Jacob A60 owners, a little attention!

Good catch and nice mod, viffer!

Saw that when i opened mine up but didn’t even investigate what it was just thought it was paste. That sucks bad!!!

Cannot see the images.
edit: now fixed

I hope that is a one off item you have there. I have 4 now and none of them has had this. On one there was a paper disk above the led, between the plastic retainer disc and the led star. But only on that one unit.

BTW: Those lux values are spot on what I get with that light once the lens is cleaned.

Mine has a paper (I’d actually call it a soft cardboard) disc as well, with a hole in the center. The hole however has been filled in with thermal paste. Someone, somewhere, obviously felt that would do the trick, but the last thing you want to be doing is relying on a film of thermal paste to transfer heat, especially when you’ve created such a small thermal path in the first place. Thermal paste is for filling in the imperfections of two surfaces to be mated, not for creating primary thermal paths.

Was planning to rebuild/mod this light anyway, so it’s not a big deal for me. Waiting for a replacement reflector from DX as well, since the reflective coating was flaking off mine in more than one place, causing a nasty mess inside the head.

….

Best if these types of notes are posted to the light’s main thread since owners are already subscribed to it.

Thanks VIFFER AND AG!!!

viffer 750. What did you use in your dremel to polish the lens that did not scratch it?

a "felt wheel":

http://www.carlodegiorgi.com/mounted-felt-wheel.html

Today I received my A60 which I won in a DX giveaway. According to DX it was shipped to me straight from the factory, my address was even handwritten on the envelope.

Of course I had to open it up. There was no paper disc under the star, but only a tiny spot of thermal compound. I applied an even layer of arctic mx-2 and the body gets warm quickly now.

The beam is quite ringy, but I guess that's hard to avoid with XR-E and a smooth reflector. It has next mode memory, but it only needs about 5-10 minutes to set back to high.

The lens was not particularly dirty, but unfortunately it has a 1cm scratch near the edge.

Oh yeah, and the thing throws... My overall impression is quite good, especially for the price.

Does anybody know how hard the light is driven on the lower mode?
Is it safe to keep it on for a couple of hours?

Mine pulled 0.52A in low. Heat won't be an issue. On a 2400mAh cell you'd get approximately 4.6hrs runtime.

-Garry

Thanks garrybunk for the quick response!
Our discoball light burnt out for tomorrows party and I figured the jacobs would give out a nice reflection from the ball, so i did a quick test… oh how right I was :party: party on

LOL!

I put the 1 Mohm resistor mod on my Jacob - reset to high now in 2-3 secs when off. I used a surface mount, 800 series I believe - very simple to solder on. I also upgraded to the R2 LED - nice, little broghter, will be updating to a Nangj driver when it comes in.

I had to order the resistor, none of the electronics stores I visited had smd resistors in stock. Minimum order was 25 pieces, so I should have some spares when they arrive :)

Last week I had two A60, let’s call them #1 and #2.

The #1 had a tighter hotspot than #2 and pulled 2.15A rising fast to 2.4A.
That was a bad sign (could be a thermal problem and the road to self destruction).
Lumens measurement was 360 fading fast to 240!

The #2 pulled a steady 2.1A and was 350 lumens fading to 330.

I disassembled #1 at the LED end. The plastic capsule around the LED had previously been removed (there was pressed a hole in it) perhaps for adjustment?.
The cooling was castatrofal, the star sat loose on a 7mm black piedestal, 0.5mm high. I thought it was a piece of metal but it was two layers of self-adhesive plastic rounds meaning the star had no cooling at all!
There was some traces of white paste that could indicate that the star had previously sat directly, with paste, on the pill.

Now what is that?

Plastic!!!

What I don’t understand is why would someone put anything beneath the star unless it can’t reach the bottom of the reflector? For an optical adjustment I would put something between the star and the reflector.
Perhaps an answer will show when I clean up and mount the LED properly, without plastic in between and look at the hotspot. After all I have the #2 to compare to, the one with the bigger hotspot. Perhaps it too needs adjustment of the reflector position, in due time…

EDIT: Yep! After removing the plastic and mounting the star properly the hotspot grew the 10-20% to become the same size as the A60 #2 (and a bit uneven). I am now convinced that it is necessary to put 0.5 mm of metal beneath the star as the reflector cannot be moved closer to the LED. The factory must have had some ugly hotspots and made that quick and very dirty solution to the worst of them.
Also, without the spacer, the star is not pressed against the pill and overheating could be the result.

The one I played with at weekend had no “spacer” for want of a better word under the star, just the anodized light engine base (funnily enough, the keygos ke-5 has exactly the same set up, has a direct drive xm-l and I don’t remember seeing many threads about them burning out…).

I just sanded back the anodizing on both lights, new diamond thermal paste (because that’s what was available locally) and reinstalled the led’s.

If I’m honest, I’m unconvinced the anodizing causes that much issue, but what do I know?

In case anyone missed my thread.

Based on their track record reported here in other threads, all Jacobs should be carefully looked at in regards to the LED mounting. Mine wasn't bad, same as gords, and I did the same thing he did - removed anodizing and used quality thermal paste. I also upgraded to an R2 emitter and did the "resistor mod" to get the stupid driver to reset to high (default) mode after 2-3 seconds of being off, rather than switching to the next mode.

I think/suspect thr newer versions are better mounted because the early bought ones had the plastic, while it seems like a couple bought more recently didn't have it.

Also, other threads/posted mentioned removing the plastic changes the vertical height of the LED mount, which may adversely affect the beam pattern - not sure of the details. You may want to check the other thread postings - BLF search for Jacob or A60.