Maxx Bling

[Chase023]

I meant that I understand you because you burnt one already hehe.. I haven't burnt one yet...

Wrote it half asleep! :p

[RC-Monster Mike]

All this talk of "paper power" really isn't what gets the truck moving. the rated watts of the motor in the specs really doesn't have anything to do with how much power it gets to the ground. The lehner basic motors, for example, are rated at 700 watts, but folks have measured power output in excess of 2000 watts with those motors (obviously not for extended periods of time!). I would surmise that given the same KV value in a motor, the motor that has higher efficiency would ultimately have the highest power output due to less power loss, and the smaller motor will almost always have more "pep" in the short term. Furthermore, I would bet that a little lehner basic motor with the same Kv value as the big maximum and the same gearing on the same vehicle would probably kick its but in a race, simply because the motor itself is smaller and has less of its own mass to move(accelerate). Long term, this would not be a good idea, as the small motor (rated for 700 watts=continous watts) would eventually burn up from trying to create all the power for a long time. The advantage of the larger motors is their ability to deliver the power continuously(in other words, the larger motors won't burn out as easily because they can handle more load over time). Also, a 2 pole motor can achieve twice the rpms with any given speed controller, for pure speed, my money would go to the 2 pole motor every time. The 4 pole motor in theory has more torque and certainly puts the power out smoother at low rpms, but is also much harder on controllers.
Having stated these opinions, I think to achieve more power/speed in your truck, Ryan, you could consider a slightly smaller motor (1930 for example, which is between the "L" and "XL" Feigao/hacker motors in size) with higher voltage. Perhaps even using smaller cells (like gp2200 cells-since you are opposed to LiPo) to minimize the weight (20 of these cells can deliver the needed power at the weight of around 14-15 3300 cells, along with fitting easily on the g-maxx chassis). You wouldn't likely lose much, if any, runtime with the smaller cells (they have a similar energy density vs. the larger cells) and a slightly slower motor. Higher voltage is usually more efficient (wire can tranfer more voltage than it can amperage) and can more easily put out the power.

Just more points to ponder! :)

[T2693]

Nice job Mike, sounds exactly like you explained to me last night, lol... ;)

Welcome Candyman, yeah I got flamed on the Traxxas forums so I don't post there at all. I was just asking a question and next thing you know, BAM, "USE THE SEARCH TOOL NOOB!", etc, so I came here and Mike and the folks are great with feedback and assistance.

Enjoy and glad to have you aboard! Nice truck, keep up the good work!

[rchippie]

Welcome candyman!!!

What exactly did you do to your chassis to get the diff to fit. Also what exactly do you have to buy diff wise. Thank's

candy man and chase, you both has (basically) the same trucks!

[Candyman2]

I looked at using different cells, those gp2200's in particular but I couldnt find any data on discharge rates, did you? it would have to sustain 100amps in a burst (im guessing here) and 20-30 for a time. Maybe I should get some and experiment. That would be the easiest option to run more voltage but with the same weight, this opens up a lot more options, but I would have to use a different controller.

The Plettenberg is 91 or 92% efficient, i cant remember, and that comes back after a run very hot, I dread to think what would hppen to a little motor in my truck! I guess I drive it harder than I thought.

As for what I did to the chassis to get the centre section (its not a diff, just a slipper) to fit was pretty much nothing, I didnt want to start hacking the chassis up in case I didnt like it. I have now filed the sides a bit to allow the use of a larger spur gear, but the rest of it was done with plates I made. The centre section is a "slipper unit for ofna dominator" thay have them at tower, i got mine of ebay. I will be changing the design soon as I have spotted a way to do it using less metal (less weight). Here is a pic or two of how it is now:

Jay: loving the airtronics, seems just about right to me, the hitec is tempting, good for crawling i've no doubt.

[Serum]

Hi Ryan!

Nice to see, you found your way to this forum ;)

I didn't knew you where powerhungry!

Here is one thing i read on a German forum;

A guy switched from motor (bigmaxximum to Lehner 2240/8) he also converted his savage to centerdiff. (very heavy build truck indeed (not in general, but the way he build it. With massice aluminium plates etc) i think a rough 1-1,5 kg heavier than your maxx and he said, that his 2240/8 had about the same power on 16 cells than his bigmaxx on 18. Knowing your unnatural silver addiction i don't know if this motor suits your needs. (though Poll®©) could help you out..

Those GP2200's, They are also 100A rated, according to the hopf-shop (A-status battery supplier) they kick out the same voltage on a 100A load than the 3300's


I want to buy a 22XX family motor. A very heavy truck (CEN .46) is able to hit the 100 km/h with a 2280 and 20 cells. (3300's). It's a heavy load for a heavy truck though i can imagine, you will be pusing your batteries to the maxx with the current it needs on such a rellative small amount amount of cells on such a HUGE motor.....

