DIY lights - LED project

[Willehond]

Eina, that's expensive stuff!  Nope, sounds like I will have to go the PVC route with mountainlion.  That carbon does look good though.  Well done.

 

Anyway, don't you need specialist equipment and an autoclave to work with the carbon resin?  Sounds way too complicated and a bit past the DIY objective.

[markStockton]

 

Anyway' date=' don't you need specialist equipment and an autoclave to work with the carbon resin?  Sounds way too complicated and a bit past the DIY objective.

[/quote']

 

I'm lucky I've been playing with composites for 20 + years, however it isn't as difficult as one imagines. To make this tube you need resin and cloth, wax,  brush and roller, acetone, overhead projector sheets, insulation tape and a suitable mandrel (I used a silicone rubber tube that goes into a glue gun). A fine digital scale is nice for mixing the epoxy correctly, but if you get the data sheet from the supplier it will have the volumetric ratios on it so you can use a medicine spoon. Finally I post cured the tube in our Defy Thermo-fan autoclave. However a black garbage bag around a box in a sunny spot in the garden does the same job.

 

As I said earlier, if you make it from epoxy glass rather than carbon, it can be done very cheaply. The only reason I used carbon is I have suitable off cuts and it looks cool.

 

[markStockton]

 

ok' date=' if i hadn't already bought the sigma karma i'd have considered commissioning markstockton to make me a light - that one of yours looks good. BUT show us a pic to show how well it works!

 

(ps, the karma is stunning - i need to take pics to show it compared to my old light

[/quote']

 

Thanks SP, I doubt I'd make lights for other people unless I can find suitable heatsinks, or have some plasma cut. Machining down a CPU heatsink by hand hand real pain.

 

Are you going to be a Teak Place next Wednesday so we can compare my light with the Sigma Karma?

 

 

Where do you get Lipo batteries? Cost?

Special charger needed?

 

 

Lipos have been widely adopted by Model Aircraft pilots. However buying them from hobby shops is just plain asking to be sexually assulted with out lubricant. Some of the specialist battery wholesalers are carrying them. In Jhb Framptons in Germiston is a good option. I'll post costs when I get my cell's.

 

Yes you need a special charger as these cells are very difficult to work with. However a good fast charger that works off 12v can be bought for around R 500.00. These are well worth it as they are very good at managing your NiCad, NiMH and Lead Acid cells as well.

 

Lipo's if charged or discharged incorrectly can and will catch fire and burn. Remember all the Laptop's that where recalled a year ago!!!

 

 

 

 

 

[markStockton]

I'm not to sure this does the light justice, however here is a photo taken last night. It is outdoors that the light excels, however as there is no immediate backdrop for the light to reflect off it is impossible to photograph.

 

Also I have nothing to really compare the light to (apart from a Mag Light) tourch.

 

 

 

A point of concern. The heatsink get's to hot to hold comfortably in about 5 minutes. I guess this means it is working and while on the bike it will have air cooling. However I didn't expect it to get this hot. It looks like a decent heatsink is a must.

 

[mountain_lion]

An outdoor shot will indeed be more meaningful.

 

Perhaps like the beam comparisons which MTBR did in their lights shine-off (dated by now, but still a very nice reference).

 

I am not surprised about the heat at all. These power LEDs get hot!

Decent size heat sink is a must.

This is also why using the dimming function of the buck-puck is important.

If you only run the LEDs at full blast when needed, the heat problem is reduced.

P=I?R, thus if you can drop the current a bit, you reduce the energy required (and thus the heat to dissipate) substantially.

 

 

[Thug]

Looking good there Mark !

 

Particularly like the housing.

 

 

[greatwhite]

Thanks SP' date=' I doubt I'd make lights for other people unless I can find suitable heatsinks, or have some plasma cut. Machining down a CPU heatsink by hand hand real pain.

[/quote']

I suspect plasma cutting an ali heat sink might be quite a bitch. Why not laser cut a couple laminations and bolt together - there a quite a few very good PC heat sinks made this way. Also try ebay for all sort of ready made stuff  (http://business.search.ebay.com/heat-sink_Industrial-Electrical-Test_W0QQcatrefZC12QQsacatZ92074)

 

I would imagine those light heat sinks they make for RAM would be great for this application too

 

Lipos have been widely adopted by Model Aircraft pilots. However buying them from hobby shops is just plain asking to be sexually assulted with out lubricant. Some of the specialist battery wholesalers are carrying them. In Jhb Framptons in Germiston is a good option. I'll post costs when I get my cell's. 
 

 

I've always bought them on ebay as well because the local price for a lipo is so high (model shops). I'm keen to see what you get from framptons

 

[Willehond]

Just a warning, this is a VERY crude setup.  I am still waiting for my proper heatsink to arrive and I will use the PVC housing again, but do a bit of a neater job!

The back of he LED's before I stuck a piece of aluminium on top of it:

 

I used an old light's handlebar  clamp and just zip tied it to it for now!

