Servicing and cleaning the Olympus BHM microscope and 3D printing a Cree LED replacement
EEVblog Main Web Site: http://www.eevblog.com
The 2nd EEVblog Channel: http://www.youtube.com/EEVblog2
Support the EEVblog through Patreon!
http://www.patreon.com/eevblog
EEVblog Amazon Store (Dave gets a cut):
http://astore.amazon.com/eevblogstore-20
T-Shirts: http://teespring.com/stores/eevblog
๐Ÿ’— Likecoin โ€“ Coins for Likes: https://likecoin.pro/ @eevblog/dil9/hcq3

Hi Everyone. So We have a nice Olympus microscope made in Japan and we're going to clean it up and fabricate a light to replace the blown bulb here. We're going to fix it up and let's see how we do. So First off,, I'm going to start by using some general wipes to clean the exterior.

When I Start opening fittings, I Don't want to put dust inside the lenses, so I'm going to get clean the outside first and then I'm going to move the lenses at the end. So We've got these isopropyl wipes here and I'm just going to go over all the surfaces. I've got to undo some of the parts, so I've got some Allen keys over here and fortunately, they're all Allen keys. I Like Allen keys irrationally.

I don't have the Allen key to fit. I've got the Allen key and on this annoyingly large screwdriver.. So, this microscope has this interesting slide here on the bottom that, if you rotate this, it goes this way, and if you rotate this, it goes this way. and this is all great because it lets me move the Allen keys into view.

Now We're going to clean all these parts in order. So, this part has some sticky glue on it. As You can see, underneath. it's quite gross.

I'm just aware of this slide... Yep, yeah, that's there, that's the meeting edge with this. so, one down at that edge. Ok, so all this crusty stuff is coming off really good.

That wasn't doing the business. The Table, when I rub this, is knocking on the wall a little bit. I'm sure the next door neighbors are waiting for someone to walk in the door: "Come in!" Okay, so I'm getting close to the lenses. I Cleaned well...

Has A lot of dust, oh man.. There are, of course, better ways to clean microscopes. I Can't grub too hard here, because if I do, I risk getting lint inside the lens assembly. I don't know how sealed it is.

And We have this assembly at the back, there's a decent chance we're just going to have to remake it. As You can see there's a back plate for this. This Back plate here goes on to the back here and secures the lamp. Those pieces that are chipped off, and I'm going to have to remake something.

So It's looking quite clean now. So The specimen table is beautiful now. Carefully put it on there. try not to get any grease.

Start off in a good condition. And I Can only gather that this doesn't have any alignment requirements. And There's only two bolts. Not All that close fitting, quite loose actually..

Okay, so lets see how smooth it is.. Oh! So This microscope, this knob adjusts the X-position, this adjusts the Y-position and this adjusts the Z-position. - Dave: "Zed" man, "Zed', you ain't no yank. And I Assume this is fine adjustment.

There is actually a screw, stuck in there. What The Hell. There is a screw jammed in the assembly. What The Hell.

Let's just assume this doesn't do anything, because it's not screwed it into anything. Now This stuff, should never be used on lenses or any glass or any optics or any surface that needs to be residue free. I Basically only use this for the paint. See, if this part actually comes off really quite nicely.
Then We have to think about how we're going to replace this light. Okay, so if we put... a torch through here, you'll notice the light is redirected through some sort of mirror assembly, and here down to the work piece. Okay! So I Have been reunited with the power supply of Doom.

Something That Dave challenged me to figure out once and really struggled with that. Anyway, So here we go, turn it on. I Found these LEDs: nice aluminium PCB, good thermal dissipation properties. these.

And I Think this is going to be bright enough for at least some testings. I've set a current limit on the power supply of about an amp, we'll see if it overheats. We have some spares. so.

All Right, let's do this! How Do I turn it on? On. Enter. Shift, enter. Shift, on.

What Did that do? Is It on? All Right, so it's really quite a bright. LED. So, we're getting exactly an amp through this. So Now what I'm going to do is: I'm going to figure out a jig that can hold this in some wire and have a 3D-printed adjustment that can move it like this.

