Armour Dreams

[Jonathan Moore]

And my attempt.

[Jonathan Moore]

I am feeling a bit crappy so I decided to follow the Governments advise and self isolate myself in the workshop.

I finished the lining panels along the inside of the hull and made the box for storing the radio operators head set, other than that there nothing to report.

[Jonathan Moore]

Well, I finally got my arse into gear and cast the first tyre on the return roller. It went fairly well, the only problem being that it was quite hard to free from the mould. I used a silicon release agent and as I couldn't get the roller to release from the base I ran a stanely knife around it, which scuffed the face but not badly and I can tidy it up, so no problem really. I spoke to the supplier today and they suggested using Vaseline, so I have used that on the one currently in the mould.



Jon

[Petr Brezina]

Top class work, Jonathan. Keep me feeded

[Jonathan Moore]

Originally Posted by Petr Brezina

Top class work, Jonathan. Keep me feeded

Don't worry Petr, there's plenty more to come.

Jon

[Jonathan Moore]

Evening All,

I hope that you are all safe and well.

I haven't done much since the last update as the sun's been out and it's time to get the garden done. I have started the polyurethane casting mould for the road wheels but I am waiting for a new cutter to arrive for the milling machine and at the moment it takes a little bit of imagination to see the finished item.

Apart from that, I now have eight track return rollers with tyres on but not finished, as the polyurethane takes about eight days to go off and I can't finish machine them until they have hardened.

Jon

[Jonathan Moore]

Evening All,

A week of lock down done and I heard on the radio it could last for 13 weeks, so progress will slow right down but it will continue until the materials run out.

I have finished the mould for the drive wheels, it's made on the same principle as the return roller mould but bigger. I am worried that because of the amount of polyurethane required, about 6.5 litres, it will have problems filling from a single pour and although I am loth to use a double pour, I have constructed the mould with two pouring holes.


Jon

[Jonathan Moore]

more pictures

[Jonathan Moore]

Pictures showing how the mould assembles around the wheel hub.

Jon

[Bob Carriere]

....always enjoying your progress and reading your email......fights cabin fever.

may be hard to obtain but are there no chemicals that you can mix to slow down the setting time.......?

...or adversely since most sets by temperature....can you refrigerate the bulk mix to give you a longer time to pour all at once..........

....can you rig up a vibrator to help the mix flow into crevasses and get rid of possible air bubbles......

.... not sure of your mix but it is common for woodworkers to heat up the mold and total mix to allow air bubble to rise from the mix....

Tilting that 65 pound bucket will be an exercise in itself.......

Bob C.

[Lynn Eades]

Jon, can you explain how you mold works please (all the many gaps at the bottom) Thank you in advance.

[Jonathan Moore]

Originally Posted by Mike Cecil

Yes, still enjoying your build and marveling at your prowess.

Lifting & tilting a 65 pound bucket - interested to see how you overcome that problem.

Maybe rig up a pouring bucket like they have in foundries - a bucket with a pouring lip, hinged within, and suspended suspended from, an inverted 'U' shaped bracket?

Mike

I am confused and if I caused the confusion then let me apologise but the weight of the polyurethane is 6.5 litres or 14.5pounds, so where did 65 pounds come from?

Lynn,

The gaps around the bottom of the mould as superfluous to requirements, the vertical pieces of steel that form them, are only there to retain the flat strip that forms the outer face of the tyre in place and at the correct angle. These vertical pieces have been machined at an angle of 5 degrees on their top face which is the correct angle for said face.

The thin metal sheet, that gets wrapped around the mould and forms the outside diameter of the tyre, is held in place by long jubilee clips. One at the bottom of the mould, that seals on the area shown on the picture below (marked with a red arrow) and one at the top the seals around the top cover.
The sealing area is pretty thin but as it has been machined I am confident that it will form a good seal.

I hope that it explains it or at least my theory.

Jon

[Mike Cecil]

From Bob's post ....

"Tilting that 65 pound bucket will be an exercise in itself......."

Apparently I misunderstood. I'll delete the misleading entry.

Mike

[Jonathan Moore]

Originally Posted by Mike Cecil

From Bob's post ....

"Tilting that 65 pound bucket will be an exercise in itself......."

Apparently I misunderstood. I'll delete the misleading entry.

Mike

Evening Mike,

It's no problem, I thought it was my fault.

Hopefully these two pictures show the angle of the face formed by the vertical pillars.

Jon

[Jonathan Moore]

Thanks Bob, I think that I am going to need all the advice that I can get on this one.

Evening All,

I thought that as I was making moulds, I might as well make the mould for the suspension arm radius bump stops.

