LED Zeppelin
Flashlight Enthusiast
Parts roundup:
- FM3V-2, or FM3H-2 3" head
- FM Ellie II tube, 4 X 18650, 14.8V
- Led Zep quad-P7 heatsink
- (4) SSC P7 LEDs, DSWOJ (Vf of both sets for these two builds measured 14.4 V @ 2.8A)
- (4) McR27XR reflectors
- D2flex board from TaskLED
The first task is to modify the stock Mag switch to momentary operation, and isolate it from the cells. I suggest referring to Sway's Momentary D Cell Mag Switch Mod thread. Be sure to test the switch for feel before assembly. You'll likely have to retrim the teeth/ribs cut off the clickie part of the switch button a couple times to get it perfect and free. I glue the two black switch button parts together and lube them before reassembly.
I made a couple notable changes to Sway's method:
The rear switch contact that normally contacts the (+) cell spring backing, has a short lead that solders to the grounding tab. Since the D2flex switching works by completing a ground, and one of the D2flex switch terminals (SW-) is already grounded through the board, it is only necessary to carry one switch contact lead up to the board. You can see the short lead in the left assembly of the picture above, just before the switch barrel is placed/drawn into the housing. Notice the only lead I pulled through the switch barrel is the (+) cell connection.
The middle assembly above shows the main ground lead (fished through the switch housing front) soldered to the ground tab. The rear switch lead is soldered to the rear of the ground tab, and it's a bit easier to do it out of the housing as pictured than when it's in place in the recess. Don't forget to insert the set screw before placing the ground tab in its recess.
Lastly the front switch lead is soldered to the front switch contact from the outside of the switch. I cut the tower off the switch so you have access to the front contact. If you don't want to mount the board to the rear of the sink, you can mount it to the tower base when it's cut as shown.
Power/LED leads should be 24 guage but the switch leads can be anything. Be sure to make them comfortably long as you will need some slack to solder and assemble.
When mounting the LEDs, I first file off any metal barbs that protrude from the side of the plastic LED surround. Some have them, some don't. The leads are flattened but not trimmed, it makes soldering easier. It goes without saying that you should mount the LEDs with regard to their polarity and serial connection.
The D2flex will likely need some minor filing to drop into the recess in the back of the sink. I've soldered the LED leads and shaped them so the board drops into place.
The new D2flex boards have a thermal protection feature with selectable trip temps. To ensure accurate sensing, I made a thermal connection between the backside of the 8-pin IC and the rear of the sink, and epoxied them together. The board recess is 0.175" deep, and with my 3/16" alum spacer, the board still sits in the shouldered recess, but not at the bottom.
The leads to the LEDs can be soldered now, but I leave one off to measure current upon completion.
To assemble the tube/head/sink without too much wire twisting, first thread the head all the way down the tube until the end of the tube is at the end of the inner head threads, see above. Apply compound to both threads beforehand.
Next solder the power and switch leads to the board. I braid the wires loosely to keep them together.
Apply compound to the bottom of the sink. I use it on the threads and a good bead at the bottom of the taper.
Pre-untwist the wires and as they coil from the twist, gently persuade them down the tube as you place the sink into the head. The bottom of the sink should be resting on the top of the tube; make sure no wires are pinched.
The picture above shows everything just before the sink is placed into the head.
Now holding the sink and tube stationary, unthread the head from the tube. As it rises it will engage the sink threads, and the small gap between the sink and tube will remain constant as the head is unthreaded more. Keep unthreading until the head rises to meet the sink. Using the #10 bolts in the opposing tapped holes in the face of the sink, tighten the sink and head together (tube is still loose). You can use a screwdriver for more leverage as shown below.
When the sink and head are tight, reverse direction and thread the head/sink back down the tube. When the sink meets the tube, tighten the sink/head/tube together using the screwdriver and holding the tube.
Disassembly is simply the reverse, and as long as you don't use epoxy, it can be easily disassembled any time.
With this method, and the long leads, wire twisting should not be a problem. If done properly the wires will only twist one revolution or so.
Finally clean and blow out the inside of the head, place the reflectors in their seats, and install the lens and bezel.
With the D2flex thermal protection set to 60 degrees C, the chrome light ran for 12 1/2 minutes unattended before tripping the protection and stepping down to level 3.
Fresh off the charger, the 18650s powered 3 A to the LEDs, but quickly dropped down to 2.8 A. The act of measuring affects the actual current, so the LEDs are seeing more. The D2flex' thermal protection is a real bonus as it will safeguard against thermal damage.
