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Old Jul 31, 2014, 03:21 PM
Cap'n
Dinghy's Avatar
United States, OR, Springfield
Joined Dec 2013
228 Posts
Help!
Looking for 1S ESC for 8.4mm brushed motors

I am trying to build a DIY replacement RX/ESC/Servos, for the HZ-PZ Ultra Micro bricks.

$60 to replace one of these bricks, Champ, UM T-28, P-51...etc ..
Dont really need stabilazition.

Goal ; Make a reliable Champ brick replacement for < half the cost of replacement.
Want to keep it light as possible, for indoor ultra micros, and foamy scratchbuilds,
using the available 8.4mm brushed 1S motors. (new version from Micro Motor Warehouse, look very good)

Lots of research/study, led me to the Lemon 6c RX Featherlite. $5.75.
HK 5320 and 5330 servos < $4 each.
....Thought the HK BR3A ESC would be the final major piece... http://www.hobbyking.com/hobbyking/s...ro_Motors.html
Ordered 2.....

Bench test seemed good, RX bound to my TX, Servos moved like they should, PZ P-51 8mm motor ran (no prop installed, so kept throttle at minimun)

Installed in my Champ with a dead $$$ brick.
Before closing up the fuse, gave it final trial run with prop.......
Before getting to half throttle, motor quit.. repeat...same.... tried 1/4 throttle, ran some for about 5-10 seconds then motor quit again.

Nutshell-----tried many batteries, different TX, 2nd RX, 2nd BR3A ESC, and a 2nd brand new never flown motor........all same failure.
Stronger/larger 1S lipos would run into a little higher throttle setting, but still failed before getting to 1/2 throttle.
Put a servo on the RX's throttle channel and that channel drove the servo as it should.

Tested Voltage output from the HK-BR3A ESC and found the voltage went from 0 to 4.11vdc (batt charge state) in the first 1/8-1/4 throttle setting.
Tested same output on a working Champ brick and found the voltage followed the throttle setting from 0 to only reach max voltage at full throttle.
These tests were performed, no load, motor disconnected.

You can follow my posts on this thread, pages 4 and 5, to get the full evolution of my trouble shooting.
http://www.rcgroups.com/forums/showt...1907035&page=4
_____

Some have suggested trying to build a useable 1S brushed ESC from a servo control board.
Looks easy enough, if I can find the correct Resistors.

However some have said that solution may not provide the reliability necessary for safety flying indoors.

One opinion from postor 'Ruzam' sums up the weaknesses of servo board ESC's
" I've converted dozens of servo boards into ESCs for my blimps (I need a reversible ESC). It's easy and it does work. Some servo boards can handle more power than others (and it doesn't seem to be directly related to the size of the servo or the motor inside).

But....

They have a very narrow dead band, and it changes with cell voltage and board temperature. So 'zero' throttle when you plug the battery in may not be 'zero' throttle when the battery runs down a little (you could even end up with reverse motor running at zero throttle). Second they have very non-linear response. You'll need to program lots of expo into your transmitter to get anything close to a smooth throttle response. I suppose it's better than nothing, but if I didn't need reverse, there's no way I'd continue using them.

Even more surprising, servo boards tend to be stupid heavy compared to an equivalent ESC. "

If the stock bricks in these planes, like the HZ Champ, can accomplish a reliable 1S ESC function on a combo, all-in one, board,
there has to be a stand alone ESC solution that could duplicate this for a reasonable price and weight.

Any ideas ?

Thanks for sticking with my loooong post.
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Old Jul 31, 2014, 03:36 PM
Registered User
West of California Speedway, East of LaLa, North of Disneyland
Joined May 2001
2,359 Posts
The HobbyKing Supermicro brand 1S ESC's are great!! ...and very light:

http://www.hobbyking.com/hobbyking/s..._3A_Mi_3A.html

HK also sells a DSM2-compatible brick for $28
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Old Jul 31, 2014, 03:56 PM
Cap'n
Dinghy's Avatar
United States, OR, Springfield
Joined Dec 2013
228 Posts
Brushed ESC

Jim, thanks for the link.

