ZY-T08 Mod - picture heavy with beamshots

thumbs up

Great job, well done.

10 out of 10. Amazing mod and to top it of the light works. Thanks for sharing.

That is some awesome work. I’m stalled about halfway through a very similar build. This is some great motivation to get back after it. I really like what you did with the pill… I may have to incorporate some at least one of your ideas - adding copper on top to raise the LED seems much better than trying to file the lip on the pill down to get it to screw in further.

I’ve got a few cut pieces of pipe press fit into the pill already… but it never occurred to me to drill holes in the aluminum to solder a copper spacer on top to the copper below. Nice work!

Sounds good, but I can’t see any photos at all.

Thanks guys :beer: .

I did some tailcap current measuring and got some numbers that don’t make sense to me.

From 2x freshly charged old sanyo’s (1s2p) led pulled 3,70 A (batteries are old and I didn’t expect them to go as high as this)
From 1x freshly charged old sanyo (1s1p) led pulled 2,93 A - this is what I don’t get. According to this, two batteries should “give” around 6A when connected parallel.

Similar thing with shitty ultrafires:
1s2p - 4,4 A
1s1p - 3,8 A

Forgive my ignorance but could someone help me understand this. Thanks.

i think the problem is the voltage drop over the batteries.

Very nice mod.

I agree with dentillozie that it is probably voltage sag. 2 cells will sag less than 1, but not by much. You could have some resistance, but it doesn't look like it. Probably have an emitter with a high Vf. If you can measure the voltage accross the emitter, that would give you some good info. Here is a chart djozz made when he tested an xml2 on copper some time ago. Link to thread in picture.

Wow, that's the world's nicest ZY-T08 mod, and that's coming from someone who has done a lot of them. Pretty awesome!

The only real resistence left that I can see is the contact plate maybe?
You could drill threw and solder the driver directly to a fitting copper-sealing under it propably ? That would take care of that.
If that doesn’t work WarHawg made a contact plate for it (don’t know if tested): Link to OSHpark .

That was your FIRST mod ???!!!
Amazed.

I can already tell you that the emitter has a high vF. All of the new XM-L2s I've tested have a high vF, and since it is a U3 it is a newer XM-L2.

Thanks again to all of You guys and for Your answers and comments :beer: . Good feedback is a real boost.

Made some measurements and these are the results:

DMM wires (12 AWG) 0.1 Ohm
From tail cap to pill 0.2 Ohms
From contact plate (battery side) to led+ 0.2 Ohms

Freshly charged ultrafires, both 4.18V
Hi 3.79V at led + & -
Med 3.02V
Low 2.69V
Moon 2.58V

Does these numbers confirm high Vf?

Yeah, that is pretty high. If you look at djozz's chart above, his older XM-L2 had a Vf of about 4.65 3.65 at 4.4amps. Decent cells will sag to 3.9 volts under even at just a 1 amp load. Sounds like you identified your issue. High emitter Vf and cell voltage sag.

Bet you're even happier to have some 25R's on the way now. Please report what they do tail current wise. I'm curious.

Great mod!

I got one that had horrible corrosion in the switch and I wasn’t sure what to do. Your plate on the tail is perfect. Thanks for sharing.

Nothing else to say except, Awesome mod!

Nicely done and very creative! Keep up the great work!

That’s a nice mod :beer:

Lot of work there. It might be the angle of the picture, but in #31, the +LED wire looks awfully close to ground?

Yes, it looks that way. Take a look at the picture 28. The pill is around 2mm below the wire. I had to move those wires as far as I could to get clerance from reflector bottom since it is sitting on the MCPCB. That’s why I sanded the edge of the pill down.

Ahh - I see :nerd_face:

:beer: