Adapting a computer monitor arm for B&L SZ4 boom stand??

Do you have any microscopy questions, which you are afraid to ask? This is your place.
Message
Author
dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Adapting a computer monitor arm for B&L SZ4 boom stand??

#1 Post by dazz » Sat Jun 05, 2021 5:02 am

Hi
I purchased a B&L SZ4 from e-bay. It does include the tube for a boom stand, but does not include the base for a boom stand. It will take about 3 months for the scope to ship here (cheapest slowest rate).
Boom stands are rare here and hideously expensive to import. My plan was to make a boom stand suitable for PCB work.

Some research indicates that a computer LCD monitor stand (cheap and easy to buy here) would have the right features. I would just need an adapter between the standard B&L boom fitting (spigot) and a monitor stand.

Has anyone tried this before?
Does anyone know where I can obtain dimensioned drawings of the B&L boom fitting so I can make an adapter before the B&L SZ4 arrives?

Dazz

User avatar
75RR
Posts: 8207
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#2 Post by 75RR » Sat Jun 05, 2021 6:17 am

.
You might want to also look at Darkroom Enlarger or Copy Stands, they might serve as well.

https://www.ebay.co.uk/itm/203298641342 ... SwrnhgKDFa
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#3 Post by dazz » Sat Jun 05, 2021 7:32 am

Hi
The feature that really appeals to me most about the monitor stands is the articulated arm. I could swing the scope into any position without having to rotate the scope in the bracket. When not in use, I could swing the scope out of the way.
Also, there is no boom sticking out the other side of the stand.
The only real downside I foresee is that the scope can tilt. I would aim to lock the tilt in one position.

Dazz

lorez2
Posts: 113
Joined: Wed Apr 21, 2021 2:06 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#4 Post by lorez2 » Sat Jun 05, 2021 2:41 pm

I would be concerned about 'wiggle'. A tiny bit of movement is magnified and will become a larger problem. The enlarger base may provide a more substantial footing for the arm you are getting.

lorez
Nikon 80i

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#5 Post by dazz » Sun Jun 06, 2021 4:17 am

Hi
I am more concerned about undamped vibration.
If I knock the scope, and it wiggles for a moment, that would be OK for me.
If I knock the scope and it keeps vibrating for a long time like a tuning fork, that would be not OK.

Buying and modifying a monitor stand, like the Loctek DLB502, is cheaper than buying or making a boom stand.
If it wiggled too much, I would look at adding a tuned mass damper.https://www.youtube.com/watch?v=f1U4SAgy60c
Probably in the form of a steel ball suspended in thick oil.

The lack of responses to this question suggests this hasn't been tried before.

Dazz
Last edited by dazz on Sun Jun 06, 2021 7:29 am, edited 1 time in total.

User avatar
75RR
Posts: 8207
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#6 Post by 75RR » Sun Jun 06, 2021 5:59 am

.
Have you tried asking over at photomacrography.net ?

A lot of the macro photographers make their own rigs and are pretty inventive ...
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#7 Post by BramHuntingNematodes » Sun Jun 06, 2021 6:43 am

I never tried it but I think it's a good idea. The SZ4 has been put in many aftermarket and improvised setups over the years, and I don't see why it wouldn't work.
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

dtsh
Posts: 977
Joined: Wed May 01, 2019 6:06 pm
Location: Wisconsin

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#8 Post by dtsh » Sun Jun 06, 2021 3:36 pm

I recall seeing a video back when I was looking for a stereo microscope where the person had been using articulating arms for monitors. From what I recall of the video, they stated it worked well enough for their purposes. A bit of digging on YouTube might uncover it as that's probably where it was. The standard caveat applies that their purposes and your might not compare.

User avatar
iconoclastica
Posts: 179
Joined: Sun Jan 20, 2019 5:43 pm

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#9 Post by iconoclastica » Sun Jun 06, 2021 4:44 pm

I have my microscope placed upon a monitor/tv arm. It's a articulated arm with a platform at the end, so it swings, folds together and, to a limited extent, adjustable in height. It is spring-damped, not designed for flat-screens, but dating from the age that monitors were still heavy.

