old4570's blog View Details
Posted by old4570 | Yesterday @ 09:56 PM | 335 Views
FF SU-27 project ...

1) Iron the Su-27 back into shape ( yes , it came a little bent )
2) Disassemble the SU-27 ( Remove the power pack )
3) Clone the Su-27 in 3mm Depron
4) Swap in the power pack from the Lipo Biplane glider ( which is a dog of the leash )
5) Cover in laminating film for strength + weight ..

So , as is ... The SU-27 is too light and under powered to deal with any kind of breeze at all !
If the breeze ruffles the hair on your head , it's too windy . If you can feel a breeze on your face ? , it's too windy .
Take the SU-27 indoors or go home .

So what to do ?
Maybe add weight and power ?



Yes , that FF lipo Biplane glider has a fantastically over powered - power pack !
The SU-27 is here , and simply awaits it's new power source ( Not here yet )
Yes , I have a FF biplane , but I am leaving that alone for now . So I must wait for the one ordered ..

The clone Su-27 ....
Hmmmm , can it possibly be made RC ?
It would be smaller than the HobbyKing one I have ..


Posted by old4570 | Yesterday @ 04:40 PM | 791 Views
Wow ! Still windy as all out doors .. 2019 is about the windiest I ever recall . I hope this is not a trend that will be repeated next year , cos I did a lot more flying in 2018 .

Wing kit , yes the Bee 490mm double wing kit has arrived , and looks nice . Everything in the box came out at 100 grams even ( 2 wings ) .

Also got a DSM 4 ch Rx I have been hankering for ..

Also the folks at Xtar sent me their VC8 charger to review / test .. Just waiting on some USB power supplies so I can do a proper test .. The ones I have now dont come close to supplying the needed power for a proper test . But so far I am finding the charger very useful and capable .

My spending has come to a close for the year I think ( just about ) as this time of year the mail begins to slow down and anything purchased in Dec may not get here until next year . I am still owed a lot of knickknacks by the universe .

Plans = I want to build a FPV wing , and to that end ordered a compact FPV camera/tx unit . I ordered a flight control board some time ago , hope it gets here .. For FPV I would like some stability control .

Waiting for stuff just

Motor tests so far = Lets compare !

0905 - 10,000kv
1103 - 7800kv
1104 - 4000kv
1105 - 5000kv
1106 - 6000kv

65mm Prop ( 2.5inch pitch ) 2s

0905 - 108g thust - 51W - 6.7A - 36,000 rpm
1103 - 106g thrust - 42.7W - 5.37A - 35,500 rpm

Cut down 3025 ( 2725 ) 2s

1103 - 122g thrust - 55.3W - 6.58A - 29,...Continue Reading
Posted by old4570 | Nov 15, 2019 @ 08:33 AM | 2,204 Views
The motor only just bolts up to the test stand .

1s tests , I record thrust VIA the stand and RPM VIA the GT power tach .
2s tests are through the stand ...

I started with the smallest prop that would bolt to the motor , my 65mm prop .

1s - 65mm - 24,600 rpm for 42 grams of thrust
2s - 65mm - 36,000+ rpm for 108 grams of thrust ( motor is getting warm , but not so much as to burn ) 6.7A / 51W

The data sheet shows a 3020 prop

1s - 3020 - 19,000+ rpm for 46 grams of thrust
2s - 3020 - I was very gentle in adding power to see if the motor would cook ..
Around 2A the motor was starting to really warm up ...
I got brave and pushed the motor to 5A for only about two seconds and the motor got finger burning hot ...
No I didn't kill the motor , it lives !
But obviously 3020 is just too much for this motor with 2s ... ( I had to try as it's on the data sheet )
I would run that little 65mm prop 2s , or maybe a smaller 3 blade .. ( dont have any right now ) ...

