Mod - Crelant 7G10 (Pic Heavy)

WARNING: The HX-1175b1 driver I used for this light has parasitic drain when off. If you copy this mod, be sure to lock out the light when not to be used. The tail cap lockout in this build works real nice, Just a slight turn to cut circuit.

This is a pretty cool light mod potential wise. Has great heat sink potential, 4 cell holder, a big reflector and AR lens, nice machining and finish, and side momentary switch.

Some Info on the Stock Light:

The Crelant 7G10 was one of the early MT-G2 lights to hit the scene. It was not well received due to low output, disliked UI, front heaviness, concerns about location of the emitter with regards to heat sinking, and reported scratchy battery tube threads. When it went on sale in the last Aliexpress carnival days sale, I purchased one because it had a 4 18650 cell holder and appeared to have decent heat sink potential. I intended to convert to XM-L2.



I was pleasantly not disappointed it appeared that all the above weaknesses would be easy to overcome. Heat sinking looked great so I decided to keep the MT-G2. First some details about the stock light that I could not find when researching the light. There are some threads on the light. Here is one.

The 1.75" 44mm driver is a direct drive with 3 30N0_ FETS. Notice that there are 2 different L- pads. One with 2 parallel FETS another with the 2 FETs feeding a third FET in series. I will have to play with this driver some time.



Emitter is way too low out of the reflector. Only a small part of the dome extends into the reflector.


The aluminum emitter base was sitting on a huge thick glob of what I assume was thermal paste. There was even an aluminum disk under it in an attempt to raise it's height. Great news for me as that meant extra room for some copper.

Mouse over below.



Nice thick aluminum walls to conduct heat to the head with plenty of threads for contact. The head has very thick walls at the base that thin down as they approach the lens side of the head. Very happy about that. Also, pill is integrated.


The reflector has a broad flat bottom that doesn't leave much room for wiring. Also, the holes for the LED wires are too close together to clear that flat bottom area. Probably not a problem as MT-G2's need to be a bit below the reflector for best focus.

The cell holder looks like it will be easy to convert from 2S2P to 4S.

The battery tube threads were fine with some silicone grease. I don't find the front heaviness an issue. It easy to hold further forward if one wants too (except when really cranking out the lumens).



Mod details:

This mod looks difficult, but this light is actually easy to mod. I just wanted to try a few things out. Only thing needed is a Noctigon, driver, and a little effort.

Mod Summary:

  • Dedomed Emitter - Drastically improves throw. Also improves tint, and CRI. For now, an old beat up emitter is being used until I decide if this config is what I want.
  • Custom Copper Star - Excellent for pulling heat and for max emitter depth into the reflector (for focusing purposes).
    • A Noctigon could just be used as best focus ended up giving .04" of clearance between top of the star and the bottom of the emitter.
  • Swapped Driver - Used HX-1175b
    • Added two R33 voltage sense resistors to get 9 amps max
    • Added a 82000 thru-hole resistors connected to Battery Positive and a 4700 thru-hole resistor connected to ground. Both connect to PB3 on the Atiny13a for Low Voltage Protection ("LVP").
    • Added copper tabs to pull heat from the Voltage Sense Resistor Bank and from the Large Diode.
  • Firmware - Used JonnyC's Star Momentary modified by Tom E for Strobe
    • This FW is great. You can go up modes with fast click, down modes with slightly less fast click, and to Strobe Mode with long click. I really like this FW.
    • Turned on Turbo Timeout and LVP.
  • 4S Cell Conversion - Stock Cell Holder is 2S2P.
  • Tailcap Lockout with just slight turn.
  • Reflector hole drilled out to 1/2" diameter. May not be necessary. I did it to check focus with emitter deeper into the reflector.

Head:

Made a couple copper disks (.071"/1.8mm thick). One the bottom disk, the other the top disk for the emitter to mount to with cut outs for copper tabs to collect power. Drilled out the disks and the LED wire holes to about .24" (6.1mm). Cut some 1/4" (6.35mm) OD copper tube to be used as a rivets to tightly mount the disks to the integrated pill. Here are some of the parts in the process of being fabricated.

NOTE: I think one could just use a normal Noctigon (on top of an other copper disk), but I wanted to try the above approach for the heck of it. The best focus was with the bottom of the reflector being about .04" above the top of the emitter base (bottom of the emitter). Here is a shot of the emitter base before proper focus was found.

