grins projector, recoil and test light builds

226 posts / 0 new
Last post
G0OSE
G0OSE's picture
Online
Last seen: 3 min 15 sec ago
Joined: 09/03/2014 - 12:34
Posts: 2312
Location: UK SW

That’s what I like to see, and engineer in flip flops! (and the lights are great too! Thumbs Up )

MRsDNF
MRsDNF's picture
Offline
Last seen: 2 months 1 week ago
Joined: 12/22/2011 - 21:18
Posts: 13473
Location: A light beam away from the missus in the land of Aus.

Must be warmer in the Hunter Valley than here. Smile
Nice pic grin. Thumbs Up

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

I dont go near the lathe without boots on now, I learnt that the hard way. Couldnt believe that another forum member who live near me has a GT4 prototype and how similar my comp build is.
This photo taken last night gives a bit better idea how big the searchlight mirror actually is. It also needs cleaning.

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

So I got home today and made up a jig to mount the light engine in front of the mirror and set the focus at 400mm with a tape measure, flicked the switch. The mirror then got a clean with alcohol wipes and polished with paper.
what a difference!!! “100w” HID




The light was moved out 10mm.


1km

2-3km or other side of town

The beam is actually twice what you can see in the photo

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

With Cree CMT-2890


MRsDNF
MRsDNF's picture
Offline
Last seen: 2 months 1 week ago
Joined: 12/22/2011 - 21:18
Posts: 13473
Location: A light beam away from the missus in the land of Aus.

Thats crazy grin. Big Smile

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia
Big Smile Glasses
grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia




CNCman
CNCman's picture
Offline
Last seen: 14 hours 56 min ago
Joined: 04/07/2018 - 10:10
Posts: 1210
Location: Mississippi Gulf Coast

That is the envy of us all Beer
I love watching your builds. Looking like a WW2 search light Thumbs Up

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

Thanks,
sometimes I do things for no real project in mind but a 4s1p 26650 battery carrier would be handy wouldnt it? You never know when you might need one and it does fit into 3inch ali tube.

That searchlight that you can see 3km away is a budget light in that configuration.
Mirror $250
A rallyexpress “200W” HID headlamp those crazy ones.$80
4×38120 3.2v lithium batteries about $100
Frame screws cable and other stuff say $150
I made the light mount
So AU$580 or US$400

I found that there was a military agreement to have a common standard around WW2 and the metric system has been around a long time. The numbers on the mirrors correspond to metric, 90cm aperture, 408mm focal length. So with that bit of information I have narrowed down the light they were used in.

I couldnt find any detail as to how they were originally mounted but now it appears to to be fixed and the light is on a pedestal and the arc is moved.
The more I find out about them the more I am drawn to building them with the original in mind. The rails on the side look like they would make it simple to balance it.

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

I want one of these
the sun on a board

kennybobby
kennybobby's picture
Offline
Last seen: 1 hour 42 min ago
Joined: 05/10/2017 - 09:13
Posts: 948
Location: huntspatch, alabama

“Ralphie, you’ll shoot your eye out”

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

CNCman
CNCman's picture
Offline
Last seen: 14 hours 56 min ago
Joined: 04/07/2018 - 10:10
Posts: 1210
Location: Mississippi Gulf Coast

grin wrote:
I want one of these
the sun on a board

.

.

Wow, that will need a cooling system ! and a generator too. Beer
.

.

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

900mm mirror with CMT-2890 @ 2.8amp ridge is about 1.6km

Enderman
Enderman's picture
Offline
Last seen: 2 weeks 17 hours ago
Joined: 11/03/2016 - 22:42
Posts: 4278
Location: Vancouver, Canada

Very nice round spot Shocked
Could def use that to spot planes in the sky.

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

Haha i would like t9 see it from a plane. with your calculator it comes out at 119Mcd. Here is a video taken that night by another forum member.

G0OSE
G0OSE's picture
Online
Last seen: 3 min 15 sec ago
Joined: 09/03/2014 - 12:34
Posts: 2312
Location: UK SW

Is there a maximum distance ‘any’ light can throw, or is it infinite? Or is the maximum throw defined buy brightness/reflector etc?
Just curious I know it’s an odd question. For example, if you had a mirror 3x the size of yours, and the light source was 3x brighter, would it go 3x further?

