Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Dec 02, 2012, 01:45 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
Dan ,

Is there any place nearby where you can fly indoors ? A gym , church sanctuary or social hall , community center multipurpose room , skating rink , etc. If the weather prevents you from flying outdoors ( where I live it rains a LOT! ) , you could get ( or make ) yourself a micro to fly indoors .

Here's a good one to make : http://www.rcgroups.com/forums/showt...ighlight=j+bug

Here's another RTF for $70 : http://www.hobby-lobby.com/micro_sti...ueryId=4058795

Al
balsa or carbon is offline Find More Posts by balsa or carbon
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 02, 2012, 02:42 PM
Registered User
Dan_D's Avatar
United States, OH, Amesville
Joined Nov 2012
149 Posts
Quote:
Originally Posted by balsa or carbon View Post
Dan ,

Is there any place nearby where you can fly indoors ? A gym , church sanctuary or social hall , community center multipurpose room , skating rink , etc. If the weather prevents you from flying outdoors ( where I live it rains a LOT! ) , you could get ( or make ) yourself a micro to fly indoors .

Al
If it's only raining I could go down to the fire station and drive the trucks out and use the bay... 60 feet by 60 feet with a 20' ceiling. However, when it's below freezing I can't do that... The water in the pipes freeze unless you do a lot of precautionary stuff. It's heck when it's -20 F and we have to go fight a fire because somebody didn't clean their wood stove chimney in the fall. Not only do we have to cope with freezing fingers and stuff, we also have to worry about the water freezing on the truck and in the hoses, AND any water you spray on the fire might end up turning to slick ice on the walks and porch, etc...
Dan_D is offline Find More Posts by Dan_D
Reply With Quote
Old Dec 02, 2012, 03:01 PM
Registered User
Dan_D's Avatar
United States, OH, Amesville
Joined Nov 2012
149 Posts
More thoughts on MEGA SUE

Well, I was looking through the catalogs for cheap servos that don't weigh much and have lots of torque... and look, it's the holy grail right next to it !!!!

I was looking at the specs for the 9 gram servos I've been using (1.7 kg/cm) and then I looked at 14, 18, etc gram servos. It sorta surprised me that the 18 grams had LESS than 2x the torque of the 9 gram servos. Then it struck me ... why not use TWO 9 gram servos...

Of course objections flooded into my mind - two inexpensive servos wouldn't necessarily have the same response, so that one might want to turn 64 degrees and the other might want to turn 61 degrees and they'd fight each other, until somebody gave up. SO, we need a compliant linkage. I thought of a number of different ones, and then I thought "Ackerman" and so I did some back of the Excel calcs... (shown below, but eminently ignorable).

The idea behind this spread sheet is to put two servos side by side 10 cm apart, hook them with a Y connector, and then put a T-bar between them. The control surface would be hooked to the T-bar. So the question was... if the linkage had 0.5 mm slop, how much angular difference could one have between two servos at about 60 degrees deflection. The chart shows the difference between the the ideal distance (10 cm) and the real distance with the mismatched angles. The allowable difference is 0.05 cm (.5 mm). The graph shows that the answer is 3 to 3.5 degrees difference between the two servos (given the same input). I checked for other angles of deflection and came up with similar answers. They don't have to be precise if there is a bit of compliance in the linkage.

THEN I had an even better idea. How about a TOTALLY compliant linkage ??

Instead of making a MEGA SUE with a 12 inch wide elevator on each side... make TWO independent 6 inch wide elevators on each side. Each one has it's own 9 gram servo. If one uses a Y connector then one has a big 12" wide elevator (or elevons if one has a suitable computer transmitter). That will double the available torque for the total elevator, at the cost of double the weight, but that's better than what I was finding in the catalogs... and it's SIMPLE. BUT, if one has a computer radio with a 8 channel receiver (like me, thanks to FE in Dayton ) one can play other games. Make one set the main controls, and use the other like mixed flaperons or whatever... all sorts of options.

And the nice thing... they are cheap servos, and being analog they don't draw a lot of power when not being activated. And they won't fight each other.

And how about SUE with CROW ???

Ad Astra
Dan_D is offline Find More Posts by Dan_D
Last edited by Dan_D; Dec 02, 2012 at 03:06 PM.
Reply With Quote
Old Dec 02, 2012, 03:49 PM
Registered User
Dan_D's Avatar
United States, OH, Amesville
Joined Nov 2012
149 Posts
HELP translate ???