Used copper tape and small tabs fabricated from .035" copper sheet to connect the emitter electrical contact pads to the leads. That emitter is my second dedome attempt done a long time ago (in emitter development years). The emitter is beat up. It was originally put in a DST. It has been in several lights since. If this light works well, I will replace the emitter (May wait for a new MT-G emitter to come out though).

Used 1/4" copper pipe to make rivets to mechanically bind emitter base to emitter base shelf. Mouse over shows back of shelf. Used thermal paste between the emitter base and shelf.

Used 2 .021" copper spacers under the reflector to thermally connect it to the emitter base.

Here is how the emitter currently looks in the reflector at the best focus height. I still need to neaten up the edges of the hole in the reflector and buy/fab a centering/insulator ring. Does anyone know of any sources for MT-G2 centering rings?

Also added thermal grease to threads between pill section and reflector section as the threads are a bit loose. Here is the head ready to go for a test drive outside to further make sure focus is satisfactory. No driver yet.

Driver:

Decided to use the HX-1175b1 driver set to about 10 9 amps (Measured at 8.4 amps, but figure DMM may be using some of it). Loaded with JonnyC's momentary STAR with Tom E's strobe modification. Seven modes 1, 3, 9, 27, 81 (2.5+ amps), 130 (5 amps) ,255 (9 amps).

Here are some of the other driver ingredents. The thru-hole resistors below are for low voltage protection. The ended up ramping down at too high a voltage. Currently have a 82000 and 4700 ohm resistors, but further adjustment is needed. For some info on the topic, check this out.

Two R20 R33 resistors added. They are so small compared to the very large stock resistors. Soldered them on the far end (from the ground ring) so that a copper thermal path could be added.`



Needed to make an adapter plate to solder the driver too. I like to create a divot to hold one end of caliper jaws. I then rotate the copper so that the other jaw marks the cuts to be made.

Then drill hole and cut the inner circle first. Then the outer circle. Adapter plate is in picture above with the various other parts to go into the light.

Driver soldered to ring.



Fabbed a heat sink tab for the voltage sense resistors. They are the hottest component on the driver. You can see it already soldered in place below. Also fabricated a heat sink tab for the large diode. Here is is resting on top of the inductor just for the picture. Mouse over is other side of the tab.

Here are both the tabs soldered in place.

Also added some potting that touched part of the inductor too. Mouse over to another angle.

Here is back of the driver in place. Added copper disk to distribute pressure stress and 1/4" copper tube to get the correct height to reach the cell holder. Mouse over shows cover in place. The cover was tore up by me trying to figure out how to get it out of the light. It's a press fit.

Cell Holder & Tail:

Only need to mod one of the holders PCB's to convert from 2S2P to 4S. Marking shows the mods needed. Solid lines represent the stock traces. Each needs to be cut (represented slash lines). Dotted lines represent new connections needed. The PCB to the right is the one that will not require being changed.

Here is the modded PCB. Center post is now 16.8 volts positive on both ends of the holder.

Copper braided springs in the tail board. Since the tail will have a lock out mod, ground ring has a layer of solder added to reduce wear and tear on the underlying trace.

Lockout mod is easy smeasy. I think DenBarrettSAR invented the mod for his Rook. Just added a card board disk to prevent electrical contact with the tail cap. Also, Kapton taped edge and bottom of the tail PCB to help prevent electrical contact with the sided of the tail cap. The tailcap was originally Locktited. Heated to around boiling point of water and used rubber jawed vice and strap wrench to remove cap.

To lock out, only a small partial turn is needed. The springs push the PCB from the tube and electrical circuit is broken.

Beam shots:

Stock light in High Mode (Mouse over for Modded Light). Unfortunately, the shot location and beam angle changed. I may try to retake the first shot. At least the change in beam pattern (due to dedome) can be seen to some extent.

Here are mouse overs with the modded light at 81 PWM (about 2.5 amps, which is slightly less than the stock High mode). Note the difference in tint, CRI, and beam pattern.

Here's a wall shot. Beige wall.

Conclusion:

Quite happy with the mod. The firmware is a joy. Can start on low with short click or high with a slightly longer click and move up or down the modes the same way. Long click goes to strobe. Any click exits strobe.

