RC Tank Warfare community hobby forum

CanadianBulldog22 wrote:My apologies to the group, I am not and never planned on coming off as an elitist. I probably could have used better phrasing. I have corrected it. I did not mean to exclude anyone nor do I mean to come off as a know it all. There is a lot I do not know. I am however a mechanical engineer, which does give me some precedence to add my technical knowledge when relevant.

I am unsure if I will continue to post on this forum at this time as there seems to be a lot of general negative attitudes. Instead of assuming the worst about what someone has written maybe try giving people the benefit of the doubt.

Chris


Chris

dgsselkirk wrote:P.S. I can hardly wait to see once you do all your mods what this tank of yours will cost!

SovereignZuul wrote:

dgsselkirk wrote:P.S. I can hardly wait to see once you do all your mods what this tank of yours will cost!

*hides my receipt pile*



I wouldn't know anything about that....

wibblywobbly wrote:Although it is always good to see members modifying tanks and improving them, there is a fine line between cost and effect.

If the wheels on an HL tank have been assembled correctly at the factory, they are free spinning and generate very little rolling resistance. The one thing that a tank is not noted for is speed, and many modellers modify their tanks with reduction gearboxes and upgraded electronics to slow them down. So, yes, fitting roller bearings is a feat of engineering, and will reduce friction, but the benefit is not going to be noticeable.

Sealed bearings are still going to get caked in mud, water and grass, so if they are run off road, the resistance is going to come from the muck that the wheels and tracks pick up rather than the bearings. In this respect HL's are easy to clean, and can be washed.

My view is (based on real life vehicles) that if a tank is running off road then unsprung weight is more of an issue. CanadianBulldog may be able to confirm or trash the notion that in order for suspension to work effectively, the weight attached to suspension should be as low as possible. If you push down on a tank it takes a lot of pressure before the suspension moves. Fitting stiffer springs makes it worse.

Off road, the tracks hit a bump, the track pushes on the road wheel, and the road wheel pushes on the spring. If the force of the upward movement is less than the spring resistance, the wheel does not move. The force is then transmitted through the suspension and simply lifts the tank. At this point the suspension is not working at all, so the whole tank lifts.

Lower unsprung weight together with a weighted tank that is balanced at the point where the suspension starts to work, and softer springs, should in theory allow the upper hull to stay where it is, and the road wheels to move on the suspension arms. Adding unsprung weight like metal road wheels, bearings etc etc creates more mass to be moved when the tracks go over a bump, so more work for the suspension to do in terms of momentum/inertia etc.

It would be interesting to hear whether what applies in the automotive world applies to plastic tanks, I have always wondered? It is a genuine question

RobG

fynsdad wrote:When I'm dead, I hope my wife doesn't sell my tanks for what I told her they cost......

CanadianBulldog22 wrote:My apologies to the group, I am not and never planned on coming off as an elitist. I probably could have used better phrasing. I have corrected it. I did not mean to exclude anyone nor do I mean to come off as a know it all. There is a lot I do not know. I am however a mechanical engineer, which does give me some precedence to add my technical knowledge when relevant.

I am unsure if I will continue to post on this forum at this time as there seems to be a lot of general negative attitudes. Instead of assuming the worst about what someone has written maybe try giving people the benefit of the doubt.

Chris


Chris