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Old Jul 15, 2010, 09:31 PM
KF5LDN FPV Junkie!!!
Wizzard033's Avatar
United States, TX, Lubbock
Joined Nov 2009
1,738 Posts
Quote:
Originally Posted by sylifis View Post
Well, finally after waiting 5 weeks for the morning fog to stop, we got a perfect weather day today....80 deg. clear blue sky and no wind, a perfect day to maiden my TSII. The field is a large soccer field and they had even removed the soccer goals so the field was clear. I inserted the two 2350mah 3s lipo's and preflighted everything. With the landing gear down, a setting of 1/4 flaps and 3/4 throttle the 3-blade props made the 4.5lbs. plane leap off the grass in about 15'...(the counter rotating props made steering a non-event, it just tracked straight without the rudder or nose steering) then it literally zoomed to 500' and I had to throttle way back in order to trim it out. Even without power it was very stable. After doing several turns around the field I decided to practice some touch and go's with the landing gear. But, as I decended to about 60' it suddenly went into an uncontrollable death spiral and landed in a bush in a nearby nursery that adjoins the edge of the field. Unbelievably, the starboard motor had broken the motor mount and flew out of the nacelle causing the spiral. The motor and it's prop landed intact with half of the motor mount that had cracked in two. The wings remained on and "surprise" the wing tie down straps "did not break" however, the starboard wing has a 4" crack that will need to be glued back together. IMO the stock plastic motor mounts may be too flimsy for the upgraded power although I haven't seen any other recent reports of them breaking. I will have to think about a way to reinforce them.
Sorry to hear about your misfortunes. I myself had TWO bench incidents while testing my Rimfire motors with my Eagle Tree. Motor #1 detached cutting into the port wing and breaking the prop. Motor #2 detached and gashed the fuse just under the battery hatch, both due too the motor mounts not being secured to the nacelles well enough. I then took 1/8th" lite ply and glued it to the motor mount and inserted it into the wing to about the spar. I have had no trouble since with the attachment points and have logged up to and exceeding 800 watts with my power setup.
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Old Jul 16, 2010, 09:20 AM
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iceman77's Avatar
Mx
Joined Mar 2008
233 Posts
hello guys, i am looking for a "PNP FPV" platform do you think the RR version will be a good start? can the this version handle the extra 200 grs. all stock?
thanks for your advice,
Ice
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Old Jul 16, 2010, 09:35 AM
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sylifis's Avatar
So. Calif.
Joined Nov 2008
464 Posts
Thanks Wiz..I'm looking at several options, 1. fiberglassing the original mount, or 2. a total redo like Quigley, 3. your suggestion or 4. a combination of these...in retrospect I should have paid more attention to this aspect and I think I will also redo the other motor mount for insurance.

Iceman, IMO the airframe will definitely handle that extra amount of weight...mine ended up about one POUND heavier than most and I didn't see any negative handling characteristics....however, you may want to consider a brushless motor upgrade and for FPV you may want to add a FMA CPD or an inexpensive Hobby City gyro to help stablize it.
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Old Jul 16, 2010, 12:08 PM
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So. Calif.
Joined Nov 2008
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This is what I came up with for repairing the motor mount. I am using a 3cm piece of plywood that I will fiberglass and that will be placed into a very thin, light piece of tin to act as a retainer, and that has two wings to goop to the sides of the nacelles plus the bottom part of the original plastic mount to goop to the bottom....the tin piece weighs almost nothing and also acts as a heat sink for the motor, and it gives some extra retaining strength when attached to the sides....plus either a dowel or screw into each./
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Last edited by sylifis; Jul 18, 2010 at 11:32 AM.
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Old Jul 17, 2010, 01:21 PM
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Joined Dec 2009
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Twin Star on a 6.6v A123 Motor?

Hello All,
I am new to rc and want to check my naive theory by all of you first.

People are claiming great results on the twin star with 2200kv motors with 3s lipo. Are these results approachable with a 3700kv motor on a 2s 2p LifePO4 6.6v battery?

Thanks

JR
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Old Jul 17, 2010, 03:08 PM
Sussex, UK
RobinBennett's Avatar
Crawley, West Sussex, UK
Joined Jun 2004
7,372 Posts
I don't know if it's been tried, but it should work - twice the Kv and half the voltage.

IMHO you'd be better off aiming for a lower Kv though - the one's I've seen use motors around 1500Kv with 3s batteries and 8" props.

2200Kv @ 3s is a small fast prop, and the TwinStar is never going to be a racer. It's not like the EasyStar where a 6" prop is the largest you can fit.
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Last edited by RobinBennett; Jul 17, 2010 at 03:12 PM. Reason: Thought I was in an EasyStar thread for a while there...
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Old Jul 17, 2010, 03:19 PM
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Joined Dec 2009
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Thanks for the response.
I think your right. The long range twin stars will go as low as 1050kv e.g. R. Freh.

