Originally Posted by --Oz--

A picture would add to the validity to this statement. Is that an installed solution or just the new un-installed parts?

The battery and motors wires have a lot to do with weight.

You want a picture of what? A Q-Brain on a scale to validate the stated weight?

:
installed on a 600MM quad. Took off 4 esc's and a power distribution board and assorted wiring and connectors which weighted 168 grams and put this on with connectors and hold downs which weights 122 grams and what a difference. More response, quiet, longer flight time and runs cool, after 7 minutes temp measured 120F. Worth the effort to install. Had to use M3 on M4 and M4 on M3 but thats not rocket science. Cheap as buying 4 esc's and PD board. Motor wires come with female gold connectors
September 13 2012

Originally Posted by joseico90

Wow..nice one there Gordon.

it would be great to get Qbrains and the like in even smaller versions, like 4x6A and 4x10A I guess is a matter of time as multis are such a growing market.

That way we could save weight and battery energy. In the case of a small quad the 3 of four BEC regulators aren't feeding anything (other than their own ESC circuits, MCU etc), and wasting some energy in the way of heat, far from efficient, and at these small sizes every battery mAh counts.

So I do hope the manufacturers are listening!

Originally Posted by Freakazoid

Hobbyking posts it as 112 grams, which would obviously be heavier than four 20A ESCs that are 18 grams each.
So I take it hobbyking boobed up on the actual weight?

Originally Posted by kaptondave

Fresh from the scales:

4 Turnigy Blue Series 20A ESCs @ 26 g each = 104 g (Actual)
1 Q-Brain 20A = 112 g (Spec) I can't weigh mine because they are mounted.

But, the Q-Brain also contains:

1 Power Distribution Board = 28 g (Actual, for the HK Quad Board)

Net Advantage to the Q-Brain = 20 g

The primary advantage of the Q-Brain IMO has nothing to do with weight. It is the much cleaner installation.

Originally Posted by kaptondave

It is better than that. There is only one BEC in the Q-Brain. The other three ESCs are OPTOs.

Originally Posted by --Oz--

A picture would add to the validity to this statement. Is that an installed solution or just the new un-installed parts?

The battery and motors wires have a lot to do with weight.

Originally Posted by Rotorhead0207

:
installed on a 600MM quad. Took off 4 esc's and a power distribution board and assorted wiring and connectors which weighted 168 grams and put this on with connectors and hold downs which weights 122 grams and what a difference. More response, quiet, longer flight time and runs cool, after 7 minutes temp measured 120F. Worth the effort to install. Had to use M3 on M4 and M4 on M3 but thats not rocket science. Cheap as buying 4 esc's and PD board. Motor wires come with female gold connectors
September 13 2012

To all the above posts, I may not have been fair when I weighed the QBrain and the 4 ESCs. The QBrain had its leads cut and shortened to 5" with no connectors on it, the ESCs had all the bullets and battery connection on them.
I connected the QBrain leads directly to the motors (2211 1700kv) but even if the QBrain weighed the same or a little more, I would still use it over the ESCs. For one, it's cheaper than the ESCs, more compact, neater install, and I never had a DOA, or one go bad out of the 8 I have been using. One thing I noticed is that the 20A and 25A weigh the same. Go figure.
Now, like Jose says, I would like to see them make some in the 10A size. I'm sure you will see them soon.

Originally Posted by Rotorhead0207

:
installed on a 600MM quad. Took off 4 esc's and a power distribution board and assorted wiring and connectors which weighted 168 grams and put this on with connectors and hold downs which weights 122 grams and what a difference. More response, quiet, longer flight time and runs cool, after 7 minutes temp measured 120F. Worth the effort to install. Had to use M3 on M4 and M4 on M3 but thats not rocket science. Cheap as buying 4 esc's and PD board. Motor wires come with female gold connectors
September 13 2012

Glad it worked for you. Did for me also but did you mean to say that your swapped M3/M1, not M3/M4? (M3 on the QB is the one with the BEC, so must connect to M1 on the KK2).

Originally Posted by Stitch1615

Will we ever be happy with what we have?

Hell no! Who do you think we are, Buddhists?

Originally Posted by kaptondave

Glad it worked for you. Did for me also but did you mean to say that your swapped M3/M1, not M3/M4? (M3 on the QB is the one with the BEC, so must connect to M1 on the KK2).

The way I do it, is to remove the white wire for the BEC plug and swap it for the red wire on the other plug. So you will have the BEC and the red sig wire on M1, and orange on M2, white on M3 and brown on M4. Now if you mount the QBrain face down, all the leads go to the right motors. With the cylinder thingies facing fwd. any questions?

Originally Posted by Gordosoar

To all the above posts, I may not have been fair when I weighed the QBrain and the 4 ESCs. The QBrain had its leads cut and shortened to 5" with no connectors on it, the ESCs had all the bullets and battery connection on them.
I connected the QBrain leads directly to the motors (2211 1700kv) but even if the QBrain weighed the same or a little more, I would still use it over the ESCs. For one, it's cheaper than the ESCs, more compact, neater install, and I never had a DOA, or one go bad out of the 8 I have been using. One thing I noticed is that the 20A and 25A weigh the same. Go figure.
Now, like Jose says, I would like to see them make some in the 10A size. I'm sure you will see them soon.

