[PSUBS-MAILIST] Light Experiments

Mon Apr 17 19:13:45 EDT 2017

Alec, not sure what is going on with the borsilicate glass lens.  the
version I use is the McAMster carr part number 8477k48.  I have installed
two of these in my first set of lights and have never had one break.  I
have two more of these lights being machined as we speak.  Again no
breakage issue.  Were the failures when the lights were turned on or during
assembly?  IF you look at the fabrication tolerance for these annealed
glass disk, its +/- 0.015" for a 2" disk so if you got one that was on the
high side of this tolerance such that the fit became tight, could be a
thermal expansion issue as the lens could get hotter than the aluminum case.

Cliff

On Mon, Apr 17, 2017 at 1:19 PM, Alec Smyth via Personal_Submersibles <
personal_submersibles at psubs.org> wrote:

> Hi Alan,
>
> The borosilicate lenses in these parts are $17 each if that is a useful
> reference. I would recommend several spares, because while resistant to
> temperature they are VERY easy to break during installation or if you just
> look at them unkindly. On one light I'm on the first one, but the other
> light took three of them before I learned just how gentle I had to be.
>
> Best,
>
> Alec
>
> On Sun, Apr 16, 2017 at 8:04 PM, Alan via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>> Rick,
>> I should mention that I have now gone with a 36V system &
>> have some pwm dimming controlled buck boost LED drivers being
>> made for me. These could drive Cliff & Alecs light. So waiting for these
>> & a reply on the borosilicate lens enquiry before I go any further.
>> Alan
>>
>> Sent from my iPad
>>
>> On 17/04/2017, at 11:39 AM, Alan via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>> High Rick,
>> to insert the male subconn fitting it has to be turned 15 times as it
>> winds down fully in to the thread; so the wire would be twisted 15 times
>> if
>> you went this way.
>> Yes the bolts go right the way through. This avoids tapping threads &
>> bolts
>> seizing. It also has the advantage that I can have longer bolts out the
>> back
>> that an attachment bracket can be bolted to.
>> The back section in the photo, has the led attached to it & an o-ring
>> groove
>> to seal against the bore of the middle section. The base of the middle
>> section
>> has an o-ring groove & the back section compresses this when the bolts
>> are tightened up. So two o-rings on this section. The top ring that clamps
>> the lens down on to an o-ring (also o-ring around the side of the lens)
>> can
>> be made a larger diameter with a second set of bolt holes so the light can
>> be mounted in a recess.
>> As the back section is the main heat sink & mount for the LED I don't have
>> room for a bunch of twisted wires. The nozzle out back is designed so I
>> can pour resin in to it, let it set, then coat the wiring about an inch
>> up &
>> the nozzle with silicone. Then I intend to mold a rubberised supporting
>> section over the silicon. It should work!
>> Pictures attached.
>> Cheers Alan
>> <image1.JPG>
>>
>> <image2.JPG>
>> Sent from my iPad
>>
>> On 17/04/2017, at 10:08 AM, Rick Patton via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>> Hi Alan,
>>
>> Thanks for the picture.
>> The size housing you are using is kinda what I wanted to go with as well.
>> Not sure what you mean about screwing something in 15 times. From the top
>> view picture you sent, looks like the front head/lens is held on against a
>> sealing surface with 6 Allan head bolts that go all the way threw the back
>> plate so I assume that the back plate is threaded and screws on against an
>> 0 ring or something?
>>  If that's the case, can't you drill and tap the back and put a sub-Conn
>> or strain relief fitting in and allow just enough length of wires to
>> protrude inside just enough to connect the LED wires to it before attaching
>> the lens? Do you have any pictures of everything inside the housing by them
>> self's?
>>
>> Rick
>>
>> On Sun, Apr 16, 2017 at 10:39 AM, Alan via Personal_Submersibles <
>> personal_submersibles at psubs.org> wrote:
>>
>>> Hi Rick,
>>> The light in the photos is mk 1 or 2. It didn't have oil in in those
>>> photos.
>>> Funny but the oil bubble & the temperature sensor had no effect on
>>> the light coming out.
>>>  The latest version has a conical lens machined in it & hides the
