Can someone do a custom extension for 3" fivemega head?

[nc_hooper]

I posted this request also in "CPF Custom Flashlight Builders and Modders" but this is probably a better place to ask.

I'm in the process of building a fairly custom SST-90 light. I'm looking at getting a 3" reflector from Phoenix Reflectors. My problem is that this reflector is 3" deep while the reflector that came with the fivemega FM3H-3 is only about 2 inches deep.

A good solution would be to have a custom piece of aluminum lathed that exactly matches the diameter of the head (approx 3 inches) and is approximately 1 inch deep. This piece would have a set of threads on both sides. Then the original bezel could be removed, this custom piece could be threaded on and then the original bezel could be threaded onto the custom piece. Also this custom piece would be sized, notched on the inside so the reflector could be precisely and snugly placed. The lens and original bezel would keep the reflector in place.

Not worried about coating the custom piece because rest of the light will be Cerakote and I can have the piece coated later.

Is anyone out there that could create this piece for me? I can provide the exact measurements and the existing head/bezel as well as the reflector (once I receive the reflector).

Thanks

 

[gadget_lover]

It is probably quite doable. It's probably easiest for the guys with big lathes with the 6 jaw chucks. There will be hidden details of the original bezel that may need to be taken into account.

Daniel

 

[nc_hooper]

That's good news. I hope someone out there can help me out. I'll also try fivemega (the creator of my head) and see if he does any one-off pieces.

BTW - will be out on vacation this week, so if I don't respond, it's not for lack of interest.

 

[Cavi Mike]

If you expect that to come out halfway decent it would need to be done on a CNC lathe unless someone is REALLY nice and wants to spend hours on it with a manual lathe. Either way, I wouldn't charge less than $100 for that.

 

[precisionworks]

If you expect that to come out halfway decent it would need to be done on a CNC lathe

For a one off part both a manual machine & a CNC machine will require about the same amount of time. Assuming equal horsepower for both the metal removal rates will be identical. The CNC will make the multiple threading passes more quickly but that is offset by the time needed to write a program for the balance of the part - as long as the threads are a standard form that is ready to call up from memory.

On this part the CNC would have no advantage over the manual lathe & might take even longer to make the first part. The second part, third part, fourth part, etc., are where the CNC will have a shorter cycle time & a lower part cost.

 

[nc_hooper]

"as long as the threads are a standard form that is ready to call up from memory" - not sure what fivemega is using for the treads. I there any way I can test this?

 

[nc_hooper]

"Either way, I wouldn't charge less than $100 for that"

$100 range is more than acceptable to me. Cavi Mike - would you have interest is doing this, or was that just a general statement?

 

[nc_hooper]

Received an email back from fivemega - unfortunately he does not do one-off work.

So I'm still looking for someone.

My main objective is to have a well heat sinked 3" head that can fit a fairly deep Phoenix reflector (about 3" deep) and have the reflector tread onto a D mag host (I'm actually using a fivemega Elephant II host but the barrel and threads are the same).

I thought my most economical approach would be to use a custom extender on my existing fivemega 3" head. But perhaps it might more sense just to have the head and bezel created from scratch. Don't know but I'm open to suggestions.

Thanks

 

[gadget_lover]

One of the neat things about fabricating stuff is that it is POSSIBLE to do almost anything, but it's a matter of time and difficulty that dictate which way works best.

The bezel extender is not a bad way to go, assuming that the extension will be long enough that you don't have the inside and outside threads on the same area. If that happens you need a thicker ring. It's definitely a case where the machinist will need all the parts to measure and test-fit as it goes.

Adding an inch to the front of the light may not look quite right. I'd suggest that you try making an extension of cardboard to see if you like the aesthetics.

Daniel

 

[cmacclel]

As far as know the Phoenix reflectors do not have a lip. How do you plan on working with that? I can make you an extension but I don't want to have to do any design work. Also just don't assume that a SST-90 is going to focus with any reflector. The LED might have to go up into the reflector to focus so a custom heatsink will definetly be needed.


Mac

 

[Cavi Mike]

Post a sketch and I'll see what I can do. The sketch doesn't have to be anything special, just make sure to have the important bits pointed out. Something like this will do: http://cavimike.com/flashlight.JPG

 

[Al Combs]

I took some measurements of my existing 3" FM reflector and found out it is much shallower (long focal length) than the standard Phoenix PA1.13 reflector. Standard about 2" deep vs about 3" for the Phoenix. This would be good for throw, combined with the fact that the shorter focal length has the LED further back in the reflector.

I wasn't sure whether to post a question here or in the H&M thread about Phoenix reflectors. The stock fivemega FM3H-3 reflector does as you note have a longer focal length than the Phoenix PA1.13. But just for clarity's sake, which reflector are you saying would be good for throw? I'm guessing you wouldn't be going to the trouble and expense if not in the hopes the Phoenix would be better. I believe you'll find the fivemega with its longer focal length, even allowing for the MOP finish, will have a smaller hotspot and higher lux readings than the Phoenix reflector. The focal length of the PA1.13 is a scant 0.2 inches. Ultra high speed parabolas have quite a bit of off axis coma. Which will tend to make the size of the hotspot even larger than focal length ratios might otherwise suggest. A discussion about which is better might be helpful before you proceed.

