Ah, I missed it! I will keep my eyes open next time

Steve

It's my nature by necessity, otherwise I'd have very very few nice things rather than a lot of okay stuff.

 

At the MIT flea market today there were three of the Bausch & Lomb microscope heads.
The vendor was asking $50 each. He probably would have taken closer to $30.

My pictures of today's MIT flea are at http://tinyurl.com/44mpwq

(* jcl *)

 

aww, too bad I'm in the cold north (Canada)

You should have spotted me man, I'm good for it!

Steve

 

Yay! I took the advice and frequented ebay often in search of a zoom scope. It may not be the best quality, but it seems decent. 200$US w/shipping

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140271994287&ssPageName=ADME:X:RTQ:US:1123

It is about the same price as the cheap asian import fixed zoom scopes, this seems that it could be quality and it has variable zoom.

Steve

 

Looks good. I didn't reaize the shipping was so much different to your country. $25 to $30 is more common for the US east coast from California. Hope you like it.

John

 

Thanks John,

I actually live about 30mins from the US border and pick up my packages from a border store. They charge 3$ a package, then I bring it across the border myself. This saves on brokerage fees and shipping.

He actually charged a bit too much for shipping, but I knew that before bidding. I won't really know how good it is until I see it, it looks alright though. Even the cheapest zoom scopes available are 400$, while 1200-2000$ being common for top grade stuff.

Steve

 

Congrats, Steve

Your next mission, Mr. Phelps, is to construct a billion candlepower lamp so that you can see items in the 'scope...

Seriously though, you're going to need a LOT of illumination to see well under that scope. A high intensity lamp will be marginal, at best - and you'll always be burning yourself on it while you're looking through the eyepieces (ask me how I know this )

Consider getting a number of high-intensity white LEDs (like Lumilux, or brighter if you can find them) and making a donut-shaped PCB that will fit around your lens. This way you can provide a lot of even lighting without generating a lot of heat. Uneven lighting will make life unpleasant. Insufficient lighting will cause eye fatigue.

 

Thanks Wookie!,

I have been wondering of a good and cheap way to do this. I purchased some 1W luxeon LEDs with 15degree reflectors, but that is for my submarine project. I'm shocked how bright they are. Maybe I will need to buy some more.

Just when I made the bold statement of "I never make my own PCBs anymore" in another post, I just may have to. A simple PCB like this doesn't deserve its own run. I will probably just mill it out on my CNC. I'll definitely post my modifications for other people to see.

I don't solder often, but when I do, I solder very tiny parts. I will definitely need a good source to get in all the nooks of the SMT components. This is very exciting, no more using 3X magnifiers to solder.

Steve

 

You have your own CNC? Geeze - mill it out yourself. That's really a no-brainer.
Consider it a prototype; it's a one-off anyway. OTOH, you could possibly make a pile of money selling a suitable scope light on auction sites, were it good enough

The light needs to be bright, yet diffused. You don't want reflections; just good illumination.

2x magnification means you need 4x of what would be considered normal room lighting.

Since your new 'scope is 10x magnification, you will need a TREMENDOUS amount of light to be able to see anything well under it.

Light intensity diminishes at the rate of the square of the distance; eg: a globe 1' away from a light source is 1/4 as bright at 2' distance. The same is true of microscope magnification. The higher the power of magnification, the more power you need to illuminate your object. But, squared.

 

Wookie,

Thanks for your continued advice, I really value it, especially from someone with as much experience as yourself.

I didn't think of the light that way, but it makes perfect sense. I will look up some specs on inspection lighting and typical room lighting in lumens, then make the appropriate corrections. I saw some nice 0.5W 'warm' white LEDs that should work well. It is possible to use the 1 to 3W luxeons too, since they're not too expensive. I am considering spinning a 2-layer PCB because I have some other stuff to throw on anyways. I get a 60 square inch run, so I will be able to fit it on.

I want to be able to control the light via PWM. Probably a good idea for examining different types of materials, dark, textured, white, etc.

I believe the scope is actually higher than 10X. There is a 'zoom' that looks to go to 3.5, which I believe is a multiplier on the 10. We'll find out anyways when I get it. Perhaps I should wait to design the light 'doughnut' until I know how much I am going to need.

Steve

 

Wookie,

Thanks for your continued advice, I really value it, especially from someone with as much experience as yourself.

I'm an old nearly blind fart. I don't want that to happen to you.

I didn't think of the light that way, but it makes perfect sense.

Please believe me. Your vision is precious. Straining your eyes is not something that you want to do. I suggest that you will need them for a long time, unless you venture into Chicago.

I will look up some specs on inspection lighting and typical room lighting in lumens, then make the appropriate corrections. I saw some nice 0.5W 'warm' white LEDs that should work well. It is possible to use the 1 to 3W luxeons too, since they're not too expensive. I am considering spinning a 2-layer PCB because I have some other stuff to throw on anyways. I get a 60 square inch run, so I will be able to fit it on.

Cool beans. Good lighting beats the heck out of bad lighting. I just wanted to wake you up to some of the parameters.

I want to be able to control the light via PWM. Probably a good idea for examining different types of materials, dark, textured, white, etc.

Absolutely! PWM's the way to go. However, you really need more like an inductor in the path with a Schottky diode to feed the current back into the LEDs. Basically, a buck regulator.

I believe the scope is actually higher than 10X. There is a 'zoom' that looks to go to 3.5, which I believe is a multiplier on the 10. We'll find out anyways when I get it. Perhaps I should wait to design the light 'doughnut' until I know how much I am going to need.

You're going to need a LOT of light.

I'm not kidding. Otherwise, it'll be like looking into a black hole.

A 3x-4x 'scope was light-starved with a single high-intensity lamp as the source. You're going far beyond that.

What you're getting will work, but you need to be able to supply enough light to be able to see anything. Straining your eyes is a very poor solution.

You'll see when you get it. Well, maybe you won't. Trust me - don't strain your eyesight. Make plans to upgrade your lighting ASAP.

 

Wookie,

I am taking your advice and am going to get on it ASAP. I have 6 PCBs to solder with fine pitch components next week, so I may need to temporarily jerry-rig something to be able to see anything at all. Thankfully I have those 1W luxeons. I may just use the five of these with the 15 degree reflectors. They provide, almost literally, blinding light on an individual basis.

I love my eyes and don't want to hurt them! I will get on top of it Thanks!

Steve