markm75

I was going to purchase the CellPro 4s charger, which does have adapters for various non CellPro battery packs.. Like PolyQuest/thunderpro. They dont list DN as a type of battery they support (though the universal adapter may work as well).

I am finally building the twinstarII, which eventually will haul up a camera (with another 950mah 3s battery).. so initial weight might be 43 oz, then 48oz with camera (motor either ripmax xtra 2829/10 or Hacker A20-26M, leaning towards hacker, either motor choice (x2) pulling about 18 amps).

My thought at first was to go with a cheaper 2100mah battery pack (lighter 5.6-6 oz) then later on throw a 3200mah (9.2 oz) to give longer flights if it is needed (I should get 15 minutes out of a 2100-2500 pack, or so i think based on what I saw).

I was originally just going to go CellPro on batteries, but then I found some cheaper alternatives.

Any thoughts on the non cell pro ones or even some of the competitive ones that are about the same price:

CellPro CP03200-3S-N http://www.fmadirect.com/detail.htm?...213&section=69 $84.95 9.2oz 20C 3200mah;

CellPro CP02100-3S-N http://www.fmadirect.com/detail.htm?...210&section=69 $47.95 5.1oz ; 18C; 5.1oz; 2100mah;

PolyQuest (poly/rc) 3s 2500mah 12C http://www.cheapbatterypacks.com/mai...owlipos&sale=Y $28.95 6.18oz

PolyQuest (poly/rc) 3s 3100mah 12C http://www.cheapbatterypacks.com/mai...owlipos&sale=Y $29.95 7.23oz

**This $29 price seems amazing, too good to be true.. I was originally looking at 15C as the value that everyone said was good enough, so CellPro had the 18/20's at those prices which seemed decent, but these Polyquests at 12C should be sufficient too? (motors will probably pull a combined amp of about 18 amps max)

Others I've found as well:

GPMP0725 Great planes : http://www2.towerhobbies.com/cgi-bin...?&I=LXNYK8&P=7 $79 3200mah 15C, has deans plug already on it; 9.8oz

GPMP0721 Great Planes: http://www2.towerhobbies.com/cgi-bin...?&I=LXNYK6&P=7 $54.99 2100mah 15C ; 6.5oz;

Fullymaxhttp://www.bphobbies.com/view.asp?id=A3097705&pid=A3467965&img=l, 9.6oz weight $89 Fullymax 3300 3s lipo with his Bp-12’s. ($90) 15C one person getting 20 min flights?

DN 2150mah 3s 15C: http://www.xushobby.com/servlet/Cate...15C+Continuous (may not have a cellpro connector?)

So in short, the CellPros, to me, seem decently priced, though I'd like to really go with a 2500mah battery pack minimally, so that makes the PolyQuests attractive, even though their C is at 12C, or better yet, the 3100mah Polyquest.

Any thoughts on this, as I'm new to choosing the right Lipo here.

packyj

A lot of people are going towards HXT batteries from unitedhobbies.com... that is when they have them in stock. Much cheaper price and good track record from most of the people that have used them

twinturbostang

Here's my combo...

TwinStarII
(2) 400F motors (from either rc-dymond.com or justgofly.com)
(2) APC 6x4E props
(2) CC Thunderbird 18 ESC's
(2) ThunderPower 3S 2100 lipo's in parallel (4200mAh total)

AUW is 47oz w/ FPV video gear onboard. Performance? She goes vertical at full throttle and 43Amps total. Or can fly at 1/4-1/3 throttle for 1/2 hour easily.

markm75

I found your motor.. pretty cool.. only around $30 , just like the Xtra 2829/10's i just got (~1100 kv or so).

Curious.. you said the total watts are 43 amps combined? Each motor is rated at 15 max.. curious how this would be the case (Still kinda new to the upgrade world)..

The extras on my 8x4's should pull 19 amps total.

I may have to switch motors some day, if I dont like the performance.. your the first whose described vertical ability with camera equipment !

twinturbostang

The 400F's are 2250kV. They will spin a lot faster than the 2829/10. If you go with those motors, you'll probably need to run a larger prop, like a 7x5 or 8x6.

