Megalennium focusing

[rdunk77]

Thanks to all you guys for sharing the knowledge. Most often I just lurk & learn. I just assembled an FM Megalennium w/1185. I had the same contact problems others experienced & solved it with a bit of solder. For some reason I can't get the focus right. My M@g85 has no dead spot in the middle but the new light w/SF KT4 head & FM bipin does. I tried the washers but that made it worse. Any suggestions will be greatly appreciated. My M@g85, MC1160, SF 6P, Stanley HID, & Fenix L2D were all built or purchased with know-how gained on CPF. Thanks again.

 

[Patriot]

For some reason I can't get the focus right. My M@g85 has no dead spot in the middle but the new light w/SF KT4 head & FM bipin does. I tried the washers but that made it worse. Any suggestions will be greatly appreciated. My M@g85, MC1160, SF 6P, Stanley HID, & Fenix L2D were all built or purchased with know-how gained on CPF. Thanks again.

Try it first with no washer. If the problem still exists and adding washers only makes it worse then make sure the bi-pins are fully seated into the holder.

 

[Steve L]

Hi,

If the problem gets worse when adding the washers (they would pull the bulb further away from the reflector) so take off the washers and try pulling the bulb out slightly from the Bi Pin holder (Don't insert it fully, so it will then be seated further inside the reflector). You might have to experiment a little to get the proper focus.

Cheers,
Steve

 

[rdunk77]

Thank you, gentlemen. The bulb was seated against the socket. I pulled it out a few mm and very lightly torqued the set screw. Problem solved. This should have been obvious early on but I'm still learning! The intensity/form factor of this little light is something. I'm hoping this one doesn't dim the way my eneloop powered M@g85 does after a minute or two. Do you know if the AW driver can be set for the 9v SF bulbs that came with the KT4 head? I'm guessing they'd in full bright mode.

 

[Steve L]

Edit: You can use the Aw driver, but the Vout will be the same as the Vin. What I'm trying to say is, if you want to use the 9v bulbs you would have to use 1 18650 dummy cell in Megalennium. The Aw switch does not step up or step down the voltage. You have to match the voltage of the bulb with the voltage of the cells (With 3 18650's fully charged, the 9v bulb will see ~12 volts).

Cheers,
Steve

 

[BSBG]

Do you know if the AW driver can be set for the 9v SF bulbs that came with the KT4 head? I'm guessing they'd in full bright mode.

Vin = Vout on the AW - there is no regulation, so you would need to run just 2 18650s and a dummy cell to run an MN15 or 16 (I assume that is what came with your head).

 

[fivemega]

I just assembled an FM Megalennium w/1185. For some reason I can't get the focus right. My M@g85 has no dead spot in the middle but the new light w/SF KT4 head & FM bipin does. I tried the washers but that made it worse.

MN sockets are not designed for WA1185 ONLY but can be used with several different type of G4 bulbs such as WA1111, Philips 5761, Osram 64250, Osram 64275, CL1057 and ...
Each bulb has different fillament height and must be properly adjusted by either lifting the bulb (for short fillament height] or washered for longer fillament height.
See this picture, courtesy of DM51 from this thread.

Do you know if the AW driver can be set for the 9v SF bulbs that came with the KT4 head?

Please note that 9v SF bulbs are nominally 9 volt but in real world they get something about 6.6 volts to 7.8 volts in action depending on bulb type and primary batteries. In some cases, they will severely overdriven using li-ion rechargeables.

 

[Patriot]

Hi,

If the problem gets worse when adding the washers (they would pull the bulb further away from the reflector) so take off the washers and try pulling the bulb out slightly from the Bi Pin holder (Don't insert it fully, so it will then be seated further inside the reflector). You might have to experiment a little to get the proper focus.

Cheers,
Steve

Steve, thanks for the correction and for helping the OP. For some reason I was thinking backwards because of an issue I was having with a 623.

 

[rdunk77]

Thanks to all for the replies. My confusion about the AW driver was due to the low/med/hi modes. I assumed it could be set for any output. Never even thought about a dummy battery, even though I've seen them mentioned often on CPF. This light seems to hold its initial brightness much better than my M@g85. I'm guessing this is because the Li-ions don't sag like the eneloops. I've never tried to measure the voltage at the bulb.

 

[Steve L]

Thanks to all for the replies. My confusion about the AW driver was due to the low/med/hi modes. I assumed it could be set for any output. Never even thought about a dummy battery, even though I've seen them mentioned often on CPF. This light seems to hold its initial brightness much better than my M@g85. I'm guessing this is because the Li-ions don't sag like the eneloops. I've never tried to measure the voltage at the bulb.

Hi rdunk,

I now see where the confusion lies. The AW switch gives you low, medium, and high by PWM (Pulse Width Modulation), not by lowering the current or voltage. On high, it's direct drive, on medium and low, the AW tail-cap rapidly pulses the bulb on and off to reduce the brightness level.
A quote from AW's sales thread:

- 3 brightness level ( PWM controlled ) - 30% - 60% - 100%

Important: The Vin=Vout, meaning the voltage you put in (batteries) is the voltage you will get out (to the bulb). I hope this helps. Feel free to ask any more questions, either here or by PM.

Best Wishes,
Steve

 

[rdunk77]

Hi Steve,

You understood exactly what was on my mind. While the peak voltage on a PWM is very close to Vin when using FET as your pass device, the average voltage is a function of the duty cycle. The ideas & creations in this forum are amazing. Still can't believe the size of the AW driver. I notice that the Li-ion powered MegaL maintains brightness much longer than my M@g85. Very similar in output on turn on. Now I have to decide what module to drop in my new 6P with the defender bezel. CPF is dangerous to the credit cards.