Okay, I've had occasion to read and "translate" English that had been converted from Chinese. Most of the time it makes sense after a bit of puzzling.
I've even had the task of converting documents written in half-English by a Korean engineer who had the attitude that people who didn't speak Korean were inferior and that he shouldn't be bothered having to waste his time on us...

But this one ... this one has me stumped. The manual for the TH9X has a section for Programmed Mixes. I was thinking of the MEGA SUE, with two elevators on each wing... have one elevator be primary, and the second elevator be secondary with a HECK of an exponential on it. So... how do I follow these instructions to set that up?
Mix purpose to accuse of form to get rid of little mistake of organism. Make it is it can take the heart conveniently even more to have not to handle. The very wanton one mixes accusing of among the channel.


Say what ???
Dan_D is offline Find More Posts by Dan_D
Reply With Quote
Old Dec 02, 2012, 06:56 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
[QUOTE=Dan_D;23421780]If it's only raining I could go down to the fire station and drive the trucks out and use the bay... 60 feet by 60 feet with a 20' ceiling.

Sounds like that bay would be GREAT for micros when it's rainy or too windy outside !
balsa or carbon is offline Find More Posts by balsa or carbon
Reply With Quote
Old Dec 02, 2012, 07:09 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
Quote:
Originally Posted by Dan_D View Post
Well, I was looking through the catalogs for cheap servos that don't weigh much and have lots of torque... and look, it's the holy grail right next to it !!!!

I was looking at the specs for the 9 gram servos I've been using (1.7 kg/cm) and then I looked at 14, 18, etc gram servos. It sorta surprised me that the 18 grams had LESS than 2x the torque of the 9 gram servos. Then it struck me ... why not use TWO 9 gram servos...

Of course objections flooded into my mind - two inexpensive servos wouldn't necessarily have the same response, so that one might want to turn 64 degrees and the other might want to turn 61 degrees and they'd fight each other, until somebody gave up. SO, we need a compliant linkage. I thought of a number of different ones, and then I thought "Ackerman" and so I did some back of the Excel calcs... (shown below, but eminently ignorable).

The idea behind this spread sheet is to put two servos side by side 10 cm apart, hook them with a Y connector, and then put a T-bar between them. The control surface would be hooked to the T-bar. So the question was... if the linkage had 0.5 mm slop, how much angular difference could one have between two servos at about 60 degrees deflection. The chart shows the difference between the the ideal distance (10 cm) and the real distance with the mismatched angles. The allowable difference is 0.05 cm (.5 mm). The graph shows that the answer is 3 to 3.5 degrees difference between the two servos (given the same input). I checked for other angles of deflection and came up with similar answers. They don't have to be precise if there is a bit of compliance in the linkage.

THEN I had an even better idea. How about a TOTALLY compliant linkage ??

Instead of making a MEGA SUE with a 12 inch wide elevator on each side... make TWO independent 6 inch wide elevators on each side. Each one has it's own 9 gram servo. If one uses a Y connector then one has a big 12" wide elevator (or elevons if one has a suitable computer transmitter). That will double the available torque for the total elevator, at the cost of double the weight, but that's better than what I was finding in the catalogs... and it's SIMPLE. BUT, if one has a computer radio with a 8 channel receiver (like me, thanks to FE in Dayton ) one can play other games. Make one set the main controls, and use the other like mixed flaperons or whatever... all sorts of options.

And the nice thing... they are cheap servos, and being analog they don't draw a lot of power when not being activated. And they won't fight each other.

And how about SUE with CROW ???

Ad Astra
Dan , another option you can consider is aerodynamic balancing , where a certain % of the control surface is in FRONT of the hinge line , as in this photo .

http://www.little-acorn.com/pics/tail00.jpg
balsa or carbon is offline Find More Posts by balsa or carbon
Reply With Quote
Old Dec 02, 2012, 07:10 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
Mix purpose to accuse of form to get rid of little mistake of organism. Make it is it can take the heart conveniently even more to have not to handle. The very wanton one mixes accusing of among the channel.


Say what ???[/QUOTE]

don't ask me !?!?
balsa or carbon is offline Find More Posts by balsa or carbon
Reply With Quote
Old Dec 02, 2012, 07:52 PM
Registered User
Dan_D's Avatar
United States, OH, Amesville
Joined Nov 2012
149 Posts
Quote:
Originally Posted by balsa or carbon View Post
Quote:
Originally Posted by Dan_D
Mix purpose to accuse of form to get rid of little mistake of organism. Make it is it can take the heart conveniently even more to have not to handle. The very wanton one mixes accusing of among the channel.


