1st homemade light from scratch- sst90 aspheric H2O proof - 10 AMPS build log

Since getting the jet 13x40 lathe and a mini mill, I am finally starting to try to use it to make some stuff. The learning to lathe thing is no joke. This thread is to document my progress on my first light from scratch.

Basics:

Led: sst90 top bin

Battery: (1) Battery Space 26650 battery (4000mah/10 amp)

Switch: mosfet with hall effect sensor and a magnet embedded in a ring on the outside of the body i.e. when you turn the ring so the south pole of the magnet is over the hall effect sensor, it turns on.

Driver: It is direct drive

Optics: Aspherical 32mm lens from surplus shed

Heatsink: solid copper slug 1 1/2" long.

Additional cooling: The body will be substantially grooved and solid t6 aluminum to act as a giant heat sink in addition.

This light will be completely water proof and divable with o rings throughout. I will probably use it primarily as a super bright fairly compact light for walking my 3 dogs. I wanted something almost as bright as my mag 3c sst90 aspheric build in as compact as possible.

The light is being built also as an exercise to build skills with the lathe and mill as I am a total newbie with a big lathe

Here are some pics of the raw build so far:

full light pic 1:


from the top:



I am going to taper the head and groove it + still have to machine the "donut switch" to fit on the outside of the head.

Here is the donut I have to machine:



It will be machined to just slightly larger the tube and be grooved or knurled and it will sit in a groove on the tube with o rings to make it rotate smoothly.

Here is a close up of the aspheric I got from surplus shed. It is supported by an o ring on the bottom which is in a groove I machined in the ledge on the inside of the head:



Here is a shot of the bottom o ring:



There is another o ring on top of the lens so it is supported on both the top and bottom by them to help provide some shock resistance as well as hopefully water and pressure proofing.

The lens is held in place by a threaded sleeve. I cut a couple of notches in the top and made a temp tool to allow it to be tightened. I will machine the top of the light better for the finished light:



Here is a shot of the bottom of the head showing the threading. Everything is 16 tpi. Learning to thread has been the biggest challenge so far, and I am still learning but everything seems to fit well without slop or binding:



Here is a shot of the threads on the tube. I am still learning here:



I will post more after I do some more machining and make the switch and heatsink.

I have access to anodizing cheap from the shop that works on my race car so the finished light will be anodized after it is finally finished.

Re: compact sst90 aspheric waterproof light build log

Nice job on your Dive light! You may want to move it over to that forum for more comments. Good luck!

Re: compact sst90 aspheric waterproof light build log

Very nice! I like your choice of the manor of switching.

As a dive light a larger diameter head would probably be better if you are going to need to use it to cut through the water (and viz) in any manner other than as a flood light for video or something like that.

Can't wait to see the finished product!

Re: compact sst90 aspheric waterproof light build log

gcbryan said:

Very nice! I like your choice of the manor of switching.

As a dive light a larger diameter head would probably be better if you are going to need to use it to cut through the water (and viz) in any manner other than as a flood light for video or something like that.

Can't wait to see the finished product!

Click to expand...

Thanks for the comments. I am still learning as I go along here.
I held the aspheric lens in front of the electrolumens edc I upgraded to an sst90 and imr 18650 (7 amps) and it has a pretty focused beam. It should also be interesting to see how much I lose vs the 3c mag aspheric that was my first light with an aspheric (MG).

Basically, I am building it as a compact light with a lot of light that will still fit in a pocket for walking the dogs etc. The water proofing is just figuring out stuff for an upcoming dedicated dive light build. I figured if it works, I can also throw it in my bc as a backup light.

Re: compact sst90 aspheric waterproof light build log

looks good, I cant wait to see it finished.

Re: compact sst90 aspheric waterproof light build log

Awesome!

I also have plans for a diving light with a magnetic outer ring and using hall effect sensors, so I am most interested in your project. Please let me know what sensors you end up using.

In my concept I am planning on using more than one sensor to try to have at least two levels, and to perhaps feed this "level" to a regulated driver from TaskLED - at least that is what I have plan so far in my head.

Please keep us posted - I am looking forward to learning from your experiences in this project.

Re: compact sst90 aspheric waterproof light build log

wquiles said:

Awesome!

I also have plans for a diving light with a magnetic outer ring and using hall effect sensors, so I am most interested in your project. Please let me know what sensors you end up using.

