Cree XM-L T6 LED 1000

General cycling advice ( NOT technical ! )
sexy wheels
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Cree XM-L T6 LED 1000

Postby sexy wheels » 17 Dec 2012, 7:43pm

I have just brought the light as on the subject line, but it came with no instructions. Does anyone know we're I can download a PDF instruction or manual.

Ayesha
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Re: Cree XM-L T6 LED 1000

Postby Ayesha » 17 Dec 2012, 9:15pm

I have three of these.
The mounting system is hopeless.

Image

The bike is upside down SHOCK HORROR !! :shock: This view of the lamp is from where the road should be :D

With rubber padding round the handlebars, I have two intertwined jubilee clips. One smaller one round the bars and a larger one round the lamp unit. Please notice the 'ear' I have turned inward ( with a pair of pliers ) which locates in one of the lamps cooling fin undercuts. This stops the jubilee clip sliding.

This is a sturdy and relatively thief proof fixture.
The spare cable is wrapped round the lamp's housing and tied onto a brake cable with a wire-twist fastener. Note: I have 'underslung' the lamp. It does not have to be on the top of the handlebars.

There were no instructions with any of the units I bought.
Plug the charger in the mains and the LED on the charger body shines green. Connect the battery and the LED turns red to indicate the battery is connected correctly and is charging. When the battery is charged, the LED turns green and the battery can remain on the charger until required for use.

Note : DO NOT look directly into the lamp ! :wink: :roll:

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philg
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Re: Cree XM-L T6 LED 1000

Postby philg » 17 Dec 2012, 9:50pm

^ for charging

In operation, some of the lights have colour coding on the ON/OFF button to let you know the state of charge. Not sure of the exact numbers, but it's something like
Green = >60%
Red = >30%
Flashing Red = it's going to go out very shortly.

Also on some lamps, to access the irritating flash mode you need to hold the button for a few seconds.

I disagree with Ayesha about the mounting - the rubber bands are simple and very effective (though not thief-proof I accept - I tie-wrap the cables in a few places)
If the lamp slips on your bars (it doesn't on mine) then wrap a layer of electricians (self-amalgamating) tape and it will stay put forever.

Ayesha
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Re: Cree XM-L T6 LED 1000

Postby Ayesha » 18 Dec 2012, 7:21am

philg wrote:^ for charging

In operation, some of the lights have colour coding on the ON/OFF button to let you know the state of charge. Not sure of the exact numbers, but it's something like
Green = >60%
Red = >30%
Flashing Red = it's going to go out very shortly.

Also on some lamps, to access the irritating flash mode you need to hold the button for a few seconds.

I disagree with Ayesha about the mounting - the rubber bands are simple and very effective (though not thief-proof I accept - I tie-wrap the cables in a few places)
If the lamp slips on your bars (it doesn't on mine) then wrap a layer of electricians (self-amalgamating) tape and it will stay put forever.


You don't have to agree or dissagree. It not a 'bike lamp mounting reality TV competition'... :D

To get the thing to stay steady on the roads round near where I live, those rubber bands had to be ULTRA TIGHT and nearly impossible to get threaded. A large screwdriver used as a lever was the final tool, before I had the jubilee clip revellation. I think the little turn up 'ear' to locate on the undercut ring was a stroke of genius.
That's my opinion, so don't bother disagreeing :wink:

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Mick F
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Re: Cree XM-L T6 LED 1000

Postby Mick F » 18 Dec 2012, 7:52am

Any chance of a link to where they were bought, please?
Cost?
Mick F. Cornwall

Brucey
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Re: Cree XM-L T6 LED 1000

Postby Brucey » 18 Dec 2012, 8:03am

there are 'quite a few' on e-bay, starting at the bottom end price-wise;

http://www.ebay.co.uk/itm/1200-Lumen-CREE-XML-T6-LED-Bike-Bicycle-Outdoor-Sports-Light-HeadLight-headLamp-/300677445326

£13.40 + £3.99 p&p

doesn't come any cheaper than that.... :shock: I bought one slightly different to this a few months ago.

BTW I would take any claims for the number of lumens with a very large pinch of salt. 50 to 80 lumens per watt is a realistic estimate.

cheers
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Mick F
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Re: Cree XM-L T6 LED 1000

Postby Mick F » 18 Dec 2012, 8:41am

Why so cheap? :shock:

Why do some lights cost hundreds of quids, when this is so cheap?
Mick F. Cornwall

Brucey
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Re: Cree XM-L T6 LED 1000

Postby Brucey » 18 Dec 2012, 8:57am

dunno.

Exploited workers? Global economy gone berserk? Middlemen creaming profit?

If I try to buy just the LED device, that costs the thick end of ten quid here.....

My cheapy light was ~£24 delivered and has been fine BTW. The beam is horrible for road use, but mine was bought for fooling around in the woods, mainly.

cheers
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Mick F
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Re: Cree XM-L T6 LED 1000

Postby Mick F » 18 Dec 2012, 9:04am

Ah, that may be it then - the beam.