But, this becomes very interesting, what about the GP2000's?!~

35 gramms each, (10 gramms lighter than the GP2200's ) 30A continues discharge, 50A for 30 seconds and 5 seconds for 100A

How higher the voltage on most of these setups, the more efficient they get too. (and the lower the current draw will be) So you could consider a Lehner 2240/XX (10/11) , using 30 of these GP2000's (same weight as 16 gp3300's!!!!!!!)

What are you waiting for.. sell the bigmaxx and the schulze, use some good oll' elbow grease and poll on that lehner... (only downsider on this is that these GP2000's are about 5 euro's each.. Worth the investment?) Or just wait a few

That 2240 motor is able to throw out about 60 n/cm of torque, about the same weight as the bigmaxx (450g) On 18/20 GP3300's it would be a blast too.. (i would get rid of my 18.97 too, if i was buying another motor)

It would be nice if Promod dropped a little message here, he is very familliar with these highpowered setups and has got a eagletree data recorder to be the judge in his experiments.

But your question about another motor would be more powerfull on 16 cells;

I personally doubt that. The plettenberg is able to pull the maxxmimum power your cells can deliver (about 1600 watt) (100W/cell) It's the efficiency of the motor that would make a difference.. A small difference if you ask me. You need more volts to juice your maxx! All and all, the GP2200's are nice, because they fit your chassis. The GP2000's are nice too, but they need a special chassisplate to fit in nice..

The Lehner motors are topnotch motor's. all the crazy speedrecords in the water are made with these motors.

[Candyman2]

I was thinking of the gp2000's I dont have confidence thay can deliver the current. If I use more voltage I will need a new controller though, what are my options? Im thinking this is gonna end up costing a fourtune and ending up with not a lot more power. Even If I took the 2240 on 18 cells (I asume my 18.97 can handle it??) would it be worth the expense.

[RC-Monster Mike]

As Serum said, I doubt you will find a lot more power using the same cells (in other words, it wouldn't be worth the expense). The Plett, Lehner or most motors mentioned in this post can use all the available battery power, so the only difference is potentially efficiency (which is a minimal difference with these high end motors). So....more voltage is where you need to look to get more power. As Serum said, the gp2200s can deliver the needed power under a load, as well as a weight reduction (even using the same cell count with 8 oz less weight will make a slight difference), and as you increase voltage, you could potentially lower the amp draw as well, which may justify the gp2000 cells. Your truck is powerful enough that an increase in power output that is noticeable enough will likely cost a few bucks. Of course, you could sell the current setup to fund the project, if that is something you considered.

[Serum]

The 2240 would be too much for the 18.97 on 18 cells imo. (keeping in mind that the 18.97 is not a stable controller)

Though i know that a person uses a 2240/8 on a warrior 9918 on 16 cells (i'll take a warrior over a 18.97 though..)

I'm planning on using a 36120 or 36150 (36 cells, 120 or 150A) on the bigger lehner.

the 36120 is allready strong enough. but 'he 150A is 'only' 70 dollars more expensive.


With the high votage setups the current draw will be much smaller, due to the fact that you use a whole other kv rated motor.

The specifications of those GP2000 come from a reliable company. I don't know how much volts they can deliver though, but that they can deliver 100A pretty much says it all.


You just need to consider that 16 cells will put out a maxximum of 1600 watts.

First of all;

I would email Schulze with the gearing ratio of your truck, and ask them if it's okay to use 18 cells. I think that the 18.97 must do what it's supposed to do. And that is handling the bigmaxx on 18 cells with your gearing ratio.

If you want to go on the safe side, go with the lehner. If your planning on driving your truck with the muscles in your butt tentioned, try the bigmaxx on 18 cells. ;)

[Candyman2]

The gp2000's weigh half what my 3300's weigh, so, in theory (again) I could run 36 cells, lol, with no weight increase. If you can say for sure the 2000's will cope with the draw. The 2200's I could run 22 at the same weight. If this is correct then we could have a good setup.

[RC-Monster Mike]

The draw of a 36 cell system would be significantly lower than the draw of a 16/18 cell system. I don't think you would have any trouble at all with the gp2000 or gp2200 cells' ability to cope with the draw. The 2200s can handle similar load as the 3300s, so these won't have any trouble at all. Enough of the 2000s will reduce the amp draw enough to power the truck without breaking a sweat as well!

[Serum]

And those high voltages give you an ultimate efficiency as well

All you need to figure out, is ho your going to drop in those cells.

20 GP3300's can push your truck faster than you want to. (100km/h, i can't imagine that's your goal)

You could consider 18/20 cells on a 2240/8. (with a 36120 controller)

check this link to see the torquemonster on 21V in action.

It has got twice the torque of the bigmaxximum, that will push a heavy truck around quick.

[hallertau2000]

Gp 2200 good
Gp 2000 not good


The 2000's just don't have the power output and cannot sustain 100 amps under load for any amount of time, have melted a few 20 cell packs, Ouch! in high 100+amp Drag applications. 2200's are just fine though

James

[Candyman2]

thank you for the info........................... people........... I think we are getting somewhere! :L: