Balancing Weight

[NEMYSIS]

I am sure clods are fun and they are cool trucks but when you are running your mouth about how a clod out performs a shafty there is no comparison, clods don't even function the same. That was the point to be made. Clods can have huge ground clearance due to no tranny and no torque related problems that a real truck with a drive shaft have.

[DISTURBIN' tha PEACE]

Originally Posted by NEMYSIS

I am sure clods are fun and they are cool trucks but when you are running your mouth about how a clod out performs a shafty there is no comparison, clods don't even function the same. That was the point to be made. Clods can have huge ground clearance due to no tranny and no torque related problems that a real truck with a drive shaft have.

Who cares? This is about COMP rigs not "scale" trucks.
Wanna win? Better have a clod

[LowRange]

Usually there's a comparison between two things when they're both occupying spots at the same competitions

[Mad Scientist]

This thread isn't even about comparing Clod/Shafties. Lets hear more talk about weight distribution.

[Maitias]

To continue this discussion on topic....

Is there a limit to the ammount of weight that can be added to a truck?

[dezfan]

No. But lighter is better.

[peej410]

i would think that a certain amount of weight would be ideal, lighter is usually better when your trying to quickly accelerate and decelerate a vehicle but i think that, in this instance there must be a sweet spot between traction and weight, am i wrong in thinking this? i realize that having a rig that weighs less means that you need less traction to move it but at the same time in some situations being able to transfer weight to one tire is important, in many of the vids ive seen most people seem to spent alot of time spinning their tires instead of trying to creep... i guess ihave to go to a competition to see it for real

[JasonInAugusta]

Originally Posted by peej410

i would think that a certain amount of weight would be ideal, lighter is usually better when your trying to quickly accelerate and decelerate a vehicle but i think that, in this instance there must be a sweet spot between traction and weight, am i wrong in thinking this?

You're right.

There's a sweet spot.

[Cloak]

Originally Posted by JasonInAugusta

You're right.

There's a sweet spot.

Speaking of sweet spot and balancing weight, I sure wouldn't mind finding the center of gravity of your avatar.

[peej410]

Originally Posted by crawlerman

.....but then again it may be different for others as I crawl mostly virtical ledges and giant jagged boulders.

hrm i climb lots of vertical ledges and jagged boulders too but what ive found is that when the batteries are on the axle when one front wheel drops off the center of gravity shifts far to the side that the wheels dropping this in turn (if your not careful) drags the rest of the rig into the hole, this is what im trying to minimize because im always dropping wheels off an edge. when i had my batts on the chassis the rig wasnt as capable so dont have a baseline to compare data to...

[peej410]

every boulder has an edge, all the stuff i play on is 6 feet tall or so but only 3 feet across usually and there are transfers between boulders which i really enjoy trying because theres usually only one line to take and it takes many many trys to get it, alot of the transfers are similar to whats seen in the first part of this video they are only about 6 foot tall. ive nailed all those transfers since that video, but id still like to get the weight off either side of the axle. when a tire drops into a hole or open space it shifts the cg in that direction, id like it to remain closer to the centerline of the chassis to allow me to drop one wheel off and keep the entire rig from following it. http://www.autosportfab.com/movies/PetesRC3.mov

[Jackyl]

This is ExactlY what I have been looking for, Dirk! Thanks for backing my original theory. Everyone was telling me that I need to put my batteries on my front axle. That to me seemed just retared to mount a pack high up on a servo, or on links to compramise articulation.

A better solution I feel is to just stuff as much steel on the belly of your crawler as you can, drive it and see how it does, start pulling a peice here or there off at a time till the weight affects how it crawls, then add another peice to get it back and another peice for luck. Then try to make it so everything doesn't look like a bad junkyward wars episode. Also, I see alot of people running foams in their tires. I think that running maximizer rims and no foams is the real deal. It holds air in the tires and doesn't allow it to escape, this allows the tires to basically be like velcro on a rock, conforming to every little contour of the rock face, or anything for that matter.

I'm currently trying to take care of torque twist with my txt. I have a gut feeling that I'm going to end up calling my truck the tank, Because it'll be as heavy as a tank when it's done.

The other thing that weight does is pre-loads your suspension. This allows you to not run a pre-load spacer on the shock, because gravity is actually your pre-load. Say you drive up to a wall at a 45 degree angle from the left (truck facing the right). Your drivers side front tire will hit first and proceed to go up the wall, the weight of the truck being pulled by gravity will force the passenger side tire towards and the torque/weight/gravity force will plant the rear end until you max out the front suspension articulation and lift a wheel. But I'm pretty sure that you should be able to touch the drivers side rear wheel the the wall before you lift a wheel or loose traction.

Just some observations.

Also what is the deal with light trucks? Everyone wants a light truck or says lighter is better, this isn't racing, weight is better! Sure you'll have less run times but it will be much more enjoyable because your rig will be much more capable. Think about it from all aspects. Weight is your friend.

and for the record I'm a clod hater, they remind me of an expensive nylint.

The other neat thing about weight is that if your heavy enough you can run tall tires and get some much needed diff clearance and not affect your cog Like I'm going to be running nylint 1:6 rims and tires on my txt axles for the diff clearance and the narrow tires that everyone praises about.

I'm not a beleiver of narrowing your tires either. Common physics shows that something narrow will have less resistance on all levels, so a narrow tire will have less contact patch than an aired down wide tire will. A narrow tire is good for any condition that you need to get to the bottom to get traction on in order to get through it. While a wide tire will sit on top because there is more surface area. For the same reason you would wear a snow show to walk on deep snow to help you from sinking into the snow instead of just walking on the snow with your feet wich would cause you to just sink into the snow. Everyone likes what they like, but I beleive that wider is better, especially wider tires on a beedlock rim with a little bit of air in the tire to do what people try to do with foam.


