Ubec / Evx
 

Hey, how can you wire an UBEC to a Novak EVX, in a way that it gets the juice from both packs equally??

Why do you want to do this? The evx has its own BEC.

To get the full 6V to the steering servo. The EVX only delivers 4.8, I was told.

What do you think?

I also think that removing the BEC duty from the EVX will help it to stay cooler.
After all, what's the reason all the brushed maxxer run rx packs?

If you just measure between the wires, where the 14.4 V is, you can connect it to that 2 wires.

Thanks Serum. I haven't thought there would be 14V on one of the input channels. I'll check tonight.

Another benefit of draining the batts more evenly: I can charge both packs in series with less worries.

Hi, there

Some info on EVX ESC.

Novak's EVX uses only one battery for BEC and if you connect 7+ Cells then overheating can occur with high-drain servos. To solve this always connect 6 Cells to BEC side and the rest Cells' to other. If you want to use UBEC connect it directly to 12+Cells, not through EVX, unless you open it and solder directly to combo junction.

And there is no 14.4V on any pins of 3-pin cable.

Artur

P.S. By the way, you can improve perfomance of EVX by replacing and changing some of the internals of ESC. Novak EVX is very user-friendly.
I can help with translation if required, but I think most of it clear from pictures.

so how many cells can be run through one? also, a little translation would help.

Up to 18-20.

I will try to translate over the weekend.

Artur

Can you take the two main wires on the evx and wire them more like the brushless systems. Just run the wire from the dean connector on one to the dean on the other. Then wire the ubec up to that.

what would you do with the bec side?

Hey Dafni. be sure you leave the on/off switch off. that and the ubec can overload the reciever.

You can do that, but I won't recommend due to the fact that front end of built-in BEC will be floating in that configuration and might create some problems.

But with 2 battery packs connection should look like the picture.

Artur

P.S. In general you can just pull red wire out of EVX 3-pin connector and use any external source for receiver and servos without interfering with EVX.

If you going to run the ubec. Can't you just unsolder the switch and be done with it to. You was talking about some mods to the inside of evx as well griffin. I like to know more. If or when you get the chance would you hook us up. If you ran the wires like I was talking about earlier. Wouldn't that bypass some of the stuff. Internal BEC and all. Take it like in the pic and un solder the other two off the evx and solder to each other.

I know people here like to modify thing around here, but wouldn't it be easier to just use the EVX the way it is supposed to be used? A good high torque servo can't be that expensive

Digging up an old topic for sure!!

but tell me, why do you think that there is no 14.4 volts on the novak?

he was talking about the 3 pin connectors on the novak.

Ahhhh Thanks coolhand!!
i thought i was going crazy...

For the same reason you upgrade plastic parts to metal :)

And you can run at higher voltage... (more power)!

I was talking about 3-pin connector.

Artur

!!!WARRANTY VOID!!!

Original link...

Novak EVX ESC works with up to 14 cells without problems. With some modifications it is possible to extend this up to 18-20 cells.
Here are the steps:
- remove ESC enclosure
http://forum.rcdesign.ru/uploads/pos...0880_thumb.jpg
- dismount small daughter board
http://forum.rcdesign.ru/uploads/pos...0924_thumb.jpg
- replace selected 10k resistor with 8.2k
http://forum.rcdesign.ru/uploads/pos...0993_thumb.jpg
(originally I replaced it with 7.5k, later testing forced to replace it with 8.2k. On selected ESC's loss of proportional speed under low power (0-35% throttle) and loss of reverse mode in 3d profile was observed. But with 8.2k resistor everything works fine.)
http://forum.rcdesign.ru/uploads/pos...1092_thumb.jpg
- put together in reverse order

Artur

P.S. Replacing stock FET's with IRF1404 or IRF3703 helps reduce heat dissipation and allows to increase current ratings 2-3 times.

And do not try to run 7-turn motors at 18 cells :)

More tweaking can be done with trimpot instead of fixed resistors, but less reliable in the field.
http://forum.rcdesign.ru/uploads/pos...4108_thumb.jpg

Voltage at FET's drivers before modification
http://forum.rcdesign.ru/uploads/pos...1044_thumb.jpg
After (with 8.2k should be around 30V)
http://forum.rcdesign.ru/uploads/pos...1153_thumb.jpg

!!!WARRANTY VOID!!!

that would make for a wicked brushed setup. what kind of motors (540-550) could you run on 18 cells?

The titans can be run on 16 cells. I have done that. That looks awesom. It would make a truck go faster and more power with less money since most of us has the stock stuff at one time.

I need to point out that this was done when brushless setup was in $400+ price range and was not as reliable as today.
But I am still keeping brushed motors for some unique applications :)

With 18cells stock emaxx (Titans, 66/18 spur/pinions) will reach 35MPH.

I've seen offering of this motors for more then $5 on Ebay...

And if you familiar with conversions, which are floating around, then it would be clear that people use all kind of brushed motors.

THINGAP motors are expensive, but great motors!

Artur

P.S. I just pointed to something obvious but list of DC-motors for RC can be long...

By the way, Novak's EVX is the ultimate platform for modifications. You can create your own CPU or driver board.
You can also adapt the CPU board from others.
Unlimited possibilities for somebody with time and a solder iron.

GriffinRU, could you make the pictures of your EVX modification larger? I can't see much, and this is very interesting!

metalman, click on the link. larger, but the same pictures are there. its just in a different language.

Full size pictures are attached in original post. Just click on picture inside the post and new window should pop up with full-size image.
If I put them here it would be hard to read the post.

Artur

Oh, okay. That website was actually down for about 10mins earlier around the time that I posted, so I wasn't able to see them. But thanks! :)

hate to bring up an old topic but i have a question. i have a stock e-maxx running spc 7 cell batts and a evx. i recently bought a hitec 645mg servo and it performs like doodoo and causes major glitching and the only cure to that is to remove the bec and use an rxpack, but i dont have room on my chassis and thats just one more thing i need to charge. so can i wire a ubec some way as my esc does get hot and i cant run 6 cells on one side and 8 on the other as my charger limits to 7 cels a pack. so any help would be great. and the servo works great in my savy an preforms flawlessly with bigger tires. thanks again
BL_maxx