Stryker F-27C Motor Upgrade!

[Gabe]

I experienced the same thing with the stock setup. It's when I started using a different prop, motor, and servos that my issues surfaced. I must be closeto the 100 mph range.

[akent]

Or more than 100, maybe, Gabe!!

I just installed the new motor and ESC! WOW!
The thing torques the motor mount forward by quite a bit here on the bench! It's hard to believe the torque!
I still haven't put a wattmeter on there, but it has WAY more pull!

Oh, I bought a collet type prop adapter and also one with set screws from HC. The collet type vibrated like crazy! The set screw type is smooth as glass. It turns out the collet one is machined offset. Oh well. You win some and you lose some with the Chinese stuff... The motor shaft is 4mm, so is bigger than stock.







I can't wait to fly this thing now!
Kent

[akent]

Here's a video from this afternoon...
The thing is pretty fast!! Unlimited vertical at half throttle!

I nail it about 1:30 in...Wow!

[19000rpm]

That looks great Kent. I'm going to get that motor on my next HK order.

[Gabe]

Sounds great! I like the involuntary laugh around 1:30 when you punch it!

[19000rpm]

Apr 21, 2010 6:47:51 GMT -6 Gabe said:

Sounds great! I like the involuntary laugh around 1:30 when you punch it!

Don't we all giggle little, or LOL, when we do a neat maneuver? I know I do. ;D

[akent]

I can't help but do the little chuckles at times like that!
===
I received my radar gun today!
It's a Bushnell Velocity, good for 200mph!!!

It can capture a baseball, so it should be easy to catch a plane or heli!

Now I just need to either go to the field, or talk my wife into coming with me...

This thing was only 95 bucks with free shipping! It even has a carrying case with it. It feels really nice. The case is made of some kind of soft plastic. The LCD is huge!
Here is the one I bought:www.opticsplanet.net/buve10frups.html

[Gabe]

Sweet! Get a speed on that thing for us! I'm really dying to know how fast we are REALLY flying and how close we are to our own estimates.

[19000rpm]

That's going to be cool. No more guessing on speed.

[akent]

Just for fun, I downloaded and have been playing with the sound doppler software.
I was able to extract a wav file from the above video and then extract parts that were passes.

So far, the doppler stuff says I was going 112.6mph during the first pass away from me and then 118.9 on the return pass of the first pass after nailing it in that video. Later passes were slower.

I don't believe that yet, until I can prove it somehow, as you must put your mouse on the leading and trailing edge of the sound profiles. It's just too easy to be wrong.

Anyway, I hope to prove this wrong or right with the radar! I still can't believe this thing is so cheap. In the golden olden days, you could never even buy one of these! They were restricted and very expensive.

I went out tonight and just aimed it out the window of my truck, driving down the road. It was consistently reading 2mph slower than my truck speedo, which is consistent with what they do with our cars. They make the speedo read faster than you are going, which in turn makes the miles accumulate faster and makes the gas mileage seem higher, etc.

I looked at the radar with my spectrum analyzer to see if it could possibly interfere with at least our 2.4ghz radios. There is zero noise from it in that band, or anywhere that I can even see!!

It turns out that this radar unit operates in the K band! That's upwards to 40 GIGAhertz and is far beyond my measuring equipment. So no, it cannot affect your RC device, no matter it's operating frequency.

I have learned a lot from this device. I would really like to know how they can build a doppler transceiver in this high of a frequency band for under 100 bucks. That's amazing.
=It is built in China=
Kent

[19000rpm]

Good info.

[akent]

Well, not good info above from me!!!!
This Stryker is NOT a 100mph plane, yet!!! NOT EVEN CLOSE!

I flew it today in 30mph crosswind gusts. In a straight line with some wind help, the radar showed 82mph.
In the other direction, 78mph.
This was on the first run. Later runs barely hit 80, after the new prop.
The folks using the radar gun were at an angle to the runs, which would show a slower speed, but they were not that much off.
I looked again at the doppler stuff, and it is in KILOMETERS/HOUR!!! NOT MPH!!!

So that showed in the 70's with the new motor in that video!!

I know this new motor is spinning a lot faster than stock. It sounds a lot more raspy, too. Is that why it 'seems' faster?

I need to hook up the power meter, and take an rpm reading, too. I will try to do that in the next day or two.

Oh, and one of the 6x4 props came apart today, too. It split right down the middle. There was a horrible noise from the plane, so I landed it. It had a horrible vibration from that. Luckily I had a new prop.

I think this plane needs a LOT of power to go much faster, too.
I do now have a few other props to try.

And the radar gun is fun! I don't think it lies, either.

I really wonder how fast this thing was stock. It sure feels a lot faster now. I might have to reinstall the stock motor!
Kent

[19000rpm]

If you're using APC "E" props try the "Sport" props. The sport props are a lot stiffer and stronger. That would also translate in to better efficiency ='s more speed.

I think you'll need to radar the plane in a lot calmer conditions, at about 90 degrees, to the plane to get a very accurate number.

[Gabe]

Kent, I've read it takes 600watts to go 100mph. I had a feeling that the Stryker "felt" faster than it was. I would prop up if I were you before reinstalling the stock motor. Try an APC 6x5.5 and see how you like that. I was told I would gain about 10mph on that prop - and it felt about right.

I would also suggest trying a 4S 2200 30C battery. The Zippy fits under the hood without mods.

[akent]

Thanks all!
I will definitely try the 6x5.5 prop. I have a couple on the way, if I remember right. Thanks Gabe.
I have a large number of 3s batteries and the ones I am running in the Stryker are the same as I run in the 450. I hate to invest in a whole new series of battery. I think for now I'll stick with 3s.

The prop I was running is the Parkzone 6x4. These are not that stiff, either. I am running the APC 6x4E on the F-22, though. I have some other 6x4's on the way from HC. I don't remember the brand.

I made a few half throttle passes yesterday and the radar showed around 70. That's amazing. A huge amount of rpm more at WOT only netted another 10mph. Something is keeping is slow. Heck, it spun high enough to make the Parkzone prop come apart!

If I can hit 90 with this thing, I'll be happy with this one. Oh, and the motor comes down cool. I think there is room to push it harder for sure.
Kent