Wow , 108 grams of thrust for a small 0905 ... Even 1s was not horrible ..
Posted by old4570 | Nov 14, 2019 @ 06:34 AM | 2,044 Views





2s On the stand

6x3 - 130 grams thrust - 3A - 10,000 rpm - 26W
6045 - 129 grams thrust - 4.69A - 7,000 rpm - 36.3W
5030 3 blade - 128 grams thrust - 3A - 10,700 rpm - 24.8W
5030 2 blade - 131 grams thrust - 2.8A - 11,200 rpm - 23.2W
4540 2 blade - 117 grams thrust - 3A - 10,700 rpm - 24.4W

3s On the stand

4230 2 blade ( cut down 5030 )
186 grams of thrust - 4.3A - 15,400 rpm - 50W

I really thought the motor might wind out on the 3s ,,, 12 x 2300 = 27,600 ..... But No !
Apparently this sample is not that grunt'y ..
On 2s it seems rather fixated on performing @ around 130 grams of thrust ..
That 5030 @ 2.8A and 131 grams of thrust , yeah I could live with that .
It be a respectable amount of thrust for the power ..
Posted by old4570 | Nov 12, 2019 @ 11:12 PM | 1,455 Views





4000kv

4 x 4 = 16,000
8 x 4 = 32,000

Lets get to it ...
The only prop on the data sheet is a 5x3 ...

5x3 2 blade ...

2s = 246 grams of thrust - 15,000 rpm - 7.7A - 57 watt
1s = 78 grams of thrust - 9,000+ rpm -

6x3 2 blade

1s = 90 grams of thrust - 8,700 rpm

Sorry , no current / power for 1s ..
Posted by old4570 | Nov 12, 2019 @ 09:13 PM | 1,172 Views


Hmmmm , remember that cute little motor ?

Yeah , I cooked it and now it's damaged ...

0802 16,000kv

4 x 16,000 = 64,000 rpm
8 x 16,000 = 128,000 rpm

I expected this might happen ..

The smallest prop I had , was still too much ..

I had to run it 2s , well it's advertised as being 2s capable ..

But that 16,000kv is just ridiculous ..

So ...... 2s .... resulted in some 41 grams of thrust at 39,000 rpm and the current peaked around 5.6A ...
Now the motor only got warm , I did not run it long enough to cook .. ( So I thought )
But obviously the motor got damaged doing a full throttle run ( 2s )

So is it really 2s capable ?????
I guess that was like lighting up a few cigarettes , the motor went up in smoke ( actually there was no smoke ) ..

What a anticlimax that was ...

Next motor test will be a racerstar 1306 4000kv ..
Supposedly 1 to 2s ...

Hmmm , how will it run 1s ????
Posted by old4570 | Nov 12, 2019 @ 04:14 PM | 739 Views
What is cooking a motor ?

In a nut shell , it is when the motor gets so hot that electric current goes to generating heat rather than forward thrust .
This may or may not , result in thermal run away !

When electricity goes to generating heat , it means power is taken away from thrust resulting in diminishing returns .
This may be hard to notice in a quad or plane until the motor dies ..
But on my test stand it is noticeable almost right away as I can monitor RPM / Thrust / current ...

Thermal Run away ! ( A really good way to kill a motor )

Again , electric current goes toward making heat rather than thrust .. In a thermal run away situation , the motor begins to slow down ( lose power ) and just get hotter and hotter till the motor seizes ( stops ) or dies ( damaged ) . On the test stand I can pick up on this almost immediately ..

As I slowly increase power , RPM / thrust and current climb . Once a peak is reached only current might go up , that extra power being fed into the motor ( if it takes more power ) is most likely going into manufacturing heat .. And as the motor gets hotter it begins to slow down ...
The faster this occurs ( seconds ) , the more likely that the motor may go into thermal overload .

It would be very difficult to pick up on this without the ability to monitor the motor properly ..
A way to avoid such would be to match your motor ( KV ) to the battery ( voltage ) and prop you want to run .

...Continue Reading
Posted by old4570 | Nov 09, 2019 @ 09:16 PM | 909 Views



This is the motor that is supposed to go on the little 450x wing .

Lets start with the 3025 prop ..

2s - 145 grams of thrust - 5.59A - 26,400 rpm - 45.5 watt
3s - 268 grams of thrust - 10A - 35,000+ rpm - 118 watt ( Getting hot )

3830(E) prop ... ( 383E )

2s - 191 grams of thrust - 8.21A - 22,000+ rpm - 62 watt

3330(E) prop ( cut down 383E )

2s - 170 grams of thrust - 7.61A - 22,800 rpm - 54.9 watt



Sorry guys , just look at how that current / power peaked from 2s to 3s with the 3025 prop ...
The larger pitchier prop would most likely peak even higher and just cook the motor .
The motor seemed to behave well with all the props tested ... Even ran solid to 35,000 rpm ..

