyboy

Flashlight Enthusiast

Mr_man

Newly Enlightened

monkeyboy

Flashlight Enthusiast

Rod911

Enlightened

Rod911

Enlightened

monkeyboy

Flashlight Enthusiast

Rod911

Enlightened

Conte

Enlightened

Conte

Enlightened

Similar threads

Latest posts