Just started a dental flashlight project

[constantine_a_f]

Hello,

I will try to repost my photos (I will give you a picassa link) and also add more information. Can you give me a description of what you used so far? Also, what is the working distance for your loupes?

I am now upgrading my light with a new led, new power source and driver.
I will use a micro buck/boost configuration without dimming and a 5 volt usb rechargeable battery pack. I will order the parts soon. I will also make my own loupes (or try to).

If you have any more questions please post them.

 

[constantine_a_f]

Here you go

https://picasaweb.google.com/103324404812037100600/DentalHeadlamp?authuser=0&feat=directlink

 

[kosPap]

VERY good work "synwnomate"...

Pattafix! hahaha! amazing!
one suggestion..please try different connectors....something like these. the shops you baught the materials from have something similar (milky white material)

http://www.andersonpower.com/products/multipole-connectors.html

 

[constantine_a_f]

VERY good work "synwnomate"...

Pattafix! hahaha! amazing!
one suggestion..please try different connectors....something like these. the shops you baught the materials from have something similar (milky white material)

http://www.andersonpower.com/products/multipole-connectors.html

I will use a standard usb cable with the Kensington battery pack so there is no need for a connector. But I like them so maybe I will go and ask for something like that as a b option. Thanks for the comment (euxaristw poly!!!)

 

[danboy]

Hello,

I will try to repost my photos (I will give you a picassa link) and also add more information. Can you give me a description of what you used so far? Also, what is the working distance for your loupes?

I am now upgrading my light with a new led, new power source and driver.
I will use a micro buck/boost configuration without dimming and a 5 volt usb rechargeable battery pack. I will order the parts soon. I will also make my own loupes (or try to).

If you have any more questions please post them.

Actually at the beginning i have bought this torch from an ebay seller: http://www.ebay.com/itm/170663654616?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Then I took out of it the cree led, the driver, the aluminium heatsink and the plastic lens, just to make it all smaller. Then, i managed to find an old broken fiber optic headlight system in some sort of technical garbage of a hospital. i took it apart, and took out the lens and the diaphragm out of it to play with all parts i got from those 2 systems to make the best possible headlight out of it

The red arrows indicate the parts i have used for the torch seen on the 3rd photo.
it's battery pack (just a plastic box i found to hold 2 AA batteries), Silver heatsink, black part of a tube, smaller lens with the diaphragm, large lens (both Glass), and the cree on the aluminium plate, connected to the black cable which leads to the driver which is hidden in the battery pack.

As you can see, it's very primitive and alot of work is still ahead... I have fixed all parts including the lens with this white tape, The long size of it is because of the optical needs, i had to move the lens to a certain distance to maintain the focused beam. now if i could find better optics for that matter, i'm sure it can be alot shorter and lighter. (there are 2 lens in the system right now, unfortunately i can't tell its parameters because i simply don't know. i just got it out of the headlight i found)



I am using Heine HR loupes x2.5 420mm. and the beam i somehow got is exactly the size of the area seen in the loupes while in working distance (420mm).


Tough project :duh2:, as Theodore Herzl said: If you will it, it ain't no dream

i have bought some 23mm glass lens in www.dealextreme.com but i don't know if it's the right angle i need. i just hope to test try it instead of the smaller lens,and i hope it will shorten it's size... i will definately continue updating the progress, come on it has to be done somehow ! no way Heine light cost 1200Euros and is made of diamonds. it's the same cree, pretty much the same optics, only different sizes.

 

[constantine_a_f]

Very nice indeed. I suppose you are going to use a headband for your system (I would If I had the parts you managed to find). I used a carclo 9 degrees TIR because of the led I chose. I wanted a high cri, high lumens led, so I designed from inside to outside. Led first, then optics, then the housing which acted as a heatsink as well (aluminum housing). The final make was small enough for me to mount it on the frame. I considered using lenses (less spill and a more concentrated beam) but it would make it harder to put together and also heavier. But you made it work ok so you should be happy. Great work!!!

ps heine as well as everybody else is extremely over the real price.

 

[danboy]

Very nice indeed. I suppose you are going to use a headband for your system (I would If I had the parts you managed to find). I used a carclo 9 degrees TIR because of the led I chose. I wanted a high cri, high lumens led, so I designed from inside to outside. Led first, then optics, then the housing which acted as a heatsink as well (aluminum housing). The final make was small enough for me to mount it on the frame. I considered using lenses (less spill and a more concentrated beam) but it would make it harder to put together and also heavier. But you made it work ok so you should be happy. Great work!!!

ps heine as well as everybody else is extremely over the real price.

Thanx! alot of work is still ahead, this is only the beginning...
I do want it to be mounted on the loupes, so now i will start looking for ways to shorten it alittle, first by finding another better suitable lens instead of the "small lens".. if I only knew what lens parameters to look for.... because now, the long distance between the "small lens" and the "bigger lens" is critical for the good focus. i suppose if i will change the smaller lens to something more suitable- i might be able to bring the "bigger lens" back closer to the led.

any ideas?

I am using a 200lm cree, and just ordered some 700lm led in Dealextreme (can't be sure it is true with dealextreme, but anyway)
-how did you came to the Carclo 9 deg. lens?

 

[constantine_a_f]

I guess (I am not an expert by any means) that a smaller f lens would allow you to put your objective lens closer (inside the focal length of the small lens). I am not sure if this is how it works. Maybe something form edmund scientific or a less expensive one from ebay.