I suppose if you were made of money , you could afford new motors as you cooked the ones you had racing ..
But seriously , 268 grams of thrust . From such a small motor ... !!!
You would probably kill the motor if you stayed on the hammer for any length of time , but I think this is the best motor tested so far for a 11 size .. ( From what I have ) ..

On 2s , with a well selected prop , I would dare say a sub 100 gram quad would scream fast enough for anyone (?) .
And powering a micro wing ? ( Yeah )
I just need to remove the 1103 from the 450x and give that a test ...

For testing props ? , I don't have a suitable motor .. I thought that 1106 might have done the job , but I was wrong .
Not that there are that many 1103 - 1106 props

Lets Compare !

0905 - 10,...Continue Reading
Posted by old4570 | Nov 08, 2019 @ 12:55 AM | 1,110 Views
It was time to put the 1104 4000kv on the test stand ..
It's raining and blowing a gale outside , so what to do ?

2s Battery

3025 - 69 grams of thrust / 19,100 rpm / 1.69A / 13.9 watt
333E - 86 grams of thrust / 16,500 rpm / 2.44A / 19.2 watt
383E - 96 grams of thrust / 15,300 rpm / 2.5A / 21.6 watt

I think the motor wants more prop on 2s

3s Battery

383E - 140+ grams of thrust / 19,000+ rpm / 4A+ / 49 watt ( Ran HOT )
333E - 140 grams of thrust / 20,700 rpm / 4.1A / 46 watt ( Did not run HOT )
20,000 rpm = 120g / 41.8w

3025 - 129 grams of thrust / 25,000 rpm / 3A / 36.5 watt ( happy camper )
20,000 rpm = 80g / 21.2w

65mm - 80 grams of thrust / 32,000 rpm / 1.69A / 20.7 watt
20,000 rpm = 30g / 6.2w


Posted by old4570 | Nov 07, 2019 @ 08:41 PM | 1,456 Views
Posted by old4570 | Nov 06, 2019 @ 11:32 PM | 1,468 Views
2s Test

383E 2 blade prop = 160+ grams of thrust , but the motor is cooking ( be that 6000kv )
333E 2 blade ( cut down 3835 ) = 157+ grams of thrust / 22,000+ rpm ( motor is cooking )
@ 20,000 rpm = 127 grams of thrust for 43.8 watts

3025 2 blade prop = 136+ grams of thrust @ 5A + / 25,000+ rpm
@ 20,000 rpm = 74 grams of thrust for 22.3 watts

65mm 2 blade prop ( pictured ) = 87 grams of thrust @ 3.2A+ / 33,000+ rpm
@ 20,000 rpm = 31 grams of thrust for 7.9 watts

This motor is supposedly 1-3s , and for me 6000kv is probably to high a KV for actual use .. ( Unless if you plan on running 3s and small props , in which case it might be ok ) But the high rpm ?
For actual use , maybe 3000kv to 4000kv would be a better choice . Especially if you want to run less current and more prop .

Even with such small motors , if you are running 2-3s , I just dont see the need for high KV .. ( Thats just me )

4v x KV ( 1s )

4x 3000kv = 12,000 rpm
4x 4000kv = 16,000 rpm
4x 5000kv = 20,000 rpm

8volt ( 2s )

8x 3000kv = 24,000 rpm
8x 4000kv = 32,000 rpm
8x 5000kv = 40,000 rpm
8x 6000kv = 48,000 rpm

I would say that for 2 to 3s , those high KV numbers are just silly ... ( For numerous reasons ) , one being the high current which tuns to heat . The other being that larger props are more efficient .
I did buy this motor for testing props ... But now , after seeing 160+ Grams of thrust ... I think I feel the need for a 1106 3000kv motor ...

UPDATE :

3s Testing ..

65mm Prop .
Wow , this motor does not like pulling more than say 35,000 rpm ..
As you approach 40,000 rpm the motor craps out ..
It did stay cool how ever , but peak RPM is reached around 50% throttle on 3s ..
Thrust is around 100 grams ..

