Help with Leica DMLB

[moletteuk]

Hi, you recently helped me deciding to buy the Leica DMLB on ebay in this thread viewtopic.php?f=16&t=14093

It arrived today. I would appreciate some help, there are problems apparent already.

So one of the eye tubes has been bashed and is no longer quite circular so the eyepiece does not fit in. I also can't seem to rotate the headpiece to move the eye tubes further apart/together, should this move freely by hand?

There are no leads for the motorized stage and no glass in the stage, so it is currently just an immobile platform with a hole in it.

The power cover thing at the back is taped on.

I'm going to see if I can manually rig up a slide on the stage to try to test the objectives.

[viktor j nilsson]

Ouch, that's not what you wanted to see - signs of receiving a pretty hard blow. Good news is that both of those things should be enough to warrant a return and full refund if you choose to do so. Or, if you decide to keep it, should be ground for a substantial refund.

You definitely should be able to move the eye tubes by hand. It does seem like the mechanism may have gotten crooked from whatever force deformed the eyepiece tubes. That would not be easy to fix, but would probably require a new head. And, since the head has both prisms and a tube lens inside, there's a significant risk it is out of alignment.

[BramHuntingNematodes]

An expander tube swage would be able to fix the eyetube but it costs more than a new head likely and won't fix the other problems. If you got a plumber buddy they might have one already.

[moletteuk]

OK, so we have managed to move the eye tubes apart a certain amount, although they don't seem to move all the way out according to the scale.

The view so far is amazing through the one eye tube using the 4x 10x 20x & 40x I think the 1.25x is bust and I'm struggling to test the 100x without a working stage.

Can someone tell me what the powered device is in picture 3?

The focussing seems to work manually with the controls on the left and should be powered on the right side if we knew or had anything to plug it into. It's behaving a bit weird on the manual side, like it is working agaisnt the motor on the right. Can anyone advise on this?

[75RR]

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Contact seller, list observable problems (emphasize the scotch tape fix) show photos and either return it or get sufficient money back to make the objectives very economical. Then look for another frame.

[viktor j nilsson]

OK, so we have managed to move the eye tubes apart a certain amount, although they don't seem to move all the way out according to the scale.

The view so far is amazing through the one eye tube using the 4x 10x 20x & 40x I think the 1.25x is bust and I'm struggling to test the 100x without a working stage.

Can someone tell me what the powered device is in picture 3?

The focussing seems to work manually with the controls on the left and should be powered on the right side if we knew or had anything to plug it into. It's behaving a bit weird on the manual side, like it is working agaisnt the motor on the right. Can anyone advise on this?

The 1.25x could have much longer working distance than the others, worth checking if you can focus if you rack the stage down much further. At least in older scopes, such low magnification objectives were not parfocal with the rest. Often not even by a mile.

The stepper motor on the right side could definitely give some resistance and weird feel. Can it easily be disconnected?

Very glad the 10,20 and 40 appear to be good. If you can get the price down as much as I think you can it could still be worthwhile to keep it for those alone. Doubt that the seller wants it back in this condition, as it seem to be a large volume surplus seller.

[dtsh]

I have had some luck reshaping minor dings in tubes by applying a C clamp across the widest section and slowly tightening to bend it back into shape; it seems to work best with thin tube and minor deformation. I tend to use a telescopic gauge in the tube to find the widest part and keep tweeking until the gauge can rotate smoothly all the way around if it needs to be precise inside (as it would here). I haven't done this with eyepiece tubes, but I have on other metal tubes.

[PeteM]

It sounds like you'll want to disassemble, clean, and lubricate the head to get the interpupillary adjustment (and likely the diopter adjustment) moving freely.

If you remove the out-of-round eyetube (to have good access for safely removing the dent) you could find or make a slowly tapered mandrel (something like a finger-ring sizer or even a Morse taper tool end) to persuade it back to round. A reasonably equipped machine shop might also have expanding arbors that could work. And as said earlier, there are pipefitting tools that could do the trick. You might even get a 30 mm eyepiece sleeve (commonly sold with cheap cameras) and grind a smooth taper on it. I've also had luck using a round heavy rod inserted through the eyetube and tapping the dented part out against an anvil surface. Sort of like the "Dent Pro" auto body repair method - tap, tap, tap . . .

You definitely don't want to run the lamp with the vents covered in tape. I'd suspect there's a crack in that housing; perhaps repairable with an epoxy glue such as JB Weld.

As Viktor said, the 1.25x objective may not be parfocal with the rest.

You'll eventually want to replace the stage. For now you might make or buy a slide carrier and move it by hand over your fancy but immobile stage.

