chippedprop

I'm still thinking the attachment of the canopy etc. system I want to use. I have a picture in my mind ... now I just need to match it up to the real world. I'm also thinking about the super strong magnets. I'm a little concerned that they will come loose with the flex of the soda bottle canopy on every day use. With the balsa blocks they wear out too, even after I harden them with thin CA.

Plus if/when I crash the canopy acts like an extra seat belt to slow the battery down as it ejects. Last crash it stayed in I think. Gryphon was there.

I may have to schedule a trip to the LHS to explore diff. anchor points. I wonder if any car stuff would work.....Hmmm!!!
Cp

chippedprop

itzobi

I would go with the 82 mg. They will last a life time. I like mopar have reused them so many times...I have lost count. They are pricey but they will last for years.
Cp

critterhunter

My best guess is also that your pack has been drained down a bit below 9V, which is the recommended cutoff voltage to protect a lipo. If it wasn't drained too much lower the pack can probably be recovered, but the sooner you do this the better it will be on the pack. Many lipo chargers has a "forced" charging mode in which it will attempt to bring the pack back up to 9V or higher by charging it a little with a low amp rate.

I've drained a few packs below 9V before and used a nimh or nicad charger to juice the pack up to 9V so my lipo charger would accept it. NOTE: This is VERY risky so do so in the middle of your driveway or somewhere where you won't risk a fire. Wear goggles and gloves when you get near it. Set your charger to a mild .1 to .3 amps or so and only charge the pack for a few minutes. Remove the pack and see if the lipo charger will not accept it. If not, place it back onto the other charger for another minute or two. It would help to have a volt meter so you can check the pack's voltage. If it's say 8V or higher then you have a good chance of recovering it. The lower the voltage the less chance of saving it. Again, BE VERY careful. Also, even if you think the pack is fine make sure you store it in a metal box somewhere where it won't cause a fire should it go nuclear.

Don't forget to double check that your ESC is set to properly cut off the motor at 9V for a 3 cell lipo to avoid future problems.

critterhunter

I think Cadetman, one of the original Lords of The Dark Side, now prefers the HS65 for his Stryker builds. I seem to remember him saying that a while back. I still like the HS81 (now called the HS82) for several reasons, one of which being that it fits snug inside the servo chamber and only requires tape being placed over the body to install it. If a servo seems loose I'll snug it in with some double sided tape. When using smaller servos I'll tape the body of the servo and put a little Gorilla glue on the bottom (well away from the horn side). It will foam up around the bottom and sides of the servo to provide a snug custom chamber. If I need to remove the servo for service I only need to slit the masking tape and pry the servo out of it.

critterhunter

I've made a custom canopy for a streamlined Stryker using a trimmed down Parkzone P51 canopy. This material is similar to bottle plastic. When gluing magnets to it I found that Epoxy won't stick well even if I roughen up the plastic with sandpaper. I found that Shoe Goo (a rubberized glue used to repair shoes and such) sticks well and holds the magnets to the canopy without problems. In fact, I tend to like it for the stock Stryker canopy to hold magnets to it as some times Epoxy won't hold well.

jumper666

Yes, be careful when working with batteries.

Post #3603: http://www.rcgroups.com/forums/showt...2#post11764622

sirpa

Hi

I am back again on the Stryker planet with my Medusa 28-56-1400 that finally arrived. I use a cheap suppo 100 A ESC with it . By the way Gryphon it's only 39 mm wide so it fits perfectly in the plane. I use two cheapo 3S-2450-25C mystery batteries in series to get one big 6 cells battery. Here are some static datas with APC props.

6x5.5 : 50 A -1088 W -21.7 V

6.5x5 : 50.7 A - 1100 W -21.71 V

6.5x6 : 58.9 A -1246 W -21.17 V

I didn't dare to try any bigger props cause the motor was scary enough like that and my batteries are rated for 62 A max only.
My packs were full so thoses datas are a bit too high compare to real flight.