Floating In the middle of the wire, the heat will hold it to itself and I can bond heat sinks to the back of this, to get a bit more thermal dissipation. And Once we have the thermal dissipation, we'll be able to leave it on for longer periods of time and maybe even leave it on a higher setting. So, I Really think this is bright enough and I think we're good to go. Okay, so we have this heatsink, probably from a PT motherboard, or maybe a North Bridge or some kind of chip on a motherboard..

And What I'm going to do is going to bond this to this, and then these will clip into... these little naughty bits, will clip into the 3d printed device. I Think it's going to be quite good. And Then we can actually just slide it.

We Can slide it along here. That will give us the positioning that we need. It does require some finely positioning. Exactly Thirty millimeters on this.

That's kind of weird, because they clearly got a metric dimension using an Imperial socket cap bulbs. But All right, so 30 millimeters precisely. And How much room do we have to work with, before the chamfer on the edge here? And We've got 24 millimeters. Okay, so I'm going into the package called "Onshape" to model the bracket.

The bracket is basically an extruded cylinder and I make some nodges on the end, which I mount to a heatsink. This will be 3d-printed and then I'll insert on the microscope. Yeah! - Woohoo! Look at that! Yeah, we need a spacer. We haven't put that in yet.

- Right. - The Holes got a bit of 3d printing through. - Look at that. Yeah, this is a bit hacky, we know, we know.

It could be engineered better, couldn't it David? - Yeah, we need some thermal adhesives to do it there. - Yep, yep, I think I've got some at home. I Forgot to bring it in. Anyway.
- Okay. - We Just want to see if it generally works. - The Baser fills in the gap for the cable part. - Yep.

- And Now we're going to turn it on. - Is It going to be focused? - Woohoo! There we go. It could be further up up. Yeah Let's go further up.

- When I Push it up far enough, the whole thing falls at an angle. Which means the angle it is being projected. - Oh Okay,, yep. I was just packing up and I realized that the camera was much, much more grainy than it should have been.

Much more, and I think I know why. We had a lens on here and previously, before we put the lens on, the whole thing was open. Yeah, probably for a very long time. They might not have, they might not have ever used this top, this top section up here.

Inside here, not sure you can see it, but it is just caked with dust. So, it's far too deep in there for me to get a tissue paper in there. So, I've been using this this lens cloth and I just haven't even touched the lens yet. This is just the ring before the lens.

Just One touch. That is how dirty it is. Okay, so now you can see. it's quite clear through there.

We couldn't do that before. It was just grey because it had that much dust. Devices Being tested by some probe. There's a lot of probe points, my gosh,, there must be a lot.

So There is also quite a lot of disagreement about whether to use cotton or synthetic wipes. I can't really figure out the harder fiber and since I'm using cotton blends wipes, I figure I might as well use pure cotton wool white tips. So It seems like every man and his dog has his own opinions about which type of cotton bud are acceptable for.... Internally There's a mechanism that opens this...

opens the window for the camera. And that window is the section with the dirt. And It seems it has glass between it, so it's dirty inside, so it has to be opened up. - Now for cleaning microscope lenses and optics, unfortunately, there seems to be a lot of variability on what people and company recommend.

Like Experts recommend in this field. But Generally it's a multi-step process. The First is to use a bulb. One of those blowing bulbs that just cleans loose dirt and things off the lens.

But If you've got really solid, compact dirt on your lens, then you want to generally as a first step, usually recommended distilled water, and then to go on to more solvent based things like isopropyl alcohol. You've got to use the hundred percent kind. And Carl Zeiss For example,, they actually recommend 85 percent petroleum ether, which is generally benzene or rubbing alcohol, mixed with 15 percent isopropanol.. So That's just their own mixture.

Others Recommend just isopropyl or, you know,, they've got their own special cleaning solution. But Generally any sort of alcohol like that should generally do the job. Now, you shouldn't use acetone, because that will attack the plastics. And Of course, the first time you're trying to get the solid dirt off the lens, if it's really caked on, then you want to use pure cotton buds.
And You don't want to rub the cotton buds back and forth. You Just want to do one swipe and then rotate it and then swipe it again and use a clean surface for every swipe of the cotton bud.. Because Otherwise,, if you keep the dirt on there, and you rub it back and forth,, you're just rubbing the dirt into the lens. You Don't want that, because you end up putting micro scratches in the lens and the coatings and all that sort of stuff.