[BramHuntingNematodes]

Maybe the tape is just for shipping. These surplus guys go crazy with boxing tape.

[moletteuk]

Thanks.

The seller has replied to say I can return it or get a partial refund, although no sum was mentioned.

The tape was just for shipping on the lamp cover, it seems to just sit in place with one lug and gravity, shame the tape has pulled off some printing with it, sigh.

I think the 1.25 probably is OK, I managed to focus it, I think it needed all the settings changing as I was still getting the iris showing black around the perimeter or something, haven't got all that figured out yet.

I think the eyepiece might be fixable by somebody with the tools and skill, and it seems to just be screwed on to the head so maybe the part would be available to buy.

I've managed to get the main part of the powered focus drive off, so the fine focus is engaged now and working better and hopefully the random movements and buzzing will stop now. The main focus wheel isn't exactly smooth, but it's usable.

I'm still struggling to check out the 100x, I've had to stop because I feel really nauseous straining at the blurriness and moving the slide about looking for the subject. I did manage to get a couple of fungi spores in view but there was a lot of detritus showing up. Is it normal for a lot more dirt to be showing at 100x?

I've laid some fungi on a couple of slides so hopefully I'll have some well covered slides to carry on investigating the 100x tomorrow.

[BramHuntingNematodes]

You can see more dirt if the NA is tamped way down-- you oiling the condenser and the slide?

[75RR]

The seller has replied to say I can return it or get a partial refund, although no sum was mentioned.

See if someone here can give you an idea of what the objectives are worth - you will need that info to gauge whether the refund is acceptable.

Damage to eyepiece tube might have been due to shipping, however if it had been well packed it should never have happened.

By the way, one lug holding the lamp cover, while something you can live with if everything else is fine, should have been mentioned if microscope was sold as used i.e. working

Use of scotch tape indicates seller aware of the problem

See ebay condition listing:

https://www.ebay.com/help/selling/listi ... olid=10001
.

[moletteuk]

OK, thanks. So how much do you guys think the objectives are worth in UK? There are 1.25x 10x 20x 40x 100x HC or HCX Fluotars and a 4x C Plan. There aren't many on ebay so quite difficult for me to gauge.


I'd appreciate some help with the stage, please. Since there is just a hole in the middle of the stage I am putting a cover slip across the middle and then putting my slide on top of that so that I have a flat surface to move the slide around to find the subject and this is working OK for everything except the 100x.


When I add oil and put the 100x into position the objective is too high and the stage won't go any higher. Firstly, will there be a 'stop' somewhere stopping the stage going higher, or have I perhaps run out of travel? Secondly, is it weird that the 100x is so far from being parfocal with the other objectives that I need to raise the stage significantly (2 or 3mm)?

[Hobbyst46]

Mechanical problems and deficiencies are real nuisance. If the microscope was listed as "used", given what you describe as the deformed eye tube alone would justify return and full refund. And the motorized stage is missing parts and/or inoperative (for whatever reason)... itself again justifies return.
In theory, keeping the microscope for a partial refund will enable you re-sell the objectives and perhaps some other fragments and make a small profit.
In practice, it would be an investment (the sum you still paid, after refund) in hardware pieces, instead of a working enjoyable microscope, which was the purpose of the initial transaction.
Instead of looking for a Leica stand, I would ask full refund and seek a complete working microscope from a reliable seller.

[75RR]

When I add oil and put the 100x into position the objective is too high and the stage won't go any higher. Firstly, will there be a 'stop' somewhere stopping the stage going higher, or have I perhaps run out of travel? Secondly, is it weird that the 100x is so far from being parfocal with the other objectives that I need to raise the stage significantly (2 or 3mm)?

Find out how high your condenser goes, then build up your makeshift slideholder - by placing slides on the two sides of the stage and then bridge your slide between them so that your slide with the cover slip is 1 / 1.5mm over the condenser lens.
.

[mrsonchus]

......instead of a working enjoyable microscope, which was the purpose of the initial transaction.
Instead of looking for a Leica stand, I would ask full refund and seek a complete working microscope from a reliable seller.

I agree with you there Hobby46 - I would send that back - looks to me personally quite disgraceful to have charged what was paid then send a bit of a wreck out. If there's one sure-fire way to have a new hobby or interest spoiled, even to the extent of becoming disheartened, it's to begin with a non-functional stand that's not going to be quick, straightforward or cheap to bring-back.

That exciting time of viewing your first specimen minutes after it arrives, then sharing the wonder with others is lost.