Lenses have to be designed, and it's lens design that costs the dosh?
Mick F. Cornwall

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deliquium
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Re: Cree XM-L T6 LED 1000

Postby deliquium » 18 Dec 2012, 9:06am

I also bought one of these from China. It took 30 days to arrive - but the seller was very communicative.

Also bought a fresnel lens for a Magicshine light (which thses seem to be identical) - this makes it useable on the road with a cut off beam pattern - otherwise I think you would upset anybody coming towards you! That cost an extra £4.25 off eBay also.
Current pedalable joys

"you would be surprised at the number of people in these parts who nearly are half people and half bicycles"

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deliquium
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Re: Cree XM-L T6 LED 1000

Postby deliquium » 18 Dec 2012, 9:08am

Current pedalable joys

"you would be surprised at the number of people in these parts who nearly are half people and half bicycles"

Ayesha
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Re: Cree XM-L T6 LED 1000

Postby Ayesha » 18 Dec 2012, 9:47am

Mick F wrote:Ah, that may be it then - the beam.

Lenses have to be designed, and it's lens design that costs the dosh?


My three have slightly different beam patterns. One has a good beam for road use. That one has a 20 deg main segment with still quite a bit of peripheral.
The other two are more spread.
Its the tolerances on assembly that move the reflection pattern around.

Personally, I don't think there was much heavy design work done. Software for optics is available.
The LED gives off light straight forward, unlike a bulb which luminates in all directions making reflector design and positioning critical. An LED of this size could be used without a paraboloic reflector, just a piece of protective clear plastic. The reflector in this lamp recovers what light is coming back off the inside of the lens, which is a plain lens. It also makes the lamp LOOK like a lamp. A 20 W LED in a small box behind a clear screen is not a roughty toughty cyclist's idea of a 'headlamp'.
Most of the aluminium body is heat-sink.

This lamp could be even cheaper if it was a 'super-bright' panel lamp with a fixture to mount it on a bicycle handlebar.

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Re: Cree XM-L T6 LED 1000

Postby Brucey » 18 Dec 2012, 10:18am

Ayesha wrote: The LED gives off light straight forward, unlike a bulb which luminates in all directions making reflector design and positioning critical. An LED of this size could be used without a paraboloic reflector.... The reflector in this lamp recovers what light is coming back off the inside of the lens.....


Respectively; no, no, yes but not for that reason, no not really if you want to see where you are going, and no this is not its primary function.

BTW with these magicshine style lamps the front unscrews (hence you can fit a diffractive optic). You can thus also fit spacers/trim parts to move the reflector and alter the beam pattern slightly. If you want to get an idea of what kind of difference you can expect by doing this, have a play with a Maglite; these also have a nominally parabolic reflector and are externally adjustable.

cheers
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Ayesha
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Re: Cree XM-L T6 LED 1000

Postby Ayesha » 18 Dec 2012, 10:54am

The first LED lamp for a bicycle I made was a ‘Superbright’ Toshiba 5mm 3000 cda ( approx. 35 lumens ) ‘Waterclear’ yellow device mounted in a plastic box from RS Components.
Placing a reflector round it made no difference. LEDs are directional by their design.

My next effort was a 9mm Toshiba ‘Superbright’ 7000 cda ( approx. 100 lumens ) epoxy resin attached ( with resistor inside ) to a Halogen bulb canister. This gave about the same luminosity as a 2.4 V halogen bulb running on 2.8 V rechargeables.
This LED ‘bulb’ went in a std 3 V bike lamp and lasted months on a pair of D size rechargeable 4 Ahr NiCd cells from RS. Problem,,, it was YELLOW.

This lasted a long time until a 1 Watt WHITE LED became available. It was in a small torch.
Then a 3 Watt Torch ( Tesco Cree ).
Then a 5 Watt Torch ( P7 lenser )

Then the 20 Watt unit we are discussing.
The LED gives off light when the semiconductor is powered. How an LED does this is emit a radio frequencies equivalent to Red, Yellow, Blue or any point in the visible electromagnetic spectrum.
To make a white LED, a Blue LED is coated with phosphor layer. The resultant light may still possess a blue hue.
In which direction the light leaves the device is dependent on the shape of the device’s clear casing, not reflectors surrounding it. If the active surface of the LED is facing forward, the electromagnetic radiation is going to be emitted forward. Very little sideways.
Before getting to the outside world, the radio waves have to pass through a glass or plastic screen, usually clear to a human eye. Not all the signal passes first time. It is reflected back to be shortly reflected back again by a conveniently shaped reflector. Direction now becomes important because the direction of reflected signal is dependent on the molecular construction of the clear screen.

Now one might argue about Photons. IMHO, these are from the superheating of a metal wire in an atmosphere of inert gas.

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Redvee
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Re: Cree XM-L T6 LED 1000

Postby Redvee » 18 Dec 2012, 11:01am

I've got a Magicshine light and the o-ring mounting was too loose for my ride so I modded the bracket with one similar to this

http://www.wiggle.co.uk/pdw-mission-con ... t-bracket/

Image