The 2200 kv'ers I am referring to are going for vertical and I am really only aiming for some modest lifting power without buying another battery when my A123 2s2P is just waiting to see some action with 6x4 props.
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Old Jul 17, 2010, 03:31 PM
Sussex, UK
RobinBennett's Avatar
Crawley, West Sussex, UK
Joined Jun 2004
7,372 Posts
Low Kv and big props would be better for vertical flight, small fast props are only for when you really need a high pitch speed.

Your batteries would probably work OK with the stock motors and slightly larger props than stock (such as a 6x4)
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Old Jul 17, 2010, 03:41 PM
Skint since 2000
ghost2212's Avatar
Reading, United Kingdom
Joined Oct 2008
1,497 Posts
Quote:
Originally Posted by jcrubino View Post
Thanks for the response.
I think your right. The long range twin stars will go as low as 1050kv e.g. R. Freh.

The 2200 kv'ers I am referring to are going for vertical and I am really only aiming for some modest lifting power without buying another battery when my A123 2s2P is just waiting to see some action with 6x4 props.
Also remember that when you are running at lower volts the power system will probably be less efficient as you will need more amps at a given wattage compared to on 3s for example.
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Old Jul 19, 2010, 01:38 PM
KF5LDN FPV Junkie!!!
Wizzard033's Avatar
United States, TX, Lubbock
Joined Nov 2009
1,738 Posts
Quote:
Originally Posted by sylifis View Post
This is what I came up with for repairing the motor mount. I am using a 3cm piece of plywood that I will fiberglass and that will be placed into a very thin, light piece of tin to act as a retainer, and that has two wings to goop to the sides of the nacelles plus the bottom part of the original plastic mount to goop to the bottom....the tin piece weighs almost nothing and also acts as a heat sink for the motor, and it gives some extra retaining strength when attached to the sides....plus either a dowel or screw into each./
Looks good sylifis the only thing different notably about mine is I added a flat peice of ply that fit horizontaly between the two "j" shaped extrutions at the very top of the mount then it extended into the wing to anchor it, I then secured it with a couple of small screws vertically through the ply and the mount.
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Old Jul 20, 2010, 09:28 AM
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sylifis's Avatar
So. Calif.
Joined Nov 2008
464 Posts
Sometimes we have to learn the hard way..you came up with a good solution...albeit some damage occured while you were bench testing as opposed to my lawn dart experience. I modified the 2nd mount and both motors are now gooped into place, I also noted a separation of the rudder that I fixed with some packing tape and a couple of hinges...can't believe we are totally fogged in again..need some good ole Texas weather. One question...have you experienced any of your control horns coming off or loose due to the extra weight?
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Last edited by sylifis; Jul 20, 2010 at 09:45 AM.
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Old Jul 20, 2010, 11:15 AM
KF5LDN FPV Junkie!!!
Wizzard033's Avatar
United States, TX, Lubbock
Joined Nov 2009
1,738 Posts
Quote:
Originally Posted by sylifis View Post
Sometimes we have to learn the hard way..you came up with a good solution...albeit some damage occured while you were bench testing as opposed to my lawn dart experience. I modified the 2nd mount and both motors are now gooped into place, I also noted a separation of the rudder that I fixed with some packing tape and a couple of hinges...can't believe we are totally fogged in again..need some good ole Texas weather. One question...have you experienced any of your control horns coming off or loose due to the extra weight?
It's been raining and windy here too. The wind is common here in the panhandle but not this time of year.

No detachment that I could attribute to the extra weight. I did however knock one loose in a hanger incident and i check them every flight now as the last time I almost over looked it in the pre-flight.
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Old Jul 27, 2010, 02:45 AM
So Cal FPV Aviator
EyeFlyPlanes's Avatar
USA, CA, Santa Clarita
Joined Feb 2008
3,575 Posts
Hey Guys,

Im looking for a motor that can get me up to 70mph, but will also give me nice low amp cruises. Any suggestions?

Im looking to stay in the $10-$30 range for motors.

Thanks.
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Old Jul 27, 2010, 03:28 AM
So Cal FPV Aviator
EyeFlyPlanes's Avatar
USA, CA, Santa Clarita
Joined Feb 2008
3,575 Posts
Yep I think I found it with this review...

Ronald Langfellner (%)

3 thumbs up!
Put 2 of them on my MPX Twinstar 2 and itīs absolutely overpowered )

Goes vertically until out of sight.

http://www.hobbycity.com/hobbyking/s...r_(Eq_AXi_2808)

I think I'll do an 8x6 prop, 3 cell lipo, and 40a esc.

Yes? Oh yes
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Old Jul 27, 2010, 05:26 AM
Sussex, UK
RobinBennett's Avatar
Crawley, West Sussex, UK
Joined Jun 2004
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Yup, they should do the job...
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