Moparmyway you were quite right about the noise of thoses motors : Really LOUD and scary . I thought my Medusa 28-40-2500 was loud but that was nothing compare to that monster which really SCREAMS !!!

So very happy and confident I went to the field to test that new motor .

First flight was a fiasco . The plane had still same trims like before with the Medusa 28-40-2500 used on big 3S . The motor had too much down trust and the plane just went to the dirt at launch. Motor mount broke at the base . That kind of mount is probably to weak for so much power :

http://www.hobbycity.com/hobbycity/s...ck_/_3g_weight

I changed the mount for a new one of same kind then corrected the downthrust and made a new attempt with a 6.5x5 for a start.
It flew this time , the plane had a lot of power but didn't go very fast to my mind . It rolls to the left when I apply full throttle . Probably some torque effect due to the fact that my motor mount is offline a few degrees to the right .

I couldn't enjoy the flight because my servos were not working properly . Actually they were for an unknown reason very weak and The plane was reacting to input controls very slowly . Thoses cheap MG from HC were working fine before with the Medusa 28-40-2500 on 3S at 760 W of power.
Maybe the BEC rated for 6S has a problem and doen't deliver 5V ? Need to change the servos and test all that before next flight.

Now the real problem came when I plugged that dean connectors from the batteries to the ESC with that adapter:

http://www.hobbycity.com/hobbycity/s...ries_Pack_lead

A huge fire ball melted the cupper in the ESC 's dean. That was a giant shortcut !!
I don't know why ? Maybe I shouldn't use deans for high power setups . I thought they could handle 80A but this is maybe not true on 6S.
The last cell of the two batteries died with the short . Too bad they were my only ones and I need to get some before I dare to try again.
I was amazed before by the big sparkle that came each time I connected the ESC to the batteries .
Do I need some 5.5 mm bullet connectors . or maybe 4 mm could be enough ?

Too many problems right now but I keep believing in that setup and when it's gonna fly it should be a blast !!!

moparmyway

Sirpa, Whats up dude??
OK, first suggestion....................get rid of deans right now. I run Castle 6.5mm bullets, but their 6mm ones would do you some justice!!!
Second suggestion.....................No spark, no fly............but you can reduce spark by 1 ohm 10 watt resistor.......PM me for details if you want
Third suggestion.........................HS85MG's needed- all of that raw power on 6s is probably making those servos you have stall!!!!
Fourth suggestion.........................Earplugs needed unless you use a bungee launcher.............Then you will want to hear the wind rush over the wings and motor (awsome noise)

(EDIT: Run 6.5x6.5 prop and then try larger. You have 100 amp ESC..............USE it!!!)(make sure you have Medusa "BIG momma" heatsink!!)
__________________________________________________ _______

To all,
My very humble advice on servos:
HS65MG....................very capable servo, works very well for Strykers under 130mph that weigh around 3 pounds or less
HS85MG....................BEST servo for 130+ mph, or heavier Strykers

Both these servos have metal gears and have bearings at output shaft, reducing shaft wobble to allmost zero. This virtually ELIMINATES any play on the elevons!!! HUGE factor for FAST flying!!!!!!!!!

HS82's......................do NOT have output shaft bearing, and wobble unless you take measures to stop it (like installing greased "O" ring under servo arm, which will SLOW down servo travel time and INCREASE servo draw.)

I tested the HS85's against the HS82's (with greased "O" ring installed) and the 85 were quicker and took less current to move!!!!!
The 65's have been bulletproof and are lightweight to boot!! They have held up phenominally to the abuse I dish out to them!!!!!!

Again, this is just my peabrain testing and advice. Its what I do for my stuff!!!

moparmyway

Sirpa,
Above readings should have....................
6x5.5 prop..............112mph
6.5x5 prop..............110mph
6.5x6 prop..............125mph

moparmyway

Mr. King Paul, Sir.............