>>> attachment
>>> bolts for the LED.
>>> Still a work in progress as I have just made enquiries regarding pressure
>>> rated borosilicate glass lenses. This light is 85mm D x 54mm long.
>>> (excluding
>>> wiring nozzle) In the attached photo I have just temporarily siliconed
>>> around
>>> the wires for the test. I do have 8 subconn male & female connectors &
>>> was
>>> thinking of tapping a hole for the male connector to fit. The only
>>> problem is
>>> how do I connect the wires? My two LED wires are either side of the LED
>>> & come
>>> down two separate angled holes & meet in a central 8mm hole. I would need
>>> to fit the LED then attach the LED wires to the subconn wires & twist
>>> them 15
>>> times to thread in the subconn fitting. The subconn wires are very stiff
>>> & it
>>> just wasn't going to work without a large amount of room for twisted
>>> wires.
>>>    I have some ideas for potting the wires that I will try & test.
>>> The housing diameter was dictated by stock material sizes but works out
>>> well.
>>> I have machined the cooling fin slots in to the bolt holes to give the
>>> fins a bit
>>> more depth.
>>> Alan
>>> <image1.JPG>
>>>
>>>
>>>
>>>
>>> Sent from my iPad
>>>
>>> On 17/04/2017, at 5:43 AM, Rick Patton via Personal_Submersibles <
>>> personal_submersibles at psubs.org> wrote:
>>>
>>> Alan,
>>>
>>> Do these pictures have the silicone oil in them? Do you have any side
>>> and back shots of the housing and other data regarding the housing like
>>> wall thickness and what fitting did you use to get the power out of the
>>> back and such?
>>>
>>> Rick
>>>
>>> On Sat, Apr 15, 2017 at 6:33 PM, Alan via Personal_Submersibles <
>>> personal_submersibles at psubs.org> wrote:
>>>
>>>> I put a temperature probe inside the housing of my 80W LED light.
>>>> The probe was up against the acrylic lens, as I was concerned about
>>>> what temperature the lens was seeing on the inside. The lens is 10mm
>>>> away from the LED.
>>>> The LED manufacturer told me that on normal LEDs the temperature
>>>> out the front of the LED can be 338F (170C) but my flip chips should
>>>> run cooler.
>>>> Briefly; when run at 30W in water they stabilised at 257F after 5
>>>> minutes.
>>>> At 45W they stabilised at 280F after 5 minutes. I stopped upping the
>>>> amps
>>>> at this stage.
>>>> Next experiment, I filled the housing with silicone oil.
>>>> At 45W it hit 116F in 4 minutes & temperature stabilised.
>>>> At 76W it hit 139F in 6 minutes & stabilised.
>>>> So oil has massive advantages in lessening temperature on the lens,
>>>> maybe because it is a buffer from the radiant heat & also transfers the
>>>> heat
>>>> out through the housing quicker.
>>>> Greg your thoughts would be appreciated on this; I am thinking that
>>>> without the
>>>> oil the acrylic lens would see temperatures at which it is formed
>>>> especially
>>>> if I went up to 80W. Although the outside of the lens was cold there
>>>> would be a
>>>> temperature transition across the thickness of the lens & it would be
>>>> considerably
>>>> weakened. I am building to 500ft, so it would potentially see 250 psi
>>>> in operation.
>>>>    At this stage I haven't made up my mind whether to go with a
>>>> borosilicate lens
>>>> or oil fill with an acrylic lens. I had a large bubble & it would be
>>>> hard to eliminate
>>>> all bubbles in the oil filling process.
>>>> Will try & attach photos.
>>>> Alan
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Sent from my iPad
>>>> _______________________________________________
>>>> Personal_Submersibles mailing list
>>>> Personal_Submersibles at psubs.org
>>>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>>>
>>>>
>>> _______________________________________________
>>> Personal_Submersibles mailing list
>>> Personal_Submersibles at psubs.org
>>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>>
>>>
>>> _______________________________________________
>>> Personal_Submersibles mailing list
>>> Personal_Submersibles at psubs.org
>>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>>
>>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>>
>> _______________________________________________
>> Personal_Submersibles mailing list
>> Personal_Submersibles at psubs.org
>> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20170417/1c56b52b/attachment.html>