In my concept I am planning on using more than one sensor to try to have at least two levels, and to perhaps feed this "level" to a regulated driver from TaskLED - at least that is what I have plan so far in my head.

Please keep us posted - I am looking forward to learning from your experiences in this project.

Click to expand...

Here is what I am using: IRLz34n and hall effect sensor melexis u51881

There is no reason why you cant have 2 or more all sensors as they are super tiny. I was actually thinking the same thing. Trying to learn the lathe part and just wanted a different switch than a judco.

Re: compact sst90 aspheric waterproof light build log

Thanks for the info on the specific switch. Are you going to use the through-hole sensor or the surface mount one?

gt40 said:

Trying to learn the lathe part and just wanted a different switch than a judco.

Click to expand...

And you are doing great with the learning part on the lathe. Nothing like a real project to try out stuff. I learned the little I know about machining from mostly this forum, and of course hands-on.

By the way, here, how did you made the o-ring groove inside the head?

Re: compact sst90 aspheric waterproof light build log

wquiles said:

Thanks for the info on the specific switch. Are you going to use the through-hole sensor or the surface mount one?



And you are doing great with the learning part on the lathe. Nothing like a real project to try out stuff. I learned the little I know about machining from mostly this forum, and of course hands-on.

By the way, here, how did you made the o-ring groove inside the head?

Click to expand...

I cut the groove with one of those kennametal multi tools you posted about using an a3 insert. I mounted so the insert was pointing in the face and it works quite well.

FYI, here is where I got the hall sensor:

http://www.sparkfun.com/commerce/product_info.php?products_id=9312

Data sheet: http://www.sparkfun.com/datasheets/Components/General/Hall-US1881EUA.pdf

I got the through hole version as it is already super tiny. I only imagine trying to solder the surface mount version.

Re: compact sst90 aspheric waterproof light build log

gt40 said:

I cut the groove with one of those kennametal multi tools you posted about using an a3 insert. I mounted so the insert was pointing in the face and it works quite well.

FYI, here is where I got the hall sensor:

http://www.sparkfun.com/commerce/product_info.php?products_id=9312

Data sheet: http://www.sparkfun.com/datasheets/Components/General/Hall-US1881EUA.pdf

I got the through hole version as it is already super tiny. I only imagine trying to solder the surface mount version.

Click to expand...

Thanks for the link. Not only mounting/soldering the surface mount part would be a little bit more work, but because it does not have the wires, it would also be harder to "aim" or position for optimum relationship to the magnet. Once I finish the development of the PhD-M6 pack I will dedicate more time/effort to working with the hall effect sensors and my MagnetoDrive concept light.

Will

Re: compact sst90 aspheric waterproof light build log

Update:

Did some work with the switch. I made a version with a reed switch I had laying around and one with the hall effect sensor.

The reed version worked perfectly. On the other hand, the hall effect sensor didn't. Apparently, I didn't feed enough voltage with the 3.3v M cell I was using for testing so I will see if it works properly at proper voltage tonight. I reviewed the data sheet on the sensor and it runs on a 3.5v to 28 volt range. I will see if it was just an issue of voltage or it doesn't put out enough to turn on the gate of the mosfet.

This is my first mosfet switch setup so I am happy it works at least with the reed. I still want to use the hall effect sensor though.

Re: compact sst90 aspheric waterproof light build log

gt40 said:

Update:

Did some work with the switch. I made a version with a reed switch I had laying around and one with the hall effect sensor.

The reed version worked perfectly. On the other hand, the hall effect sensor didn't. Apparently, I didn't feed enough voltage with the 3.3v M cell I was using for testing so I will see if it works properly at proper voltage tonight. I reviewed the data sheet on the sensor and it runs on a 3.5v to 28 volt range. I will see if it was just an issue of voltage or it doesn't put out enough to turn on the gate of the mosfet.

This is my first mosfet switch setup so I am happy it works at least with the reed. I still want to use the hall effect sensor though.

Click to expand...

That is always an advantage for the reed switch - being a passive element it does not need voltage/current to turn ON/OFF.

Please keep us posted

Re: compact sst90 aspheric waterproof light build log

UPDATE:

Got the body more roughed out with the ring switch and stuff. I am almost done with the heatsink too. Here are a few more pics:

Bodyshot:



Ring with magnet hole. I found some 1/8" diameter really strong magnets. The magnet will be in the hole with some colored epoxy or brass cover:



Backshot:



Inside the head shot showing the aspheric:



Close up of the ring knurling:



Threaded inside sleeve to hold the aspheric lens against the o ring:





Lens o ring:



Lens:



Head threads:



Final shot in my hand for perspective:



I have ordered a bunch of different hall effect sensors to test and hopefully find one that will work with the mosfet I am using. The circuit does work fine though with my reed switches.