Yes, 21.5Amps per motor, and still ticking. You are correct, they are rated at 15Amps. You'll find that a lot of the quality components are underrated though. And in some cases you can push them past the manufacturers ratings. These motors seem to be great bargains. Very good quality and great performance, at a great price. Now, keep in mind, I don't run full throttle for long periods of time. Just a quick burst if I need to gain some speed or altitude quickly. And they have been living happily with no problems. As always though, your mileage may vary. BTW, I also have a 400DF in my AeroCat. It is rated at 20Amps, but I've pushed it to 33Amps!! [X(] I've never seen 13oz of foam move so fast! [>:]

It sure is a sight to see a big honkin TwinStar go straight up!

markm75

LOL.. Quite funny sounds cool.. though the purists out there would probably have a fit over it going so fast.. but then again.. I'm no purist

What camera gear (and battery) are you running on there? Any pics?

Hey.. I see your in Germantown, MD.. I used to live down there for 5 years.. till a few years ago, back in PA.. lived around Oak Mill apts down there.. Do you fly down at that rockville flying area? I always liked that one.. with the cement runway and all.

Cheers

twinturbostang

Check my user name. I live for speed, and MORE POWER!!

Actually, I don't have any pictures of the current configuration. I have moved components around a few times. I'll have to take some of the new setup. The breakdown of parts is...

KX131 380 line camera (KPC-S226)
Lawmate 2.4GHz 500mW transmitter and matching receiver
480mAh 2 cell Lipo (for powering camera and transmitter)
Dimension Engineering 5V regulator
Custom pan/tilt system for camera (HS81 for pan, HS55 for tilt)

Are you talking about CASA? That's the place off of Guide Drive in Rockville. Haven't been there yet, although a friend of mine is on the board of directors. I'm going to try to get out there sometime this year. There's also DC-RC which is just outside of Germantown. It's a nice field.

markm75

How do you like the 2.4ghz? Are you also using 2.4ghz radio control too? If so.. any issues with interference.. any issues with interference of other 2.4ghz stuff.. how bout range? I was going to go with the rangevideo 900mhz stuff, figured i'd get better range etc? How bout battery life on the lipo.. how long can you record for? Are you doing any goggles or gyro stuff as of yet..

Still a newbie on cam stuff so sorry for mass questions.. the 5v regulator.. is that what goes in the plane or what you use on the ground to power the video RX? You said your using 2S on the video TX.. is that enough volts.. At least the Tx's i was looking at .. they required 12 volts.. so I was thinking 3S 450-850mah 12-20C type packs for mine.. and for the ground about the same, though I still dont know how they all connect, specially the ground rx unit to the lipo pack.

I never got to check out the DC-RC, but yeah.. CASA.. I used to be a member there.. nice field too

twinturbostang

The 2.4GHz works really good so far. I am using standard 72MHz RC control right now. Trying to use the new 2.4GHz RC transmitters (like Spektrum) in conjunction with a 2.4GHz video transmitter can have issues, and is usually not recommended since both signals are trying to occupy the same frequency space. With my system, so far I have been out 1/2 mile away from myself with perfect video. I didn't go any farther than that because I ran out of space at that particular field. And I was also starting to get some very slight RC glitching. I have swapped to a different receiver now (Berg 7P) and am looking to try an push it farther. But so far, the video link was been rock stable at those ranges. That's with the standard 3dbi whip antenna on the transmitter, and a patch antenna (of approx. 8dbi) on the receiver.

900MHz may be coming back soon though. With the push for 2.4GHz RC control, people are looking to move their video systems back to 900MHz to avoid conflicts. I have seen a few people using the 900MHz stuff (www.rcdon.com) and it appears to work really good too. In theory, watt for watt, the lower frequency of 900MHz should give you more range. The RC link seems to be the limiting factor though, as my example showed.

My 480mAh pack should give 45 minutes or so of power, at just over 500mA current draw. However, since I am relying on the video link to fly with, I have never pushed the limits of the battery. Yes, I am using video goggles to fly with, and I have a head tracking system that I use with my pan/tilt.

