Pentium 40 ESCs now have swiching UBEC!!!

[The Don]

Good news! The Pentium 40 ESC has now been upgraded. Instead of a 3 amp linear BEC, they now come with a switching 3 amp UBEC!

Don

[NoM'rcrashPlease]

excuse my ignorance, but does this means that I don't have to buy another bec if I wan't to go tith a 4cell set up???

Thanx..

[The Don]

Yep :) The switching UBEC is built into the ESC.

Don

[NoM'rcrashPlease]

OOOOOOHHHHHH:)

thanx..

[johnm15141]

When I can I buy some? I want 2 for my e-flite F-15 and a pair of coolwind motors? (or would another motor be better, I plan to use 4S in my F-15...

Thanks!

[The Don]

When I can I buy some? I want 2 for my e-flite F-15 and a pair of coolwind motors? (or would another motor be better, I plan to use 4S in my F-15...

Thanks!

I have a new shipment due in about a week. The Wicked 4000 on 4S in the Elfite will be about 950 watts :)

Don

[johnm15141]

Great!

I'll take two Pentium 40's and two Wicked 4000's. I plan to use the stock fans cut back to 3 blades on a 4S battery.

I also plan to use retracts so I'll be running a lot of Servos, should the two UBecs be run in Parallel or does one them need to be disconnected?

[johnm15141]

Hi Don,

I hate to bug you but I was looking at your website and can't find the cool-wind motors for my e-flite F-15 anymore? I have been watching for the 40 Amp ESC with the new UBEC and when its available I will get 2. I was planning on buying two and two if that is a good combo for the e-flite F-15. If you have a better recommendation. let me know....

I see a lot of people complaining their F-15s wallow on the recommended setup I want to do it right from the start. I'm extremely (get it? "extreme!" ha ha) happy with the recommended setup for my Alfa Mig 15....

[The Don]

The Wicked 4000 are located here,
http://donsrc.com/cart/index.php?act=viewProd&productId=62
you want them with the 2.3mm shaft.

They have been shipped to me by Express Mail and are due mos likely Monday next week (due to 4th of July). I have added them to stock and a note saying they are on backorder. The Pentium 40s will be a day or two after that as they are in a seperate shipment.

Don

[johnm15141]

Say "when" I'm ready to punch!

Thanks for the quick response to my question!

I can't wait...!

[dr.E]

save three for me...pm me when the shipment comes in.....

[fh64_lucky]

Don,your awsum!In the last few weeks I have ordered a couple ESCs,motor,and Projeti from you.You ship stuff super fast,and everything works great!I truely hope you keep rocking like ya are now,as I will do buisness with you anytime!The motor for my F-16 with your added ESC sound sweet on my 4s setup.Finally,after 4 weeks of trying to get it upgraded,It all came together in the last week due to your service. :) Joe

[keyman923]

Don
Great news on the upgrade, any chance you might carry 20-50S or the 20-28M motor in the future

[coolboarder]

I just got some flights in with the 60amp esc and I must say it out performed my $90+ dollar airboss in regards to handling the high RPM.

The airboss is in another plane and I saved $40 bucks.

I will buy again


ON topic. this is good news :)

[The Don]

Tracking says the ESCs will be here tomorrow:) I am adding them to stock on the website.

Don

[johnm15141]

Order Placed!

I'm going to put two coolwind and two 40A Esc in my e-flite F-15 and run them on 4S with SF Fan...

[The Don]

Excellent! Just remember that since these are switching BECs, you will need to disconnect the red wire on one ESC before you connect them to the Y harness.

Don

[Tommy D]

Ok, I just have to ask. Your Pentium 40A ESC, can it REALLY work @40A with a 4S pack and 4 servos with NO external BEC?

I have a CC-45 in a model now with an external BEC running on 4S with 4 servos. It sure would be nice to remove the external BEC and free up some room.

So lets hear from guys who are now running this ESC! Any magic smoke yet? :D

Thanks!

Tommy D

[The Don]

I just finished my xflight A-7 and it is 4S, 450-500 watts on 4S with 4 servos, no external UBEC. This will be my first plane using the new switching BEC version. The most servos I ever used on 4S with the linear 3A BEC was three.

Don

[keyman923]

Any idea of what the weight difference is on the new 1? I'm guessing around 10-15 more grams and well worth it.

[Tommy D]

Hi Don

Thanks for the non-hype no BS answer to my question. I would rather here "I don't know" vs "yeah sure", if you know what I mean.

So tonight I placed an order for 2 of the 40A ESCs. You can be sure Ill be flight testing it ASAP on 4S and 4 servos. It will live in a very friendly enviroment so I doubt heat will be an issue.

Kindest Regards

Tommy D

[jimsky]

I plan on doing some testing prior to using bugger in my A-7 Corsair, so here are a few pictures I took...

General quick comments:

Two board design, an ESC FET board and a switching BEC/ESC control board joined via two opposing connecters...nice basic design, allows good symetrical mating of the two boards. Mixed through hole and surface mount boards.