Agro
Agro's picture
Online
Last seen: 1 min 39 sec ago
Joined: 05/14/2017 - 11:16
Posts: 6822
Location: Ślōnsk

Mathematically it’s infinite – you can always create a larger mirror. But at some point you’ll arrive with a light that has extremely low intensity at any distance – it just produces a beam that widens very slowly but is extremely large even at the start.

Physically – dunno.

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia
G0OSE wrote:
Is there a maximum distance ‘any’ light can throw, or is it infinite? Or is the maximum throw defined buy brightness/reflector etc? Just curious I know it’s an odd question. For example, if you had a mirror 3x the size of yours, and the light source was 3x brighter, would it go 3x further?

I am not exactly sure but someone did some calculations on here and it was suggested that you need to increase the reflector surface area 4x to double the throw. I have a few big quads in to works one will be 4 GT reflectors with 4 sbt-90.2s once that light is built I will be able to take measurements and compare the numbers, I am hoping to out throw the lemax by 1km. Will be interesting to see what the numbers are.
Another thing I think determines throw and beam size is focal length. Longer focal length will give you smaller beam diameter and more throw than a shorter focal length.
Another thing is light source size.it is very hard to take pics next week or so I will try again.the 2890 has a 22mm light surface and I would estimate the spot size at 1.6km to be around 150m. A 100w HID will give a spot diameter the width of the road about probably 10-15m
Light from stars travels for years II dont really know if there is a limit.

kennybobby
kennybobby's picture
Offline
Last seen: 1 hour 42 min ago
Joined: 05/10/2017 - 09:13
Posts: 948
Location: huntspatch, alabama

It also depends upon the media and environment, e.g. in vacuum vs in air. For laser distance measurements the barometric pressure, humidity, temperature affect the wavelength.

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

G0OSE
G0OSE's picture
Online
Last seen: 3 min 15 sec ago
Joined: 09/03/2014 - 12:34
Posts: 2312
Location: UK SW
grin wrote:
G0OSE wrote:
Is there a maximum distance ‘any’ light can throw, or is it infinite? Or is the maximum throw defined buy brightness/reflector etc? Just curious I know it’s an odd question. For example, if you had a mirror 3x the size of yours, and the light source was 3x brighter, would it go 3x further?

I am not exactly sure but someone did some calculations on here and it was suggested that you need to increase the reflector surface area 4x to double the throw. I have a few big quads in to works one will be 4 GT reflectors with 4 sbt-90.2s once that light is built I will be able to take measurements and compare the numbers, I am hoping to out throw the lemax by 1km. Will be interesting to see what the numbers are.
Another thing I think determines throw and beam size is focal length. Longer focal length will give you smaller beam diameter and more throw than a shorter focal length.
Another thing is light source size.it is very hard to take pics next week or so I will try again.the 2890 has a 22mm light surface and I would estimate the spot size at 1.6km to be around 150m. A 100w HID will give a spot diameter the width of the road about probably 10-15m
Light from stars travels for years I don’t really know if there is a limit.

Interesting. I nearly mentioned stars, but didn’t for fear of looking an idiot lol! And… they don’t have reflectors. That being the case, I can only imagine there is not limit, only to the one ‘viewing it’.
Stars are just pure brightness, and we can see some with our eyes – others we need telescopes for.
In theory, someone could see your light from the furthest depths of the universe, given a big enough telescope….. gets you thinking lol!

Enderman
Enderman's picture
Offline
Last seen: 2 weeks 17 hours ago
Joined: 11/03/2016 - 22:42
Posts: 4278
Location: Vancouver, Canada

G0OSE wrote:
Is there a maximum distance ‘any’ light can throw, or is it infinite? Or is the maximum throw defined buy brightness/reflector etc?
Just curious I know it’s an odd question. For example, if you had a mirror 3x the size of yours, and the light source was 3x brighter, would it go 3x further?

