Another DIY Light Question

JJ said:

My DIY headlight project is stalled due to a friend's observation
that my original lens material of choice (Lexan type stuff) will
probably melt from the heat of the lamp (G.E. "Quartzline" FHX 25
watt). Is this true? All of my original assumptioms about the
amount of heat these things produce are apparently wrong (my buddy
pointed out that my original choice for wiring is also not robust
enough). Suggestions?

Find a new acronym before gene.daniel's lawyer calls. He's trade-marked
"DIY" in this newsgroup.

(Sorry, no help on the question; I'm a slave to retail.)

JJ said:

My DIY headlight project is stalled due to a friend's observation that my
original lens material of choice (Lexan type stuff) will probably melt from
the heat of the lamp (G.E. "Quartzline" FHX 25 watt). Is this true? All of
my original assumptioms about the amount of heat these things produce are
apparently wrong (my buddy pointed out that my original choice for wiring is
also not robust enough). Suggestions?

lexan would not work at all. does the lamp not come in a glass front
version?
I bought the wrong bulbs last time and the one i had worked fine in
the rain without glass.
you don't need much in the way of wiring for 25 watts. 18 gage zip
cord is more then enough.
what batteries are you going to use? 25 watts will suck a fair amount
of power. about 2.5 ah a hour. I got maybe 1.5 hours on a 20 watt 12v
cell running 19.6v 3ah niMh cells. maybe 1 20 minutes if I ran it at
16v.
Knight-Toolworks
http://www.knight-toolworks.com
affordable handmade wooden planes

Here's my suggestion for a diy headlight -

take a MR-11 bulb - (smaller than the MR16 series), take it to the
hardware store - the plumbing section. You will find that there is a
certain size of drainage pipe (the type that is found directly under
the sink) into which the bulb will fit. buy a bit of pipe and the round
ring that screws onto it. also a little teflon tape if you don't have
any at home.

(Also, you might want to look for something that you can stick on the
other end of the pipe. As for me, I found something in I think the
gas-pipe section (or was it still plumbing?), it was a type of
hexagonal lock-ring with a round lip and a threaded interior. I was
later able to find an electrical switch that fit perfectly.)

Then go to a glazier. have him make a couple of round disks that fit
into the round ring of the drain pipe. Or buy a bit of 1/8" glass and
cut it yourself.

To assemble, put several layers of teflon tape around the threads,
leaving a good amount sticking past the lip so it can be folded over
and cushion the bulb. Then insert the bulb, then the glass and the
ring.

The rest is just finding ways to mount, wire, and seal it.

Hope this was helpful. Sorry I am not in a more descriptive mood.
Questions?

Peter

JJ said:

My DIY headlight project is stalled due to a friend's observation that my
original lens material of choice (Lexan type stuff) will probably melt from
the heat of the lamp (G.E. "Quartzline" FHX 25 watt). Is this true? All of
my original assumptioms about the amount of heat these things produce are
apparently wrong (my buddy pointed out that my original choice for wiring is
also not robust enough). Suggestions?

Thanks!

-Jeff

[email hidden] wrote:
.........

Quoted message said:

Then go to a glazier. have him make a couple of round disks that fit
into the round ring of the drain pipe. Or buy a bit of 1/8" glass and
cut it yourself.

No need for that if you buy a "closed" MR11 as it will come with its own
glass cover. In fact most MR11s that I see (in the UK) are of the closed
type, including cheap ones.

~PB

[email hidden] wrote:
.........

Quoted message said:

Then go to a glazier. have him make a couple of round disks that fit
into the round ring of the drain pipe. Or buy a bit of 1/8" glass and
cut it yourself.

No need for that if you buy a "closed" MR11 as it will come with its own
glass cover. In fact most MR11s that I see (in the UK) are of the closed
type, including cheap ones.

~PB

Quoted message said:

The rest is just finding ways to mount, wire, and seal it.

"just"? In my quest for headlighting my bikes (especially my recumbent)
with both homebrews and commercial systems, the hardest part has been
finding a good mounting scheme.

For me, "good" means it's stable, adjustable if desired, puts out light
from a good position, and in the case of the recumbent, doesn't shine
light on my feet and cranks, and doesn't block my view of the road.

I still haven't found it for my 'bent yet.

--
I do not accept unsolicited commercial e-mail. Remove NO_UCE for
legitimate replies.

"JJ" <[email hidden]> wrote in message
news:[email hidden]...

.... (my buddy pointed out that my original choice for wiring is

Quoted message said:

also not robust enough). Suggestions?

....

Your essential question is, "What guage wire do I really need?" To
"really" answer it, I (a degreed EE) would need to know the battery
voltage, length of wire run, and the allowable voltage loss in the
wire. However, you can get a workable solution more easily.