The main FETs for the ESC circuit are heat sunk via the use of a thermally conductive "gap pad" and an 0.060" thick 1" by 1" aluminum plate.

DC input bypass cap is a known brand electrolytic (Ruby-Con), 105 degree C rated, long life, low impedance capacitor. Not cheap no name crap...

Switching BEC is fully shielded...excellent design. This full top cover along with the ground plane circuit board design is effective in minimizing any switching noise from "leaking" out creating havoc with other circuity. I was planning on making some temperature measurments of various BEC components but I'm not removing the shield.

General good workmanship. A solder mask is used on all board surface...they ain't cutting corners to save pennies.

I've got a 5V @ 3 amp load that rated for 150 watts...I plan on powering the ESC via a 4S pack, fully load the BEC at 3 amps and monitor the BEC output voltage and output ripple and noise. I'll check temperatures and maybe do a thermal map of the BEC shield since I can't make component measurments. If anything looks fishy I'll power the ESC with a 40 amp motor load and test again.

Looking foward to seeing what results I obtain...

Jimsky

[The Don]

WOW thanks for the photos and info! :eek:

Don

[jimsky]

I ran a few quick tests tonight...in a nutshell the BEC can provide 3 amps while powered from a 4S pack, but the switching BEC circuitry gets warm pretty quickly.

1.66 Ohm Load
This is a 3 amp load on the 5Vdc BEC output. Actual measured voltage was 4.71 volts. Measured ripple was 40mV, less than 1%... pretty good. After 60 seconds of operation the voltage was still stable but I could not hold my hand on the BEC shield, indicating it was above 65 degrees C. Too hot in my book.

2.5 Ohm Load
This is a 2 amp load on the 5Vdc BEC output. Actual measured voltage was 4.87 volts. Measured ripple was 25mV. The BEC shield was warm but comfortable, I think this would be an acceptable contineous load.

5 Ohm Load
This is a 1 amp load on the 5Vdc BEC output. Actual measured voltage was 5.01 volts. Measured ripple was 20mV. No problem with BEC circuitry heating.

No Load
This is an open circuit on the 5Vdc BEC output. Actual measured voltage was 5.23 volts. Measured ripple was 15mV. No problem with BEC circuitry heating.

The load regulation is kind of poor (like 10%) but most likely OK for this application. The ripple frequency was measured to be 2.2uS or about 450KHz, kind of what I expected.

If operating at it's rated 5Vdc @ 3 amps that's 15 watts of output power. If the converter used is say 90% efficient than that's 1.5 watts of losses. 1.5 watts of heat dissipated in that small BEC shield box...it's going to get hot...no way around that. I'd call it a good 2 amp BEC with 3 amp peak capability for now.

Quick tests indicate to me the BEC should be fine powering four (4) HS-55 servos while operating from a 4S pack. Current draw should be nowhere near 3 amps, and the BEC can provide 3 amps...it just gets hot but did not go into thermal limit even after 60 seconds of operation.

More tests are in order, but I think I'll be using this in my new A-7 Corsair.

Jimsky

[The Don]

Thanks for the detailed report. How does this compare to other ESCs?

Don

[jimsky]

Well most other "regular" ESC's use a linear regulator (or two) to provide the +5Vdc BEC output. Linear regulators offer good performance but their drawback is power dissipation as the supply voltage increases. At 2S all is wonderful, at 3S you have to limit current draw to prevent overheating...at 4S they are almost unusable.

Your ESC has a switching BEC regulator, this eliminates the problem with excessive power dissipation at increased supply voltage. But it's more complicated and it adds a possible noise source (the converter switching frequency) to foul up other electronics.

I've used external switching BEC's (Dimension Engineering and Castle Creations) before, but your ESC has this feature built in...I think this is where the industry will be going. I never tested those external BEC's, I just used them with no problems.

I figured since this was an ESC and switching BEC all in one package (and reasonably priced I might add) it warrented a bit of investigation.

Take what you like and leave the rest...your milage may vary...just sharing my observations...

Jimsky

[jimsky]

I took a couple thermal maps of the switching BEC circuitry. I ran the ESC from a 4S 2200 pack and placed a 1.66 ohm (3 amp) load on the output of the BEC. I had to “paint” the glossy metal BEC shield black with a Sharpie because the thermal imaging camera was having problems obtaining temperature measurements from such a shiny surface.

My calibrated finger was not far off stating that the shield was 65 degrees C after one minute, check out the first image. After 3 minutes of operation the maximum hot spot temperature of the shield was 100 degrees C. God only knows just how hot the individual components are inside the shielded box.

As previously stated I’d call this a 2 amp continuous/3 amp peak rated BEC.

Jimsky

[herk1]

Hey Don - What's the "Lifesaver" ring thingy on the receiver wire of the Pentium 40? If that is something to reduce R-F interference, can Spektrum users do without it?

Also, FWIW: personally I would rather not have pre-tinned wires on a new ESC -- especially one that has such short wires -- because before putting on wire extensions, I clip that soldered part off first anyway (so I can get a little interleaving between wire strands at the connection before soldering together).