- I Made sure nothing's in here, because anything in here will go in there. There's no lens in here, so I'm just going to feed this microfiber cloth through it. Now, that has obviously put fibers in there. I Get these out.

I'm cleaning this one more time. Again, so it go a few specs of dust since I cleaned it. And I haven't cleaned the inside with Windex. It really does a tremendous job compared to the isopropyl..

So, this lens here. I'm going to clean it again. Last Time I stated there was something, maybe damage, to this one. Turns Out it wasn't damaged, it was something adhered to it.

I Don't know, maybe someone sneezed on it a few years ago? But It was just caked on and isopropyl didn't get it off, but the Windex did. So Now it's looking beautiful. Yeah, it looked almost like an epoxy, but Windex wouldn't remove epoxy. Time to use some wafers! Alright.

Thank you again whoever sent this in the mail bag. You are a legend. I think that's really awesome. So I've got this other wafer.

Actually, thought it is much more interesting than the one I'm looking at now: this is the test piece, this one here. I suppose for testing the manufacturing process. This one's, I think, an actual wafer. That's much more interesting.

Now I should be able to swap lenses, while staying in focus. Ah, pretty close... So that's, from 40 to 20. Thank you, AT&T.

Look at the sensitivity of this. Notice The screen is shaking. It's probably the aircon system. All People walking around the building.

So, I'm just going to stamp my foot. Not hard but, just near it. Absolutely requires very solid foundations to operate. Truck goes by, I'm sure this shakes.

Okay, I Noticed that it was still kind of... a bit, had like a... film or something on it. The actual wafer had had been quite dirty, so I cleaned it.

Now it's... the film has gone away. I don't know. I Think this is a win.

So, for the light assembly, I Basically use one of those LED... these power LEDs on the aluminium. PCB. I put some thermal compound between this and a random motherboard heatsink, and just shoved it in a constant current source.

So, I just cable tied these on there. I Could probably use some thermal adhesive, but cable ties are fine; hold it on pretty tight. And Yeah, now I'm not really having any overheating problems. LM317, yeah, those can make current sources of about a Watt, so that should be exactly what we need.
Okay, so we've got our 317 and a couple resistors and a capacitor. That's all that's needed for an LM317 current source. All you do, for an LM317 current source is: you tie this to the middle pin; That's the output. And Then all you need to do is tie it to the adjust pin, which is probably pin 1.

I think that's this pin. I Got it over here: Pin one is the adjust. Yeah, so it's pretty simple. Then We're going to solder this.

Okay, so it's all soldered now. Now We're just going to snip off the excess leads and then we're gonna hook it up. Okay, so I don't really want to be soldering to the pins in the middle, so I'm going to kind of literally cut them off. This is kind of bodgie.

I soldered the USB connector, and usually the USB connector itself would be supported by a circuit board PCB, and that would take the strain. In This case, nothing's really supporting it, so I'm going to have to put some hot melt, which will kind of relieve strain on the cables and stop this from snapping off over time. Okay, the hot melt has been neatened up a little bit. So Now I'm ready to join it to the constant current source.

Just Checking the polarity of the connector. Can't be bothered to check the datasheet. Time to mark the ground. Now What we have is the constant current source.

I've got it just connected to the Amp range here. And There it is, connected to the USB pack. And We're getting 300 milliamps, just as we should. Just Going to attach a heatsink to the thing.

The First test is: if this battery pack turns on, its shorted. Okay, it doesn't, so it should turn on when I Plug this into the Amp setting. Okay, that's the Amp range. Are You going to turn on? Yes, you do! 300 Milliamps, we're good.

I've finished the little package and here's the constant current source. Here It's measuring the current. I Changed it from a micro USB connector to a cord because the micro USB connector, I kind of filled with glue. So Here we go, nice and neat.

And Let's go plug it in. So The lights is on the device and it's on right now. You Can see that tiny, white dot at the bottom. Probably not.

There We go. Plugged into the computer's USB port. So Now we don't have to have a huge power supply here. - Winner!.


