7XL & 9920? Good or Bad Idea?
 

Well i am thinking about this combo, will it work together on 12 and 14 cells or would i need a different controller?

This combo works excellent on 12-14 cells.

I agree with Mike, from personal experience. But I only run 14 cells.

I praised this combo here, just a few hours ago
http://www.rc-monster.com/forum/show...=&threadid=907

be brave use 18 cells or are you scared

Scared? No way! But there is no need to push things when you already have plenty on 14. You still have to drive it, controll it.

And you want to stay in the most efficient rpm range anyway.

Thanks dafni and mike, i only have 12 and 14 cell packs. I want to keeps things cool, and have good run time.

The 7XL is your ticket, then. Have fun!

Low temps, enough torque and the ability to run on 18 cells!!

@820 maxx, it has got nothing to do with fear.. it's just common sence.. (in combination with Daniels intelligence..)

:Love: Thanks

So would a 7xl on 16 cells be comparable to a 9l on 12 or 14 cells but with a lot more torque?

The 7xl on 16 cells would destroy a 9L on 12-14 cells in both torque and speed, with similar or even slightly better runtime!

I ran my 7xl on 12 batts at first. I liked it. Did great. I got greedy. Stepped up to 18 cells. It was fast. I don't think you will be disappointed there mike d. I ran mine geared a little high. So i had a little more heat. 66 pur with 22 pinion 18 cells race traffic on highway in 55 mph zone. Was whooping a few.

I think my next motor will be a 7xl then. I will be starting out with 14 cells so what kind of gearing would be good to start, 16/66 maybe?

Stock gearing should work pretty well, actually.

Well mike as you can see i ordered the 7XL. I actually was driving and the end of the motor that the pinion sits on broke right off. Is this common to happen, or did i do something wrong?

Are you talking about a snapped shaft? A 5mm shaft? Modified in any way (dremel flat spot)??
If it's really a snaped shaft, it very uncommon.

Would be the first one I heard of, but I wonder what Mike will say.

Sorry dafni, its the 1/8th shaft that uses standard pinions. I've never heard of this happening, many of my friends have that size shaft and have never broke one. And no i did not have the gear mesh to tight.

As far as I know, the 1/8inch feigao shafts are not recommended for trucks.

I kind of find that odd because the novak hvmaxx has a 1/8th shaft and thats for the emaxx. I am curious if anyone else has thoughts about this.

What did you snap the shaft off there mike? You the first i heard of snaping a shaft of any motor. Let me know how you like that 7xl. I think you will like it. Have to learn trigger control. :)

I have two C50 maxx motors and both have the shafts broke.

Thank you,
Promod

Wow thanks for the input guys, maybe 1/8th shafts breaking in trucks is more common than i might realize.

You have to let us know if you break the 5mm shaft.

I have a feeling i wont be able to.

The 1/8" shafts CAN and have been broken. Mostly from mounting the pinion out towards the end and running a lot of power. If you want to push the performance envelope, the 5mm shaft is the reliable way to go. I wouldn't say a broken shaft is "common", but it does happen every so often( I have had 1 broken shaft and 1 bent shaft come back in the last year).

the hvmaxx has got a 1/8th shaft too, but it is not as powerfull as the 7XL or the L series. It is rather common to break a 1/8th shaft.

Yeah well it sucks but oh well, i ordered the 7Xl and an 18 tooth pinion, i think thats a good place to start with gearing. But maybe with this big of a motor i might be able to go up some?

Watch the temps and decide!

I wrote something about my recent experience with this motors' gearing here:
http://www.rc-monster.com/forum/show...2662#post12662
(4th post on page 2)

DAF

Thanks dafni, i will be running 12 and 14 cell packs so an 18 tooth might be perfect then. I wont be running on any tracks nor doing any speed runs, just bashing in my yard and the street.

Are you going to run the stock diffs there mike d?

No i am not, i'm using fast lane diff cups and integy aluminum diff cases front and rear. I think they are ok for now, they have lasted me over two years with no problems.

If you keep the cell count down you should be fine. More cells eqaul more power and weight.

That is true. I think i would like to upgrade to some UE diffs 6 gear i think. Whats the difference with the 6 and 8 gear diffs anyways, is one stronger than the other?

The 8 diff supposed to be the toughest. The 6 supposed to tough. I got the 6 diff coming. I go from there. It will survive in front no problem. The rear will go first. I don't think I have nothing to worry about. Make me want to put a big motor back on my truck. Have drive train to support it.

How about a 7xl in a rc10l3 at 24volts? I'm thinking about a similar setup for my l3.

for 24 volts i would problably go with 8xl. Just my opinion.

In an L3, go with a way smaller motor. Something like a lehner basic 2000 or something?

Yeah, the Feigao xl motor is severe overkill in a pan car. basic xl or similar would even be overkill, though not nearly as severe. It sure would MOVE, though!

I'm looking for a speed record that can touch 125mph or even higher using a gear ratio under 2.1:1. Yep, I guess the 7xl is not a good choice at all, but the lehner xl 2400 would do the work or something with lower rpm. The kontronik FUN-500-19 motor is a very good choice, too. These kontronik motors are fantastic and I still think that its a good idea for Mike to test one of them and see for himself.

Well i received my 7XL today. I installed in my truck geared it 18/66 with 12 cells and wow what a difference compared to the 9L. Not nearly as fast but a lot more powerfull and smoother, no cogging. I am charging my 7 cell packs right now and will go out for another run to see the difference from 12 cells. Oh yeah temps were at 155 degrees after a full run, not bad i think.