Regarding wiring, the required guage depends on current rather than
power. You have a 25 watt load, and if it required a 25 volt battery,
you'd need the wire to carry 1 amp of current. This can be done
reliably with very thin wire, as small as 30 guage if you can tolerate
considerable voltage loss. If it requires a 1 volt battery, the wire
would need to carry 25 amps of current. This wire would need to be
much heavier than 12 guage to minimize voltage loss, and is not IMHO
likely to be the right answer.

Conservatively you'll have at least 12 volts, so let's use that (I
don't really know the requirements for an MR-11). You'll then need to
carry 2.1 amps for at most 10 feet loop distance. For a 1/2 volt
loss, you then need a wire size 23 guage or larger (smaller guage
number). 24 guage is slightly too small.

So if you try some 23 guage wire and the light dims too much when the
battery begins to sag, try some heavier wire. 20 guage is easy to get
at hardware stores and would be safe in every respect. Also larger
wires are stronger than thinner ones, and hence would be a bit more
trouble-free on a bike.

I'd recommend you start with 22 guage zip-cord from the hardware store
and see if you like it. If the light output is too sensitive to
battery charge level, re-wire it with bigger wire. You'll find a
practical upper limit.

Good luck!

Another thing: halogen lamps are REALLY hot. I don't think you should
run one without protecting it from moisture, if it is not inherently
protected!

Ken

AAAHHH, darn it, I knew that part of my question would be mis-interpreted.
I am an electronics technician, so yes, I know all about Ohm's Law, etc. (I
just don't know much about Halogen lamps and the amount of heat they
produce). What my buddy was pointing out, when I showed him my original
parts kit for this project, was that the insulation on the wires (the part
of the wires that will be inside the housing) will melt from the heat. NOT
heat due to current flow times resistance, but rather the heat from the damn
lamp. He suggested I would have to buy one of the ceramic
sockets/connectors that are meant for these bulbs, which also have the
heat-resistance wires coming out of them. After that wiring has exited the
housing, then I could use just about any wire for the rest of the distance
to the battery.

Thanks to everyone for their suggestions and ideas. Looks like I'll just
end up leaving the front of this light exposed to the elements, as going to
a glazier for a specially cut piece of glass seems like too much trouble
(and expense).

-Jeff

"carkid1" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"JJ" <[email hidden]> wrote in message
news:[email hidden]...

... (my buddy pointed out that my original choice for wiring is

Quoted message said:

also not robust enough). Suggestions?

...

Your essential question is, "What guage wire do I really need?" To
"really" answer it, I (a degreed EE) would need to know the battery
voltage, length of wire run, and the allowable voltage loss in the
wire. However, you can get a workable solution more easily.

Quoted message said:

number). 24 guage is slightly too small.

So if you try some 23 guage wire

(much of Ken's text snipped for brevity)

JJ said:

He suggested I would have to buy one of the ceramic
sockets/connectors that are meant for these bulbs, which also have the
heat-resistance wires coming out of them. After that wiring has exited the
housing, then I could use just about any wire for the rest of the distance
to the battery.

Wait! No need to go the expensive route. You can get teflon
insulated wire. The teflon doesn't melt unless it gets REALLY hot
(>800 degrees F if I recall correctly). I solder the stuff all the
time with my soldering iron set >700 F and never have any problem with
the insulation melting. The teflon will be better able to survive
exposure to weather than any other wire insulation you'll find, too.

Connecting to the lamp should be pretty easy- you might try using
small springs that just fit over the pins on the bulb. Slip the
springs over the wire ends, then put the wire against the lamp pin,
then slide the spring down over both the wire and the pin.

Question: will standard halogen lamps survive the mechanical pounding
they will receive on a bike?

Quoted message said:

To assemble, put several layers of teflon tape around the threads,
leaving a good amount sticking past the lip so it can be folded over
and cushion the bulb. Then insert the bulb, then the glass and the
ring.

The rest is just finding ways to mount, wire, and seal it.

or save a lot of effort and buy these (G)
http://www.jcwhitney.com/autoparts/ItemBrowse/c-10101/s-10101/p-100000201440/mediaCode-ZX/appId-100000201440/Pr-p_CATENTRY_ID:100000201440
http://tinyurl.com/dsk62
they are nice and small look nice and are mr11 lights. as long as you
don't have a switch they housing does not need to be waterproof.
Knight-Toolworks
http://www.knight-toolworks.com
affordable handmade wooden planes

Quoted message said:

Question: will standard halogen lamps survive the mechanical pounding
they will receive on a bike?

Yes, they are tough things, except for the glass cover which may crack if
you're very unlucky. There doesn't seem to be much physical difference
between any MR11, despite most being designed for domestic applications.
I have used some of the very best and some of the very cheapest.

