Mk3 reflector gunsight.

[markbee]

Hello all!
I've recently come across a mk3 reflector gunsight as used in Lancaster / Wellington turrets and am trying to get into it to see if it works. I've taken the u shaped bracket off the top and common sense tells me the lens must unscrew to get to the bulb etc. This is stuck and i don't want to force it in case i'm wrong.
Anyone know the way in to these???
Thanks. Mark.

 

[Airframes]

I can't help directly, but if no one else suggests anything, then perhaps get in touch with the Yorkshire Air Museum, at Elvington, near York. They have a comprehensive display of RAF WW2 gunnery items, from gunsights to turrets, and all that goes with it, and I would guess that someone associated with the Air Gunners display would either have a manual, or be able to offer advice.

 

[Crimea_River]

Next time I'm down at the bomber museum in Nanton. I'll ask the guys if they know. There's a restored turret there, not to mention a whole Lanc!

 

[markbee]

Thanks both of you for the info. It's still got me baffled!

 

[herman1rg]

Be careful that it isn't a left-hand thread

 

[markbee]

I have tried it gently both ways and it still wont budge. My Grandpa was on Lancasters in the war so i bet he would have known. Still got me baffled!

 

[Airframes]

Can you post photos of the top and bottom, at 'normal' viewing distance and close up, and one of each side?

 

[Crimea_River]

Heading to Nanton Saturday. May be able to get some info.

 

[Airframes]

Good show Andy!

 

[Crimea_River]

Photos would help a lot when I ask the question.

 

[markbee]

Hi there. Sorry for the delay. Work commitments. As you can see there seems to be no way in through the casing. I have taken the actual sight off and the only possible way i can see in is through the lens. I've 'arrowed' the parts that i think may be detachable.
Thanks for all your help!

 

[markbee]

 

[Crimea_River]

OK, I'll see what I can find out. It looks like in the last picture you managed to get the reflector unit off. I assume you are now trying to open the box. Did you take out the screws holding the bulb placard to the box? I'm thinking these may go in deep and could be clamping the two box halves together. The adjacent face on the box may have a hook in the casting.

 

[markbee]

Yes i've taken them out. I've even taken the electrical wire retainer screws out. They're all about 1/4 of an inch long so no joy there. You can't really see it in the pic but by the bulb plate there is also another 'recess' which is round and it also has something sealed in it. If it's sealed i'm sure you're not supposed to get into it but there must be some way of changing the bulb.......

 

[Airframes]

It's not a sight I'm particularly familiar with (not that I'm that familiar with any in the true sense!), but bulb replacement is normally possible with the site in situ, when in flight, so that it can be done as required. I'm just wondering if the bulb mount is on the end of the 'Off/Adjust' knob, which perhaps pulls out?
Probably better to wait and see if Andy receives any info, but maybe worth an exploratory 'wiggle'.

 

[Crimea_River]

OK, back from Nanton. I have a contact name now but have not been in touch as yet. The Nanton Museum has a fully functional tail turret from a Lancaster and, based on your pics, I was able to confirm that it includes the gunsight that looks identical to yours and it's functional. The chap whose name I have is the engineer on the museum's Lanc and he's pulled much of it apart. I'll try to get in touch with him tomorrow and if necessary e-mail him the pics in your post.

 

[Airframes]

Good work Andy.

 

[markbee]

I've sussed it! The lens unscrews at the base. I soaked it in wd40 last night and this morning put a lot more pressure on it than i would have liked and it came apart. There's no bulb in it so now to source a bulb.
Thanks all of you for your trouble and your time! Really appreciate it!
Mark.

 

[markbee]

Thank you Crimea River. Any more info would be much appreciated.

 

[markbee]

I thought you might like to see it now i've managed to get it apart. I shone a torch up through the lens see how it actually works. Sorry about the quality of the pic but it's the best i could manage holding a torch and the sight in one hand and the camera in the other.