Easily-done, nobody would have expected to receive the 'scope in that condition. Too much money really to invest in parts that may or may not lead to a functioning 'scope months down the line with luck. I'm really sorry you've had this experience, try not to let it put you off.

John.

[BramHuntingNematodes]

also if you're selling a junked scope for a thousand quid you think you could at least package it well

[ScienceMatters]

I agree with the others that you will probably be happiest in obtaining a new stand. But are the Fluotar objectives in good condition? If so, those are WELL worth the price you paid. If you can get a partial refund, buy another Leica stand, and use those Fluotar objectives on it, you’ll have a really nice setup. If the objectives aren’t clear and working, then you’re probably best off returning the whole thing and starting over with the new knowledge you’ve gained.

[PeteM]

+1 to ScienceMatters

[moletteuk]

Thanks for the ongoing help and advice.

I'm still struggling with the 100x. I'm persevering so I can decide whether to try to negotiate or just send the whole lot back.

Thanks to 75RR I removed the stage clips so I could place a slid on either side for supports and I raised the condenser to within a mm or so. I set the condenser apperture around 0.9 for the 100x. Last night I had a quick go and fairly easily managed to then focus the 100x on a slide and got what seemed like a good view.

This morning I just can't get the 100x to focus at all. It's nowhere near parfocal with 10, 20 or 40x which are all fairly parfocal with each other. I haven't struggled like this with my old antique microscope, but I just can't figure out what is going on and why it's so hard.

Any ideas?

[75RR]

.

This morning I just can't get the 100x to focus at all. It's nowhere near parfocal with 10, 20 or 40x which are all fairly parfocal with each other.

Make sure that the slide is not upside down i.e. cover slip on the bottom.

Easy to do - I think most of us have done it at one time.

Also you may want to oil the objective to the slide, much improved view.

If you do not have immersion oil then there are emergency alternatives, like olive oil ...

[moletteuk]

I've tried about 5 different slides, cover slip definitely the right way up, definitely oiled, I just can't even find the subject at all.

[75RR]

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Center and then close the condenser down using the 100x, then go to the 4x and without moving the condenser find the subject, then go back to the 100x

[moletteuk]

OK, I just randomly got it to focus! And then I put my hand on the stage to adjust the position of the slide and now it won't focus again. The stage wobbles when I touch it. If the stage isn't perfectly square on to the objective, will that be enough to stop it focussing?

[75RR]

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Very much so - we are talking µm here

Can you check under the stage for loose screws?

[Hobbyst46]

In the absence of a proper mechanical slide holder, it would be very difficult to experiment anything with a 100X objective, even when oiled.
Note that the width of the field of view for a 100X is only 200-250 micrometer, the smallest lateral shake of the hands will shift the object away from view.
And the working distance is about 0.1mm, so absolute stability of the stage (and all the added slides) is a must.

[moletteuk]

Well, at least this is all a good learning opportunity, even if that's not quite what I intended!

We've got the stage off, it seems to be held in place with one grub screw which has chewed up the metal, so it not longer properly bites.

[75RR]

Last night I had a quick go and fairly easily managed to then focus the 100x on a slide and got what seemed like a good view.

Might want to take that as the 100x is ok and negotiate accordingly. Seems a new stand is called for.

Article on how to check for delamination just in case: https://www.microscopy-uk.org.uk/mag/ar ... delam.html

+

Also here are Ebay sold prices (in green) for HCX PL Fluotar and HC PL Fluotar to give you an idea on how the negotiations need to go to make it worth your while.

https://www.ebay.co.uk/sch/i.html?_dmd= ... r&_sacat=0

https://www.ebay.co.uk/sch/i.html?_dmd= ... r&_sacat=0

[moletteuk]

Thanks for the link 75RR. I've had a look with a hand lens at a couple of the objectives but I was struggling to make much of what I was seeing. We got the stage a bit more steady but I think it must have been steady in the wrong plane because I can't get it to focus now, so I'm definitely at the end of the exploratory road.

I've got some thinking to do, but I think my gut is telling me to err on the side of caution and return it unless he wants to offer me the majority of my money back.

[zzffnn]

I also think the main scope body is not easily repairable in your hands, moletteuk. Most likely, the scope has had severe mechanical trauma, which bent its eye tube and damaged its mechanical stage.

Remember scope parts usually sell for more than a complete scope (it may not be fair to you, the buyer, if you get individual prices of parts and add them together). The scope main body, being so heavy and bulky, costs quite a bit for shipping and is not easy to buy or sell.

And remember when you are returning, the return cost is on the seller, because he lied to you.