What is considered proper running weight?

[atcttge]

One thing I noticed - the stock springs are quite stiff, seeing how much weight I've added, the tank's suspension hasn't sagged yet, either when standing still or when it is running on flat terrain.

It only makes me want to add more and more weight, up to 20 pounds like BarryC here, but my problem would be room to put the weights (I'm thinking inside the turret as well), and if the JP480 motors + Ultimate Gearbox II can still propel the tank at various terrain profiles (i.e., fast on level paved ground, fast on rough terrain, and still be strong enough to climb 45-degree or more dry inclines). Currently, my tank (and my wallet hahahaha) can't afford the 550 gearboxes as there's no space (and funds) for the upgrade.

[ALPHA]

Hi guys,

Thanks for your insight and suggestions!

I will be using the axle supports and will seal them to the hull. This will seal up the giant holes where the drive shafts exit.

My plan is to run the reinforcement doublers the length of the hull side encompassing all suspension arms except the forward most L & R. Those will have to be separate pieces unless I removed the existing gusset just forward of my forward bulkhead; I do not want to do that. The doublers will be sandwiched vertically between the aluminum bulkhead attach angles and the hull side which will be screwed into place. They will first be glued into place though my normal approach will not work due to the large area. I normally coat both surfaces to be joined with liquid adhesive until both remain "wet/tacky" them press and clamp them together until cured. It can get a little messy but once cured the plastic will fail before the glue joint does!

I have considered the additional strengthening of the stack up using screws and likely will. I am also thinking about and additional bulkhead somewhere near center but it will have to clear the turret mounted Electrical Slip Ring and well as all the lower electronic installations, not sure there will be room. Gussets could be used but only on the RH side as the battery will occupy the LH side. I may be able to use the "new" battery enclosure as the nucleus of the needed bracing.

That sounds like it will do the trick...make your model last years down the road

I am going to reinstall the original springs, then using Michael C's approach of finding the right combination of springs and mounting holes to get the balance needed to "suspend" the weight on the springs. I have "SWAGed a targeted "sprung" weight of between 15 - 20 lbs with an overall weight between 20 - 25 lbs. I want to keep the weight as low as possible but still get the "ride" I am looking for. I want to see the "suspension work" as well, it is such a part of watching a machine like a tank operate.

Thanks for all you help, more to come!
Barry

Going back to the original springs might negate the need for the bracing....with that said though ...the bracing should make for a much sounder structure

Good Luck Barry


ALPHA

[spongehoobtank82]

Hi, Just wondered if you had considered one think, damping, I know your after the same suspension movement as a real tank but without compression/ rebound damping won't the tank just end up bouncing around alot over terrain also another consideration is spring weight, just something to consider, this build is looking amazing by the way!

[BarryC]

Going back to the original springs might negate the need for the bracing....with that said though ...the bracing should make for a much sounder structure

Good Luck Barry


ALPHA[/quote]

Hey Alpha,

I am going to give the springs a try and I will stick with the added bracing as I agree it will make a "sounder structure" in the long run.

Cheers,
Barry

[BarryC]

Hi, Just wondered if you had considered one think, damping, I know your after the same suspension movement as a real tank but without compression/ rebound damping won't the tank just end up bouncing around alot over terrain also another consideration is spring weight, just something to consider, this build is looking amazing by the way!

I wish there was an easy way to "dampen" the shock springs. A workable system could be devised but would require internal springs mounted in opposition to the return rate of the suspension springs. If the small "anti rotation" arm on the suspension arm were twice it's current length then an opposing spring could be mounted to it and pulled in tension against the main spring. This would have the affect of controlling the return rate of the main spring and dampening the suspension arm movement. The hull side walls would need to be much, much sturdier and likely made out of metal to boot.

I think the best solution is to try and get the weight on the springs to a point where their return rate is dampened because of the weight on them. I am hoping this will keep them from rebounding too quickly.

Thanks for the kind words. I am having fun and learning at the same time, a Win, Win in my book.

Barry

[spongehoobtank82]

Well if you needed to you could use the suspension arm mounting bolt as a friction damper by adding a washer to it,to press on the arm as you tighten the bolt, but I guess this approach would also loosen the bolt over time. Just an idea, might not even be necessary, not on all the bolts as real tanks don't dampen all the road wherwheels.

[BarryC]

Hi Guys,

This is a diagram of the stack-up I "plan" to use to secure the lead sheet to the hull lower plate. I will use the same screws and blind nuts that are to hold the Belly Armor with additional fasteners down the middle for added security. I believe that .040" styrene sheet will be adequate for the "false floor" if not then .060" will do. I am also considering bushings in the holes to prevent shifting due to the screw diameter being smaller than the hole required for the blind nut. I will bond the lead sheets together with industrial strength contact adhesive.

This will also add greatly to the rigidity of the hull floor.

More to follow
Barry