Amutorch AT40

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g_damian
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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.

But…
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

Edited by: g_damian on 08/09/2018 - 16:23
djozz
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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.

link to djozz tests 

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will34
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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.

SKV89
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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.

g_damian
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will34 wrote:
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.

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

g_damian
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SKV89 wrote:
I’m curious why the beam on the stock 219c version is so smooth but with the optisolis, you can see the flower petals.

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

will34
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g_damian wrote:
will34 wrote:
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.

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

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.

g_damian
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will34 wrote:
Switch PCB not contacting the body of the flashlight, adding some kind of spacer to the existing plastic ring to add pressure can help.

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! Party