I believe that Brazman has the fastest stryker on video right now...........BUT, if Eagletree is correct, then once my video has doppler confirmation, and I post it...........I will own the tempory "claim" on having the "Fastest prop Stryker"..........(PS mine is ONLY a 28mm motor in the stock mount)

I say temporary because I know Brazman is currently building something fast, that Aussie never rests!!!!!
AND, I am POSITIVE that there are a few "BIG" builds coming down the pike[sm=lol.gif][sm=tongue_smile.gif][sm=wink_smile.gif]
Here is one of them.....................
(edit..........YES, it is a CC180!!)

jumper666

I am curious. What is the current speed record for a prop driven Stryker?

Gryphon

jumper666,

Current speed record is whatever Brazman and Moparmyway say they are flying at.

Both are stand up guys who only want the facts. I've been in contact with them both extensively. I know they are the type that would rather round down versus round up when it comes to that topic.

They are more than capable to show video and Doppler as their proof for the nay Sayers....and the doubters (is that a word???)


_________________________________________

Folks,

For people wondering about the number of wires in the connectors (see above pic). CC 180A ESCs have 2 fat red wires that go to the same connector, and they have 2 fat black wires that go to the other connector.

So you may ask what that third wire on each connectors is for......... it is for easy removal of UBEC....and whatever else a person can imagine.

http://www.castlecreations.com/produ...oenix-180.html


Gryphon

moparmyway

The current speed record is Brazman at 140..............his video has been dopplered close enough to say it!!!

Mine has gone over that, BUT Eagletree is no doppler, and there are rumors (which might be true) out there saying that Eagletree airspeed and GPS arent that accurate, so I MUST get mine video'd so it can be dopplered. Whatever the doppler says is what it will be!!! If Eagletree is not correct, then I am no record holder right now, but if Eagletree is correct, then I am going over 145 (thats conservative, but it is safe to say!!)

__________________________________________________ ______________________

Yo Big Daddy-O,
Hows your build going??
got any pictures?
I have seen some prop strikes around forums lately, and my 4 pounder couldnt be hand launched anymore, so I got a zip-start (bungee) from hosemonster..............WOW, what an awsome way to get flying!!!! So long as youre carefull about the transmitter, zero chance of whacking off some finger, or getting a slice job! Awsome noise as the plane gets going and the prop starts spinning before you power up!!!!! VERY SMOOTHE!!!!

__________________________________________________ ______________________

I give all credit to Gryphon for the third wire, his war-gaming is what spawned the idea, and I also use it for a 1 ohm (10 watt) resistor to connect to with alligator clips as a jumper to virtually eliminate the HUGE spark that the 125 or the 180 (The 180 is a GARGANTUAN ZAP/CRACK) gives off when connecting to any cell. The larger the cell count, the larger the spark!!!!!

Brazman

Nice work Moparmyway. My build is very slow at the moment but I'll get there. I'm not sure I'll be able to bungee at the club field but I will find out. I don't doubt that the eagletree is fairly accurate it's just difficult to use it to convince everybody that you did it unless you back it up with video.

Hayabusas

Moparmayway:

I got the eagletree gps unit to see what speed i could get but after a reading of 280km/h + i ripped it out of the plane and put it in my drawer...... if there is anybody else using it lets compare data and find out whats wrong.
It would be grate to compare data from gps and doppler, ie the movie used for doppler should be of a flight using gps.....and then compare data.


Gryphon: Have you heard a song going like this; don't worry, be happy!!

Dc2LightTech

with the sound recoreded for the doppler, how do you measure the speed? do you measure the frequncy and calculate, or do you have a program?

Brazman

You use a program that measure the shift in frequency (doppler shift) as the aircraft passes.

Dc2LightTech

Can I get a copy?

Hayabusas

BRAZMAN:

Can you describe how a doppler measurment is done, how accurate is it?

Dc2LightTech

its like ,speed of sound*(f1-f2)/(f1+f2)=speed of plane, f1=high freq, f2 = low freq but you still have to measure the freq. (its been a few years that i had physics

moparmyway

Yeah, youre absolutely correct on this one!!
Thats why I used the Eagletree for testing (both airspeed and GPS) and tried to get video today, just way too windy!!!
I will have that video soon enough, and have a few Strykers that fly fast, so I will only launch the Nemesis when I am warmed up from some other fast flights!!!

