Olympus bhmj

[Antartica]

Came across a cheap Olympus bhmj on Craigslist. The manual says it uses a 20mm pilar for the stand.

Can anyone point me to a good boom stand for it? Some links on eBay would be helpful. I can’t find one and want to make sure I get one that fits it and is sturdy.

Thanks

[woyjwjl]

What component are you referring to?

[Antartica]

321BC592-7607-4951-A83C-8ADE0E3A187F.jpeg (94.47 KiB) Viewed 3967 times

I’m referring to the BHMJ focus block. It goes on a boom stand.

[MichaelG.]

You are right to ask … 20mm is rather small, so I suggest the boom needs to be much more substantial than that.

Here, for inspiration, is one which looks reasonably well-supported:

https://www.sci-bay.com/product/olympus ... icroscope/

MichaelG.

.

P.S. __ it looks a very useful microscope … I found an early Instruction Manual here:
https://ltt.arizona.edu/sites/ltt.lab.a ... ctions.pdf

[Antartica]

Thanks. I did see that manual. I’m trying to go for a similar setup to the one below but can’t find a similar stand

6F7FBBF6-0183-46BB-8265-C3111F9772A2.jpeg (115.82 KiB) Viewed 3946 times

[MichaelG.]

Sorry … I must have misunderstood you

I thought you were looking for a Boom Stand, not a simple vertical column.

MichaelG.

[Antartica]

Sorry … I must have misunderstood you

I thought you were looking for a Boom Stand, not a simple vertical column.

MichaelG.

No worries. Maybe I wasn’t clear enough. Right now I only have the bhmj focus block that I showed in the first photo. But it needs a pole and base. So that’s what I’m looking for so that I can create something similar to the last photo. But I need some assistance in finding the right pole/base

[MichaelG.]

I can’t be certain, but I think the pole in your last photo is just something that someone has fitted to replace the short item on a standard [Olympus?] base. The X-Y stage is obviously an after-market item.

As configured, it’s probably acceptable for casual visual work, but: if you are contemplating photography, I would recommend using something stiffer than 20mm.

MichaelG.

[MichaelG.]

Note: Just for general clarification

The term ‘Boom’ originates in Sailing:
http://robroy.dyndns.info/RCmodels/A600/mast_boom.php

The similarity is obvious.

MichaelG.

[MichaelG.]

[ IMPORTANT UPDATE ]

I think you might find it useful to read this discussion :

http://www.photomacrography.net/forum/v ... hp?t=19692

Have you actually measured 20mm ??

MichaelG.

[Antartica]

[ IMPORTANT UPDATE ]

I think you might find it useful to read this discussion :

http://www.photomacrography.net/forum/v ... hp?t=19692

Have you actually measured 20mm ??

MichaelG.

Thank you!!! You’re right. Looks like I need a 21.6 ish rod and NOT a 20mm

Now the search for such a rod and base continues. If anyone has suggestions please let me know

[Scoper]

Almost 21.6mm is approximately 13/16 inch…

The search for a setup with the exact dimensions for the vertical support may take awhile so you may want to consider building.

If you have to construct this..

Realize that the vertical support can be made of other materials such as a HARD wood dowel..which is easier to acquire and modify.

If the vertical support is solid, a slot running the length of the support will assist in horizontal registration.

Also using metal the vertical support can be hollow without seriously affecting the rigidity of the system.

The base will need to serve as a counterweight so its weight will need to be considered but many choices are available.

[PeteM]

Stainless steel tubing, with a reasonably thick wall (say 4mm or 3/16"), is the best relatively affordable option for the post. Some cheap posts are poorly-plated steel. Better OEM ones may have a thick and durable plating. It doesn't have to be as long as in the photo, unless you are examining tall items since the parfocal distance of those objectives is only 45mm.

There are several options besides finding an Olympus OEM post:

1) Bore or ream out the hole in the BHMJ block to a standard tubing dimension. In this case, to 22mm. I'd use a spiral-cut expanding reamer as the easiest approach. A straight-bladed adjustable reamer - often used in electric motor repair shops - would also work. You might need to find a machinist or shop who already has one.

2) Have the tube lathe-turned out of stainless, brass, or aluminum tube to fit. Stainless holds up best, but is harder to machine. You don't want to turn down a plated tube. Once a tube is at diameter, I'll often run a 1-2mm deep slot down the tube for the setscrew at the back if various heights need to be accommodated. Just be sure the tube is thick enough to handle this.

As a kluge, a tube could probably be carefully and laboriously sanded down on a wood lathe by the .2mm or so (.4mm on diameter) a 22mm tube might need. A bit more work if you start with a 7/8" tube. A wood turner would likely have a power sander and a long steady rest - and be able to do the job fairly quickly.

3) Find the next size down standard tube and shim it to fit. In this case, maybe 20mm or 3/4". Then place a bit of brass shim stock around it to make up the diameter. This is permanently inserted, even Loctited or glued, inside the BHMJ's hole once you have a good trial fit. This will be a bit clumsy for adjustment, especially if you don't fix it in place, but the block itself will have enough adjustment for focusing if you are examining mostly thin epi specimens.

4) If you don't need much adjustment, you could use the pole socket you already have - and mate it to an upright/stand of your choice. Half a dozen ways to do this.