I will try the 3025 next

3025 (3s)
33,600+ rpm / 9A+ / 225 grams of thrust / 108 Watts / Cooking !!!!!
20,000 rpm / 78 grams of thrust / 28.5 watt
Posted by old4570 | Nov 06, 2019 @ 08:36 PM | 1,369 Views


Bee 490mm wing kits ( 2x )
2 wings apparently ..
I'm not supposed to buy anything till Xmas , but !
Posted by old4570 | Nov 05, 2019 @ 10:16 PM | 638 Views
DW 600mm flying wing ..

Another wing I have had my eye on for a while ..
Since it was on sale recently , I decided it was time to drop the hammer .

As pictured ( everything in the picture ) , the weight of the kit is 52.8 grams ..
This would leave us some 47.2 grams to play with to try and make weight ( 100 grams / minus a few grams )

Hmmm , a sub 10 gram motor ( 1306 ? )
two 5 gram servos ?
A 5 gram ESC , and micro RX ( less than 10 grams total )

So around 30 grams maybe ? leaving some weight for a 2s battery .



I still have two motors owing to me ( somewhere in the postal universe = I hope )
A 1306 and is the other a 1406 (?) Nope a 1410 !

This waiting for stuff
Posted by old4570 | Nov 04, 2019 @ 02:51 AM | 2,542 Views


This is a very interesting kit , and the thing that I really wanted to know was the base weight !
As pictured , with the components as is , the weight is 68.5 grams .

I don't think this one will go sub 100 grams , with only some 31.5 grams to play with . ( Servos / Rx / ESC / Motor / and the battery )

Link = https://www.banggood.com/custlink/DDvG6eoW6q

Though , you should be able to get it in the air for around $50 USD with budget components .
Posted by old4570 | Nov 01, 2019 @ 09:15 PM | 2,900 Views




Tested on the Turnigy V3 test stand

2s

7045 2 blade = 12.3A / 470 grams of thrust / 10,800 rpm
6045 2 blade = 8.2A / 384 grams of thrust / 13,400 rpm
5051 3 blade = 8.57A / 295 grams of thrust / 13,190 rpm

3s

5051 3 blade = 13.66A / 500 grams of thrust / 17,100 rpm
5042 3 blade = 10A / 434 grams of thrust / 19,800 rpm
6045 2 blade = 13.2A / 653 grams of thrust / 17,400 rpm



I don't have a 6x3 or 5x3 that will fit this motor .. So I had to use props on hand that fit .
I did see over 150 watts with the 3s battery , the motor just got a little warm . So at around 150W looks like we are starting to load up the motor . How much more it will take before it cooks ? I would say that on paper the motor is under rated quite a bit . Personally I would be happy to run this motor to 150W for short bursts , like take off or a speed pass .
I have two wing kits , one is 800mm . ANd I have seen a lot of people put 2204's in that 800mm wing . If it can be built to 150 grams or less ? Then we might be looking at a thrust to weight ration of 4.3 to 1 or better ? on 3s . ( Thats crazy ) or 3:1 on 2s ....

Motor Link @ banggood
Posted by old4570 | Oct 31, 2019 @ 07:34 PM | 3,518 Views
BG been having a bit of a sale ..
So I purchased two wings I have had my eye on ..

1105 5000kv motor came / This is the motor that should be in the 450x wing ( well , should ) . It's the best packaged motor I have ever seen .

That twin wing FF powered model got here : And the CG is w.a.y ( way ) back from where it should be . I slapped on a BBQ skewer and used it to find the CG . Yeah as pictured is close .. No I dont like the model at all , so why did I rush to buy another ?
Might have something to do with the Lipo powered motor and timer .. This thing screams , and has some serious grunt for motion . I think the power system is worth the money alone .. Also ordered another FF SU27 .. PLAN = take the power train out of the slug ( twin wing ) and put it into the SU27 FF model .. ( Oh dear ! ) Could be interesting ( could be )

1103 in the 450x - Got some 65mm props , ??? RPM as the GT power tach can't get a solid read ..
Though the AMPs is down , maxing out at around 3A or a little less ... ( Full throttle )
I kind of think that prop is too small as the RPM peaks around 75% throttle and did the tach read 39,000rpm or was it an error ?


I have two wings to play with .. and two small motors on the way ..
Maybe two more sub 100 gram wings ?
we will see ...
Posted by old4570 | Oct 29, 2019 @ 08:54 PM | 2,170 Views
Continues from Part 2

So I have verified RPM / Current Draw / Thrust to my satisfaction .
And I am happy to trust the V3 stand to report the truth to me . ( well , as close as it can )
This is not a laboratory grade instrument , but the results are consistent / repeatable / and ball park enough to be very useful .

