Amutorch AT40

TL;DR: Bad design and quality problems. EDIT: but can be fixed.

Bought AT40 on GB. The plan was to put Optisolis in it.

First disappointment - dead on arrival. Reason - battery tube is too short and does not make contact with the driver. I thought: not a problem, I need different driver for Optisolis anyway.

The original driver in AT40 is glued. After heating with standard soldering iron, it was possible to remove it. Driver diameter is 21,6 mm. I replaced it with Nanjg 105E, 20 mm, with some copper pieces around the driver it is perfect fit now.

After testing it a bit, a problem with connection was discovered. I thought that the problem was my copper hack around the nanjg. Tried to redo it with no success.

Tailcap is also glued. The only way to insert battery is by unscrewing the head.
EDIT: tailcap is not glued.

Then it struck me. Maybe the problem is with the switch. I took multimeter, turned the switch on, measured voltage between battery positive and an edge of the tube. 3.85V. Seems to be ok, but if you apply some pressure on the battery, voltage reading goes nuts.

EDIT: for the fix see #8

Album with all pictures

Thanks for the description. I want to mod my AT40 with Optisolis leds as well, but will use a XM-board so that the 4 leds will be closer to each other. I’m thinking of just leaving the stock driver in.

I think the reason your volt reading goes nuts when applying pressure on the battery is because of the negative contact plate on the switch side. It’s a large diameter, thin brass plate that barely touches the negative side of the cell, poorly soldered too. Mine won’t work after a battery change but if I hit it hard it makes contact and works. The switch PCB itself is also very thin and what presses it against the battery tube is a plastic disc, I think they could’ve done better.

Have you tried removing the clip? I removed mine with the clip on but it would be lot easier if I removed it. There was no indication of glue being used.

Thanks for the very useful pictures. Luckily my AT40 that I ordered on Day 1 works perfectly. I’m curious why the beam on the stock 219c version is so smooth but with the optisolis, you can see the flower petals.

You’re right! Thanks for the tip. I wonder if connection problem can be fixed. Looks like regular omten switch.

That’s because on original board leds are closer to the center.

Connection problem can be because of two reasons:

-Negative contact is a large flat disk and won’t clear double wrapping or wrap towards the center of the battery. Remove switch PCB and solder a spring or brass button.
-Switch PCB not contacting the body of the flashlight, adding some kind of spacer to the existing plastic ring to add pressure can help.

Mine works flawlessly now.

That was the case!

First changed switch to omten:

Second soldered brass button:

Third threw away white ring and black plastic washer and installed new one, thicker (middle one):

Now it works! :partying_face:

I was looking to buy a mule type light and this one caught my attention. I was wondering, with the new 3V XHP50 being available if this would be a good upgrade for this light? I’m sure heat would be an issue but I wouldn’t expect it to be any worse than the Nichia’s. I brought it up in this thread because it had the most thorough tear down. not even sure if this driver would be a good option for a single LED. kind of a novice when it comes to more than replacing parts. Any opinions would be appreciated.

If one XHP50 is intended (not 4), that would be a valid option, in fact the beam would improve with the light source more centered, and this being almost a mule the rainbow that the XHP50.2 is famous for does not happen.

Just received a AT40 from Neal (ordered 5/20). I ordered the "Nichia" option and was extremely surprised to find 219B's in it! I'm using it as a host only for a Carclo quad so now I've got the [tint & bin unknown but still cool to have] 219B's for something else

Isn’t the 219c’s a 3535 footprint? If so wouldn’t an Xp-L fit on this board? Still think I’m going to try a 50.2 just to see how well it would work. Bought a second one as a host.

I just ordered two of these with the Nichia option. I’m interested in adding a driver that can do a moonlight mode. Any suggestions on where to look for such a driver? This will be my first flashlight mod, but not my first time modifying circuits.

I used sanded down 22mm TA drivers in mine and hand cut / shaped Cu rings for contact.

I’ve built myself 2 and am currently building a 3rd for a friend. By far the hardest part is cutting the ring.

How did you attach the rings to the driver?
I am looking to do something similar with my Amutorch VG10, as “explained” here: [HELP] Thinking about MODS: Amutorch VG10 & Blitzwolf BW-ET1

And I’ve been looking for some help on that part! Any help is much appreciated :wink:
Thanks in advance!

Soldered it to the drivers exposed ground ring.

Any specific careful you had to have while soldering (apart from isolating the “legs” of the 7135 chips)?
Did you use a regular soldering iron or some specific station?

Thanks for the answers in advance :+1:

It was a bit difficult, I kept the entire thing warm with my hot air gun but 0.5mm thick copper is a relitivly large mass so I still had to actually hit it with my iron to get it to flow (which is why there’s solder visible on the outside face, from contact from the iron tip)

Hum, ok, that will make me think about what I have available to make the ring and the solder and the driver “attach well” without messing too much with the driver. Otherwise I may provoke and accidental de-soldering on the chips or fry any of them. I don’t have ho air gun, so I will have to use the soldering Iron and eventually my stove. I may need to find some pieces to work as a plate and hold the ring so that I can put the solder and the driver onto it while hot, to make it solder.

Thanks for your input on this! Nice work and thanks for the tips :wink:

Are there any drivers with good UIs which would work with moonlight mode which wouldn’t require such advanced installation techniques? Where can I start looking?