It was an experiment, but after two years I still love the construction. The scope is quickly out of the way and back when (not) needed. The whole contraption is prone to vibrations, of course, but the microscpe (labo/optipot hybrid) is stiff, so that is no drawback, even when taking photos. In fact, I see the image moving with the shutter, but the photos are sharp nonetheless. So much so, that I wonder why one would want a tons heavy block of granite...

I don't think it would work with the object on the table though. My Mz7.5 is on a traditional boom-stand. The vibration there is acceptable yet well noticable.

BramHuntingNematodes
Posts: 1538
Joined: Tue Jan 21, 2020 1:29 am
Location: Georgia, USA

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#10 Post by BramHuntingNematodes » Sun Jun 06, 2021 5:01 pm

iconoclastica wrote:
Sun Jun 06, 2021 4:44 pm
So much so, that I wonder why one would want a tons heavy block of granite...
Long exposure times?
1942 Bausch and Lomb Series T Dynoptic, Custom Illumination

User avatar
iconoclastica
Posts: 179
Joined: Sun Jan 20, 2019 5:43 pm

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#11 Post by iconoclastica » Sun Jun 06, 2021 5:15 pm

What's important is whether the camera makes movements relative to the specimen. If the construction is stiff, 60 seconds during an earthquake will still be sharp...
Long exposures can be helpful when they average out residual shake from the camera mechanics.
I suppose the correct answer has something to do with exposure time, but it's not as simple as that.

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#12 Post by dazz » Mon Jun 07, 2021 12:12 am

Hi
It is reassuring to know that others have succeeded with a monitor stand based scope stand.
I have no plans or gear to take photos so that is not an issue.
I have just purchased a monitor stand for the B&H SZ4 but I am not expecting the SZ4 to arrive for another 3 months or so. Sea freight is cheap but really slow.

I have purchased a DLB502 https://www.youtube.com/watch?v=Jf5gUyQn4dU
I will probably screw it onto a big heavy piece of 10mm steel plate.
I will almost certainly modify the head to replace the monitor ANSI mount with a mount compatible with the SZ4.

Here is a YT video on the range of monitor stand choices. https://www.youtube.com/watch?v=__K4V8pFhf4
Even the highest price monitor stand would be much cheaper than buying a scope stand locally (if they can be found).

Dazz

User avatar
iconoclastica
Posts: 179
Joined: Sun Jan 20, 2019 5:43 pm

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#13 Post by iconoclastica » Mon Jun 07, 2021 1:11 pm

If that works it is an interesting option. Please let us know once you have the scope and the arm operating together.

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#14 Post by dazz » Tue Jun 08, 2021 5:18 am

Hi
I do anticipate shake (wiggle) will be a problem.
Looking at potential solutions, magnetic damping looks promising. https://www.youtube.com/watch?v=MglUIiBy2lQ
A better option than oil because magnets don't leak and make a mess.

I will let you know what the outcome is.

Dazz

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#15 Post by dazz » Thu Jun 10, 2021 11:01 am

Hi
Here is a Chinese version of a monitor-like stand for microscopes.
It looks rather flimsy but is a proof of concept.

Dazz
Attachments
HTB16uQaacrrK1Rjy1zeq6xalFXaG.jpg
HTB16uQaacrrK1Rjy1zeq6xalFXaG.jpg (108.49 KiB) Viewed 9287 times

User avatar
iconoclastica
Posts: 179
Joined: Sun Jan 20, 2019 5:43 pm

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#16 Post by iconoclastica » Thu Jun 10, 2021 1:55 pm

Dentists use wonderful swing arms for their lamps and instrument consoles. Often they are ceiling mounted.

jfiresto
Posts: 342
Joined: Fri Feb 15, 2019 8:19 am
Location: Northern Germany

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#17 Post by jfiresto » Thu Jun 10, 2021 4:09 pm

I bet this would be a tolerably rigid microscope stand, but perhaps too much for the ceiling:
m8_stand.jpg
m8_stand.jpg (31.74 KiB) Viewed 9264 times
-John

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#18 Post by dazz » Wed Jun 23, 2021 7:23 am

Hi
My monitor stand/arm has arrived.
I have purchased a DLB502 https://www.youtube.com/watch?v=Jf5gUyQn4dU
It is strong and looks like it will be sufficiently rigid. It has a reach far longer than I will ever need. It is far better made than I would do if I made one.
I think I will mount it on a big thick metal plate. That will be more rigid than a desk top.