Light can travel infinitely, that’s how we can see outer parts of the universe, it’s because light has travelled a few billion years to get here.
So there really is no limit.
The only thing is that on earth there is atmosphere and particles and other stuff that blocks light so the intensity actually begins to decrease at a rate faster than 1/r^2, but yes you can always make a light more powerful and have it go further.
Also yes, if your mirror has 3x the front area and your light source is 3x brighter then you have 9x the candela, which means it will go 3x farther (because sqrt(9) = 3) but slightly less when you take into account the atmospheric losses as I mentioned above.
CNCman
CNCman's picture
Offline
Last seen: 14 hours 56 min ago
Joined: 04/07/2018 - 10:10
Posts: 1210
Location: Mississippi Gulf Coast

[quote=grin]900mm mirror with CMT-2890 @ 2.8amp ridge is about 1.6km

.
Wow 1.6km and bright as day. Shocked
I’m thinking you may need a camera set up in a telescope to see its full range !
I really like the pic from across town, burning a hole in the sky Beer

likevvii
Offline
Last seen: 8 hours 32 min ago
Joined: 04/28/2014 - 10:12
Posts: 422
Location: USA, California

Have you considered a lux meter for some measurements?

G0OSE
G0OSE's picture
Online
Last seen: 3 min 15 sec ago
Joined: 09/03/2014 - 12:34
Posts: 2312
Location: UK SW

Enderman wrote:
G0OSE wrote:
Is there a maximum distance ‘any’ light can throw, or is it infinite? Or is the maximum throw defined buy brightness/reflector etc?
Just curious I know it’s an odd question. For example, if you had a mirror 3x the size of yours, and the light source was 3x brighter, would it go 3x further?

Light can travel infinitely, that’s how we can see outer parts of the universe, it’s because light has travelled a few billion years to get here.
So there really is no limit.
The only thing is that on earth there is atmosphere and particles and other stuff that blocks light so the intensity actually begins to decrease at a rate faster than 1/r^2, but yes you can always make a light more powerful and have it go further.
Also yes, if your mirror has 3x the front area and your light source is 3x brighter then you have 9x the candela, which means it will go 3x farther (because sqrt(9) = 3) but slightly less when you take into account the atmospheric losses as I mentioned above.

Thank you Thumbs Up , I kinda knew you’d step in and I know you are very knowledgable about it – I can’t believe I was right though lol! (3x further)
G0OSE
G0OSE's picture
Online
Last seen: 3 min 15 sec ago
Joined: 09/03/2014 - 12:34
Posts: 2312
Location: UK SW

Grin , I know OZ is a vast country so I don’t want to sound ignorant – but I always thought there were a lot of helicopters there (sorry, tv programs here always showing sheep rounded up by heli lol)
It would be AMAZING to see the beam from above! – know anyone with a heli – OR a drone? Silly

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

Thanks for the feedback. Even constructive criticism welcome.
I am waiting for a telescope so I can see the beam, I just hope it has enough range.
I have a decent light meter but I have not been able to get consistent results so I dont like to post the readings. The other thing is this is not really a light yet and the light source is hard to focus properly because the mount isnt solid.
Goose seeing the beam from a plane would be something else there is an airport about 6km from me so I have been thinking about how to do it. I have a gsm module I can control from my phone. the lights just need a bit more work.

The next challange is going to be difficult

G0OSE
G0OSE's picture
Online
Last seen: 3 min 15 sec ago
Joined: 09/03/2014 - 12:34
Posts: 2312
Location: UK SW

Parachute jump whilst filming…… Silly and get lit up! wow! NOW THAT would be a video! maybe make you pootube legend! Evil
Maybe rope in that Felix Baumgartner Austrian daredevil! (just kidding lol) or put a balloon on a tether with a go pro?

grin
Offline
Last seen: 2 days 7 hours ago
Joined: 01/05/2019 - 09:15
Posts: 550
Location: Hunter Valley, Australia

Haha I cant do night jumps yet. They have an airshow here and I would be good to light some tiger moths or p51 even yakolevs over the local town.

G0OSE
G0OSE's picture
Online
Last seen: 3 min 15 sec ago
Joined: 09/03/2014 - 12:34
Posts: 2312
Location: UK SW

grin wrote:
Haha I cant do night jumps yet. They have an airshow here and I would be good to light some tiger moths or p51 even yakolevs over the local town.

Doh! I forgot about the night bit, just a tiny detail lol! Facepalm

Pages