[Vito]

I am putting together a 6 servo plane that I will run on 4 cells. The servos are all micro and two of them are flaps so they won't be used much. Is the BEC on the 40A or 60A up to this load?
Thanks in advance
Vito

[The Don]

You should be ok on that setup.

Don

[herk1]

Don, which side of the Pentium 40 is better to expose to cooling air...the side with the label, or the other side?...i.e. as in the first photo below, or the second?

[The Don]

I usually place the label on the heat sink side. But to be safe hold the ESC sideways. The heat sink is on the same side as the motor wires are on. The bulge on the opposite side is the case protecting the switching BEC.

Don

[herk1]

I didn't realize there was a heatsink inside the shrinkwrap. Yes mine has that bulge on the opposite side of the label. So I'll install it label-side-visible, like the first photo then. Thanks!

[The Don]

They have a metal plate that touches all the tops of the FETS to dissipate heat.

Don

[asm_]

Jim,

I am just wondering exactly where were you measauring the BEC output voltage under load. The reason I am asking is becuase I did a few tests on commonly available switching BECs on the market today. I had to remove the test result from the web because I soon realize the tiny 22 awg servo wires use for most external BEC is having much significant effect on output voltage then I have anticipated. On a short 10" run of the servo wire under 3A load, the voltage can drop as much as 0.5v.

So, in my test, those BEC that performed better under heavy 3A load was simply because they have shorter and heavier gauge wire.

Brian

[jimsky]

Something doesn't make sense:

22AWG wire is around 16 ohms per 1000 feet. So 1 foot of wire is 16 milliohms. The voltage drop at 3 amps due to 16 milliohms of resistance is only 48 millivolts.

Jimsky

[asm_]

I know, I didn't think it would make that much of difference too. But, when I measured directly at the pads at the BEC board, the voltage drop was only 0.05v.

By the way, this is Dimension's Sport BEC I was testing.

I will run more test when I get the chance.

Brian

[herk1]

Don - I had just taxied into position for takeoff with my Pentium-40 - equipped plane, and when I pushed up the power for takeoff, the motor just sputtered. I pushed up the power all the way and it still just kind of sputtered at the same very low RPM (so low that you could see the individual prop blades). I pulled the power off and walked up to the plane to see if there was something blocking the prop or what. Everything looked fine, so I pushed up the power again and the motor (Scorpion 2215-1860) spun up normally this time. I went ahead and flew, and nothing weird happened again.

I didn't change any settings on the Pentium from the way it came. Should the timing or something be different from the stock setting for a Scorpion motor? This only happened once out of the several flights I have on the plane. The only thing I'm worried about is if this were to happen inflight (stuck-in-idle). Is a startup glitch like this unlikely to happen inflight, since the prop and motor is constantly turning?

[The Don]

Typically the timing is set to low by default. I would change to "high" for that outrunner.

[Vito]

Don,
Maybe a similar issue as Herk. I just tried my new Pentium with an AXI 2826-12 and I got twitches but it didn't start the motor. I tried it on 3 cells, 4 cells and every combination of timing and soft start without improvement. The Pentium is covered in black heatshrink and has the switching power supply.
Any ideas? I have used the older (yellow) version on essentially the same motor without a problem.
Vito

[The Don]

I would set to "high" timing and "normal" start up. Also make sure you have good solder joints on each motor ESC wire connection. You may want to resolder just be sure as I run into a similar issue on the EDF motors and when I tell people to resolder with lots of heat then they work fine. Also is this a never used ESC or was it working now does not work?

Don

[Vito]

I will resolder the connectors to be sure. This is a new ESC.
Vito

[Vito]

Don,
I just cut off the heat shrink on the connectors and they looked like excellent joints (for me anyway). I reflowed the motor joints and hooked it up not expecting any change. It works fine. I guess I need to rethink what a good solder joint looks like.
What service! 8 minutes after I post a question until the no cost fix. You da man.
Thanks
Vito

[The Don]

Glad it is working for you :) I don't know why but that is a common problem, I tell people to resolder then the troubles go away :D

Don

[HighNear90]

Are these going to be in stock soon? I need one.

[The Don]

Yep more one the way. You guys buy them as fast as I get them in stock :-)

Don

[KRAZY KAT]

Hello Don, I just recieved my my 40 amp speed control. My question is that it's yellow and not black, also it does not say switching bec on the yellow one. Is the yellow one still a switching bec?? Thanks Don

[The Don]

The last batch I got were yellow for some reason. The sticker should have the version number on it.

Don

[KRAZY KAT]

Hello Don is the version 3.1 the switching bec??

[The Don]

Hello Don is the version 3.1 the switching bec??

Yep, there should also be a green iron ring on the sevo lead as well.

Don

[KRAZY KAT]

yup, thanks Don.

[Cubcrazy]

I have had my eye on Dons products via these boards, and placed my first order tonight. Pentium 40 ESC. I ordered it quite late at night(1030pm EST) and within 2 hrs I get a confirmation email from Don saying packed and ready to ship. WOW!! I am planning to get some EDF jets over this winter and I know exactly where ALL my motor/electrical parts are coming from.