Dyno powered triple cutter R2

[ktronik]

the drag does not bother me on the MTB... I have even raced with it...still beat most of the field... :thumbsup:

I have hacked up a side by side 'light bar' style 4 LED version using separate cree's & optics... as you said side by side makes for good twisty single track lighing...

Where did you see the 5 rebel MR11?? with optic as well??

K

 

[znomit]

Ktronic, group buy from Brum offers penta rebel optics.
Good luck finding rebel 100s
Don't forget to post beamshots (have a handlebar mount for SLR so might do some shots next week).

Martin, I guess I could wire parallel UV crees to .... no no no its getting too complicated!

 

[Martin]

Rebel 100s here.

 

[Eamon]

If you don't mind my asking, what switch did you use?

 

[znomit]

I used this switch a 3pdt toggle switch, plus a simple on off switch.

I put a waterproof boot over the toggle switch.

You can probably find a triple throw switch and use the center throw for "off", eliminating one switch. I wanted to separate the high/low from the on/off, because finding yourself "off" when you were looking for "high" is not so cool.

 

[Martin]

Triple throw switch with center = off

 

[wheelierider]

I agree that inadvertenly switching the light to off would be a problem. How about an off-low-high toggle? That's what I will be doing to mine. I'm working on my light housing right now. I plan on using the same cicuit.

This thread has been a real motivator to get it done. We have 3 shimano dynohubs and they all use wimpy and unreliable halogen bulbs at the moment.

 

[znomit]

Wheelie, Martins switch is a low/off/high toggle. The center position is the hardest to find so this is probably the safest place for "off". Mine is designed to be idiot proof(thats me!) because I know after 6hrs in the saddle its hard to remember which way the switch goes.

Get rid of those halogens!
Cutter is now shipping the quad LED MR11 too. 600lm off the dyno!

Have finished my GID upgrades, and have built a camera mount for the bars so can get some on board beamshots this weekend... just waiting to get the bike back from the shop with a new front shifter(did 320 hilly km on the weekend stuck in the small ring).

 

[barnefko]

Hi.
Maybe stupid question - but don`t you get heat problems when you fill out the entire housing with epoxy or silicone?

greetz

 

[znomit]

The light isn't filled with silicone or epoxy.
To perfectly seal the ends I mixed up some epoxy, added a drop of food colouring to give the orange glow, and poured out onto mylar(overhead projection sheets work as good as anything). The little puddle is a mm or two thick. The housing sits end on into the puddle for a day until cured. Peel off the mylar and whack off the excess epoxy. Top make it easier I used release agent on the bits of the housing I didn't want the epoxy binding to. You can sort of see the process here, though I used carbon for that light.
A note on the food colouring, adding water to the epoxy makes the excess left in the mixing pot get quite hot and the water steams off. Mix small quantities!

To seal the front hole I cut out a circle from the mylar sheet, a little bigger than the housing window. Ran a bead of silicone around the hole and stuck it on.
The back of the housing where the wires exit also gets a little silicone to stop water coming in.

 

[znomit]

Regarding your mount, you might want to add some sort of rubber damper if you have not already done so. I've read reports that indicate that that mounting position is hard on the bracket, presumably because fork crown brackets are usually longer than bar-mounted ones.

FrontRanger, you are right (damn you).
Went over a judder bar tonight fast enough that my cateye 1100 flew off the seatbag loop. A few km later the mount snapped. Was climbing a hill at the time so no drama. Taped the light to the bars to get home (man it got warm with the tape over it).

Anyhoo, will probably throw this onto my MTB with a simpler mount.

Was just thinking today about a dual triple. With a series//parallel switch setup so I can run at 500mA, 250mA, or 125mA (250, 500 and 850(!) lm). Most of the time 250 will be fine but in the rain 500mA will rock.

Wonder when Cutter is getting more R2s...

 

[FrontRanger]

FrontRanger, you are right (damn you).
Went over a judder bar tonight fast enough that my cateye 1100 flew off the seatbag loop. A few km later the mount snapped. Was climbing a hill at the time so no drama.

Darn. Well, at least you weren't on a high-speed descent.

Where did it break - at the 90-degree bend above the fork mounting hole?

 

[znomit]

Where did it break - at the 90-degree bend above the fork mounting hole?

Yeah, broke a couple of mm in front of the bend. Actually the night before it was drooping a little and I gave it a wee bend back up.
Looking at it today theres plenty of material left to attach it to a bar mount. I dont want to crack it open because I got the glow in the dark mix just right.
Had a few ideas today for a carbon bar mount. Have some woven carbon tubing which looks ideal. Job for next week.
Impending fatherhood means I can't spend the next few months in the workshop on entirely new lights!

 

[znomit]

Back to the good old cateye mount. I've modified a few of these.
They are good because you can still swivel the light l/r and up/down. Mounts are about 15$ I think. I hang the light upside down so they sit under the arm rests on the aero bars.

You need to drill a hole in the Q release mount and grind the head down on a screw to fit in. Then dremmel out the part that goes around the bars to create a space for the screw head.

