Olympus BH2 Objective Turret

Interested in used equipment to buy, sell, or trade? Post here to find other members with matching needs. Personal equipment only, no dealers please.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Olympus BH2 Objective Turret

Post by dolmadis »

Hi

Does anyone have a spare Olympus BH2 Objective Turret in the bit box which is not operational/broken please?

All I need is the rectangular dovetail to act as a template for a part on which to create a single lens mount for a vertical rig.

(There used to be a commercial part but long since discontinued and nothing has turned up in surplus or auction sites for nearly two years of looking.)

Alternatively is there anyone who has one and can accurately measure one for me so that RAF can work from these dimensions?

Thanks


John

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

I could use one too.
Years ago I bought a stand with a big table/movements designed for Si wafers.
One of those "projects".

There was a fellow here a while ago who I'm sure could machine such a thing.... if anyone comes up with dims.
Chris R

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

fingers crossed...........

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Image


Is that it?
Male 30mm wide, 46.5mm at longest = diameter
4.5 thick, 30° angle with 1mm not angled.
straight edge 36
hole about 28.5
screws 24 x 21.4 ish centres.

Female at tightest (front) point is 27mm.
I don't know if that's the same as the other scope, this is a BHMJ.

Dims edited.
Last edited by ChrisR on Sat Feb 09, 2019 9:37 pm, edited 2 times in total.
Chris R

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

Thanks.

I will check with my stand.

BR

John

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

Hi ChrisR

I think our stand heads are a different in certain respects based on what I could measure confidently on a comparable basis to your measurements.

30mm wide (same)
Straight outside edge = 38mm
Overall length furthest rounded end to end = 48mm
4.0mm thick (4.5)
1.0 mm not angled

Hard to measure angle

BR


John

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

I've edited a bit, one dim was wrong.
Mine's a little shorter/ smaller diameter, but the dovetail is the same. I expect they're meant to be the same, though if one goes in to the slot less far??
Mine's 11.5 radius difference between the outer and inner curves.

If I find another I forgot I had, I'll let you know!
Chris R

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

Thanks for the update.

I should not rule out some small variations left by my very old manual measure.

A friend, not on here, has reminded me that there are three dovetail sled BH2 turret variants;

- BH2 BHS (easy removable)
- BH2 BHT (4 screws)
- BH2 BHTU (with lens inside)

Based on this it would seem that we are both dealing with the BH2 BHT (4 screws).

If I get hold of a spare dovetail sled I will send it to RAF.

What sort of lens mount would you have in mind?

Any other requirements?

BR


John

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

Well, there's 25.44mm between the top side of the dovetail and the objective mount flange, so there's some room for adapters.

I don't know if my other scope stand referred to, is one of those other standards.

I'd think of accommodating a range of bits and pieces. Even Mitutoyo is too big though - the narrow face of the dovetail plate is about 26mm wide. M42, obviously bigger than the dovetails, would be a useful thread to work from if you wanted to get a tube lens in there, say.
There are adapters for 26mm to rms, for example.

OTOH if you want parfocality with other Oly stuff you'd need to respect the exact 25.44mm, I expect.
I have seen things like this made at the Makerspace I use, but I don't know what the CAD program is.
Chris R

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

Thanks Chris and especially the "25.44".

My own choice would be to specify M42 like the MM-11 mount prototyped by Smokedaddy.

I shall probably ask RAF to machine up a whole new adapter from the a sledge template.

When I have a spare that is.

BR


John

Alan Wood
Posts: 382
Joined: Wed Dec 29, 2010 3:09 pm
Location: Near London, U.K.
Contact:

Post by Alan Wood »

Just nitpicking, but the BHS, the BHT and the BHM (and the BHA version of the BH) all take nosepieces that slide in on a rectangular dovetail.

The CH-2 takes the same nosepieces but attached by 4 screws; there is no dovetail. I replaced the original 4-way nosepiece on mine with a 5-way one after removing the dovetail. Sorry, I don't know where the dovetail is now.

Not all nosepieces will fit a CH-2, they need 2 extra screw holes to left and right of the dovetail.

Image

Alan Wood

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

Thanks Alan.

John

naturepics43
Posts: 88
Joined: Mon May 11, 2015 9:21 pm
Location: Hocking County, Ohio , USA

Post by naturepics43 »


dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

From what I can see........no it is not the right version.

And being in the UK I will wish to avoid the extra costs incurred from purchasing from non EU Countries. (well from the EU up to 29/3/19 !!)

Thank you for posting.

BR


John

dolmadis
Posts: 899
Joined: Wed Dec 07, 2011 1:51 pm
Location: UK

Post by dolmadis »

Whilst I have not secured a spare nosepiece or sled yet I have dropped an email to Raf to see if it is something he can fabricate.

BR

John

Post Reply Previous topicNext topic