BTW, I love the concept of a light based on an Elephant II body with an FM3H-3 head.:thumbsup: A head that large is a perfect match for the SST-90. Perhaps it can even be used at continuous full power. Don't forget AS5 or MX-2 on the focusing threads. I built my SST-90 in a regular MagLite because it's what I could afford.:(

 

[nc_hooper]

gadget lover,

Thanks for your thoughts on this. I fairly certain that there will be plenty of room for the treads. I bought a caliper and will be doing some detailed measurements this week while on vacation. There is a very specific length that I'll be looking for (designing). First, I need to fit a refelctor that is almost 1 inch deeper. Next, this reflectors focal length is shorter so the LED will be further back in the reflector. And finally, I want to maximize the size of the heat sync so would like to have it extend till the end of the battery tube and then have a short post for the SST-90. The heat sync will be custom built and sized.

Not too worried about the asthetics - I think it will look OK if the extender matches well with the head and bezel. At some point, planning to have the entire light Ceraloted, so that should also add some continuity.

Thanks

 

[nc_hooper]

Cavi Mike,

That's great. Will do. But going on vacation tomorrow through New Years (camping / boating) and will not have internet access. But I'll make some detailed measurements while on vacation and will send you a stetch.

Thanks

 

[nc_hooper]

Al Combs,

Thanks for the suggestions and comments. Yes, I reason I'm trying to go through all this throuble is to maximize throw. From what I've read on CPF (mostly SaaBlusters tread), maximizing throw mainly comes down to two variables. First is the surface brightness of the LED. I'm planning to drive the SST-90 at 9 amps so I hope the surface brightness is the same or a little bit more than my XML driven at 3 amps. I currently can use that XML with withe the FM3H-3 head or a FM Throwmaster. The size of the hot spot is approximately the same, but the FM3H-3 slightly out throws the Throwmaster, probably because of the 3" vs 2.5" diameter. I think the Throwmaster get's close because it is a deeper reflector. Either head out throws a standard mag reflector or a rebel reflector by a lot - it's not even close. They also out throw by a lot my Olight M31 with the SST-50 driven at about 5 amps. I know that the newer Olight MXM with XML throws further thatn the M31 but only by a bit. I'm guessing that I'm somewhere in the 80,000 to 90,000 cd range with the larger reflectors. I also have a Dereelight Aspheric XRE R2 driven at 1.5 amps and the throw is about the same. Also have a Deft EDC LR and the previously mentioned lights out throw it by quite a bit. The only LED I currently have that out throws these light is a Fenix TK70 running two 32650 cells.

Back to reflectors - other than surface brightness, the other variable is the reflector. Smooth reflectors throw further, and the FM3H-3 reflector I have is also smooth (very slight lathe marks). From what I've read, the greater the distance between the LED and reflector surface, the smaller the LED will "look", increasing throw. So giiven two 3" diameter reflectors (with similiar surfaces) I think the one that is 3" deep with definately out throw the one that is 2" deep. And then there is focal length. I seems that most of these reflectors where not designed for LEDs and therefore the have longer focal lengths. So with the stock reflectors, I need to mount the LED on a fairly tall post so I can get it far enough into the reflector. A reflector with a shorter focal length could use a shorter post. I have not seen an Olight SR90 in real life, but how deep is that reflector? I know it's diameter is about 4". The SR90 seems to do a good job throwing the SST-90. Perhaps I should get the reflector first and run a few tests.

And finally there is the dispersion pattern of the LED. For reflectors, it seems like a de-domed SST-90 will through farther, though the total lumens will be lower. I have started a thread about this in the LED section of CPF.

And yes, I do really like the idea of the Elephant II with the FM3H-3 head. 4x18650 give adequate power in a fairly small host. Plus 18650's keep getting better. And the FM3H-3 has some really nice heat sinking fins. I'm hoping with a custom heat sink (maximized in size) that the thermal properties will be quite good. Also have a DerWichtel 9 amp driver for it and am trying to figure out the best location for the potentiometer - the light will have constantly variable brightness.

Have a good one

 

[nc_hooper]

Mac,

Yes, I trying to figure that out (the lip thing). I've been in direct correspondence with the president of Phonix reflectors (he's been very responsive) and I know the reflector is quite thin (25 mils I think). I'm hoping the they could still cut a small lip into the reflector. They don't have any problems reducing the diameter a bit by shortening the reflector (PA1.13). Will see what they say. I think that I can get the star board on my SSR-90 ground down a bit to fit the standard hole (0.70" - about 18mm).

I would be very happy if you made the extension, I'm still working out the details (design). I think the biggest challenge will be securing / centering the reflector. I'll be on vacation this week (with no internet access), but I'm planning to make some detailed measurements then (finally purchased some calipers). I think my next step would be to get the reflector (cut by Pheonix slightly shorter so it will fit the diameter). I'm hoping they can make a small lip - I think the reflector is considerably thinner metal than the one from fivemega so the lip would be fairly small. As I mentioned on a previous post, I will also determine the exact length. Three variables here - mainly fitting a reflector that is about 1" deeper, then going a bit deeper because of the shorter focal length (the LED focal point will be further back in the reflector), and finally a bit further back still so the custom heat sink can go all the way to the battery tube end (with a short 18mm post for the LED). I want to get as close as possibe to my desired length. Then any fine tuning can be done by using the Mag-like focusing ability or by moving the heat sink slightly in the battery tube.

I'll keep you informed when I get back. Have read many of your threads and it would be great to get a custom piece from you.

Thanks