Last friday I did the last 100 odd km of a 212km ride in the dark on back country roads with this. Fantastic. I'm so happy with it I've ordered a quad R2 board and wide optic from cutter and the LBS has done me a good deal on an 3n70 so will kit out the MTB with a dyno.

 

[znomit]

Have had a few good rides out on the road bike with this setup. It is outstanding.
So good I thought why not put one onto the MTB?

You need a bit more light than on the road and a wider beam.
I went for a quad R2 and medium MR11 optic from cutter.
I thought about doing the same type of housing but Nightlightning MR11 housings are good and reasonably cheap.
Brains from Martin. Dynauto switches between high power at high speed and boost at low speeds. I originally picked this up for the road bike but you don't really need the autoswitching function on the road. You always have time to switch manually.
Mount and Dynamo from the LBS.
I went with the older shimano NX70 hub because they had one in stock and I got a good deal on it.
If I rode the MTB a lot or competitively I'd look at a newer model.

All I had to fabricate was the aluminium bracket between cateye mounts and lighthead,
and put a switch hole in the plastic cap that stops the steerer tube top. Also a small amount of glow in the dark inside the light head.
Mechanically it was very easy to put together.
Ill put a tie around the lighthead to catch it in case of bracket failure.

Thats the on/off button on top of the steerer tube.
Heres whats inside:

My steerer tube has a taper near the bottom so the board wont fall through... capacitors hang below it.
The dyno wires and LED wires run out the bottom (LED via connector).

And heres the business end:

Should put out around 650lm.
:rock::rock::rock::rock::rock:

 

[n4zou]

That is one cool light idea I like the yellow sidelight idea

do you notice any drag when you switch on the lights.

and is there a way to use the dyno output to keep your backup light charged . or even to charge your cell phone or ipod.
on long touring trips

what a well green idea or would you be putting out too much CO2

Here is the circuit I use to recharge my cell phone or GPS unit on my touring bike.

If you've googled "bicycle dynamo" you've seen the complicated regulation circuits for your typical 6Vac-3W (500mA) dynamo. These circuits were required before Ni-MH batteries were available. Ni-MH batteries have a electrical quality that makes my circuit design possible. As voltage approaches 1.2 Vdc the internal impedance starts increasing. 4 1.2Volt Ni-MH batteries connected in series provides 5.2 Volts of regulated power. The reason for this is due to the increasing impedance so it becomes impossible for the dynamo to overcome it and produce excess voltage. This voltage is well within the standards set for USB ports available on positive pin1 and ground on pin 4. Pins 2 and 3 are data lines and are not required. The batteries also provide a sink for excess current which is used to recharge the batteries. USB standards limit current at the USB connector to 500mA which is what most bicycles dynamos produce. If your device uses less than 500mA then you'll have a little recharging of the batteries as you ride along. Considering stops you might never be able to completely recharge the Ni-MH batteries while any USB device is plugged into it. To recharge the batteries you'll need to disconnect any device plugged into the USB socket and ride with the dynamo engaged. Check your battery for the time required at 500mA to fully recharge them. 500mA just happens to be the suggested rapid recharge rate for Ni-MH batteries. You can use your cycle computer to keep up with recharge time. All of them have a trip time feature. When your moving it's clocking your time and when your stopped it stops. Simply reset the trip time on the cycle computer and when your calculated recharge time shows on the cycle computers trip clock disengage the dynamo. The batteries you use must be solder tab type as well as all connections of the bridge rectifier and batteries. If you lose any connection between batteries and bridge rectifier unfiltered and unregulated power will flow into your device possibly damaging it.
This circuit works with hub or tire driven dynamos. The switch allows disconnecting the batteries from the bridge rectifier when the bicycle will be unused. Nothing is perfect so there will be very slow discharge through the diodes over a period of several days or even weeks. Ni-MH batteries slowly discharge even when disconnected so always check and top them off before starting a tour.
For those of you not trained in electronics here is a drawing showing how to build a bridge rectifier.

You will notice some drag when the lights are on or when using it with the Ni-MH batteries. I use a bottle type dynamo on my touring bike as there is no drag when it's mechanically disengaged from the tire. There is a little more drag than a hub dynamo but I forget about the slight drag after about 15 minutes of riding with it engaged. Hub dynamos have less drag when electrically engaged than tire driven types but do have drag when disengaged and they weigh more than tire driven types. I personally prefer a bottle type on my touring bike but I do have a hub dynamo wheel for my road bike when doing more than a couple of hours of riding that bike at night.

 

[ktronik]

Hey Zom,

the button is 'outrageous'...:thumbsup:

simple, small & compact... great work...

 

[znomit]

Yeah, its pretty tidy eh?
If I could find a two pole three throw rotary switch smaller than an inch diameter I'd have on/off and dimmer in one... and an old school rotary knob on top, way cool.

 

[Martin]

..If I could find a two pole three throw rotary switch smaller than an inch diameter..

Grayhill has half inch, even sealed versions. I used to salvage these from American military gear.
But what you've built now is indeed very nice !

 

[znomit]

Martin, you're magic! :twothumbs
My next wish is one with

• Push on, pull off, for on/off control
• 2 rotary positions for dimming mode