:?

[SlinkySam]

Originally Posted by Jackyl

Also what is the deal with light trucks? Everyone wants a light truck or says lighter is better, this isn't racing, weight is better! Sure you'll have less run times but it will be much more enjoyable because your rig will be much more capable. Think about it from all aspects. Weight is your friend.

I must disagree with you at this point in my trials. I have the bare essentials in my crawler (battery, tranny, axles, tires, electronics) mounted low of course, nor do I run wheel weights either. My chassis weighs just mere ounces. I plan on removing more weight where I can because it has made my crawler so much more capable that it is rediculous. Now you might not agree with me or believe me, but if you need any proof, just ask some of the Nor-Cal boys who have seen it go. Now I still run the standard Nimh battery because I am too cheap to pay for the Lipos, but I sure wouldn't mind trying some out. So in my experiences, weight isn't your friend unless you are the winch truck and you need to be heavy

-Sam

[bugman72]

I'd have to agree with SlinkySam as well. At one point, each one of my 2.2 tire/wheel combos weighed 10.8oz each. I thought that the additional weight would make my crawler unstoppable. It did well and I never had to worry about carrying a wheel up an incline due to torque twist. But, my truck seemed to labor everywhere it went. It was really sluggish and just didn't seem to have the torque that it once did.

I shed all of the weight on the tires, got some 2/3A batteries and placed them low on the front axle and the difference was night and day. Gobs of torque, the truck seemed to just bound up the ledges and it was a lot more predictable when in a precarious situation.

I think the key, as this thread originally pointed out, is to get all of the necessary weight (electronics, motor, tranny, etc) as low as possible and as balanced as you can. Don't just load on the weight like an off-the-wagon Jenny Craig participant and an all-you-can-eat donut buffet (mmm...I wish there were one of those!)

There is a very fine line between just ENOUGH weight and TOO MUCH weight. It boils down to a lot of experimentation and a LOT of time on the rocks doing R&D.

[Roobforme]

I know this thread is old, but being a noob I just got around to reading it. I wanted to thank you all who contributed to it. I've been crawling in 1:1 and know what it takes to make them succesful. However I've found that what makes a 1:1 succed doesn't nessicaily make an RC succed. So, I'm glad to somebody else has done the work for us all. Thank you.

[bob1961]

is this supers or 2.2 we are talking bout....i thought 2.2 class doesn't allow more then 1 motor "a motor on each axle" .......................bob

....

[modestjon]

If the weight is supposed to be low and center, does anyone know how to aquire the right setup for an Axial Scorpion RTR with out giving it a major facelift??? I've been trying a few different things about the weight, but I'm a noob and really don't know what I am looking for. So far, the weight up front does great just for the rocks in my back yard. Any other suggestions to fix the weight problem so I can crawl damn near everything?

[XPLORx4]

Crawlability is not only about weight placement. Here are some things I have done to tune my rig:

I have tweaked my RTR by first locking the front diff and installing the 14T pinion. Then, I installed medium springs in the front and added 5.5 oz of stick-on wheel weights inside each front wheel and 3 oz in each rear wheel. I star-cut the foam inserts and drilled a 1/8" hole in each wheel to allow the tires to conform better to the terrain. One of the first things that failed on my RTR were the rear lower links and the steering linkage, so I upgraded those to the bent lower links, and that helped a lot to improve breakover angle so I don't get high-centered as often.

Finally, I installed an extended battery/servo tray, and last night I disassembled and reconfigured my 2000mAh NiCd 6-cell stick-pack battery by placing the 2 end-cells underneath the middle cells and resoldering them together. This helped lower the CoG a lot, but I haven't crawled it on real terrain yet. I need to do a little testing to see how it works. Depending on how well it works, I may swap the front and rear wheels in order to balance out the CoG.

The bottom line, as I have learned, is that there really is no "right setup" for a crawler. I'm discovering that it's a lot of trial and error.

[ohmyCLOD!]

Originally Posted by Shorty40

Sounds like someone has a shafty that cant keep up with the Clods

That's for sure.
Theres plenty of room for comparison between shafters and clods, they are both rc. You can't really call a shafty the "real deal", you still stand outside the vehicle with yer remote. As far as a clod with one motor at each wheel, im gonna try that sometime with a lego PLC brain, shootin for an autonomous crawler...

[flexman]

(noob)

wow, awesome thread guys...i was hoping something like this could be found on this forum and imo this is a gold mine...i've done a lot of 4wd'ing and in a 1:1 the one thing you always seem to be chasing is tractive effort - ie keeping some weight on all of the wheels so you can utilise their grip with your powertrain. preloading the springs with weight IS a certain way to retain the traction - to an extent.

what i haven't seen yet is a system that allows a more even pressure on all four wheels. i'm talking about a system that an australian company, kinetic suspension developed and then sold, before they moved to swaybars with the same effect...used in wrc and lexus etc etc.

basically its an air pressure system with a reservior and four small rams acting on the lower trailing and leading links, interconnected. on a sideways slope there needs to be some type of control as without normal swaybars (which defeats the point), as you can imagine, it would simply tip over. this system allowed an open-diffed hilux with road tyres to traverse over grassy terrain, articulating at full diagonal to its bumpstops, keeping even weight on all four wheels with no 'tearing' whatsoever of the surface- surely there would be a way to implement such a system on scale?...