Avatar photo

By YTB

22 thoughts on “Eevblog #992 part 2 – how to clean service a microscope”
  1. Avataaar/Circle Created with python_avatars B. Smith says:

    He is unofficially a Yankee now ๐Ÿ˜† ๐Ÿคฃ

  2. Avataaar/Circle Created with python_avatars Amra says:

    Hexane is what we were always told to use to clean lenses back when I was in lab, we were told to use this because its virtually non polar and because the carbon-hydrogen bond in special in that it doesn't interact with other materials (something about how its liquid state is maintained almost entirely via van der waals forces), where other commonly used solvents like xylene may be non-polar, but they contain aromatic rings which interact with other materials.

  3. Avataaar/Circle Created with python_avatars Jakob says:

    Why would you like allen keys? Do you enjoy carpal tunnel?

  4. Avataaar/Circle Created with python_avatars chad cole says:

    Hey! Any chance we can get a link to the 3d printer files for the adapter you've done up? I just got one of these scopes myself and the bulb is missing so I figured I'd attempt your mod! Thanks.

  5. Avataaar/Circle Created with python_avatars Pink Panther says:

    I need to service my scope bc there are not shops in this one horse town for microscopes.
    The title is misleading. WASTED MY TIME. (no thumbs up)

  6. Avataaar/Circle Created with python_avatars Bendirval says:

    Where is part 1? Can you link to it in the description?

  7. Avataaar/Circle Created with python_avatars Richard DePas says:

    We used to use these type of microscopes on air flotation tables. They were a bugger to get dialed in but it would allow them to be used vibration free.

  8. Avataaar/Circle Created with python_avatars Sabatini says:

    Gracias, muy buen trabajo

  9. Avataaar/Circle Created with python_avatars ranny day says:

    Dude!
    Do you know how lucky you are to be picked by "The Great Dave Jones" to be his "apprentice"?
    Quit thinking "I'm recording what are people gonna think……………..?" in the back of your mind
    That's killing you!
    Get your confidence back!
    Speak your mind!
    Don't worry what we think!
    We are watching to find out what you think! LOL
    Quit pausing,studdering,second guessing yourself. I'm not sure but i think the master has said
    "GROW A PAIR"
    Man you have a great opportunity to do great things!
    Relax stop being nervous and speak your mind…….
    best wishes…………..

  10. Avataaar/Circle Created with python_avatars danijel124 says:

    Would it hurt the lens to use an air compressor?

  11. Avataaar/Circle Created with python_avatars ifrit05 says:

    I'm a Yankee and I still say "Zed".

  12. Avataaar/Circle Created with python_avatars Robert Mosรฉn says:

    Watched him doing the plasma TV repair, seems like a fun dude. Is he doing some uni-essay-work at your workshop?

  13. Avataaar/Circle Created with python_avatars Stefano RR says:

    Dave forgot to say chicken dinner

  14. Avataaar/Circle Created with python_avatars Aperson says:

    I'm American. I've caught myself saying "zed" a few times.

  15. Avataaar/Circle Created with python_avatars JG says:

    I though the operating term on EEVblog was "hot snot"

  16. Avataaar/Circle Created with python_avatars EL TIGRE CHINO says:

    jajaja new flavors to eevblog

  17. Avataaar/Circle Created with python_avatars Jar says:

    David, you need to take control of editing next! Ahahaha…. the power. Loving the comedy bench PSU.

  18. Avataaar/Circle Created with python_avatars AskAScientistShow says:

    In relation to the shacking, if you clamp the sample to the solid microscope stage you'll reduce most of that. Also, in medical research we often have our better microscopes sitting on a 250-750kg stone table top and sometimes these tables will have mechanical dampers built into the legs.

  19. Avataaar/Circle Created with python_avatars dasuboot123 says:

    Why not simply put all the parts inside of a dishwasher altogether with one of these "100% free of streaks" tabs?

  20. Avataaar/Circle Created with python_avatars Ozzie Peck says:

    that heatsink is probably from the PCH on an intel based motherboard. (if it was from a computer motherboard that is)

  21. Avataaar/Circle Created with python_avatars becky15675 says:

    can you NOT cut bits out. thank you

  22. Avataaar/Circle Created with python_avatars Dave Blane says:

    WHO is this guy?
    WHY do we care about cleaning a microscope?
    Dave needs to clear out the HOARD.

Leave a Reply

Your email address will not be published. Required fields are marked *