 

I used an old binocular case to house the batteries and tied it to the bottom of the stem with a velcro strap:

Willehond2008-04-04 15:30:16

[Cois]

I bought a light system a time back with speed control and all that funny things (Alien light system)

Problem No 1:  Not waterproof.

No 2:  Bulk - It is large it is plastic and doesn't look great.

No 3:  Uses 4 AA's.  I use recharge 2700's (lasts about 3 hours)

I want to try my hand at making a new better system.  Waterproof and all that.  With a metal body.

Where do I start.  I can use the parts of my old light.

I know how to solder and work my way round some wires, but know nothing on lights.

Is there someone who can assist me in this.  Just need guidance.

 

[markStockton]

 

Just a warning' date=' this is a VERY crude setup.  I am still waiting for my proper heatsink to arrive and I will use the PVC housing again, but do a bit of a neater job![ /QUOTE']

 

Very nice, where did you get the heatsink? Won't you please post the details?

 

[Willehond]

Just a warning' date=' this is a VERY crude setup.  I am still waiting for my proper heatsink to arrive and I will use the PVC housing again, but do a bit of a neater job![/quote']

Very nice, where did you get the heatsink? Won't you please post the details?

Mark,

 

The heatsink is the most expensive bit of the whole setup, but it fits perfectly!  Unfortunately you have to buy it from Germany and they don't ship to SA.  The Yak has a contact who is bringing it over for us in a week's time though.  Will post some pics when I have it installed. (I also can't post apic of it as the Hub says I don have sufficient authorization! )

 

http://www.pur-led.de/product_info.php?info=p1076_Hochleistungs-Aluminium-Stiftk-hlk-rper-31g---Power-LED-K-hlk-rp.html

 

Price: 7,99 EUR *

incl. 19 % Tax excl. Shipping costs

 

 

 

[markStockton]

 

Mark' date='

 

The heatsink is the most expensive bit of the whole setup, but it fits perfectly!  Unfortunately you have to buy it from Germany and they don't ship to SA.  The Yak has a contact who is bringing it over for us in a week's time though.  Will post some pics when I have it installed. (I also can't post apic of it as the Hub says I don have sufficient authorization! )

 

http://www.pur-led.de/product_info.php?info=p1076_Hochleistungs-Aluminium-Stiftk-hlk-rper-31g---Power-LED-K-hlk-rp.html

 

Price: 7,99 EUR *

incl. 19 % Tax excl. Shipping costs

[/quote']

 

Your light is going to turn out so nicely. I think it is time to plan my next one with new (er) 3W high power LED's.

 

[mountain_lion]

OK, my collection of lenses and LEDs have arrived so now I can start experimenting.

 

I also found this and like the idea:

http://www.freelights.co.uk

http://www.reelight.com

 

I might even try making something similar for my hybrid.

Now what did I do with that coil wire I had a few years ago...

 

 

[mountain_lion]

 

 

Lipos have been widely adopted by Model Aircraft pilots. However buying them from hobby shops is just plain asking to be sexually assulted with out lubricant. Some of the specialist battery wholesalers are carrying them. In Jhb Framptons in Germiston is a good option. I'll post costs when I get my cell's.

 

Yes you need a special charger as these cells are very difficult to work with. However a good fast charger that works off 12v can be bought for around R 500.00. These are well worth it as they are very good at managing your NiCad' date=' NiMH and Lead Acid cells as well.

[/quote']

 

Mark, got any prices for the Lipos yet?

 

My tests show that 8x AA NiMH can light three 1W LEDs in series, but the 3021 buck puck driver only manages to get the load current up to about 600mA.

With 12 AA's the problem goes away and the buck puck manages a load current of 1000mA.

 

Unfortunately I do not have a lux meter. Without a meter it is

difficult to judge how much extra light you actually get with the

higher current.

 

 

I have 12 AA rechargeables, but it is a whole mix of capacity ratings with some quite old, which is not ideal. I need some of these for other electronics, plus Mrs mountain_lion also wants a light.

Buying another 12 (or more) NiMH AAs is not going to be cheap.

Might be worth it to look at getting Lithium type batteries plus charger.

 

mountain_lion2008-04-16 08:36:20

[mountain_lion]

I Googled a bit and found this site specialising in radio controlled toys

http://www.rclines.co.za

They stock LiPo batteries and chargers but as others have said you pay $$$ at the hobby shops!

 

Buying a LiPo battery and charger will push the price of a home made light very close to that of the cheaper commercial offerings.

Looks like my 12V sealed lead acid batteries or else NiMH AA's will have to do, unless a cheaper source of LiPo's can be found...

 

 

[Willehond]

mountain_lion, I have been riding with 8AA batteries in the light and I am VERY happy with the outcome.  I wasn't aware that it only getting up to 600mA, but I can only imagine what 1000mA must look like!  I still think the light spread and intensity is great for the price, but the battery setup will push it way out for me if it goes up to rechargeable battery packs.  You need at least two for longer events which makes it infeasible.

My current setup is good enough to let cars dim their lights and taxi's even wait for me at intersections.  I also passed a hitchiker with a gobsmacked look on his face last week.  I don't think he quite thought a bicycle could have such a powerful light on it!