Tikka XP - still dangerous ;) (xp-g mod)

[abbotsmike]

what is the SKU of the LED you ordered. One of my LED's was actually from DX.

SKU: 1445

 

[The Fred]

Ah yes, I thought so. I was just searching for that very one.
You're confident that this one wont emit a messed up beam pattern with the Tikka XP lens?
Oh! And I need a tiny amount of thermal paste since I cant recover the little blob that came off the original LED.
Is SKU 4593 the right thing?
cheers!

 

[abbotsmike]

Ah yes, I thought so. I was just searching for that very one.
You're confident that this one wont emit a messed up beam pattern with the Tikka XP lens?
Oh! And I need a tiny amount of thermal paste since I cant recover the little blob that came off the original LED.
Is SKU 4593 the right thing?
cheers!

Mine actually had a slight ring in the hotspot as standard, but I shimmed the star forward, moving the optic closer to the LED, and it has gotten rid of that. I did it using small strips of electrical tape underneath where the star sits. I used 5 layers, but I guess it would be a trial and error thing. I was inspired to get on with it by the beamshots in this thread! Very happy with the improved tint (for me) and noticeable increase in brightness. The flood on boost is now fantastic! I managed to recycle the old paste, but that stuff looks fine to me.

 

[The Fred]

A slight hotspot ring is not going to be an issue. I just want reassuring that the beam wont come out looking like an "out of focus" maglite.
I'm trying to get the same beam as before with the original LED. I don't want to shim the star forward because I want it to maintain contact with the thermistor underneath.

 

[abbotsmike]

A slight hotspot ring is not going to be an issue. I just want reassuring that the beam wont come out looking like an "out of focus" maglite.
I'm trying to get the same beam as before with the original LED. I don't want to shim the star forward because I want it to maintain contact with the thermistor underneath.

When I say 'hotspot ring' I mean that the hotspot has a slightly less bright circle in the middle. The shimming isn't a problem with regards to the thermistor. Due to the long wires it is on, its natural springiness holds it up against the star. I bent mine upwards slightly more than that to make sure. It now has a perfect hotspot, like it did with the stock LED. At a guess, it has moved forward by <1mm

 

[The Fred]

Sorry for misunderstanding you there! I'm going for it, and hopefully it wont be a total fiasco!
I'll post some pics when its finished.

Thanks for the help!

Freddie

 

[tam17]

Cool mod, Szemhazai! :thumbsup:

I wonder if someone tried to perform this mod starting from a bare XP-G, having no proprietary MCPCB or star at hand?:sick2:

That's my only option at the moment and I doubt if it's feasible at all, considering the size of this emitter (hand soldering almost impossible!), and having in mind the necessity of good heatsinking.

The only XP-G I can get at the moment is bare NW 4000K. Any help would be highly appreciated.

Cheers,

Tam

 

[Szemhazai]

You can cut any star to the appropriate size and then solder led into it and glue it to the old star... That's not a big problem

 

[tam17]

Thanks for your support, Szemhazai!

I have a cheapo 1W Luxeon clone with a CCT of approx. 8000K which is useless to me, but its star could be tailored like a micro PCB like the one shown in your tutorial. It won't be thick enough, but I'd have to shim it anyway to get the beam right. If I understand well, I'd have to solder wires to the points on the upper surface on the XP-G, and that's what frightens me most (must get a small pointed-tip soldering iron and good magnifying glass, since the XP-G's footprint is only 3x3mm IIRC!):sick2:

Still I have to find suitable non-conducting thermal epoxy (or improvise one). I wonder would the slow-setting epoxy mixed with fine aluminum oxide powder do the trick?

Cheers,

Tam

 

[one_half_3544]

Cool. Will definetly try this.

Does the runtime change anyhow?

 

[Szemhazai]

No - it may be a bit longer because Vf of the XP-G is much lower than Luxeon I.

 

[tam17]

I've finally pulled the trigger on this mod - and succeeded. The emitter is XP-G Neutral White (4,000K). It took an evening to accomplish the soldering, and next day was reserved for potting and beam tune-up. A bit tricky job for a beginner like me, since I've bought the bare emitter, the only one available at the moment. Photos and comments are here.

Thanks to all participants in this thread - especially to szemhazai :thanks:

Cheers,

Tam

 

[The Fred]

Nice one! You beat me to it! I was delayed by the post people so I've only just got my LED. I'm off to start work!

Cheers!!!

 

[Berguie]

Mine actually had a slight ring in the hotspot as standard, but I shimmed the star forward, moving the optic closer to the LED, and it has gotten rid of that. I did it using small strips of electrical tape underneath where the star sits. I used 5 layers, but I guess it would be a trial and error thing. I was inspired to get on with it by the beamshots in this thread! Very happy with the improved tint (for me) and noticeable increase in brightness. The flood on boost is now fantastic! I managed to recycle the old paste, but that stuff looks fine to me.

Hi, when you shimmed the star with the electrical tape, did you need to modify the older? There is not space to shimme it by 1mm or the older won't grip.
Thans for your answer & best regards,

Berguie

 

[Berguie]

Re: Tikka XP - still dangerous

PScalfano, no, it won't work without additional modification to the holder - you will have to trim it about 2mm. XP-G needs to be about 2mm higher than SSC P4 / Luxeon.

Hi, I would like to know which xp-g led you took and where you bought it?
thanks & best regards,
Berguie