So exactly what can the V3 test stand do ?

Power Meter

If you watched the video in part 2 ?

Battery - You can see the voltage sag under load ! , as well the current supplied . Did anyone think that perhaps you could use the test stand to TEST your battery pack ? I see plenty of posts on RCG where people ask questions or complain about their batteries . How hard would it be to replicate the conditions your battery has to put up with and then actually see in real time what the pack is doing !
That's are far as I'm getting into batteries - because it's a can of worms ! and we are talking V3 test stand right now .

Motor - There is a saying , a chain is only as strong as it's weakest link . And we can expand on that to = A quad racer is only as fast as it's slowest engine .
With a test stand , you could test your motors for the weak link .

ANd Thrust

Propeller - This is unfortunately not as uncomplicated as it should be .. Unless you use a large enough motor with a high enough KV so that all propellers can be tested with as little induced variable as possible .
This is why we need constants ..
The motor...Continue Reading
Posted by old4570 | Oct 28, 2019 @ 11:28 PM | 2,272 Views
Turnigy V3 thrust stand .. (1 min 57 sec)


Quick and dirty video showing the thrust stand in use ...

I checked the thrust results :

The way I did it was the cheap nasty and EASY way .
I have digital scales , so I just powered up the test stand , powered up the scales .
Zeroed the scales , and then applied the scales directly to the test stand ..

Then I could compare both digital read outs ..
This is by no means laboratory accurate , but as near as I could tell the test stand was replicating the force from the digital scales .

So the test stand looks to give real world results .

....


PART 1

Part 3
Posted by old4570 | Oct 27, 2019 @ 10:38 PM | 2,010 Views
PART 1 ( of many many parts )

At last a motor is here !
Be a budget 2204 / 2300kv 2-3s ( 12A - 120W - 14 pole )

The very first thing I wanted to check was RPM accuracy as I had seen a complaint or two about this !
Now the very first thing anyone has to understand is :
You have to input the correct pole count for your motor !!! or you will get the wrong RPM read out .
This motor is 14 pole ( advertised as ) .

Setting the test stand to 14 pole :
setting motor speed to 10,000rpm as reported by the test stand
My GT power tacho reported some 9200rpm .. ( 3 blade mode as it was a 3 blade prop )
So where is the discrepancy ? With one or the other or in between ?
I would suggest the read outs are close enough to make any data viable and usable .

The prop was not well balanced .
The test stand being metal , means quite a bit of vibration against a hard surface ( table top ) . ( yeah , balance the prop )
So this is all I have done ..
Mounted the motor , connect things up , and do a quick test run checking RPM ..
Next I will have to check that current draw reading .. ( And balance the prop )

AMPs Test :

I just checked , and the AMPs look to be good ..
So it looks like I can trust the current draw reported by the test stand ..
I threw a 4 blade on as it runs much smoother ..
So I can definitely do some RPM / Watt's / @ RPM range / Thrust - tests ....

So I guess I will have to do some thrust accuracy testing now ..

PART 2
Posted by old4570 | Oct 27, 2019 @ 04:53 PM | 1,681 Views


Maybe not quite that bad ( To hell and back ) ..
I cut down that 3025 and just had to see how it changed things ( 2725 ) , I mean I was getting more RPM .

Off I went , it was overcast and then the sun came out driving up the humidity !

By the the time I got to the football field it was fully humid ( This be bad for me ) and I was sweating ( more bad )
Sweat seems to attract flies , and I got me some half dozen or so once I started flying ( both hands on the Tx )

So there I was flying with half a dozen flies crawling over my face .. The stress was monumental ( I despise flies ) ...
I was forced to make two emergency landings ( power off crashes ) to swat the flies away as I could no longer stand it .
It was so bad my fingers were a quiver on the Tx as the flies crawled on my face .
Not being able to shoo them away was so gawd awful ..

Oh yeah , the 450x was undamaged , they be so light that once you cut power it's very hard to damage them . ( I really like that ) .
And the cut down prop , I don't know ? Was it the flies , or is the 450x actually flying faster ..
I will post a short video soon .

450x with a cut down prop (0 min 44 sec)


Once airborne , I cut the throttle back down bellow 50% , take off throttle is around 70%