Thanks, this is exactly what I was looking for. I figured there'd be a difference between the "that looks cool" and "that works well" spring rates. I didn't think it'd be a factor of two though. Has anyone pushed their springs past the event horizon?
On Wed, Jun 11, 2014 at 3:16 PM, Derek Engelhaupt <[email protected]> wrote: > 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. > -- ---------- Donald Shankin -- -- 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.
