Franks's formula pretty much works out about right for the KV-2 I have. 12 axles at about 120-140lbs completed weight, and I'm using 30lb. springs. Mine would be on the stiff side of his calculations. I'm also using "die springs" which don't seem to compress that much in a static state, but seem to work really well at absorbing shock.
Derek On Wed, Jun 11, 2014 at 2:03 PM, Frank Pittelli <[email protected]> wrote: > Here are my rules of thumb, based on experience with suspensions in the > SU-100 (tension springs), Semovente (leaf springs) and Patton (torsion > springs). > > 1) Estimate (or measure) the battle weight of your tank (W). Multiply by > two (2) and divide by the number of road-wheel axles (A) to determine the > "minimum" weight per axles (WPA(min) = 2 * W / A) > > 2) The minimum weight per axle, WPA(min), is a good starting point. Each > suspension will be at 50% of travel when sitting still and will be able to > move 50% more under dynamic loads. The WPA(min) is a nice looking > suspension for video purpose, easily riding up and down when going over > objects. Great for that "that's neat" suspension video, but not as good > for real battle-field situations, like flying over a large tree root at > full speed. > > 3) For a little stiffer suspension, multiply by 4 to yield WPA(stiff) = 4 > * W / A. In that case, each suspension will be about 25% depressed when > the tank is sitting still and will be able to travel 3 times further under > dynamic loads. The video doesn't look as nice, but the suspension will > take more abuse and there is less chance of deforming the suspension > springs (be they compression, tension, leaf or torsion) during a real > battle. > > The SU-100 has been using a WPA(min) suspension for many, many years and > it's still working well. But, keep in mind that the SU-100 has > historically been the slowest tank on the battlefield, so it wasn't flying > over tree roots and having to land hard. It also has mechanical limits to > absorb the really big shocks without damaging the springs. > > The Semovente and Patton both started out using WPA(min) suspensions, but > both have been increased to WPA(stiff) suspensions after initial field > tests. Because they rely on leaf and torsion springs without mechanical > stops the stiffer springs are needed to prevent deformation of the springs > during heavy load events. > > > > On 6/11/2014 2:36 PM, Don Shankin wrote: > >> I'm curious about what I should expect to be using for springs for my >> suspension. Are you all balancing the overall effective spring force to >> the weight of your tank? This seems like something that is just >> discovered through trial and error, but I'd be interested in what you >> find works best. >> > > -- > -- > You are currently subscribed to the "R/C Tank Combat" group. > To post a message, send email to [email protected] > To unsubscribe, send email to [email protected] > Visit the group at http://groups.google.com/group/rctankcombat > > --- You received this message because you are subscribed to the Google > Groups "R/C Tank Combat" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat --- You received this message because you are subscribed to the Google Groups "R/C Tank Combat" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