Yes, the 5v reg goes on the plane. The video transmitter and camera I have are both 5V devices. There are 12V transmitters and cameras out there too (sounds like yours are). But in my case I need to regulate to 5V. And that's why the 2 cell lipo works perfect for this. For the ground station, which is all 12V stuff, I just power it directly from a 3 cell lipo. Works great! No regulator needed. Just make sure you use a pack with large enough capacity to keep the voltage up for a while (I use either a 2000 or 3100mAh pack). The amp draw of my devices is only around 1A. So that keeps the voltage up for a long time. Even if it drops to 11V though, you should still be fine. The video receivers usually have built in regulators anyways, so dropping the voltage to 11V shouldn't be a problem. You will want to test your system to make sure of course.

BTW, a buddy of mine has a 12V video transmitter and camera on his plane, and he powers them directly from a 3cell lipo onboard. Seems to work really well. Somewhere around 1000mAh capacity I think. He's got a TwinstarII also, so no problems with the added weight.

markm75

twinturbostang:

Since you have a ts2.. maybe you can help with my issues.. from another thread here is my issues/questions: Sorry to thread, as this is slightly off topic.


-----------------
I've seen this type of rule of thumb b4:


50 watts per lb = trainer/slow flyer
75-100 watts per lb = sport aerobatics
100-150 watts or more per lb = 3d


But I'm curious on my rough estimate of thrust I did with my TS2..

My twinstar 2 has xtra 2829/10 motors (rated at 9-12 amps operating range or 15 amps max) x 2. I'm using Tbird 18 amp ESCs (2 of them).. with the battery leads going into a Y cable of deans adapters which then goes into the female port on the battery (3s 3200mah 20C 9.2oz lipo).

Prop is 8x4e APC x 2.

I did a rough (bad lighting) rpm test in the basement and got 8222 on each prop ( i think this should be more like 10k).

I've seen stats on the total amp draw for this motor combo and it should be 19 amps/ 210 watts.

My crude thrust test, using a scale.. standing the plane on its nose.. zeroing it out.. came out to 43 oz or so (+-1oz). The weight of my plane is 43.9oz AUW (no paint/decals as of yet).

With this thrust value (ignoring watts/amps).. does it imply very good possible performance.. if so.. which of the 3 categories above would it fall.. ie: "Aerobatic"? I'm not yet ready to take it for a test flight due to some conflicting Astro readings.

I put deans on the Astro Super Whattmeter 101.. But I think i put the female/male ends on the wrong sides..

As a result I ended up plugging the LOAD side into the battery (lipo) and the SOURCE into the motor deans Y cable coming out. Some have said this shouldnt matter, that my values would be the same in either direction?

At any rate, I read 12.25 amps or 136 watts (this should be both motors combined), which seems very low. I've done the whole pre throttle full then back to low thing with the ESC.. the only thing I can think of is that maybe the source/load do matter somehow or the throttle at 100% is not really 100% (atv is at 100%).


Any thoughts on this issue as well?

Thanks for any assistance.

Danny.act

My Feedback: (9)

Interesting information and facts about Brushless tuning of the MPX TS II, different BL setups, select "construction" on side bar and scroll down for BL info, don't forget to take a look at the Video section also!
http://www.bungymania.com/twinstar2/index2.html

markm75

Nice site.. very nice indeed.

Side question for us ts2 owners.. I know this is offtopic .. but oh well ...

Anyone know where online I could find latches similar to the ones used in #39 on this link? http://www.wattflyer.com/forums/sho...?t=13518&page=2

I want to find alternative to either magnets or the default latches for the canopy..

I like this bolt and nut method better, specially if a cam is ontop

RickAvery

This one has two Hi-Maxx 2812-850s, CC 25 ESCs, 9X6, MAS counter rotating 3 blade props, steerable nose wheel and flies 10+ mins on a cheapo Hi-Model, (from RC Hot deals), 2200, 3cell, 20c Lipo. After 10+ mins of flight, the battery is barely warm. A rock solid flyer.
Rick

markm75

Whats your amps/wattage on a fully charged battery?