I chose the luxeon rebel because of its high cri (90) that would allow me to do color matching. I opted for a 90-120 lm because I (correctly) thought that over 200 would actually annoy my patients if by mistake while working on the 12 o'clock position, I looked at their eyes. Also, there was the problem of heat dissipation and energy consumption (the final make never heats up to more than 30 degrees Celsius and can run for over 30 hr without recharging the battery pack-if I stay near 100 lm). I actually ended up using the led at 2/3 that around 80 lm via my dimmer. If you cannot tolerate the light heating you indirectly at your mouth with your eyes opened, then don't use a high lm led or give your patients protective eyeware (I guess that is the standard of care anyway-but not everyone will like it).

Please make sure that the heatsink you use is enough, so that you have a long lived led and a less burned forhead (remember you are wearing this on your head for more than 4h per day). You can find a heatsink calculator here along with other precious information http://www.luxeonstar.com/kb_results.asp. I also got my driver from there.

I also chose a luxeon rebel because I wanted a low degree optic / tir in front of it. I found out via this site http://www.led-tech.de/en/High-Power-Supply-c_106_0.html , all the available tir to led configurations and I opted that the carclo+luxeon was the best because of the 9 degrees total angle (be careful some of the angles mentioned are half, i.e. 10-->20-->doctor please you are hurting my eyes).

So that's how I chose the carclo. I have a nice round beam with pretty much no spill and the same field as my loupes (zeiss g 2.5 TTL, extented field of view).

I will make an upgrade with a 95 cri, 90-100 lm led when they have it in stock and I also started designing my own loupes.

You have a nice thing going there. I like a lot the spot size you achieved.

Get a local shop to machine you a housing when you finish. I could help you design it in autocad if you like. It will cost you some more money but you will have a very comfortable (temperature wise and size wise) light at the end.

PS. Have a look at these sites for more info on lenses (amateur info-but info nonetheless)
http://www.funsci.com/fun3_en/lens/lens.htm#5
http://www.physicsclassroom.com/class/refrn/u14l5a.cfm

You can also use this to do some rudimentary ray tracing (and have some fun understanding the nature of the problem you faced)

http://www.arachnoid.com/OpticalRayTracer/index.html#The_Applet go to configure and put more beams in the beam count (20-30) and also change source y start to 0 (that is your led).

Hope I helped

 

[Walterk]

Very nice ! Good work there, very nice beam.
I like the diaphragm a lot, it's a 'first' on cpf I think.
Did you notice a big difference in spot diameter?
Did you notice a more clean edge of the beam?

 

[danboy]

I guess ...

...Hope I helped

Thank you very much Constantine! I will s study this info and try to figure everything out!

 

[constantine_a_f]

Thank you very much Constantine! I will s study this info and try to figure everything out!

Ok and please post everything here. You've done an amazing job so far and I would really like to see it come together!

 

[danboy]

Very nice ! Good work there, very nice beam.
I like the diaphragm a lot, it's a 'first' on cpf I think.
Did you notice a big difference in spot diameter?
Did you notice a more clean edge of the beam?

thanx Walterk!
The difference in spot diameter is proportional to the aperture of the dia-gm.
the previous photos were taken with it fully opened, so the beautiful focused spot is not because of the diaphragm but because of the smaller lens.
i took few photos of the diaphragm changes, so you can see the difference.

the next is pretty much the same distance from the wall, but smaller aperture:

anyway, it's a good option for those who need to be in control of the beam size, i need it fixed - same as the area i can see through the loupes, so I used the diaphragm only because it can hold the smaller lens in place )))

 

[Walterk]

Thx for the pictures. Its a good way to have a sharp cut-off as it stops stray-light.

 

[MikeAusC]

In tests I've done with dual-lens systems, the brightest spot is obtained when the projected spot is essentially an image of the first lens, focussed by the second lens.

 

[danboy]

In tests I've done with dual-lens systems, the brightest spot is obtained when the projected spot is essentially an image of the first lens, focussed by the second lens.

Actually in this case, the image seen without the second lens is the square led, and even if i play with it back and forth while changing the square to rounder spot, the second lens would make it round and focused no matter what was the first projection. i mean it wouldn't make the cree led projection look more focused, it just makes it round and sharp, as i posted...

 

[MikeAusC]

Actually in this case, the image seen without the second lens is the square led, and even if i play with it back and forth while changing the square to rounder spot, the second lens would make it round and focused no matter what was the first projection. ...

Actually . . . . that's what I wrote ?

 

[danboy]

Actually . . . . that's what I wrote ?

I just wanted to add that the 2nd lens would make the spot round and relatively focused no matter what was the spot "shape" after the 1st lens.

On the other hand,
when i used the two lens together on a constant distance, moving the LED closer and away from the 1st smaller lens- only changed the (final)spot diameter alittle and affected the light intensity on the center/peripheral areas of the spot.

Sorry if i didnt understand u correctly at the beginning

 

[pgjohnson2244]

Here you go

https://picasaweb.google.com/103324404812037100600/DentalHeadlamp?authuser=0&feat=directlink

Hey Constantine - I'm a dental student in the U.S. and just designed my own headlight. It was received well by my classmates so I decided to manufacture them myself. I went through a very similar process that you've been describing. Here is my website - www.johnsondentallabs.com

 

[billyjones454]

Hey Constantine - I'm a dental student in the U.S. and just designed my own headlight. It was received well by my classmates so I decided to manufacture them myself. I went through a very similar process that you've been describing. Here is my website - www.johnsondentallabs.com

Cool light! When I made mine, I used, neodymium magnet to mount them. its the best mounting system.

I'm not even remotely satisfied with 120 lumens however. I'll take a larger light for more lumens.

 

[pgjohnson2244]

Cool light! When I made mine, I used, neodymium magnet to mount them. its the best mounting system.

I'm not even remotely satisfied with 120 lumens however. I'll take a larger light for more lumens.

Thanks. It has been a big undertaking, especially during dental school. I played with a several other LEDs and different drivers; it was kind of a balance in keeping the weight down and keeping the LED bright enough. Great minds must think alike with the magnets