hornetnz

Hey, could anyone answer my lipo questions up the page? Would be greatly appreciated!

chippedprop

Hornetnz

Sorry i did not respond to you sooner. work work work 14 hrs days.

Ok
You're running an out runner.
1-I need to know what brand
2-I need to know what size
3-What size prop are you running with current set up

Lipo batterys are really not dangerous unless you........

damage by crashing
over charge
over amp....... REALLY over amp
draw pack voltage down under mfg. rec. levels

If you follow the guide lines, most batteries come with these, you'll most likely never have a issue.

I would suggest a balancer.
I'll send you a PM about that.

Once I get the info about your motor I'll be able to steer you into the right direction on ESC
Cp

itzobi

My Feedback: (3)

I dont want to try and replace the pushrods, only the stock Clevises, I tried buying some 2-56, but the diameter is too large, any ideas?

moparmyway

Itzobi,
Only thing I can reccomend is to replace pushrods with 2-56, stock ones will deflect / bend on you sooner or later and your plane will want to eat dirt/grass/rocks.
Sorry its not what you want to hear, but thats how my 2 cents works out

Anyone else want to weigh in??

itzobi

My Feedback: (3)

gotcha, I found an older post by Gryphon with precise instructions on exactly how to do so. So I will buy the stuff piece by piece, looks like the most expensive thing is the Z bending pliers. Thanks for the input!

moparmyway

Itzobi,
You are well on your way in the spiral into total darkness.................welcome [>:][>:][>:][>:][>:]

Flightops_69

hehe, "...the force is strong in this one"

Itzobi, what page did you find the instructions for the push-rods? Need some of that info myself.

Gryph, I'm about to put a 7*4 APC prop on my bird. (ARC 28-47-2; 4S 20C 2350khv; 60amp ESC) Was wondering what amps I can expect to pull, and what to expect before take off? Thanks for your help! (am I in the dark side yet or did I just come out the other side?)

Gryphon

I guess I have some catching up to do. I will try to do some replies tonight.

Here are a couple of quick ones for latest posts:


itzobi,
You can just get (2) solder on clevises for the non threaded ends of the rods (servo arm end).

So that makes (2) threaded clevises and (2) solder on Clevises...and no "Z" bend pliers will be needed. Of course everything should be 2-56 size to match the (2) 12" 2-56 size rods (threaded on one end, cutoff extra length of rod…measure accurately).
Make sure to keep all holes nice and tight.
If you drill to exact size, very possibly there will be some play.
Enlarge any holes to a little under the required size and work the clevises through to keep everything nice and snug to avoid slop.

_______________

Flighttop,

I’ll send you an IM with AMPs.
I believe you’ll be in the low 80’s MPH speed in level flight and no wind. Motor is slightly over amped but it will soon unload amps and I would not really be worried about motor. Enjoy the colder winter temps. )…..WARP factor 7 during climbing….LOL…

You should be able to get similar climbing(90-95%) and waste less in motor with 6.5X4.0 for same top speeds.
Aeronaut makes electric prop in that size and a pair of them are sold together for fairly cheap.
Either prop will unload to low amps and you should have fairly good flight duration in level flight at high speed…climbing will spike the amps back up (for great climbing).

I would run APC Pylon 6.5X5.0 for pretty good climbing and high speed…check battery temps as you gradually extend full throttle duration on each subsequent flight.
After 6.5X5.0, then ponder any additional pitch like 6.5"X5.5� for possible 3 MPH higher speeds if so desired.
6.5X6.0 does not look favorable.


Gryphon

Flightops_69

Thanks for the info Gryph! I couldnt wait though, and flew her before dinner. Can I just say, her climbing is literally out of this world!! I did notice a significant decrease in battery time though, and after reading your post I can see why! Think I'll shave down a prop to get the right specs!

Gryphon

hornetnz,

Tell Chippedprop, if your ESC is Lipo compatible.
That means if your Low Voltage Cutoff (LVC) is compatible with lipoly requirements. So for 3S (3V cutoff per cell), you need to have a setting for 9V cutoff. And its max voltage needs to be adequate for 3S lipoly.

Post link to the ESC or manual so Chippedprop can help you quicker and easier.
Tell him what prop you are using and any AMP readings that you may have taken.

_________

Here is some off the hip wild guess work: I don’t believe I’ve heard more than 85 MPH for that motor…and those might have been wild guesses by some folks.
Assuming 85 MPH…let’s compare the power it needs to 100 MPH.
85MPH / 100MPH = 0.85 new speed is 0.85 times the reference 100 MPH speed(which needs 600W).
0.85 X 0.85 X 0.85 = 0.614 times the power is needed.
0.614 X 600W = 368W , (Now let’s assume 10.5V under load)
368W / 10.5V = 35A My wild guess is that this is the most AMPs you will need.
3S-2100 20C should be plenty….or 3S-2500 15C for longer flight duration if you like.