I'm sure I missed some things so feel free to ask any questions.
- FM3V-2, or FM3H-2 3" head
- FM Ellie II tube, 4 X 18650, 14.8V
- Led Zep quad-P7 heatsink
- (4) SSC P7 LEDs, DSWOJ (Vf of both sets for these two builds measured 14.4 V @ 2.8A)
- (4) McR27XR reflectors
- D2flex board from TaskLED
The first task is to modify the stock Mag switch to momentary operation, and isolate it from the cells. I suggest referring to Sway's Momentary D Cell Mag Switch Mod thread. Be sure to test the switch for feel before assembly. You'll likely have to retrim the teeth/ribs cut off the clickie part of the switch button a couple times to get it perfect and free. I glue the two black switch button parts together and lube them before reassembly.
I made a couple notable changes to Sway's method:
The rear switch contact that normally contacts the (+) cell spring backing, has a short lead that solders to the grounding tab. Since the D2flex switching works by completing a ground, and one of the D2flex switch terminals (SW-) is already grounded through the board, it is only necessary to carry one switch contact lead up to the board. You can see the short lead in the left assembly of the picture above, just before the switch barrel is placed/drawn into the housing. Notice the only lead I pulled through the switch barrel is the (+) cell connection.
The middle assembly above shows the main ground lead (fished through the switch housing front) soldered to the ground tab. The rear switch lead is soldered to the rear of the ground tab, and it's a bit easier to do it out of the housing as pictured than when it's in place in the recess. Don't forget to insert the set screw before placing the ground tab in its recess.
Lastly the front switch lead is soldered to the front switch contact from the outside of the switch. I cut the tower off the switch so you have access to the front contact. If you don't want to mount the board to the rear of the sink, you can mount it to the tower base when it's cut as shown.
Power/LED leads should be 24 guage but the switch leads can be anything. Be sure to make them comfortably long as you will need some slack to solder and assemble.
When mounting the LEDs, I first file off any metal barbs that protrude from the side of the plastic LED surround. Some have them, some don't. The leads are flattened but not trimmed, it makes soldering easier. It goes without saying that you should mount the LEDs with regard to their polarity and serial connection.
The D2flex will likely need some minor filing to drop into the recess in the back of the sink. I've soldered the LED leads and shaped them so the board drops into place.
The new D2flex boards have a thermal protection feature with selectable trip temps. To ensure accurate sensing, I made a thermal connection between the backside of the 8-pin IC and the rear of the sink, and epoxied them together. The board recess is 0.175" deep, and with my 3/16" alum spacer, the board still sits in the shouldered recess, but not at the bottom.
The leads to the LEDs can be soldered now, but I leave one off to measure current upon completion.
To assemble the tube/head/sink without too much wire twisting, first thread the head all the way down the tube until the end of the tube is at the end of the inner head threads, see above. Apply compound to both threads beforehand.
Next solder the power and switch leads to the board. I braid the wires loosely to keep them together.
Apply compound to the bottom of the sink. I use it on the threads and a good bead at the bottom of the taper.
Pre-untwist the wires and as they coil from the twist, gently persuade them down the tube as you place the sink into the head. The bottom of the sink should be resting on the top of the tube; make sure no wires are pinched.
The picture above shows everything just before the sink is placed into the head.
Now holding the sink and tube stationary, unthread the head from the tube. As it rises it will engage the sink threads, and the small gap between the sink and tube will remain constant as the head is unthreaded more. Keep unthreading until the head rises to meet the sink. Using the #10 bolts in the opposing tapped holes in the face of the sink, tighten the sink and head together (tube is still loose). You can use a screwdriver for more leverage as shown below.
When the sink and head are tight, reverse direction and thread the head/sink back down the tube. When the sink meets the tube, tighten the sink/head/tube together using the screwdriver and holding the tube.
Disassembly is simply the reverse, and as long as you don't use epoxy, it can be easily disassembled any time.
With this method, and the long leads, wire twisting should not be a problem. If done properly the wires will only twist one revolution or so.
Finally clean and blow out the inside of the head, place the reflectors in their seats, and install the lens and bezel.
With the D2flex thermal protection set to 60 degrees C, the chrome light ran for 12 1/2 minutes unattended before tripping the protection and stepping down to level 3.
Fresh off the charger, the 18650s powered 3 A to the LEDs, but quickly dropped down to 2.8 A. The act of measuring affects the actual current, so the LEDs are seeing more. The D2flex' thermal protection is a real bonus as it will safeguard against thermal damage.
I'm sure I missed some things so feel free to ask any questions.
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