A socket to mate the tube to a sturdy base is easily made. With option #3, you could buy a standard tube and base.

[Scarodactyl]

Realize that the vertical support can be made of other materials such as a HARD wood dowel..which is easier to acquire and modify

It cannot, wood is not rigid enough for demanding high mag work.

My suggestion: unbolt the post holder. It's nonstandard and way too small, just like Nikon's stupid 24.5mm posts for their equivalent part. Get a different coarse/fine focus assembly and make an intermediate adapter to bolt them all together. This is easy enough with some aluminum flat stock, a ruler and a drill press.

[Antartica]

Realize that the vertical support can be made of other materials such as a HARD wood dowel..which is easier to acquire and modify

It cannot, wood is not rigid enough for demanding high mag work.

My suggestion: unbolt the post holder. It's nonstandard and way too small, just like Nikon's stupid 24.5mm posts for their equivalent part. Get a different coarse/fine focus assembly and make an intermediate adapter to bolt them all together. This is easy enough with some aluminum flat stock, a ruler and a drill press.

Can you provide a bit more details? Perhaps some links to parts?

And I really like this setup below. This is probably what I should aim for. Does anyone know which measuring/toolmakers microscope this is?

25F3F7E6-0DAC-4264-B861-F006B3B24A24.jpeg (119.2 KiB) Viewed 3787 times

26D49A0A-D4AA-44AA-97BF-35ED616DB657.jpeg (116.03 KiB) Viewed 3787 times

[woyjwjl]

There should be in the Chinese market, but due to weight, transportation costs will exceed the product itself

[Antartica]

Thanks wok, but I think I want a setup using the measuring stand/base I showed in the last photos. I just need to find a compatible or suitable model. If anyone has suggestions please let me know

[Scarodactyl]

That looks like a third party setup by e.g. McBain. Olympus had their STM line that worked well, I had one for a bit but ended up going Nikon. A Nikon measurescope would likely work well too.

[MichaelG.]

.

Recommended viewing:
https://mundaymicroscope.com/product/ol ... bjectives/

MichaelG.
.
Edit: __ and here, I presume, is where your photos came from:
https://www.sitekprocess.com/ccp5042-z- ... -51916.htm

[Antartica]

.

Recommended viewing:
https://mundaymicroscope.com/product/ol ... bjectives/

MichaelG.
.
Edit: __ and here, I presume, is where your photos came from:
https://www.sitekprocess.com/ccp5042-z- ... -51916.htm

Yes, thanks Michael

I just need to find that stand.

[Scarodactyl]

https://www.ebay.com/itm/273803001643
This one looks really nice but it's priced optimistically.
https://www.ebay.com/itm/304656756512
Some problem, good base but kind of spendy.
You might find a better deal by digging deeper though, they can be listed under many different brand and part names.

[Tailgunner]

Stainless steel tubing, with a reasonably thick wall (say 4mm or 3/16"), is the best relatively affordable option for the post. Some cheap posts are poorly-plated steel. Better OEM ones may have a thick and durable plating. It doesn't have to be as long as in the photo, unless you are examining tall items since the parfocal distance of those objectives is only 45mm.

There are several options besides finding an Olympus OEM post:

1) Bore or ream out the hole in the BHMJ block to a standard tubing dimension. In this case, to 22mm. I'd use a spiral-cut expanding reamer as the easiest approach. A straight-bladed adjustable reamer - often used in electric motor repair shops - would also work. You might need to find a machinist or shop who already has one.

2) Have the tube lathe-turned out of stainless, brass, or aluminum tube to fit. Stainless holds up best, but is harder to machine. You don't want to turn down a plated tube. Once a tube is at diameter, I'll often run a 1-2mm deep slot down the tube for the setscrew at the back if various heights need to be accommodated. Just be sure the tube is thick enough to handle this.

As a kluge, a tube could probably be carefully and laboriously sanded down on a wood lathe by the .2mm or so (.4mm on diameter) a 22mm tube might need. A bit more work if you start with a 7/8" tube. A wood turner would likely have a power sander and a long steady rest - and be able to do the job fairly quickly.

3) Find the next size down standard tube and shim it to fit. In this case, maybe 20mm or 3/4". Then place a bit of brass shim stock around it to make up the diameter. This is permanently inserted, even Loctited or glued, inside the BHMJ's hole once you have a good trial fit. This will be a bit clumsy for adjustment, especially if you don't fix it in place, but the block itself will have enough adjustment for focusing if you are examining mostly thin epi specimens.

4) If you don't need much adjustment, you could use the pole socket you already have - and mate it to an upright/stand of your choice. Half a dozen ways to do this.

A socket to mate the tube to a sturdy base is easily made. With option #3, you could buy a standard tube and base.

The BHMJ block is that cast iron? I ordered a piece of chromed steel bar that they use in hydraulic pistons. De diameter is 22mm with f7 tolerance (I do not know what that tolerance means).
So I think I would have to let the block be reamed out to this diameter. Is it difficult to take the BHMJ block apart. I would want to take the control knobs of and de sliding part so that I would only have to take the part to the machine shop that needs machining. I tried searching for a service manual for the BHMJ microscope but I haven't found any. Maybe someone has more insight on this matter.

[PeteM]

The block is aluminum.