Note that MR11 systems such as Lumicycle are used successfully for rough
mountain biking.

~PB

JJ said:

AAAHHH, darn it, I knew that part of my question would be
mis-interpreted. I am an electronics technician, so yes, I know all
about Ohm's Law, etc. (I just don't know much about Halogen lamps and
the amount of heat they produce). What my buddy was pointing out,
when I showed him my original parts kit for this project, was that
the insulation on the wires (the part of the wires that will be
inside the housing) will melt from the heat. NOT heat due to current
flow times resistance, but rather the heat from the damn lamp. He
suggested I would have to buy one of the ceramic sockets/connectors
that are meant for these bulbs, which also have the heat-resistance
wires coming out of them.

How about heat-shrink tubing? Would that be enough to protect "ordinary"
wire? (I know that's not what it's designed for but I wonder if it would
work). I'm not sure there's enough heat to melt ordinary insulation
anyway. Yes it gets very hot in there, but /that/ hot?

By the way, the light should be turned off when you are stationary when
using anything more powerful than a 12W bulb, especially if overvolting.
The heat gets crazy otherwise. It then becomes enough to melt (and
possibly ignite) stuff and cause nasty burns. Air-cooling helps!

.....

Quoted message said:

Looks like I'll
just end up leaving the front of this light exposed to the elements,
as going to a glazier for a specially cut piece of glass seems like
too much trouble (and expense).

As I mentioned in my other reply, that's not an issue when using "closed"
dichroics as they have their own glass cover at the front of the
reflector. No need for anything in front of that (commercial lights like
Lumicycle don't have), nor any need to use the "open" type of MR11.

~PB

Pete Biggs said:

JJ wrote:

Quoted message said:

Quoted message said:

Looks like I'll
just end up leaving the front of this light exposed to the
elements, as going to a glazier for a specially cut piece of
glass seems like too much trouble (and expense).

As I mentioned in my other reply, that's not an issue when using
"closed" dichroics as they have their own glass cover at the front
of the reflector. No need for anything in front of that
(commercial lights like Lumicycle don't have), nor any need to use
the "open" type of MR11.

If heat in the enclosure is a problem, you don't want to use a
dichroic-coated lamp. The dichroic coating is designed to reflect the
visible light out the front but transmit the infrared (i.e. most of the
radiation) out through the back of the reflector. If you're lighting
something that's heat-sensitive that's a good idea, but for keeping the
fixture cool it's not so good.

--
Ray Heindl
(remove the Xs to reply)

Good point, but for me it was a bit of serendipity to find that the
MR-11 fit into the drain-pipe, and I felt that was information worth
sharing. My mounting scheme involving screws and wingnuts, and my
wire-seals involving epoxy are a real kludge. It doesn't seem elegant
enough to explain.

Peter

PS: forgot to mention in my other post that I put a thin rubber O-ring
between the ring and the glass so that the ring could be reasonably
tightened without cracking anything.

Victor Kan said:

Quoted message said:

The rest is just finding ways to mount, wire, and seal it.

"just"? In my quest for headlighting my bikes (especially my recumbent)
with both homebrews and commercial systems, the hardest part has been
finding a good mounting scheme.

For me, "good" means it's stable, adjustable if desired, puts out light
from a good position, and in the case of the recumbent, doesn't shine
light on my feet and cranks, and doesn't block my view of the road.

I still haven't found it for my 'bent yet.

--
I do not accept unsolicited commercial e-mail. Remove NO_UCE for
legitimate replies.

Actually, the cost should not be much. When I had the glass-man do it
several years ago, I think it only cost me 3 or 4 dollars to cut a
couple circles.

However, if you can find a closed front bulb, like Pete Biggs suggests,
I would go that route.

Peter

JJ said:

<snip>

Quoted message said:

Thanks to everyone for their suggestions and ideas. Looks like I'll just
end up leaving the front of this light exposed to the elements, as going to
a glazier for a specially cut piece of glass seems like too much trouble
(and expense).

-Jeff

Ray Heindl said:

If heat in the enclosure is a problem, you don't want to use a
dichroic-coated lamp. The dichroic coating is designed to reflect the
visible light out the front but transmit the infrared (i.e. most of
the radiation) out through the back of the reflector. If you're
lighting something that's heat-sensitive that's a good idea, but for
keeping the fixture cool it's not so good.

