Armour Dreams

[Jonathan Moore]

Looking forward a bit I need to start thinking about casting the polyurethane tyres on the return rollers and the road wheels. This process is new to me so I have done a lot of research, talked to those who should know and I think that I have a plan that should work. I am going to start with the return rollers and have decided that a mould that forms the outside diameter and the front angled face to finished dimensions would give the best results and reduce the amount of post casting machining.

[Jonathan Moore]

This is the kit of parts for the mould. The plates were then bored and turned so that they run true and the angle for the front face turned in. A centre shaft turned to locate and bolted in the base plate.

[Jonathan Moore]

The hub is the placed over the centre shaft and a spacer sits on top of the hub. This spacer seals the top of the hub and forms an air gap. A top plate is placed on top of the spacer, this has pouring holes cut in it and is turned to the same diameter as the base plate, which is the finished diameter of the roller. A tin outer cover is then wrapped around the outside thus forming the finished outside diameter.

[Jonathan Moore]

Jubilees clips, top and bottom of the mould hold the outer sheet in place and finally the whole assembly is bolted together.

The polyurethane, release agent and vacuum chamber are all currently in bound, all I have to do before commencing the casting is to shot blast the hubs and add some extra bands around the outside of the hubs to increase the surface area so that the tyres have a bigger area to bond to.

Confused join the que.

Jon

[Chris Abraham]

Great work you are doing. I am planning to have a go at doing a Vickers light tank or a A13 cruiser tank, have the fabrication skills and tooling but you try finding the drawings with measurements, thats the hardest part in my book, at the moment i am doing a lot of homework. Trips to Bovington are very trying as theres always one measurement that you forget to take. Keep up the good work.

[Jonathan Moore]

Originally Posted by Chris Abraham

Great work you are doing. I am planning to have a go at doing a Vickers light tank or a A13 cruiser tank, have the fabrication skills and tooling but you try finding the drawings with measurements, thats the hardest part in my book, at the moment i am doing a lot of homework. Trips to Bovington are very trying as theres always one measurement that you forget to take. Keep up the good work.

Morning Chris,
Have you got the two Black prince Books on the A13, I am a bit anal but they are, in my opinion, fantastic books and contain a mountain of technical detail. It might be worth mentioning your project on the HMVF forum. The other source of reference is a good quality model.

Regards,

Jon

[Chris Abraham]

Originally Posted by Jonathan Moore

Morning Chris,
Have you got the two Black prince Books on the A13, I am a bit anal but they are, in my opinion, fantastic books and contain a mountain of technical detail. It might be worth mentioning your project on the HMVF forum. The other source of reference is a good quality model.

Regards,

Jon

Hi Jon, i have got the P.M Knight books on the A13, gives a really good account of the construction details of the tank. A tank often seen in 1940 used in France and the Western desert and here in the UK but only one left, A French museum scrapped one not that long ago I have also bought a good quality model like you mentioned but it will be a tape measure job to proof scale the sizes. As for drawings i am finding it difficult to find anything really especially hull plate sizes etc, i even tried Bovington but the didnt have much. I do wonder where these factory drawings went on most British tanks as its a bit of a mystery, i have asked all over, someone sitting on them.
As for your mould to cast the urethane i have noticed that tank bogie wheels have groves in them or raised steps to stop the rubbers sliding off, the A13 has them on their aluminium wheels they use.

[Tony Smith]

Originally Posted by Jonathan Moore

J
The polyurethane, release agent and vacuum chamber are all currently in bound, all I have to do before commencing the casting is to shot blast the hubs and add some extra bands around the outside of the hubs to increase the surface area so that the tyres have a bigger area to bond to.

Jon

Have you given any thought to adding vanes or fins to the hub to key into the "body" of urethane? Not making any claims that they should be there, but they would reduce the propensity for the urethane to shear off the hub. Fine line, of course, as too much would reduce the elasticity and absorbtion of the urethane.

[Jonathan Moore]

Originally Posted by Tony Smith

Have you given any thought to adding vanes or fins to the hub to key into the "body" of urethane? Not making any claims that they should be there, but they would reduce the propensity for the urethane to shear off the hub. Fine line, of course, as too much would reduce the elasticity and absorbtion of the urethane.

Morning Toni,

Thanks for the reply, I not sure what you mean by vanes but my intention is to weld a couple of bands, either of flat steel of 5mm dia bar, around the circumference of the hub to act as anchors. Many years ago I had the job of turning the rubber tyres off of some forklift wheels and when the rubber was removed, it revealed a series of small V grooves machined into the hubs circumference for this exact purpose, I could go down that route, I am not sure yet.

Regard,

Jon

[Tony Smith]

Originally Posted by Jonathan Moore

Morning Toni,

Thanks for the reply, I not sure what you mean by vanes ..........

Regard,

Jon

Like the cleats on steel tractor wheels.

[RichardT10829]

Absolute exquisite work !

[Jonathan Moore]

Originally Posted by RichardT10829

Absolute exquisite work !

Thanks Richard.

Afternoon All,

The ammunition for the MG34 machine gun, in the early versions of the Panzer ll, was loaded into saddle drum magazines, these were stored along the hull side behind the driver.
The saddle drums were expensive to manufacture, bulky to store and apparently they had a tendency to cause stoppages, so later models were supplied with Gurtsacs to hold the ammunition. A canvas bag with a steel top, it was still quite complex but easier to store and cheaper to manufacture.

[Jonathan Moore]

The Gurtsacs were stored in the same area as the saddle drums but the storage method was far simpler to manufacture, being just a horizontal lip that the Gurtsacs slipped over. You can just make it out on the picture below.

The interior picture is from the Tank museums Ausf F and as I have no pictures of the interior of a Ausf C with the MG34 ammunition stored in Gurtsacs I have had to base my work on the information that I have.

[Jonathan Moore]

Bolted to the upper left hand side of this structure, would have been a carrier for the radio operators gas mask canister.