After I am done with the heatsink and switch I will do some grooving and cleanup. Sorry about the crappy phone pics...

Re: compact sst90 aspheric waterproof light build log

Very cool - nice progress

What keeps the ON/OFF ring in place? A lip on the body, side facing the tailcup, and the head on the other? Is it metal on metal, or you have a sleeve/spacer of some kind?

Re: compact sst90 aspheric waterproof light build log

wquiles said:

Very cool - nice progress

What keeps the ON/OFF ring in place? A lip on the body, side facing the tailcup, and the head on the other? Is it metal on metal, or you have a sleeve/spacer of some kind?

Click to expand...

The ring is held in place by the fact that it sits on a portion of the tube that is smaller in diameter than the rest of the body and snug because of o rings. I only put one on and it holds nice now. The head of the flashlight stops just short of the ring when it is tightened down and so the ring is "captive between the head and larger body section following the ring, yet rotates without binding. I made a ring with inside grooves to match the o rings on top of that so it isn't going anywhere.

Here is a pic of the tube without the ring:

Re: compact sst90 aspheric waterproof light build log

gt40 said:

The ring is held in place by the fact that it sits on a portion of the tube that is smaller in diameter than the rest of the body and snug because of o rings. I only put one on and it holds nice now. The head of the flashlight stops just short of the ring when it is tightened down and so the ring is "captive between the head and larger body section following the ring, yet rotates without binding. I made a ring with inside grooves to match the o rings on top of that so it isn't going anywhere.

Here is a pic of the tube without the ring:

(snip pic)

Click to expand...

Gotcha - that makes sense, and thanks much for the additional picture. I like the o-ring idea :thumbsup:

Re: compact sst90 aspheric waterproof light build log

I finally got a working hall effect sensor based switch!

I tried a whole bunch of sensors nothing would work. The tiny amount of current in the 20ma to 50 ma range just wouldn't turn on the mosfet I was using. I tried a darlington transister and hall effect switch combo and presto. This works really well. The transister is rated at 80 watts range and ran completely cool running a p7 led. Here is short video of the circuit. Excuse the bench but I was trying over 2 dozen combos till I got this:

http://vimeo.com/13236791

The components to make this south pole magnetic activated circuit are:



1. darlington transister

2. hall effect sensor

THAT'S IT...

I don't think you can even make simpler circuit. This seems to go on and off more reliably than the reed switch I was going to use as a back up.

Re: compact sst90 aspheric waterproof light build(Updated video of Hall switch workin

That is a little confusing to me. Can you please post a diagram/schematic of the exact circuit that you are using, with all of the parts that you are using?

The MOSFET's don't need current to turn ON, just enough voltage at the gate (I am assuming you are using an N-channel MOSFET). It could be that since the Darlington transistor has higher gain, that it then provided enough voltage at the gate of the MOSFET to finally turn it ON.

Re: compact sst90 aspheric waterproof light build(Updated video of Hall switch workin

wquiles said:

That is a little confusing to me. Can you please post a diagram/schematic of the exact circuit that you are using, with all of the parts that you are using?

The MOSFET's don't need current to turn ON, just enough voltage at the gate (I am assuming you are using an N-channel MOSFET). It could be that since the Darlington transistor has higher gain, that it then provided enough voltage at the gate of the MOSFET to finally turn it ON.

Click to expand...

I am not an engineer here and know just enough to be dangerous.

Here is a diagram:



Non of the regular n mosfets i tried would work and I tried latching, bipolar, etc hall sensors and a simple unipolar one seems to work, but only with the darlington transisters. Not sure why but the circuit is turning on and off every time and doesn't seem to get hot so far. I will try it with the sst90 at 8-9 amps and see if that is the case still but it works and is pretty tiny. You could easily get 2 transisters and hall sensors together to create a high and low with this.

Re: compact sst90 aspheric waterproof light build(Updated video of Hall switch workin

What is your supply voltage?
Which hall effect sensor are you using?
Which MOSFET are you using?

Im studying electrical engineering, so i might be able to locate your problem.