Throw calculated to 163kcd when measured at 3 meters. I wouldn't mind a wider spill, but it's acceptable as I prefer more throw to wider spill if I have to make a choice. There is a very faint lighter spill that hits all the way to your feet, but you don't see it unless the hot spot is a good distance from you.

No heat sinking issues. No detected thermal sag in 90 second turbo mode and light is just starting to warm up at 90 seconds. Need to extend turbo time out.

Tail current is 6 amps at 14 volts (due to voltage sag) on High (9 amps to emitter). Tail cap reading was with stock 20 amp DMM stock leads. So actual tail current may be higher.

To Do's:

  • Need to dress up hole in reflector. Anyone know where MT-G2 insulation disks can be purchased?
  • The low voltage protection needs fine tuning. Currently it steps down at too high a voltage.
  • Replace beat up emitter, eventually.
  • Maybe replace the reflector with a shallow reflector for wider spill and even more heat sink capability.

Great mod as always 4wheeler.
MT-G2 can handle this angry driver?

Thank you zeremefico. Yes, the driver seems well matched for the MT-G2 using 3S or 4S cells. I think it's wise to augment the heat sinking on the large diode and voltage sense resistors though.

Awesome, looking forward towards the results.
10A to the emitter sure does sound like fun. :slight_smile:

Thank you Ryan. How is college going for you bro?

College is pretty awesome so far, thanks for asking.
The workload has been steadily increasing for the two weeks but still is manageable.
I’m looking forward to trying out the machine shop equipment and perhaps make my own light.

I've always thought the 7G10 would be a great light to mod into a beast. It's great to see you doing it. Can't wait to see your finished results! :D

Thanks Johnny. Hoping for a good result.

The spill area my be a bit narrow for my taste, but I hope not because the reflector looks so cool to me. If it is too narrow, I could always swap in a shallower 80ish mm reflector and beef up the heat sink even more.

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The +B spring is very Thin , maybe You would change or add solder wire.
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Thanks Pok. Totally agree with you.

What a shame to see such a poorly put together light from a know manufacturer. Your mods are looking good. It should leave the stock light for dead.

True, but it does provide an opportunity to have a real nice light for a good price to a modder.

Thank you MRsDNF.

This looks like a fun mod. Makes me wish I had one, but I’m over my head in the modding of drivers and firmware department. I’ll be keeping my eye on this mod.

I always thought MTGs liked to be higher up in the reflector?

You’ve probably got it al figured out, but I picked up a couple of These 26mm MCPCBs incase I come across one of those wide flat bottom reflectors.

So far you seem to have become the King of the souped up HX1175B driver. I’ve not yet driven an MT-G2 past 7A. I definitely want to see the copper work in the pill as you put it all together.

Thanks Ouchy. I'm no focus expert. So I could be wrong. I should also say that I have dedomed very single MT-G2 that I've put in a light. I think that makes focus more critical because it significantly reduces the apparent emission surface.

Those bases sound real good. Over an inch in diameter. Also looks like the copper is flush with the top of the MCPCB. Both are the main reasons I go through the trouble of rolling my own. Definitely worth the price. I will be ordering at least a couple of those too. Thanks for reporting them.

I have only used the HX-1175b with hardy MT-G2's. RMM has sacrificed scores of xml's in an attempt to tame the driver for broader applications. For that reason, I gladly pass my crown to him.

I have finally got back to the light and have it mostly completed. OP updated and beam shots added.

What a performer. Great mod. Making that copper star thingy yourself is wicked! It would take me forever I think. Great writeup too and I love all the mouseovers. TY for sharing.

Thanks Ledsmoke. That copper star did take me a lot of time. I learned from it, but don't see using that approach again. Will try something different next time that I hope is easier.

EDIT: I should add that this light would be easy to mod with just a Noctigon and driver swap. I just wanted to try some stuff out. OP updated with more info. Probably won't be doing much to this light for now. I'm starting an ECU build and swap for one of my cars.

What an amazing effort. I admire your electronic work and metal working. The result was well worth it going by your pictures. Thanks for sharing.

Edit, As far as I'm aware there are no isolators available for the MTG led.

Thank you very much MRsDNF.

Seems like a good business opportunity, those MT-G2 isolators. Any vendors listening?

Nice photo!