Sprung weight?

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billpe
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Re: Sprung weight?

Post by billpe »

Serial just doubles Mah capacity.
RobW
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Re: Sprung weight?

Post by RobW »

billpe
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Re: Sprung weight?

Post by billpe »

Sorry, that was a typo, parallel doubles capacity, serial is voltage. I should be able to remember that properly considering that since I've just build a car which runs 2x2S in serial to form a 4S power source.

I assume you can run parallel Nimh batteries but I can't say I've ever tried.
RobW
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Re: Sprung weight?

Post by RobW »

Could be the solution for some of the heavier builds where the batteries don't last?
billpe
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Re: Sprung weight?

Post by billpe »

Yeah, probably would. Can get some pretty good and cheap 5000Mah nimh batteries these days so 10,000Mah might get you an hour in a heavy tank but you'd get longer with a pair of 9000Mah 2S Lipos but they're way more expensive for good ones.
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atcttge
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Re: Sprung weight?

Post by atcttge »

lposter, ISTR a youtube vid of an RC tank and one of the comments by the video uploader was that he softened the springs for the four front ones (2 on either side) to give it some realism or something like that. Sorry, I can't recall the exact vid.
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jackalope
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Re: Sprung weight?

Post by jackalope »

Heating the springs with a torch is the only way I know of weakening a spring. Anyone know another way that doesn't require an oxygen acetylene torch?
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jackalope
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Re: Sprung weight?

Post by jackalope »

I guess my problem is my tanks all have torsion bar suspension and I've yet to find anyone who sells weaker torsion bars.
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wibblywobbly
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Re: Sprung weight?

Post by wibblywobbly »

Depends on the tank. If they are the clock spring type on the suspension arms, then remove the arm, drill a new hole where the spring pegs into the hull, and replace the spring, it will then have less 'push' on the roadwheel. Things get more difficult with Bulldogs and Pershings as they have a different arrangement, but they are quite soft anyway.

The slight risk with softening them too much is that due to the lack of push, the track horns may ride out of the roadwheel next to the drive sprocket, especially when turning, so it would be safer to leave these as standard.

The unsprung weight thing is well known in the car and motorcycle world. Anything and everything that is isolated from the upper, is made as light as possible. Weight on the end of suspension is a bad thing as more weight = greater inertia to get it moving. less weight and the suspension works easier/faster etc. The other thing to reduce is friction, as this will add to the forces acting against the suspension movement.
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atcttge
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Re: Sprung weight?

Post by atcttge »

I got me those lead strips with adhesive backing from a Goodyear shop and placed them in the tank. Stupid me forgot to weigh them before sticking to the hull. Anyhow, I got six strips on the sides of the hull (3 per side) and two strips cut in half at the hull front. Seems to have worked as the tank doesn't rise that much anymore when rolling over my foot in a test. :D I'm going to add more weight up front so the hull dips when the tank stops from a run.
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