If your ESC is 3S Lipoly compatible I would try keeping it for a while till you get some AMP readings.

Same prop that you ran on 8 cell NiMh/NiCd will now draw more AMPs on 3S lipoly due to higher voltage. Not that you are trying to keep same amps or anything, but if you did want to flow the same amps, then you must reduce prop size a little as compared to whatever you are using now.

I think you should stick with this ESC if it is lipoly compatible and save your money for a complete upgrade later on if you decide to get a large power increase.
For 75-80 MPH, 30A ESCs should be plenty as long as it is 3S lipoly compatible….consider increasing air to the ESC and away from the ESC by opening up the side air vents and modifying the very rear slots on the rear cover.


The guys on the thread will help answer your other questions.

***Use Yahoo and Google search engines to get prop data for that motor. I have seen a few test results on it, and even a table of data...not sure where it was, so start looking if you don't have a wattmeter or if you want an idea before a battery purchase.

__________________________________________________ _

Flightops_69, sirpa, and moparmyway are set.


sirpa,

Thanks for the detailed write up, I realize the extra effort that it took.

__________________________________________________

jonwhatley,

That beach in the video has been my backyard for 30 years.....I know it so well. The frontage roads inclines at the end of the beach and there is a GREAT restaurant there. Been there few times even one Valentine day....that water is so cold and it is usually windy there. Be careful with getting sand in that motor.

Awesome video...please keep them coming....Stinson beach next????? and don't claim you took a wrong turn if you get to a nude beach on the way.
Make sure the brakes on your car work well.

__________________________________________________ _

alros100,

Getting sleepy, I'll try to answer tomorrow. I worked on it once before and lost my write up.


Gryphon

dodongtisoy

This stuff gets addicting. I found this forum a few months ago, and I cannot stop reading it. After seeing some of the possiblities with the Stryker, I followed some advice from the forum and have built a new fuse with CF rods and Balsa elevons. While at the LHS the salesman talked me into the six series eflite 2700 kv motor. I purchased this a long time ago, but wish I could get the Mega, seems to be the motor of choice for high speeds. I will eventually build another with a faster motor, but am wondering what my best prop choice will be for max speed and climbing ability. The set up so far will be the 2700 kv six series, 2200 mA 25c TP battery, and a 40 Amp Eflte ESC...having never flown a set up with this ESC and motor, what kind of speed can I expect? And what will be the best prop to use? I have read so many threads that I'm having a hard time knowing where to go back for this info. Thank you all for your brilliance and sharing your knowledge of the Stryker. It was my first plane and I love it. Currently have two, working on building #3...thanks for your help.

Dodongtisoy

moparmyway

dodongtisoy,
APC 6x4 will pull around 47-48a static and unload to about 38a in the air (level flight) since your TP battery is the X-Treme V2 25c. Climbing will increase the current draw, so keep that to short durations (less than 20 seconds).

BEST thing you can do for now is to increase the cooling to your ESC by covering first 5 or 6 holes of rear cover with 3M X-Treme tape (basically cover every hole up to ESC) and opening or enlarging the next 3 slots just after ESC, then cut off everything after that. Also cut the floor of the front opening to make it look more teardrop. The larger front opening will get in alot more air to cool battery and ESC, and the rear cover mods will allow that air out. Remember you want air to pass over your ESC (which should be laying flat with finns up) and exit AFTER it passes it.

Pitch speed on 6x4 will be about 88mph at 23,300rpm at 10.2v......................just under 80mph level flight

APC 6x5.5 will not unload as much (pulls about 45a level flight), and if you modify rear cover to cool ESC, you should find it faster by about 10 mph or so, but battery and ESC will want to heat up on you.

BEST prop will be AFTER you get a larger mAH battery and larger ESC (your ESC is close to its limit also)........................you will need to answer some very specific questions that elders will have for you, I dont consider myself in their realm, I am just a peon, but I do have inflight data on this motor and know its limits very well.

APC 6x5.5 is at your limit for your battery and ESC (your ESC and battery will be heating up). The motor can take alot more, but best prop question can be aswered after your Q and A session is over.
Questions to think about are along the lines of future wants/needs and budget. You will want to purchase smartly

Good luck

Richard39

My Feedback: (14)

Good morning.... I have recently tried to boost the performance on my F-27 A with a three cell lipo , 2100, and it worked for two flights... now it does not have enough power to fly... what have I done to this stock Stryker....? What do I need to do to correct?