Any tips on how you did the gear.. IE: Where you bough them, how you attached them.. any sort of "plates" to prevent them from pushing up into the foam.. Steerable gear.. is this off the rudder servo or another servo? AUW?

Cheers

RickAvery

Markm75,
This is my Bro-in-laws' plane. I'm not sure of the watts/volts... Will try to get that info. Here are a couple of pics I took for another interested noes wheel steerer. What you can't see in the pics is an extention to the steering rod. A GWS prop adapter. Also not visible is the piece of thin plywood that the steering rod also passes through. This is to support the front to back/side to side loads on the steering rod. I think the size of the ply is something like 1.5" X 2", maybe 3/32" or 1/8" thickness. It;s taken some very hard nose heavy landings and even bent so far back that the wheel made a dent in the foam.
Rick

PS; Sorry for no pics. I live in a rural area with a satallite internet connection which is a bit unreliable at times & would not upload the pics. Will try again this evening.

markm75

I dont think I asked you this before.. but for your custom pan/tilt setup.. do you have any details on how you did this.. is that just standard plywood or balsa you used for the base board?

I was thinking of taking two servo's and somehow joining them together to give both pan/tilt with the camera.. but I'm not sure on this.

Initially I wont be doing First person flying, just video recordings.. but I want to get everything set ahead of time.

Do you think I should rig up the tilt/pan now, so I dont have to redo it later.. if just doing the camera.. would I want it pointed straight ahead or slightly downward (for static video recording, maybe trying FPV from a laptop at some point though).. What position is best to put the camera.. I originally was thinking somewhere on the Nose, but the canopy seems to be more popular..

Any tips on the whole gryo thing.. did you get your gyro and goggles as one unit (i'm not too familiar with gyros).. Do you need a gyro on both the plane and the goggles..

Eventually I was going to get a goggle setup like this.. with gryo built in : http://www.rc-tech.ch/web/index.php?...mid=26&lang=en

I'm assuming these goggles are good as well.

How are your goggles in sunlight.. do you need to shade them at all?

Thanks for any help

I'm almost ready to get the camera gear going

mtbrider

hi just ordered my Twistar II Reciever Ready model and was wondering if i can use my 3 cell 2100 lipo made by Align. anyone know if the stock esc and motor can take the battery?
thanks

markm75

I believe you can, except that without a "lipo" safe ESC, you run the risk of battery damage and other issues.

The lipo safe ESC's will auto cutoff (and warn you) when you get close.

The motor may also burn out after a few uses (maybe alot of uses though).

I switched my bird out completely from stock and run 3S 3200 MAH cellpro batteries.

mtbrider

alright, what battery would you reccomend for just starting out then? just a normal 8 cell 2000 nimh?

markm75

I'm not sure on the non-lipo batteries.. I haven't messed too much with them, except the ones I had in my zagi's (sold)...

Did your kit not come with batteries I take it?

markm75

Have you looked here:

http://www.hobby-lobby.com/twinstar2.htm

They list a battery option, which I believe is a good choice based on what I've seen, anyway.

mtbrider

yeah my kit didnt come with batteries, pretty much what i need to complete it is a reciever (ar6000) is what im probably gonna use, and Battery.

mrasmm

you could also try adding a lipo cut off to your system. Either of the first two would work, depending on what you want out of it. not a bad price over having to buy an ESC if it's worth alot of money
http://www.commonsenserc.com/index.php?cPath=32_40

mtbrider

alright so i put a new lipo compatible esc onto the multiplex twin motor unit, and i am getting no power to reciever or motor. any suggestions? ill try and get some pics soon
Thanks

Danny.act

My Feedback: (9)

mtbrider,

Things to check out:
-Is it a BEC (Battery eliminator circuit) type ESC ?
-Did You checked the settings on the ESC (correct battery type, etc...)?
-Check that the ESC is plugged in the correct channel on your receiver.
-It is possible that You have to reverse your throttle channel on the transmitter (usually the case with Futaba).

In any case:
-DO NOT change the plus or minus connections on the battery connection side of Your ESC !

What type and brand ESC did You installed?