The only problem I may have is that it is designed to carry a min 1.5kg load. I may need to add some ballast but that is easy.
Also easy will be changing the monitor mounting bracket for a custom made B&L socket.

Now I just need to wait for the B&L SZ4 to arrive from the USA. I don't expect to see it before August. If it was a bad buy, there is no danger of sending back for a refund. Cheaper to buy another.

Dazz

MichaelG.
Posts: 3976
Joined: Mon Apr 10, 2017 8:24 am
Location: North Wales

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#19 Post by MichaelG. » Wed Jun 23, 2021 8:46 am

That looks an excellent range of movement, Dazz

Should be very suitable if you bolt it down to a hefty base.

MichaelG.
Too many 'projects'

User avatar
75RR
Posts: 8207
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#20 Post by 75RR » Wed Jun 23, 2021 10:17 am

dazz wrote:
Wed Jun 23, 2021 7:23 am
Hi
My monitor stand/arm has arrived.

Now I just need to wait for the B&L SZ4 to arrive from the USA. I don't expect to see it before August. If it was a bad buy, there is no danger of sending back for a refund. Cheaper to buy another.
Look forward to your impressions when you put everything together.

By the way, what was the difference in shipping between Air and Sea?
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#21 Post by dazz » Thu Jun 24, 2021 1:03 am

75RR wrote:
Wed Jun 23, 2021 10:17 am
...

By the way, what was the difference in shipping between Air and Sea?
Shipping by sea about the same as the price of the B&L SZ4.

Shipping by air about 2x the price of the B&L SZ4.

International shipping has been completed wrecked by the grounding of airlines and disruption to sea service. The cost is now excessive, the service is rubbish.

Dazz

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

How big to make the stand table for a computer monitor arm ??

#22 Post by dazz » Sun Jun 27, 2021 9:58 pm

Hi
The next problem I have is now big to make the table that the computer monitor arm is attached to.

There seems to be two approaches. One is to have a big lump of metal. I can see the problem with this is flex in the desk top.
The other approach is to have a big metal plate. That is the approach I favour. An example is shown on the attachments.

So my question is how big should I make the big metal plate??? Given the reach of the monitor arm and the weight of the B&L SZ4, I am thinking a plate 500mm x 500mm x 15mm.

Dazz
Attachments
1556565576.jpg
1556565576.jpg (174.04 KiB) Viewed 9021 times
1556565536.jpg
1556565536.jpg (163.45 KiB) Viewed 9021 times
1556565503.jpg
1556565503.jpg (156.31 KiB) Viewed 9021 times

User avatar
75RR
Posts: 8207
Joined: Sun Oct 12, 2014 2:34 am
Location: Estepona, Spain

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#23 Post by 75RR » Mon Jun 28, 2021 9:02 pm

.
If the desk is up against a wall, have you considered fixing it to the wall. Looks feasible from the video you linked to.

Would save you desk space.
.
Attachments
clamp.png
clamp.png (164.62 KiB) Viewed 8966 times
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#24 Post by dazz » Tue Jun 29, 2021 12:39 am

Hi
Yes, the stand came with a wall mount and yes I have considered using it. The monitor arm has enough length to reach half way across the room (only a slight exaggeration). I am working in a domestic room where SWMBO would object to holes in the wall.
If I was working in my (cold) workshop, wall mounting would be the best option.

The arm comes with a table edge clamp, but my table is quiet flexible.

I have also considered a hybrid option with the monitor sitting on a lump of steel that is mounted on the big metal plate. That is my fall back option.
My thoughts are that a big metal plate will be rigid and cheap. If I get the plate powder coated, it will look good. If it is relatively thin (say 10mm), it will become part of of the base table.
If the plate is too big, I can cut it down.

Dazz

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#25 Post by dazz » Tue Oct 05, 2021 9:08 pm

Hi
After waiting 4months for my ebay Bausch & Lomb SZ4 purchase to be delivered, I went ahead and made the adapter for the computer monitor stand.

I made the adapter from steel because the monitor stand specifications include a minimum weight. The steel adapter adds enough weight to bring the combined weight of the adapter and SZ4 to within spec. Most of the features were machined on my lathes. The connection between the adapter was designed to be strong and rigid. Apart from removing redundant fittings, the monitor stand did not require any modifications. The adapter was made to accept a standard B&L mount without modifications.