I am also POSITIVE that this record (if it is one) WILL be SHATTERED soon enough, so I wont bask in the glory too much now!!!

(edit) will try for video a few times before Monday............................we will see!!!!!
Left wing area on Punkin (Orange one) where paint is gone is where airspeed pitot tube sat glued and taped, GPS and Eagletree 150a unit sat taped to canopy. (good luck fitting in plane) Everything was removed for max speed runs and doppler video.
Nemesis (red one) is MUCH faster, and only had Eagletree and GPS (no airspeed pitot tube)!!!

moparmyway

OK, I dont seem to have any huge error(s) in my readings, I know very well what 135 feels like, and that was radar confirmed several times. The Nemesis is way faster, so it looks like my Eagletree is close..............I will have both to compare to soon enough!!!!!

Send me PM with eagletree file if you want me to look it over??!!

Gryphon

moparmyway,

With retention of air brakes and more efficient use of space under the hatches and elsewhere, all the parts can fit......because I did it. (My receivers were out on the wing too).

And my battery bay was carved out for a tight fit of 6S-5000 but held 5S-5000.

But it took ridiculous amount of thinking and planning....hell, I even managed to keep the whole length of CC125A wire...but never again.

As we talked about before, in future I will always chop the ESC wires to make my life easier....we can always add on some wire for future projects. We can do those ourselves.

Recently I noticed there is a service that Castle Creations provides:...replacing wires (at a small cost).

I need to PM you the pics of my first experience with use of Gorilla glue. Came out o.k. when I used the white (faster drying) stuff to replace my stock rods with C.F. tube.
I held down the C.F. for almost 15 minutes. Thank you for the pointers.

The 3 C.F. strips on the very rear got 30 minute epoxy as usual.

I've been taking a lot of pics for the last month……… from the various things.
I'll share those after I finish this 2nd build in a row (2 more weeks).

Tomorrow my brother will be getting pointers from me on the free/new/never used Eagle Tree V2 that I gave him along with the expander/brushless RPM sensor….He’ll try it on his MEGA 16/25/3 1700KV TP 4S/5S 3300 25C Stryker and His HELI 450 and 500 (both run on 6S I believe).


Gryphon

Mr. Mugen

Shoot man 140 is the record? I will set out to break it soon. Hell I saw 138mph and wasn't even into it yet....some will argue it was in a dive (a dive from 10 foot off the deck?!) Anyway glad to see you all are pushing the limits! I plan to push harder this summer. WInter has all but passed and now it is time for some summer fun. So to make good proof what do I need other than my eagletree and a camera?

Kevin

Strykerstriker

Its a sad day[]

It started out fine with a mild breeze and good flying conditions so i loaded up "Speeddriven" my 16/25/3 with (5s 2400mah battery and graupner speed 6,5x6,5) all the eagletree stuff i got and up and away it went.

Used the first couple of rounds to check trim, and the flew as far away as i dared, turned around and opend up.......as the speed picked up the tourqe tried to roll but im used to that and was in full controll until.............. suddenly it just rolled over and went WOT into the ground..... alltitude was low so no time to react..

Later i found that the stock clevises on one of the elevons had snapped of......damn stock things, the whole fuse was a stock C body.

5S lipo is wrecked, shaft on my mega 16/25/3 is broken of[:-], recivier is smashed..... rest of equipment is ok,,,

Eagletree shows 960w, 57amp. NO gps signal so i did not get a speedsignal..DAMN

I just cant belive that the shaft just snapped of..... guess its gonna be another moneytransfer to MEGA now.

Well,,, nothing to cry over, as last night i closed the last deal to get my new stryker up and running,,,, then i will get som gps speed,,,,, and its gonna be HIGH

Will try to upload some crash pics later.