Thread Tools
Jan 22, 2017, 06:38 PM
Registered User
Thread OP
1S . Sorry, should have mentioned that.
Sign up now
to remove ads between posts
Jan 22, 2017, 07:05 PM
Registered User
Tim Cullip's Avatar
That sounds impressive. Good thrust for that current draw. Do you know what rpm it was at?

Tim
Jan 22, 2017, 09:05 PM
Aedificem ergo sum
cybermike's Avatar
I ran some 1S tests on the BR1103 6500kV motor using the props I had and a few different ESCs. I used a bench supply, clamp-on ammeter and optical tach, so those numbers are all pretty accurate. The thrust numbers are a little suspect due to the scale vibrating around, binding on my L-arm, etc.

For ESCs, I used the XP-3A clone I built with upgraded FETs and flashed with BLHeli firmware, a stock RacerStar 1AS 3A (also with BLHeli), and the same RacerStar with upgraded FETs. For some reason, my clone ESC gives higher performance than the RacerStar, so I suspect the BLHeli timing settings are different. Unfortunately, I can't get my programmer to work with the RacerStar, so I can't compare the settings. The FET upgrade does make a difference - about 200 additional RPM to the prop at roughly the same amp draw. You would expect higher thrust numbers, but I didn't see that, which is another reason I am suspect of my scale.

Clearly, this motor likes 3" and 4" props best. The motor starts to get hot over 3A. You could probably get away with a 5x3 if you don't run it full throttle all the time.

Next up will be the BR1103 8000kV and BR1004 4000kV.

Mike C.
Jan 23, 2017, 05:33 AM
Registered User
Thread OP
Best 3" prop I have found is the Gemfan 3025. More thrust at lower amps than the GWS props.

I did my tests with the Racerstar 6A 1-2S ESC (which works OK on 3S as well).

The 1104 4000kV seems to give app. the same amount of thrust for a given prop but with lower current. Even though it is app. 2 grams heavier than the 1103 it's propably the better motor for 1S planes as you can use a smaller lipo.
Jan 23, 2017, 01:17 PM
Unregistered User
emma97's Avatar
Moral of the story: do NOT upgrade the cheap ESC with new FETs? I would be interested in what part number was used.

ps Does anybody have an opinion on 1s operation for these which are listed for the 1103:

http://www.banggood.com/10-Pairs-Rac...op-buytogether

Those are small so probably not for 1s? But what about these which I have 60 pcs (all 3 colors) and been using with 8.5mm for some time now:

http://www.banggood.com/5X-Eachine-7...?rmmds=myorder
Last edited by emma97; Jan 23, 2017 at 01:57 PM. Reason: maybe not better
Jan 23, 2017, 01:34 PM
Aedificem ergo sum
cybermike's Avatar
Quote:
Originally Posted by emma97
Moral of the story: do NOT upgrade the cheap ESC with new FETs (unless you want less thrust and g/w)? I would be interested in what part number was used.
The FET part numbers (original and the new ones with roughly 1/3 the on-state resistance) are at the bottom of the chart I posted, and as I stated in my post, the thrust numbers are probably not accurate because of my setup. Obviously, if you get several hundred more RPM at the same amp draw, then you will have higher thrust. Frankly, nobody's "hobby grade" thrust measurements are very accurate because of the nature of the setups used to measure thrust. Volts, amps and RPM are a lot easier to measure accurately.

Mike C.
Jan 23, 2017, 01:45 PM
Unregistered User
emma97's Avatar
Yes, I see your comments now. But even if it was reversed the difference seems not worth it.

ps I was interested in actual part number to compare with my AO3400. I have an entire reel and found them best deal so far for my DIY brushed ESC. There are some with better Ron but not 3 cents ea. I also have 2302 and 2306 but found not good by comparison.
Last edited by emma97; Jan 23, 2017 at 01:54 PM.
Jan 23, 2017, 02:33 PM
Aedificem ergo sum
cybermike's Avatar
The main advantage is the DMN2041L is good for about 4.5 amps vs the barely 3 amps for the Si2302 so there is a bit more headroom. But yeah, I probably won't make a habit of replacing them.
Jan 23, 2017, 03:15 PM
Unregistered User
emma97's Avatar
Unless of course some good luck results in burnout and we MUST do it. lol

In my case it was not so much running anything at any limits but temperature. To keep weight of finished ESC below a few milligrams FET is attached directly to the MCU (see pic). With no crystal even a little heat can throw timing off. The AO3400 were good for like 6 amps so ran cooler but mostly they cost about 1/10th as much as DMN2041L and most of the others.