The complete assembly is shown temporarily fitted onto the kitchen bench. The SZ4 is at working height where the book on the bench is in focus. The SZ4 came with a 0.3X auxiliary lens so the height is almost too high.

Early impressions are that the stand is rigid and damped in the vertical plain. It is less rigid and less damped side to side. I may look at adding a magnetic damper if it proves to be a problem.

The stand has a long reach. Longer than I need. The plan is to attach the stand to a 10kg metal plate (300mm x 400mm x 10mm).

I am currently designing a LED ring light 3D printed.
Attachments
SZ4 Adapter Cross Section a.jpg
SZ4 Adapter Cross Section a.jpg (139.29 KiB) Viewed 7229 times
IMG_0929.jpg
IMG_0929.jpg (110.93 KiB) Viewed 7229 times
IMG_0926.jpg
IMG_0926.jpg (93.95 KiB) Viewed 7229 times

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#26 Post by dazz » Thu Oct 14, 2021 9:37 pm

Hi
Just some photos of the unfinished base plate with stand fitted.

There is no doubt that the stand is more flexible than the B&L versions. It wobbles when knocked. I plan to fix that with a tuned mass damper.

Tests show the lower stand arm oscillates in torsion.
Attachments
The stand can be manipulated to see most areas of the base plate.
The stand can be manipulated to see most areas of the base plate.
IMG_1006_renamed_19934.jpg (69.75 KiB) Viewed 6893 times
The base plate has mounting holes machined on two corners.  This maximizes coverage of the plate and surrounding area, plus allows the SZ4 to be swung away while consuming the minimum of desk real estate.
The base plate has mounting holes machined on two corners. This maximizes coverage of the plate and surrounding area, plus allows the SZ4 to be swung away while consuming the minimum of desk real estate.
IMG_1005_renamed_22440.jpg (95.64 KiB) Viewed 6893 times
The articulated arm allows the stand to be located out of the way and for the SZ4 to be pointed in any direction.   The stand allows the SZ4 to be swung half way across the room (only a slight exaggeration)
The articulated arm allows the stand to be located out of the way and for the SZ4 to be pointed in any direction. The stand allows the SZ4 to be swung half way across the room (only a slight exaggeration)
IMG_1004_renamed_10377.jpg (73.64 KiB) Viewed 6893 times

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#27 Post by dazz » Fri Oct 15, 2021 7:42 pm

Hi
I thought I should explain a little about a tuned mass damper (TMD).
TMDs are widely used to reduce oscillation in the presence of energy input. In effect, they soak up energy that would otherwise cause a system to oscillate.
Examples include damping machine tool vibration to reducing seismic response of a building.

I simple terms, a TMD is a spring and mass that oscillate at about the same frequency as the main system (in my case a SZ4 on the end of a monitor arm). The added mass can be quite small, but the heavier it is, the greater the potential for soaking up energy. When the SZ4 is bumped, energy will be transferred from the SZ4 to the TMD. Damping in the connection between the mass and the SZ4 will convert kinetic energy to heat.
Probably better explained at this link: https://www.youtube.com/watch?v=f1U4SAgy60c.

So a TMD won't stop the initial flex and movement of a SZ4 on a monitor stand. It will significantly reduce the oscillation in response to the knock that caused the stand to flex. There is a good chance that it will improve the usability of the SZ4 when compared to a very rigid stand mounted on a flexing table.

It is going to take me a while to figure out the best way to implement a TMD on the end of a computer monitor stand. There are a lot of ways it can be done. This thread is likely to go quiet for a while.

Scarodactyl
Posts: 2775
Joined: Sat Mar 03, 2018 9:09 pm

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#28 Post by Scarodactyl » Fri Oct 15, 2021 8:09 pm

I like how it looks! Very similar to the Diagnostic Instruments arm stand that Leica appears to resell. I just set a friend up with one of those and I thought it was a really nice piece of kit. There are some Chinese copies as well that are surprisingly cheap, though of course the quality is probably not comparable.

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#29 Post by dazz » Sat Oct 16, 2021 10:00 am

Hi
I found this brochure https://www.yumpu.com/en/document/read/ ... arm-stands on stands.
There has to be a lot of flex in those extended arm stands. That in itself is probably not a major issue. If you bump something and the image moves, then stops, that should be OK. If you bump something and the image keeps oscillating then that would be an issue. Even if the stand was completely rigid, the table might be flexible and that would cause image instability.