I do want to use them because there is a good choice of dichroic MR11s
with wattages and beams that are great for cycling, and they allow the the
housing to be kept simple, small and cheap. Yes they send a lot of heat
backwards but this is not a problem with the low-power ones nor high-power
ones when cooled by moving air. Lumicycle and others have been
successfully using these kind of lamps for years. See www.lumicycle.co.uk
and www.fireballlights.co.uk

~PB

So if the issue is to survive high temperatures, look for some
military surplus Teflon-insulated wire, not the FEP types.
Silver-plated conductors have a higher temp rating than tinned, and
nickel-tinned the highest of all. Some polyester insulations are good
for 105 degrees C. Plenum-rated wire has robustness pretty close to
the aero wires.

I agree with the ceramic socket idea, especially it could be exposed
to moisture.

Can't you scribe a circle with a glass cutter and make a DIY glass
cover? I guess ventilation than becomes an issue.

Ken

"JJ" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

AAAHHH, darn it, I knew that part of my question would be
mis-interpreted.
I am an electronics technician, so yes, I know all about Ohm's Law,
etc. (I
just don't know much about Halogen lamps and the amount of heat they
produce). What my buddy was pointing out, when I showed him my
original
parts kit for this project, was that the insulation on the wires
(the part
of the wires that will be inside the housing) will melt from the
heat. NOT
heat due to current flow times resistance, but rather the heat from
the damn
lamp. He suggested I would have to buy one of the ceramic
sockets/connectors that are meant for these bulbs, which also have
the
heat-resistance wires coming out of them. After that wiring has
exited the
housing, then I could use just about any wire for the rest of the
distance
to the battery.

Thanks to everyone for their suggestions and ideas. Looks like I'll
just
end up leaving the front of this light exposed to the elements, as
going to
a glazier for a specially cut piece of glass seems like too much
trouble
(and expense).

-Jeff

"carkid1" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"JJ" <[email hidden]> wrote in message
news:[email hidden]...

... (my buddy pointed out that my original choice for wiring is

Quoted message said:

also not robust enough). Suggestions?

...

Your essential question is, "What guage wire do I really need?" To
"really" answer it, I (a degreed EE) would need to know the battery
voltage, length of wire run, and the allowable voltage loss in the
wire. However, you can get a workable solution more easily.

Quoted message said:

number). 24 guage is slightly too small.

So if you try some 23 guage wire

(much of Ken's text snipped for brevity)

JJ said:

AAAHHH, darn it, I knew that part of my question would be mis-interpreted.
I am an electronics technician, so yes, I know all about Ohm's Law, etc. (I
just don't know much about Halogen lamps and the amount of heat they
produce). What my buddy was pointing out, when I showed him my original
parts kit for this project, was that the insulation on the wires (the part
of the wires that will be inside the housing) will melt from the heat. NOT
heat due to current flow times resistance, but rather the heat from the damn
lamp. He suggested I would have to buy one of the ceramic
sockets/connectors that are meant for these bulbs, which also have the
heat-resistance wires coming out of them. After that wiring has exited the
housing, then I could use just about any wire for the rest of the distance
to the battery.

Thanks to everyone for their suggestions and ideas. Looks like I'll just
end up leaving the front of this light exposed to the elements, as going to
a glazier for a specially cut piece of glass seems like too much trouble
(and expense).

Soldering regular 18ga zip cord to the pins of the lamp works fine. They are a
little hard to solder since the alloy was designed more for it's thermal
characteristics relative to glass than solderability, but scrape it clean, use a
flux and you'll be fine. (don't clean lamp sockets or vacuum tube pins with a
file) If you want a socket, it will be on the shelf at your local electrical
supply shop. The ones contractors go to for lamps and fixtures. MR11 and 16 come
with their own front glass.

This is all so bodgeable it's boggling. there are vast levels of
overcomplication surrounding this.

Ron

RonSonic said:

Soldering regular 18ga zip cord to the pins of the lamp works fine. They are a
little hard to solder since the alloy was designed more for it's thermal
characteristics relative to glass than solderability, but scrape it clean, use a
flux and you'll be fine.

What I did, IIRC, was crimp brass tubing of the proper size onto the
end of each wire in a zip cord. These tubes were a simple friction fit
onto each pin of the MR-11 bulb. Get the tube at a hobby shop. If
necessary, pinch it slightly for a friction fit on the pins.

I don't remember now what the wattage of the bulb was, but it was
probably 10 or 12 watts, and probably dichromic. The bulb was mounted
in a small aluminum can. I used that lamp (on and off) for perhaps a
couple years with no problems, until I got tired of playing with
rechargeable lights.

The only problem I had was that the bulb came with no cover, so I cut
one out of thin clear plastic - a flexible kind that comes as packaging
for lots of consumer goods. It withstood the heat for a while, but
eventually distorted and darkened. I don't recall if the problem came
on a hot day, or by running the light while stationary, or what. But
if I were to begin using that light again, I'd either run the bulb
bare, or cut my own glass shield.

- Frank Krygowski