MRS 3D model

[Mark Heaps]

Also for those that did not serve but have bought a Chieftain kit and are thinking of adding the MRS light source, you need to also have the MRS mirror and shroud at the end of the barrel. REME would not have fitted the mirror and shroud to the barrel if the tank was not equipped for MRS, firstly because it would not have been neccessary and secondly it was a balls-ache. I once had to fit the mirror after a barrel change on a Challenger 1 in the middle of winter, we had to erect a 9*9 tent over the end of the barrel and have 6 kero heaters on overnight in it to get the required glue to set. The range guard that night had to go without heating in their tent.
So mirror & shroud completely wrong without the light source. Light source fitted but no mirror & shroud, very unrealistic. The REME would not have released the tank back to the squadron in that state unless there were urgent requirements.

[Mark Heaps]

And for anyone thinking of doing the MRS light source and placing a LED in it, do not do so.
It did not project light, that was not its purpose.

[John Clarke]

Got a nice little Lazzzer pen for mine, blinding idea eh

OIP.jpg (11.19 KiB) Viewed 1625 times

[Charles A Stewart]

Thanks Mark.

I was wondering. One less light to fret over.

Cheers

Charles

[Mark Heaps]

Simple explanation of the MRS Muzzle Reference System. A dim bulb in the MRS light source that could be adjusted horizontally and vertically, and a mirror at the end of the barrel.
When the gunner depressed the gun to a particular angle, aligning two marks, and switched on the light source, he would see the light source reflected off the mirror as a dot of light.
After initial bore-sighting ( calibrating the sight to the barrel ), the position of the light source would be adjusted so that it appeared coincident with the gunner´s central aiming mark.
During firing the barrel would heat up and bend affecting the accuracy, the thermal jacket on the barrel was there to help reduce the effects but could not eliminate it.
The gunner would then during suitable pauses in firing, again depress the gun to the alignment marks, switch on the light source, and adjust his reticle aiming pattern according to the new position of the reflected light.
Not perfect, requiring some skill by the gunner on aligning the marks, but very effective ensuring good accuracy during prolonged firing.
On Chiftain, the MRS light source was a seperate item as shown here. Challenger 1 & 2 have it as well but it is integrated in the sight hood.

[John Clarke]

Thanks for the reference Mark, through the books I've read the MRS projection was V halogen lamp shining its bright light though a large fibre optic red filter, thereby putting a red dot on the shrouded stainless steel reflector at the end of the barrel. The MRS red beam was selected manually for a few seconds to occasionally check the gun alignment by the gunner in his main targeting sight and prevent nosey observers seeing the check before MA firing commenced.
I suppose if the gunners sight was damaged the gunner would have to return to dead reckoning with the backup reserve sight.
Back in the good old days high intensity LEDs in "pocket lazers" didn't exist. But now we could use the tiny things to emulate the Halogen lamp red dot unit. How technology trampled on
It would have been interesting to have looked inside the MRS unit, to be taken back to a time of mud, sweat and tears.
Not.

[Vince Cutajar]

Finished the other side of the MRS.

Some more test printing next.

Vince

[John Clarke]

Wow

[Steve Norris]

Hi Vince
Very nice,, the only bit I can see that may need slight adjustment is the plate at the back end which should be below the level of the top plate.

[Vince Cutajar]

Steve do you mean the cover (marked with the arrow) has to be lower than the rest of the body? In that case by how much?

Thanks for the input.

Vince

[Vince Cutajar]

I see it now.
This better I guess.

Thanks again.

Vince

[Kevin Hunter]

Great stuff Vince.
Loved the work you did with Phil W. Good to see you at it again.
Regards
Kevin

[Steve Norris]

Hi Vince
Looking better now.
Regards
Steve

[Vince Cutajar]

This is how today's print looks like. Did not bother with the spacers. The side cover was printed separately and glued to the main body.

Steve's modification is not shown here as I had already started the print. Maybe next time.
Today I found out that the top cover that Steve mentioned printed better in a vertical orientation.

Next, working on the front. As somebody said, "I have a clever plan". Let's see.

Vince

[Steve Norris]

Vince,
That looks very good, a little bit of clean up is all that is required.
Regards
Steve