At this time I am looking for the performance of a stock B model with lipo....

hornetnz

Gryph, I sent him a pm...but fyi im using a BP 30a esc that is programmable with a aeronuts 2409-12t motor, 7x6sf apc prop. I'm guessing I will need a bigger esc when I goto lipo. Would it be worthwhile to upgrade motor as well? Im not looking for 100mph, just slightly more speed and more vertical than im getting with nimh packs.

Flightops_69

Had my best in-flight crash today, was even better then when I "smoked" my stock motor. I was playing around with the new 7*4 prop at very high altitudes, and decided to do some extreme aerobatics at high altitude (just in case something "bad" happens) hehe, well, right after I came out of a loop at full throttle, my plane looked like it shook, I heard the motor rpm increase suddenly, and then watched both vertical stabs go flying off along with my prop. (didnt know that till it landed) plane went into an immediate flat spin and it took over a minute for her to get to the ground. The flat spin saved her. the only damage was 2 balsa wood stabs sheered off, and a lost prop and prop adapter, oh and one of my pull rods came off the servo. All easy fixes, but dang, it looked pretty cool when it happened!!

Wayne Miller

Hi,

I just saw a post where they put a jet on a small foamy and I thought you might be interested. Here is the link: http://www.rccanada.ca/rccforum/showthread.php?t=81965

Fly4Fun,

Wayne

visioneer_one

My Feedback: (506)

Flutter.

Best check over the airframe and your linkages - look for servo gear slop, loose or busted aileron hinges, etc. Also a good idea to check for cracked or loose CF spars, especially if you've glued them in with epoxy. (foam flexes, epoxy doesn't.)

visioneer_one

My Feedback: (506)

'A' model? With the brushed motor?

moparmyway

Flightops_69,
What prop adapter were you using, and how did you tighten it?

__________________________________________________ ______

Wayne Miller,
Now thats something new to me, what are they feeding ye-all up there????

I am not sure if I remember weather or not if you were going to hit your motor with 4s...................have you tried it yet?

Wayne Miller

Hi moparmyway,

I haven't tried the motor with 4S mainly because I haven't been flying. The cold and snow has come and it looks like it is here to stay. Once it warms up a little and we lose a little snow I should be flying again.

Hope all is well with you.

Fly4Fun,

Wayne

moparmyway

Wayne Miller,
Its cold here also, but probably no where near as cold as you. I flew Stryk 1 (see post 1865, on page 75) in the beginning of week, it was 27f out and 15mph winds, she is very fast. I am very leary about flying in snow with my Strykers, high dollar setups and dont want any problems, but I did fly my other aircraft with my kids in Sundays snowstorm, had to land before snow accumulated on my runway, so it was a short flight, very fun though. Let me know when you try, OK?
Later

Richard39

My Feedback: (14)

... Yes, I believe that is the brushed motor..... The A and the B model F-27 used the same motor but the B model could be flown with Lipo and the A model was set up for 900 Mah battery... Is that true? a friend is flying the B model with lipo and I just had to try... What parts may I have hurt with the lipo?

chippedprop

Richard39

It sounds to me as to have pulled the voltage below the mfg, ratings in the lipo.
Lipos HAVE to have used with the correct ESC as to not pull the cells below 3.0 volts. I guessing your lipo is toast. Once you run them flat it screws up the chemistry in the battery cells
The web page below is a example of a simple fix
I just googled low voltage cut off lipo and it came up. You can shop around to find the same thing

Look for low voltage cut off for lipo
http://www.espritmodel.com/index.asp...OD&ProdID=4383

So a lesson learned. Ask here before it bites you in the rear!!!
Cp

Richard39

My Feedback: (14)

The lipo battery still has power.... but I am not sure how much until I do some testing....I checked the webpage and saw the low voltage cut off... did not realize that something like that was available... thanks..

For Now I am concerned that I may have damaged the motor or the ESC... does anyone have a thought on that?

Mr. Mugen

I doubt you ruined either the motor or esc, but it is possible. How many volts does your pack have right now? If below 9 then you have possibley damaged the pack. Take a different battery (makes no difference what the cell make up is, as long as it is under 12v) and hook up the motor direct for a second to see if the motor works. It will want to lunge forward so have the plane blocked so it can't travel toward your hand. If that proves god then plug your esc back in and try another pack. If that proves good then your battery is shot. Do you have a buddy with a battery to try? Or a lhs? They will allow you to test it I am sure (while crossing their fingers hoping it works so they can sell you a new one)......

Kevin

PS....If all else fails....build a super stryker..