Weighed mine and it is 122 exactly. Full leads and connectors.

Originally Posted by Gordosoar

One thing I noticed is that the 20A and 25A weigh the same. Go figure.

That's because they are physically the same, only the FET's are of a slightly higher quality to allow for the extra 5A.

The HK F-20 and F-30 are also identical apart from the FET's, yet HK list the F-20A as 30g and the F-30A as 32g.
If you take the heat shrink off both you wouldn't know which is which.
A lot of ESC's are like this for good reason.

Originally Posted by Stitch1615

Weighed mine and it is 122 exactly. Full leads and connectors.

Now I have to go weigh mine again.
How does that compare with 4 20A ESCs?

Originally Posted by Senator315

That's because they are physically the same, only the FET's are of a slightly higher quality to allow for the extra 5A.

The HK F-20 and F-30 are also identical apart from the FET's, yet HK list the F-20A as 30g and the F-30A as 32g.
If you take the heat shrink off both you wouldn't know which is which.
A lot of ESC's are like this for good reason.

Aha, learn something new every day. The difference might be in heavier leads to the battery side of the Esc.

Originally Posted by kaptondave

You want a picture of what? A Q-Brain on a scale to validate the stated weight?

I just wanted to see what is what (apples to apples), a picture gives a lot of answers without writing a lot, I preferred to see an installed solution, to check the wire lengths and such, not some stock HK picture. This would be an easy compare to separate ESC's installation. Also this would give some idea of the cooling over mounting on the arms solution. (ballerina flying does not apply)

I just weighed a new F30-a 30A (not 20 or 25A Qbrain rating), 26.4g out of the package, so 105.6g for 4, less than qbrain before I chuck the 2g ferrite bead on the servo lead (saving 8g) and then shorten the wires. Maybe you believe what you read on the internet, I dont, I like science, aka testing.

With drilling the heat sink, light weight shrink wrap (with ventilation holes), shorter wires, all solder (no stupid bullets) and a few other mods (caps, lin regs,etc), I could take off ~15% to 20% weight (it will come sooner or later).

After racing RC on-road for 21 years being sponsored, I know all about saving weight to shave a few ms off lap times.

I am not worried about weight (yet) with my current quad at 7:1 PTW, as most quads don't break the 4:1 PTW After many 2 minutes runs of WOT flying with this quad, I am ready for my HP and am ready to build my next quad shooting for 10:1+ PTW, so yes weight will be a top concern on that build, but it is slowly coming together and back burner to other projects (APM2.5, FPV, Z1 glider, 1.6m P51 and personal record mission attempt).

BTW, if you have a problem with one channel on the qbrain (bad crash, water, etc), does that cost 4 times as much to fix (aka = brain-fart)? (I seen how they grind the P/N off the uBEC IC, so if it goes, it's done)

Originally Posted by Gordosoar

The way I do it, is to remove the white wire for the BEC plug and swap it for the red wire on the other plug. So you will have the BEC and the red sig wire on M1, and orange on M2, white on M3 and brown on M4. Now if you mount the QBrain face down, all the leads go to the right motors. With the cylinder thingies facing fwd. any questions?

That works. I just took a different path and swapped labels instead of wires. Seemed easier. Otherwise, I feel that the upside-down mounting could compromise the heat sink, but heat does not seem to be an issue unless driving it hard.

Originally Posted by kaptondave

Glad it worked for you. Did for me also but did you mean to say that your swapped M3/M1, not M3/M4? (M3 on the QB is the one with the BEC, so must connect to M1 on the KK2).

took the red lead and put it on M1

Originally Posted by kaptondave

That works. I just took a different path and swapped labels instead of wires. Seemed easier. Otherwise, I feel that the upside-down mounting could compromise the heat sink, but heat does not seem to be an issue unless driving it hard.

I had it go into thermal slowdown in the heat of summer after 1/2 way thru pack #4 one after the other with no cool down between OAT was probably 30C 5 minute wait and flew off the rest of the pack no further problem.
Edit: first and only time that I've had any sort of problem with it in over a year of flying. I'd hazard a quess about 125 flights it did a slow down not a cut. It drifted down at about 1/2 power.

Originally Posted by Senator315

That's because they are physically the same, only the FET's are of a slightly higher quality to allow for the extra 5A.

The HK F-20 and F-30 are also identical apart from the FET's, yet HK list the F-20A as 30g and the F-30A as 32g.
If you take the heat shrink off both you wouldn't know which is which.
A lot of ESC's are like this for good reason.

The pairs I have seen with the same board in the SimonK ESC database have usually been missing a column of PFETs for the reduced amp version. Like going from 6 to 9 or 12 to 15 total FETs. That would account for a slight difference in weight.

I wonder if HK is actually putting a 20A sticker on the 30A version in some cases; like they ran out of 20A's.