Motor/ESC questions - RC-Monster Forums

BrianG · **Motor/ESC questions -** 05.05.2006, 09:19 PM

I'm building a new BL Revo and was looking for a good motor and ESC choice. My current BL Revo is using 14 cells with an 8XL, and am happy with it, but it is heavy so I'm using it mainly for bashing.

The new one will be light specifically for racing so I was looking at a 9xl or 10xl, but don't know if it will have enough oomph. I plan on using 4s or 5s Li-Ion cells (propably 4s) to help keep the weight down. According to my figures, it should reach a decent top speed, but also want aggressive acceleration. I know I can gear up, but don't want to go too far.

Then, I was looking at ESCs. Currently using a BK 12020, but was thinking of trying one of the new Quarks. I actually made a post about it here, but not getting any replies (maybe because it's in the wrong area??).

Opinions?

squeeforever · 05.05.2006, 09:22 PM

I have a 10xl on 14 and soon 16 cells and it is AWESOME. It seems as though its almost as fast as my Lehner XL3100 was on 12 cells.... Honestly, a 10xl will be more than enough for racing.

BrianG · 05.05.2006, 10:07 PM

Thanks Squee (BTW: I almost miss that wacky dancing kid thing). So, you're running that setup on a Revo?

What about my ESC questions (in the link). Below is the text from that post for your convenience. :)

Quote:

Originally Posted by BrianG

I'm thinking about picking up the Quark 80 or 125 but can't decide which to get. I plan on using a Wanderer 9xl on 18v Li-Ion (built-in LVC should come in handy), so current should stay reasonably low, but I always like to get the beefier ESC so it won't have to work as hard or heat up as much. So, I'm leaning towards the 125 model. However, the price difference is making me think twice. I want super reliability.

HotnCold; you said there's no heatsink. Is the case plastic or metal? From the little I can see on the RCM site, it looks like it has shallow fins on the sides, but it's hard to tell. Also, does it come with motor wires? The pic shows white-ish wires, but it looks like they might be a required add-on. If they are included, how long are they?

Echoing a previous post; these DO look better than the BK's, which look half built. I like the case to keep out crap and provides more protection.

squeeforever · 05.06.2006, 11:15 AM

Yea, im running it in my Evo. See my thread, "Brushless Revo 2.0". As for the esc's I would probably go for the Quark 80. I think it should be PLENTY for a 9 or 10xl since a 7020 will run one.

coolhandcountry · 05.06.2006, 07:08 PM

Well it would depend on the way you gear it to. If you racing it on a 9xl I would go for the bigger quark so no worries will running the piss out it. The 7020 will run the 9xl but have to watch gearing and it won't take a lot of hard driving. I have a video on the 9xl on 12 cells if you look in the rc pics file. It don't do to shabby.

BrianG · 05.06.2006, 08:15 PM

I was planning on a 9xl, but am now leaning towards 10xl. I'm using the stock Revo tranny so I have a decent amount of choices for spur/pinion combos. I plan on racing so I don't want any chance of things overheating from stress (assuming gearing is correct of course). I too think the Quark 80 will handle it, but figured it's bigger brother would heat up less and not be as stressed so it will stay cooler longer. I don't want to use a fan either. However, I read somewhere that it is advisable to use an ESC that somewhat matches the motor - something about the current feedback from the motor being more accurate (read: better control) if the max amount of current the motor will pull is roughly equal to the ESC rating. Maybe the quark will let me add a little larger heatsink; but I can't find some decent 360* views to be sure.

BrianG · 05.08.2006, 07:35 PM

Well, I did it. I ordered the following:

- BK 10xl
- Quark 125B (I know, I know, it's overkill; but I really don't want any overheating issues).
- RCM XL Heatsink
- UBEC
- Some 5.5mm connectors (how come they don't come in sets anymore? Not that I really care, just curious)

Hopefully, that will work nice for my racing Revo. Now to wait for a motor mount and some Li-Ion (or equivalent) batts, preferably >= 4Ah...

Dafni · 05.15.2006, 03:16 PM

BrainG, good decision. FYI, the Quark comes with short motorleads attached, 3 sets of 5.5mm connectors(!), shrink tubes in 3 colors, an on/off switch, a nice manual and in a small cardboard box... what a nice package! BK, go figure!

DAF

Sylvester · 05.15.2006, 04:15 PM

Quote:

Originally Posted by Dafni

BrainG, good decision. FYI, the Quark comes with short motorleads attached, 3 sets of 5.5mm connectors(!), shrink tubes in 3 colors, an on/off switch, a nice manual and in a small cardboard box... what a nice package! BK, go figure!

DAF

Now Daf, how would you know what comes in the package? :dft012:

BrianG · 05.15.2006, 06:29 PM

Thanks Dafni. I received everything on Saturday - great shipping speed Mike!

I am quite impressed with the Quark ESC. Below is a little "review":

Pros:
The whole case except for the very top (where the switch and LEDs are) and ends is aluminum. The sides are formed into a heatsink. I feel much more secure mounting it without fear of snapping an internal component or something. I removed the top plate to see the construction and it is quite nice. The FETs are surface mount and stacked like the BK, but there seems to be a better fit between the FET top and PCB bottom for more efficient heat transfer. (Be careful if you decide to slide the top off though, I accidentally snapped a capacitor from near the switch. It was a pain to resolder.) I really like the reverse mode where you press forward to stop, but have to go back to neutral and forward again to go into reverse. With BK's, the truck will stop and then go into reverse so you have to be careful not to hold the brake/reverse too long. The ESC lets you program in some noise prevention, brake drag amount in neutral, throttle dynamics, and whole bunch of other stuff. Very nice.

Cons:
The instructions to enter basic and advanced programming modes probably could be written a tad clearer, but it's fine overall. There was nothing in the manual about changing motor direction so I imagine you just swap two wires. The Lipo cut-off voltage is a little confusing. You can set the cut-off voltage per cell but you can't set how many cells you are using. It must measure the total voltage and assume you have x number of cells. IMO, I'd rather set the number of cells manually.

Unfortunately, I have not run it yet, except having the motor hooked up unloaded for programming and a little playing.