quark 125b

hi
ive just brought my self a quark 125b do you recon i will have any heat problems im going to run it in a e revo with 9xl and 12 nimh cells

[lincpimp]

Originally Posted by brushless revo

hi
ive just brought my self a quark 125b do you recon i will have any heat problems im going to run it in a e revo with 9xl and 12 nimh cells

I have a few 125b escs and they work fine with the correct gearing. I am sure that you will have issues with the 12 nimh before the esc...

thanks for reply im only going to use 12 cells for the time being and then im going to buy a 5s lipo im just thinking if i will have to buy the rcm heatsink for it what do ua think

[sjcrss]

I use the RCm heatsink on the backside of my quark, along with 2 40mm 5vdc fans wired into the spare slot on my rx, and I have yet to have any heat issues at all, and I have yet to do the internal mod as well.

ok how hot does it get compared to runinng it with out the heat sink????

and what are every ones views on the 125b monster ????????

[BrianG]

The case really does not enough thermal mass to shed the heat it produces IMO. Adding extra thermal mass and surface area does wonders to control the heat. Plus, the flat bottom makes it easy to add whatever heatsink that will work for whatever mounting you plan to use.

Another issue with the Quarks is the thick thermal sticky pad they use to attach the FETs to the heatsink. This pad doesn't move heat as well as thermal epoxy and tend to build up. You can take the ESC apart, remove the pad, and use thermal epoxy instead, but it will most likely void the warranty. However, I've done this mod and added extra heatsinking to both of my Quarks and they run a LOT cooler, even without any fans.

There are two other issues to consider:

1) They don't run 6s despite their rating, so you are limited to 5s or 16 cells.

2) Reverse brake is not quite right. When moving forwards, the brake is proportional. But in reverse, the brake is a sudden stop. Of course this is a non-issue if running in forward only mode.

Other than that, the Quarks run silky smooth and just about any motor. And warranty work is fast and easy from all reports.

ok thanks very much great reply help a lot with all my thoughts
i chose the quark over the mamba max did i take the right option ???????????????
im not going to change anything internly as i wil no doutly muck it up lol

[jhautz]

Originally Posted by BrianG

The case really does not enough thermal mass to shed the heat it produces IMO. Adding extra thermal mass and surface area does wonders to control the heat. Plus, the flat bottom makes it easy to add whatever heatsink that will work for whatever mounting you plan to use.

Another issue with the Quarks is the thick thermal sticky pad they use to attach the FETs to the heatsink. This pad doesn't move heat as well as thermal epoxy and tend to build up. You can take the ESC apart, remove the pad, and use thermal epoxy instead, but it will most likely void the warranty. However, I've done this mod and added extra heatsinking to both of my Quarks and they run a LOT cooler, even without any fans.

There are two other issues to consider:

1) They don't run 6s despite their rating, so you are limited to 5s or 16 cells.

2) Reverse brake is not quite right. When moving forwards, the brake is proportional. But in reverse, the brake is a sudden stop. Of course this is a non-issue if running in forward only mode.

Other than that, the Quarks run silky smooth and just about any motor. And warranty work is fast and easy from all reports.

I have a slightly different opinion here. I have had success with the quarks with only using the heatsink on the back of the case, for a while.(about a summer or so of running for me) Then as the esc gets older the contact between the fets and the thermal tape on the inside of the case starts to get loose and the heatsink no longer does the trick. The internal thermal mod then needs to be done to keep it cool. Running in a Revo without the heatsink... forget it, don't even bother.

As far as the 6s problem goes, the quark does run 6s. I have run it many times on both the 125 and the 80 version of the quark. The issue is at start up with a freshly charged pack it tends to stutter or cog. Once its moving there is no issue, and once the pack starts to come down from its freshly charged voltage the problem completely disappears. SO yes I agree with Brian that it does not run 6s as well as it should, but I disagree because it does run the 6s.

I've never seen or at least noticed the reverse braking thing that Brian mentioned. I rarely use reverse and when I do I'm not going very fast. Just to back out of some trouble so I guess that's why I never even noticed it.

On the plus side of the Quark, I still believe it is the smoothest running esc out there on 5s or less. Nothing I have tried has matched the silky smooth start up and very controllable and reliable throttle and braking. I have tried just about everything that is currently available at one point or another and once the thermal mod is done on the quark its still the best ESC out there IMO.]

[BrianG]

I ran my Quark with just an added heatsink for a little while without the internal mod. Once I did it, I noticed temps were much better. Not only that, but it cooled faster. That alone tells me the thermal pad is not the best. Probably makes it much easier for the Quark tech guys to repair the ESC since the pad is so easily removed.

Yeah, I guess I should have said that 6s is "shaky". It really should be rated for 5.5s. Many people won't want to bother to discharge their packs enough to get under the "Quark barrier", nor do many people have adjustable CC/CV threshold values.

The braking thing is no big deal really, just something to think about when comparing the pros and cons of all the ESCs out there. You really only notice the reverse-to-brake issue when moving backwards at a decent clip.

But, I do agree that it is VERY smooth. As long as you're not geared to the moon, you can crawl very slowly (<1mph) without cogging. And I like the low speed motor startup algorithm much better than the MM. It is my favorite ESC so far too, although I've never tried an MGM, only a BK Warrior 12020 and the MM.

ok is the internal mod hard and can it go rong
and does it definatly avoid the warentee
thanks

[BrianG]

It's not hard to do, but you do have to fab up a spacer to make up for the lack of the thickness from the thermal pad. Here is a pic showing what I mean:



Yes, things could go wrong. You could damage a FET or something accidentally. If using the wrong thermal compound and it squishes out onto the FET leads, you could cause problems. There are always risks to modding. You just have to weight the gains vs the risk. I thought it was worth it, but then again, I'm comfortable with this type of thing.

A couple people here have sent in a modded Quark and they honored it, but one person also got a note back with the repaired ESC saying that they wouldn't honor his warranty again. So, I dunno. I would err on the side of caution and assume they won't honor it.

What you could do is run it as-is for now and see how it goes. At least add a heatsink to the outside of the case (that won't void the warranty). If temps become a problem, then you can decide if you want to take the risk in modding it.

[Patrick]

Out of the 20 or so times I've ran my quark on 6s I haven't had any issues with it. Even with a battery straight off the charger it's never acted weird when first plugged in.

will i need a rcm heat sink on 12 cells ???????

[BrianG]

It's not the amount of voltage that creates heat, but the amount of current. Yeah, higher V setup can potentially draw more current, but typically lower voltage systems have to work harder to obtain the same output power, so current has to increase.

[neweuser]

Originally Posted by brushless revo

will i need a rcm heat sink on 12 cells ???????

I would. I have ran my Quark without it on 12 cells and it thermalled. That was using a 1930 lehner motor.

I have had my quark going on over a year. Got a heatsink, run it on 5s and 4s with no issues. You made a good choice. I would get the heatsink just to keep things in perspective.

I have one of the first Quark 125b's that came out. Never had to take it apart ever. Still going strong. The reverse brake, I've had that problem, so I jsut run my forward and brake. Never need reverse as I don't hit many things to need reverse and usually drive in areas that are open or can turn around in when bashing.