Damping is specifically mentioned in the brochure but I don't see any indication of damping at the business end. The damping could be housed inside the arm but unlikely. One stand uses damped feet on the base plate.

I am planning to have a mass in the shape of a disc, mounted vertically, like a large coin on edge. The mass would be suspended by at least 3 springs radiating from the edge. Damping would be from strong magnets mounted on both sides of the disc. The disc will probably be made of a combination of lead and aluminium.

This arrangement will give 2D tuned damping. The problem I will have is obtaining suitable springs. I can design a TDM, I can model it, but if I can't buy the springs I need with the right specifications, that will be a problem. I can buy springs, but typically the packaging does not include their technical specifications. I will need to experiment, and that will take a while.

dazz
Posts: 58
Joined: Fri Mar 26, 2021 12:42 am

Re: Adapting a computer monitor arm for B&L SZ4 boom stand??

#30 Post by dazz » Sun Oct 17, 2021 8:53 pm

Hi
I could make a tuned mass damper (TMD) by a lot of experimentation, or I can start by figuring out what the TMD component values should be so I can look for the right ones.

First off, I measured the spring rate. This was achieved by applying a known force to the monitor arm, and measuring the deflection. I used a dial indicator to measure deflection. I used a precision, lab quality can of beer to apply the force via a thread. This gave me the measured value of the spring rate k.

I then measured the natural frequency of oscillation. I did this by using a Gill Blade 25 contactless linear position transducer here: https://www.gillsc.com/products/positio ... on-sensor/. The output was displayed on my oscilloscope. The Blade 25 allowed measurement of the arm movement by taping a U shaped strip of metal onto the SZ4 The transducer was taped onto a block of wood. It is a very simple setup with no friction between the SZ4 and the transducer.

It turns out the period of oscillation is 200ms, or 5Hz. So the TMD needs to have a similar natural frequency.

With this information, I can start designing the TMD.

If the tuned mass is about 10% of the SZ4 and monitor arm it will be about 300g.
That will require a spring rate of about k=300N/m.
If the SZ4 has a 1mm amplitude range of movement, the TMD will require a range of 10mm.

Natural damping of the arm is almost zero, so the TMD will need to provide all damping. I will achieve this with magnetic eddy currents in aluminium sheet.

So:
The weight of the tuned mass is easily adjusted.
Knowing the approx spring rate and range of movement will help identify the right type of spring, but it is unlikely I will know the spring rate until I make measurements.
Achieving the right value of damping with magnets is something I will only be able to do with experimentation. I can calculate the correct value of damping, but I can't calculate the damping applied with magnetic eddy currents for this setup.
Attachments
Tapping the SZ4 excited oscillation, measured with the Gill Blade 25.  There is almost no damping.  The period of oscillation was measured at 200ms.
Tapping the SZ4 excited oscillation, measured with the Gill Blade 25. There is almost no damping. The period of oscillation was measured at 200ms.
undamped SZ4 monitor mount.jpg (73.06 KiB) Viewed 6746 times
A closeup of the Gill Blade 25 transducer and activator taped in position.
A closeup of the Gill Blade 25 transducer and activator taped in position.
IMG_1024.jpg (104.28 KiB) Viewed 6746 times
A view of the dynamic frequency measurement setup.  A contactless Gill Blade 25 tranducer, taped to a block of wood, was used to measure the natural frequency of oscillation.
A view of the dynamic frequency measurement setup. A contactless Gill Blade 25 tranducer, taped to a block of wood, was used to measure the natural frequency of oscillation.
IMG_1025.jpg (122.63 KiB) Viewed 6746 times
A closer view of the spring rate measurement setup.
A closer view of the spring rate measurement setup.
IMG_1023.jpg (129.52 KiB) Viewed 6746 times
The setup to measure the spring rate of the monitor arm.  A lateral deflection force was applied by a calibrated can of beer, via a thread.  Static deflection was measured with a DTI.
The setup to measure the spring rate of the monitor arm. A lateral deflection force was applied by a calibrated can of beer, via a thread. Static deflection was measured with a DTI.
IMG_1019.jpg (110.02 KiB) Viewed 6746 times

Post Reply