Back on topic I'm curious how those 75mm BG props perform because they are bigger, lighter, and cheaper than the "official" 65mm ones. I also have a large qty of Syma x5 props. What with China NY my 1103 motors might not get here for 6-8weeks so wondering if I need to order other props or if those will do.
Jan 23, 2017, 05:06 PM
Aedificem ergo sum
cybermike's Avatar
Quote:
Originally Posted by epilot
The 1104 4000kV seems to give app. the same amount of thrust for a given prop but with lower current. Even though it is app. 2 grams heavier than the 1103 it's propably the better motor for 1S planes as you can use a smaller lipo.
I concur, and the power stayed on long enough for me to run the tests. Much nicer numbers for 1S, up to 5x4.3, and the UMX Corsair 3-blade prop looks pretty good too. Also, less difference between the speed controls, and more accurate thrust numbers. I believe the XP-3A timing to be more advanced than the RacerStar.

This is the motor going into my 1/24 Zero!
Jan 25, 2017, 08:26 PM
Registered User
speedy01's Avatar
Deleted
Last edited by speedy01; Jan 26, 2017 at 06:11 AM. Reason: Bad Info
Jan 25, 2017, 08:29 PM
Registered User
Petefoss's Avatar
Is that same motor in the AS3Xtra Gene? The "hotter" wind 8.5 mm?
Jan 26, 2017, 06:10 AM
Registered User
speedy01's Avatar
Quote:
Originally Posted by Petefoss
Is that same motor in the AS3Xtra Gene? The "hotter" wind 8.5 mm?
Hmmmm ... I measured the UMX Radian Motor (in the model), and it's 23mm ... as is listed for the the AS3Xtra.

BUT

EFLU 2916 is the UMX Radian motor; while EFLU 5152 is the 23mm AS3Xtra motor; and the 8.5mmx23mm in the UMX Yak-54 is not specified on the E-Flite web site.

So I don't know which is the "hotter" wind! and I had better get my facts straight!

I need to recalibrate my brain when I get back home tonight by doing some search and refreshing! Thanks for the gentle prod, Pete.

Gene K
Jan 26, 2017, 09:02 AM
Gravity is a harsh mistress.
Tim Wolff's Avatar
Quote:
Originally Posted by speedy01
Hmmmm ... I measured the UMX Radian Motor (in the model), and it's 23mm ... as is listed for the the AS3Xtra.

BUT

EFLU 2916 is the UMX Radian motor; while EFLU 5152 is the 23mm AS3Xtra motor; and the 8.5mmx23mm in the UMX Yak-54 is not specified on the E-Flite web site.

So I don't know which is the "hotter" wind! and I had better get my facts straight!

I need to recalibrate my brain when I get back home tonight by doing some search and refreshing! Thanks for the gentle prod, Pete.

Gene K
AFAIK the part # difference is due to different lead lengths. I recall ordering a alternate part # for the AS3Xtra when the replacement motors were backordered. The lead length didn't matter as I cut them off and replaced them with a heavier gauge wire anyway.
Jan 26, 2017, 09:24 AM
Registered User
Thread OP
Back to BL motors. The RPM meter and power supply I ordered have arrived. I have also received 1103 10K kV motors. With a bit of luck 1104 6500kV motors will be here tomorrow. This means I can do some more testing this weekend.

I expect the current draw to be fairly high for the 10K motors but they might just be usable for a fast prop in slot type micro jet model.


Quick Reply
Message:

Thread Tools