VICKERS MK6B's resto

[James P]

Originally Posted by colin jones

I have posted a couple of pics of the original componentry I have and I can't help keep saying how lucky I am to have these parts. I just don't know how I could have done this with photos or measurements alone. Anyway you can see what I have to make next and I will have to make it around one of the original turret baskets I have otherwise it just won't turn properly.

As usual your work is stellar and I have nothing but the utmost respect for the time, effort and skills you are pouring into this project that is a true Legacy project. I fully get it about no matter how far gone a part or piece is it still holds a ton of value telling your locations for holes, shapes, radiuses, etc. I resorted to gluing huge flakes of rust together to determine a radius on one project. Looking forward to further posts of your work and the bring back to life of the tanks.

[colin jones]

Thankyou very much James, I appreciate you comment and I certainly agree that no matter how small the part is, it can hold vital information. Sometimes you don't know what a small part is until you get to certain stages and things just fall into place. I am at that stage right now. There are some small round wooden blocks bolted into the bin parts I am doing and I had no information as to their use until David Dunlop asked me if I had info of each bin use. After getting a Vickers ammo tin and putting it into the original part, I then realized they were spacer blocks for the .303 tins and could be unscrewed for the .5 tins. So that was great for me to find a use for them and now I will be making some of them as well. So a big thanks to David for asking the question
Anyway I had to make the rear door that has a pressing in it so I decided to make a press set for them. I need 1 for each tank and there is another door above which after these are pressed out and completes I can easily modify the press set to make a smaller pressing for the above door and then just de-weld the material for another use. As it is only aluminium, it will probably only take 15 or so tonne to form it and my pressbrake is a 40 tonner so there will be plenty of power.

[colin jones]

I am happy"ish" with the result but have to manage the stretching that occurred. It's not too difficult but quite time consuming to fix and manage. There is also a rolled wire edge that is in sections so that is another part to do and it incorporates a double slide pin for locking. One good thing of having a press set is, no matter how many you do they will all be the same.�� I'm about 80% on one door and will finish the other one tomorrow.

[Mike Cecil]

The originals were probably formed using a die set in a hydraulic double-action press: the first part of the very slow stroke clamps the entire sheet flat, the second part is the actual forming die that stretches the material to shape. The clamping before forming prevents the sheet from wrinkling around the edges and away from the forming die.

It always amazed me just how far the right material can be stretched - deep stainless steel wash-up sinks, for example, are/were done this way.

Amazing work, Colin. Very, very skilful.

Do you have an original .50" Vickers ammunition box to use as a sample?

Mike

[Bob Carriere]

....... Eventually when I tackle the restoration of my CMP trailer I will need to do similar indentations, in a sun burst fashion, on the front head board of the trailer box........ now I know how.....

When is the real issue !!!!!!

How did you resolve the warping that resulted from the stretching of the sheet metal????? my piece will be narrow but long...about 30 inches x 80 inches...... 14 gauge..... top edge and side ends will be prebent in a double return box shape.......at a fabricator and will add stiffness.

Cheers

[colin jones]

Thankyou Mike and Bob, I could have mostly eliminated the warping by making a different bottom die. I should not have just done a narrow perimeter form as that is what created the warp. Instead it should have been the full size of my pressing area as that puts the same pressure everywhere. I guess I was just a bit slack really . The better way would have been to mill the shape I wanted into a thicker piece of metal as that would cover all areas or plug weld a laser/plasma sheet on the top. Either way it was just lack of support and I knew it would happen but being aluminium it is easier to shrink and stretch.
This is a problem when using bead rollers as that too creates stretching. As I am no panel beater, YouTube is a valuable source of information but I used a rubber mallet to shrink and stretch the material. Not as easy task on steel. The dies I made to press my bottom engine covers were heavy and pressed the entire area of the covers so I got very minimal distortion.
The wire rolled edge certainly stiffens it up and I clamped the whole thing down before I formed the edges. I learn a bit more each time I make things like this.
Oh, and Mike! No I don't have any .50 Vickers ammo boxes�� unfortunately and would be very happy to do a deal with anyone that has some�� Please��

[jack neville]

I can recommend Mikes advice Colin. Sandwich the ally between two plates, secured by any means and you will get no warpage. I did this tool box lid for the Walker Bulldog resto project that Weapsim did for the Cairns tank museum.
i couldn't get enough pressure at 100 tons in one go so had to step it along.
Still came out neatly.