Darkseid

iTrader: (9)

I hear alot of talk about running the spool and making the car more efficient with the spool. Is any testing being done with dual diffs?

Or is it just us mortals that run dual diff setups?

TCR

Exactly

wcoyote

Frankly, I am just interested in seeing one run. Or to see how easy or difficult it is to set up. I got my XXX-S G+ awhile back and have really had no problems with it. Most of the info I got about the car and any issues with it I knew beforehand, thanks to this site. It was the right choice for me since I was just starting out in TC. Now that I have learned some more of the basics and have been learning the adjustments, I should be ready for a lighter car. Hopefully this one will fit the bill. Just not sure I want a fully open drivetrain, since I practice at times on regular unswept asphalt.
I like the Yokomo stuff (infact I almost got one instead of the XXX-S), but I thought the adjustments were too much to handle and learn for a newbie. Since my LHS does Losi and Associated mostly,and HPI stock seemed limited to the RTR's and the Savage, Yokomo parts would always have to be special ordered. I was waiting to see if there were going to be anything new soon. And wouldn't you know it....

That would be the reason for my interest. I'll keep researching and listening to what you guys think once the car is in your hands.

Darkseid

iTrader: (9)

Wcoyote: I hear you on the open drivetrain thing, its been a while for me too since I've run an open drive train in electric. My last one was the Schumacher Mission. I had so much trouble with the belts and pulleys that it drove me to shaft drive! Since then its been Academy STR-4pro, Yok SD, and HPI Pro 4........all shaft.

I'm a little hesitant about the return to belts and open drivetrains, but I figure my nitro car manages to survive parking lot racing, so this car should be fine as well.

Potato

I'm not trying to add any more arguing on this thread, but wasn't the XXX-S's purported advantage its one belt drivetrain? I just thought it was ridiculous when they advertised that "one belt is more efficient than two." It's interesting how much hype and marketing play a greater role than actual engineering and physics.

PS. I am not bashing or judging the XXX-S or the JRX-S. I'm just pointing out the interesting discrepancy that illustrates the role of hype/marketing in this business and in many others as well.

Tim Johnson

Just uploaded a new version of the Team Losi JRX-S Setup sheet. It has a liitle more color added to it, and you can print it as well. I am still currently working on an editable version.

Click here to view the setup sheet

wcoyote

To clarify the one belt as opposed to two. One is better in a lot of reasons mainly because of possibility of less drag. The S bend for the spur in the belt did make it a little less efficient than what a end to end belt would be. A straight line is always better than a curve. But also remember a shaft driven car utilizes gear mesh to get to the Diff. Gears are less efficent than a belt in any aspect. That is why engines in cars usually use chain or belt driven cams. Gears have more drag. Drag effects accelleration and decelleration. The main thing was Losi said that it enhances cornering ability because the less drag from belts. That is also why Losi came out with a belt kit with a less severe bend needed for the spur. So even with the S bend, the belt still is more efficent because it has less drag than gears. The only way to make a belt better is to adjust the tension. You get too much play in the gears, in time, you loose efficiency. Belts don't until they break.
Two belts would usually have more drag because you are using the center pulley to equal the belt tension. Nevemind the more something contacts the more drag potential. With the pulley, having front belt tighter than the rear means you could be putting more strain (drag) on one side of the pulley vs the other. Almost like tweaking the pulley.

wcoyote

Darkseid,

If the open drive train becomes an issue, I may just have to use some of that clear plastic film they use on the off road cars to keep the chassis from getting scratched. I'll just make the holes in it smaller than the cutouts. That way, I have the clearance needed, but still have smaller holes to keep out the gravel and etc. It will be interesting to see if I will need additional motor cooling if I do it.

ROBORAT

iTrader: (7)

anyone know what those little white plastic "clips" are that are used to secure the lead wires of the electronics (seen in the pic below)? seems like the best thing to have to help get your wiring as neat as possible on the jrxs .... anyone know who makes those or how to get hold of them?

IMPACTPLAYR

iTrader: (7)

I agreee with most of what you said, however this statement is wrong.... Automotive manufacturers use belt or chain driven camgears because of cost and cost alone.... look at the aftermarket, even the highest quality valvetrain chain drive for a Chevy 350 cost around $75-100... meanwhile a Pete Jackson geardrive is at least double or more..... maybe even triple.

You also failed to mention that gears have the potential to transmit much more power.....

However Automotive tech cannot really be used fr example in RC Tech.... it just doesn't work the same....

Someone else could say.... 99% of all automobiles ever manufactured gave been gear/shaft driven, so it must be an absolute better solution to transmit power to the ground in RC.....Now would the automobile>Rc analogy be correct for them too????

Tim Johnson

they are simple clips. you can get them at frys electronics, an automotive shop, or a boat shop.

Tim Johnson

those discussing the belt/shaft drive. Look at tamiya. Tamiya built two cars. one belt and one shaft. The Belt drive car does better in racing than the shaft drive. you can go over theory all day but what will really happen on the track will be different. BTW there is a thread just for Belt/Shaft discussion.
Check it out.

Where are you going to drive your JRX-S for the first time?

wcoyote

IMPACTPLAYR,
You forgot to mention that another reason gear drive is not used is because of durability. You break a tooth and everything goes. The power thing might be attributed to the overall mass. If those are one piece forged in the race cars like I think they are, that also helps the durability. And you are dealing with more power in a real car. And yes I do know about racing. My brother is a drag car mechanic. I was trying to simplify it.
The point is that for R/C, belts are strong enough to withstand the power that is currently availible. Plus you don't usually have to worry about a gear tooth braking, which I have seen happen on more than one occassion.
And also it's all about friction. Gears produce more plus they wear out and produce more play over time. Belts usually break before the teeth wear out to really make a difference. Plain and simple. Two belts also will give you more friction. Efficiency was the question to be addressed.

Darkseid

iTrader: (9)

Thats the same thing I said a while back when I went over the most recent race winning cars...

I hope you have better luck than I did, because the people pretty much ignored my post then, and continued arguing about the belt vs. shaft thing.

Unfortunately, considering when the car will be released(Winter), it will most likely be on carpet. I don't care for carpet racing, but you gotta do what you gotta do...

Tim Johnson

well cooll at least it is racing. LOL I have not race onroad before, but i have raced off road and Oval, so im thinking of taking my car out to Crystal park for some practice on a big track before going over to So cal r/c. So Cal is a really small tight course. I plan on going stock, not mod. Not sure if i want to race mod or not....LOL