If I end up converting to "brushless" that HK ESC is on my list.
What I am looking for right now is a "brushed" esc to use with
$5.75 usd, LemonRX 6ch featherlte rx, and PZ 8mm brushed/geared motors.

Two HK BR3A esc's fail to fill the bill.
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Old Jul 31, 2014, 06:34 PM
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West of California Speedway, East of LaLa, North of Disneyland
Joined May 2001
2,359 Posts
Sorry for my dumb mistake.

I read "8.5 mm motor" and my brain whizzed right on by!!
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Old Aug 01, 2014, 06:19 AM
Mack
Peter Mack's Avatar
Australia, VIC, Mentone
Joined Jun 2004
539 Posts
Dinghy, I'm surprised you have had problems with the HK 3amp brushed esc. I have at least 6 of these and have never experienced any problems. I usually use the Orange Rx that the esc plugs straight into, but a recent model: http://www.rcgroups.com/forums/showt...ighlight=Dunny
employs your Lemon Rx (- tricky to solder up but the lack of weight is worth it?). The motors are usually the 8mm+ variety from HK, 9 Eagles, Parkzone or Hubsan quad spares. All have worked perfectly with the esc in question, either geared or direct drive. You have me worried now... Maybe someone electronically knowledgeable can help?
Just a thought; are you using the Tx supplied with the Champ? If so there are probably compatibility issues. I use the Spektrum Dx6i. The HK Orange Tx would be an economical option.
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Old Aug 01, 2014, 10:53 AM
Cap'n
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United States, OR, Springfield
Joined Dec 2013
228 Posts
Yes, all reviews said the BR3A would work. I use an HK ORG T-Six DSM2 transmitter and the stock champ "batwing" tx. Both results the same.

I have tried two P-51 motors, one used and still flying today, and a brand new one verified working OK on my working Champ brick. Same failures each way.

I tried two differnt Lemon RX's, 10 different (working lipo's), both ESC's....all combinations....same failure.

Servo hooked up to throttle channel in each set up, works perfectly.

HK has (so far) been very difficult to work with. Have opened a second customer service ticket to try and get to a different representative, and maybe get some kind of response besides, repetitive "canned" responses. Wish there was some way to call and talk to a human.
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Old Aug 01, 2014, 01:11 PM
Go small or go home
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Canada, SK, Regina
Joined Mar 2008
1,499 Posts
Ha ha, good luck with HK customer service. I love HK. I order their stuff all the time. Small orders, less than $100 at a time. I order multiples of everything I buy just in case something turns up broken (the extra items add to the parts bin). And 99% of the time it's all good (orders even arrive faster than expected). But I've had an order go south and it's not worth the time and energy to fight with CS over it. Anyway...

I think you might have been burnt on a bad batch of ESCs. From your previous thread, I think you've tried everything we could all think of to troubleshoot. I've had good luck with the micro 'brushless' ESCs, but I've never tried any of their brushed ones. You should probably put in a second order for a couple new ESCs. I'm sure you've already done this, but check the ESC carefully for mis-placed solder bridging (or not fully connecting) pins on the board. If it's a factory defect, bad solder joints would be a reasonable cause.
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Old Aug 01, 2014, 04:59 PM
Cap'n
Dinghy's Avatar
United States, OR, Springfield
Joined Dec 2013
228 Posts
Quote:
Originally Posted by ruzam View Post
Ha ha, good luck with HK customer service. ............

I think you might have been burnt on a bad batch of ESCs. From your previous thread, I think you've tried everything we could all think of to troubleshoot. I've had good luck with the micro 'brushless' ESCs, but I've never tried any of their brushed ones. You should probably put in a second order for a couple new ESCs. I'm sure you've already done this, but check the ESC carefully for mis-placed solder bridging (or not fully connecting) pins on the board. If it's a factory defect, bad solder joints would be a reasonable cause.
Glad to give youa laugh...but giving up is not in my creed.

I had not closely inspected the CB...........hmmmm,

Do you see a problem with the solder bridge on the two pins when the two black wires go ??

Do your BR3A ESC's have this same solder bridge ??

Cleaning up that 'blob' looks possible, if the chip isnt too heat sensitive.
I wont tackle it until I know "for sure' that this isnt intentionally bridged.