[Jonathan Moore]

The 7 larger holes are there to allow the polyurethane to coat both sides of the steel retention bracket and bond through the holes. Hopefully it will work, tomorrow morning I shall find out if it has.

Jon

[David Dunlop]

Is there much off gassing from those items as they cure, Jon? Will your shop end up being mouse free for a while?

David

[Jonathan Moore]

Evening David,

The two items that I have done so far are degassed with a pump next door in the vehicle area, which is much bigger and not heated, then I get out and return in the morning. The road wheels will be slightly different as I can't degas once the polyurethane has been poured into the mould. As for noxious gases, I don't stick around to find out but judging by the number of mice that I have caught where the vehicles are stored, it doesn't appear to be a problem.


Jon

[Jonathan Moore]

Evening,

And the results are in...…...It looks pretty good to my eye, a bit of fettling when it's cured but on the whole I am pleased with it. There was a bit of leakage due to a small gap between the base of the upright and the base in one area but now that the resin has filled the gap it won't happen again.

[Jonathan Moore]

You can see in this picture the line of the retaining bracket and that the resin has coated both sides.

Thank goodness, success.

Jon.

[David Dunlop]

Jon.

I can hardly wait to see how much the external look of the hull is going to change once the rubber clad items start to go on.

Something that has never occurred to me until now, is whether or not balancing of the larger road wheels on armour is necessary. My uninformed thought is these wheels, although large and heavy, probably never reach a high enough RPM for any that might be out of balance, to cause a problem.

Hope your supply lines stay open and you and the family stay safe.

David

[Jonathan Moore]

Morning David,

It's strange that you should mention that as it crossed my mind yesterday as I was trial fitting the jubilee clips and I have no idea. I really don't think that it will matter on my recreation but I wonder how they balance modern tank road wheels or maybe it doesn't matter.

Any thoughts,Anyone?

Jon

[Grant Bowker]

This isn't strictly relevant, but I know of a fleet of school busses that didn't have a balanced wheel/tire in the entire lot. My experience was as a replacement driver so I ended up driving most of them. They had other issues but none hopped down the road speeds 0-98 km/hr.

[Jonathan Moore]

Evening,

I thought that before I get too excited and cast all ten, I had better see if they fitted first. They still need fettling but I am pleased with them.

Jon

[Jonathan Moore]

Evening All,

In truth there's not a lot to show you at the moment, I have stripped the front interior out of the tank in readiness for testing the final drive set up and I am in the process of reinstalling everything but this time the drive chain will be in it's finished state. I have rebuilt the final drives and waiting for some parts to be delivered before I can fill the steering box with oil.

I am on the third and final version of the steering box filler cover, that's it, no more changing my mind.

I have also made a more representative version of the Morse key holder, as it was pointed out to me that this item was originally adjustable, well now it is.

[Jonathan Moore]

Today, was the day, when it was all tested. Sorry for the sound quality in the video, it's the camera's fault. Everything worked as it should do, there were no oil leaks, so I am a happy man. Although there are some small modifications that I am going to make. Now that the engine has a load on it, even if it is no where near what it will have to deal with, it's exhaust note has changed and is quite pleasant, in a noisy sort of gruff way.

https://youtu.be/LyIzzA4MhoU

Jon

[David Dunlop]

Awesome, Jon!

You must be quite pleased with the power train progress to this point.

David

[Bob Carriere]

.... you look so much younger!!!!!

The lad seemed to be enjoying himself.......

Very nice work Jon.......

Bob C.

[Jonathan Moore]

Originally Posted by David Dunlop

Awesome, Jon!
You must be quite pleased with the power train progress to this point.

I am David, I now have to concentrate on the drive wheel and sprocket both of which are going to be a challenge, however I think the sprocket, being 25mm thick, is beyond my cutting capacity so I will have to find a company to produce it for me.

Originally Posted by Bob Carriere

.... you look so much younger!!!!!
The lad seemed to be enjoying himself.......
Very nice work Jon.......

Bob, I sometimes wish it was me but then again...….

Toby, my youngest, was brought up having to share Dads eccentricities and some of it has rubbed off, he's currently restoring a very rusty 1964? New Holland bailer. It was his first time at the controls and he's dreaming of the future or maybe the past.

Thanks for your support,

Jon

[Tim Bell]

Do you have a picture of the morse key which goes on that holder.

Asking purely because I have a WW2 German Morse key somewhere mounted on a metal plate... I had assumed it was an amateur mod post ww2... but perhaps it is for this holder!

If I find the morse key, I will post a pic.

Exceptional work - you have me wondering what you would have created if you had been working as a Tank designer in the 1940s.

Cheers

Tim