Full metal Type-99A, CNC production technology

[SteelBird]

Came across this video on YouTube. That looks really nice but no torsion bars and main gun elevation too high.

[c.rainford73]

Very nice SteelBird... I agree the suspension is a bit of a concern with all the added weight but cool non the less
You have a knack for finding the interesting stuff for sure!

[SteelBird]

Nowadays, most popular RC tank scale is 1:16 following by 1:6, 1:8 and 1:4. Larger scale than these are usually scratch built and not RC. Large scale RC tanks are usually made by CNC technology and in small number due to low demand but their prices are sky high. I am just thinking, if they produce large RC tanks using CNC but plastic as materials, would that reduces price?

[RobW]

The CNC cost is a function of set up (wouldn't change), material cost & machining time. If the throughput is increased and material cost reduced then it could be cheaper: by how much would depend on which of the factors is most critical to cost.

Note, you also have a mass v volume v area issue. At 1/16 the plastic tanks are fairly light, so most parts can be plastic and rarely break. Scale up to 1/8 scale (easy maths) and the unit is twice the length, 4 times the cross section but 8 times the volume (and therefore weight) - does plastic still work?

[silversurfer1947]

Plastic will deform under load. You can have problems with warping plastic when dealing with 1/16th scale. If you went up to 1/6 then additional reinforcement and strengthening would be needed. To the best of my knowledge, the only plastic 1/6 tank is the Stuart, which, being rather small will not be subject to the ame stresses and strains as say a Tiger 1.

[RobW]

And adding metal reinforcing will push up the manufacture costs, probably beyond using just metal.

Those 4 axis USB CNC machines Alwyn found could be a game changer for the hobby market. Not sure they'd be up for machine gun barrels, but might make re-manufacturing suspension arms possible?

[971wright]

Hi Nice bit of engineering, would need more work to make it full RC, the price of this would be very expensive, probably in the thousands.
Don't think we will ever see one running at a tank meet, probably will all be sold to be an executive piece on a desk.


regards pete

[SteelBird]

Plastic will deform under load. You can have problems with warping plastic when dealing with 1/16th scale. If you went up to 1/6 then additional reinforcement and strengthening would be needed. To the best of my knowledge, the only plastic 1/6 tank is the Stuart, which, being rather small will not be subject to the ame stresses and strains as say a Tiger 1.

Are you talking about the 1/6 Dragon M4A3? The tank was design to be full plastic (maybe with small amount of metal) and is a static model though someone try to modify it into RC. The plastic of the Dragon M4A3 is very thin and light. What I mean is a rather thick and strong plastic. However, it's just an idea, not necessary to be real.

[Raminator]

It still wouldn't be strong enough, and it probably wouldn't be all that much cheaper. Like Rob said, the CNC setup is the expensive part, not the materials. Take a look at Chris Ludwig's kits; they're all CNC machined out of styrene sheet.

[wibblywobbly]

The big difference in production costs is that a plastic tank can be injection moulded in one go, and all the parts assembled. CNC production means manufacturing each part separately, and it takes a lot longer for each part. The Mato metal tanks are white metal moulded, so that keeps the cost down, but the detail isn't as crisp as a CNC tank would be.

At the end of the day, if the CAD drawings have been done for a plastic tank, then those same files can be converted and loaded into a CNC machine.

The way I look at it is that once it is painted, it is pretty much impossible to tell whether a part is plastic or metal. I've been running tanks for almost ten years, indoors and out, and have never had anything break, warp, or malfunction. The bonus with heavy tanks is the way that they look when going over bumpy terrain, as they don't bounce around, indoors all tanks just run on the level. One day when I can get hold of a load of lead, I will try adding ballast to plastic tank and see what happens.