Thank-you for the suggestion......
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Old Aug 01, 2014, 05:19 PM
Go small or go home
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Canada, SK, Regina
Joined Mar 2008
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Quote:
Originally Posted by Dinghy View Post
Do you see a problem with the solder bridge on the two pins when the two black wires go ??

Do your BR3A ESC's have this same solder bridge ??

Cleaning up that 'blob' looks possible, if the chip isnt too heat sensitive.
I wont tackle it until I know "for sure' that this isnt intentionally bridged.
I can't say for sure through the heat shrink (I don't own any BR3As). It's common to bridge pins on ESCs to combine fets (or provide more heat sink to the chip). Looks like the bridging is supposed to be there (or at least the same for both ESC). But there does seem to be a lot more solder than needs to be there and the supporting chips aren't exactly lined up very well either. I would have stripped of the original wires and cleaned up the excess solder to save weight. At the very least, remove the heat shrink so you can get a good look at all the joints and traces. It's odd that you can get them to 'sort of' work and low power. Usually when something like this fails, it's all or nothing.
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Old Aug 03, 2014, 11:51 AM
Cap'n
Dinghy's Avatar
United States, OR, Springfield
Joined Dec 2013
228 Posts
Quote:
Originally Posted by Peter Mack View Post
Dinghy, I'm surprised you have had problems with the HK 3amp brushed esc. I have at least 6 of these and have never experienced any problems. ..........................
Since you have some working expamples of the BR3A esc,
Do yours have the same solder bridge shown in my pictures shown above ??

thanks.
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Old Aug 03, 2014, 02:31 PM
Weltherrschaft will be mine
Germany, SN, Leipzig
Joined Nov 2012
331 Posts
I do admire your skills and determination honestly im struggling to flash bl heli to a esc atm, so u see I have no clue how u do that...... but why not
buy a wl toys v911 or f939 brick and a flysky module for under 30 bucks total, weighs a gramm more but does the job
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Old Aug 03, 2014, 03:40 PM
:)
Dongo's Avatar
Here, There, Somewhere
Joined Jul 2004
271 Posts
Hello Dinghy,

If you are willing to experiment a bit, bidproduct has several different brushed 1s and 2s ESCs (some uni and bi directional as well).

Go here: http://www.bidproduct.com/more/cartlist.php?cat=1

and search "mini small". You will have to look through the 8 or so pages to find them.

I bought a 3A 1s one some years back and it worked well enough. I haven't bought any of the ones they currently have so I can't comment on them.

Daniel
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Old Aug 03, 2014, 07:57 PM
Go small or go home
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Canada, SK, Regina
Joined Mar 2008
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Quote:
Originally Posted by Dongo View Post
Hello Dinghy,

If you are willing to experiment a bit, bidproduct has several different brushed 1s and 2s ESCs (some uni and bi directional as well).

Go here: http://www.bidproduct.com/more/cartlist.php?cat=1

and search "mini small". You will have to look through the 8 or so pages to find them.

I bought a 3A 1s one some years back and it worked well enough. I haven't bought any of the ones they currently have so I can't comment on them.

Daniel
I see they have quite a number of micro brushed ESC. How do you know what you're getting? I don't see any kind of usable descriptions?
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Old Aug 03, 2014, 09:02 PM
Cap'n
Dinghy's Avatar
United States, OR, Springfield
Joined Dec 2013
228 Posts
HK Customer Service....

ALERT !

After 2+ weeks,...sending video proof of failure, (4 times), ..... placeing a 2nd warrantee ticket,...
finally got HK's attention....

2 new replacement BR3A ESC's will be shipped to me from the USA warehouse.

persistance, patience and more persisitance.

Now just hope I get ones that work, like Peter Mack has.
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Old Aug 03, 2014, 09:27 PM
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Dongo's Avatar
Here, There, Somewhere
Joined Jul 2004
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Quote:
Originally Posted by ruzam View Post
I see they have quite a number of micro brushed ESC. How do you know what you're getting? I don't see any kind of usable descriptions?
You basically have to go by the pictures which have some connection details and the 1-3 lines of description. I have emailed them in the past with questions. They were a little slow but they did answer.

As I mentioned, you may have to experiment a little if you want to try them.

Daniel
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