Noob 8XL & 9920 Questions

Hey Guys,

Just about ready to start my build. I have a couple of questions. I will ask more later I'm sure.

My stock emaxx has an on/off switch. Do you guys use one with your brushless setups?

I will be running 12-24 cells. My understanding is that I do not need a UBEC. Is this correct?

Thanks!

[Nick]

You will need a UBEC for over 12 cells but you can use a powerpack for the reciever instead (like those you use in nitros).

Most of us don't use switches, isn't really needed, just plug in when you want to go, disconnect when your finished although I'm sure it wouldn't be hard to make a switch for going into the ESC if you really wanted too.

Theres a big difference between 12 and 24 cells. :P

[maxxdude1234]

1) The 9920 does not have an on/off switch, no need for one really.

2) Firstly the 9920 will only take 20cells max. If you run any more than 12cells you will need a uBEC, but even on 12cells I would still use one.

[R00ST]

I have 9920/8xl setup in my e-revo and its a great setup. Its an awesome combination of power and run time. Just messing around I could get 30 mins on the 3800's (running 14 cells).

Thanks guys!

12-14 cells is what I meant to say.

Would I need a UBEC for 14?

Thanks!

[R00ST]

Yes, the lowest you can run without ubec/receiver pack is 12 cells, but I am told at that it even gets warm. I would just pick one up and save yourself the hassle down the road with charging receiver packs.

[Nick]

I use a reciever pack, UBEC was twitchy, performance was poor. Took it off straight away was like major interference.

Takes like 15minutes to charge a reciever pack, not the end of the world.

What receiver pack door you guys like? Will it work with the stock emaxx receiver?

Thanks again!

[R00ST]

I run receiver packs that come stock with the revo. they are 6.0 volt and I think 1100mah.

Any receiver pack will work, just pick something in the style that will best suit the place you want to put it. (ie hump pack, flat etc etc) and get the highest capacity you can, or possibly if you can get them cheap enough by a couple of them. yes they work with the stock receiver, just plug it into the "BEC" slot.

How often do you recharge it? When do you know? I would hate to see my new setup fly down the street out of control..

[maxxdude1234]

Originally posted by Nick
I use a reciever pack, UBEC was twitchy, performance was poor. Took it off straight away was like major interference.

Takes like 15minutes to charge a reciever pack, not the end of the world.

you have to mount the uBEC so that the back is facing the reciever. Never heard of that problem before

[crazyjr]

Originally posted by bigabike
Thanks guys!

12-14 cells is what I meant to say.

Would I need a UBEC for 14?

Thanks!

You had me worried for a minute there.

Venum makes an 1100 5cell pack that is cheaper than the traxxas pack and just as good.

Racers edge makes a 1400 5 cell that is good as well cheaper than the traxxas

[R00ST]

cheaper than retail probably, but check ebay. I picked up two traxxas packs with chargers for 13 shipped - all brand new stuff.

[Scott711]

Originally posted by maxxdude1234
you have to mount the uBEC so that the back is facing the reciever. Never heard of that problem before

Please clarify about mounting the ubec. I will be mounting one up soon and want to avoid any trouble. It seems to me that you just wire it into your esc leads and then plug it into the receiver battery slot. Does it matter where it's mounted on your chassis?

[maxxdude1234]

Originally posted by Scott711
Please clarify about mounting the ubec. I will be mounting one up soon and want to avoid any trouble. It seems to me that you just wire it into your esc leads and then plug it into the receiver battery slot. Does it matter where it's mounted on your chassis?

The manual from the uBEC says: 'If mounting near electronics, place flat side of BEC toward the other items for maximum shielding.'