Say what ???
don't ask me !?!?
Mind you... "The very wanton one... " ... sounds PERFECT for a NEKKID SUE.
Dan_D is offline Find More Posts by Dan_D
Reply With Quote
Old Dec 03, 2012, 11:02 PM
Registered User
Dan_D's Avatar
United States, OH, Amesville
Joined Nov 2012
149 Posts
Rainy Day thoughts

So, it was raining again today... so, between short bouts of work, I read RCgroups, and thought about things.

How does one connect a multi engine plane's throttle, especially if one has a TH9X ?

Does one use two ESC's, or just one?

One ESC - It would have to be a pretty big single ESC... would there be danger of feedback between the two motors causing hunting or beat frequency behavior? Would the two engines be well enough balanced that the thrust will be close enough, or would you have a built in turn ?


Two ESC's - Do you connect them to the receiver with a Y cable, or two channels? With the TH9X I can see how to slave one second channel to the normal throttle, and use sub trim to adjust relative thrust. If/when I get the new programming card and firmware, I can also see how to use ep9x to set up one of the pots to adjust the relative thrust of the two engines. Does one use just one battery, or can one use two? I can see some possible problems with loop problems if you use two batteries, two ESC's, two connections to the receiver... or not ???

If one uses a second battery for lights, does one just connect it and not go through the receiver? So the lights are on for the flight, or off? If you want to use the aux channels on the receiver to control the lights, are you committed to using the main battery, or do you hook up an electrically isolated switch (such as an opto switch) or a mechanical switch on a servo to isolate the second battery from the main battery ?

And speaking of having gone NUTS... I spent some time reading about the ARDUPilot and quad copters. I found a nice kit from JRDrones that costs "only" $600... add in the FPV and a few goodies, and it's about a K-buck. OUCH. Then I thought that I have a lot of junk... I mean "treasures"... laying about the place, and I can probably raise $1K on eBay by selling ju... treasures. Anybody want to buy a floor model autoclave suitable for a medical clinic or tatoo parlor ??? So, my goal is to clean up da joint and use the proceeds to buy a FPV ARDUpilot quad copter, and test it for the fire department. Kewl, eh ? I'll be able to go play AND tell the missus it's for the good of the community !!!

I am still thinking about building the MEGA SUE... but it's gonna be heavy. Even if I put two motors on it, I don't think the combo I have been using will be good enough. Any suggestions ?? I'm gone all next week, so if I order now (from US, not China) I might have the parts ready by the time I get back... and then it's time to build, fly, curse the snow, etc... Hmmm... snow... gotta think about plastic or foam instead of paper.

Thanks for all the help.

Ad Astra

(Hey, should I change my name to Ad Astra ??? Can one change a name, or do you make a new user? )
Dan_D is offline Find More Posts by Dan_D
Reply With Quote
Old Dec 04, 2012, 01:31 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
Hey Ad Astra ,

I haven't done multi-engine on a plane but I have on a tricopter , and each motor needs its own ESC . For a twin engine plane use a Y harness going to throttle channel with the + wire disabled on one ESC . And you can either Y harness into one battery or use two batteries .

On my night flyers I use a separate battery for the LED's mounted on the CG . A few of my flying buddies use this http://www.hobbyking.com/hobbyking/s...f_Switch_.html controller from HobbyKing that plugs into the receiver ( gear or aux ) so they can turn the LED's on/off or change to different flashing patterns . The controller is powered through the receiver , but the LED's are powered ( higher voltage ) through either by a separate battery or Y harnessed into the main battery .

If you don't think the two motors you have will be enough to fly MEGA SUE , HobbyPartz has a number of motor/ESC combos with MEGA power . This one is for planes up to 44 POUNDS ! http://www.hobbypartz.com/98p-mars-b...90a-combo.html Notice that the ESC's for the bigger motors don't have BEC's , so you'll have to get a separate BEC .

Al
balsa or carbon is offline Find More Posts by balsa or carbon
Reply With Quote
Old Dec 04, 2012, 03:57 PM
Registered User
Dan_D's Avatar
United States, OH, Amesville
Joined Nov 2012
149 Posts
and now, to make it BIGGER !!!

Quote:
Originally Posted by balsa or carbon View Post
If you don't think the two motors you have will be enough to fly MEGA SUE , HobbyPartz has a number of motor/ESC combos with MEGA power . This one is for planes up to 44 POUNDS ! http://www.hobbypartz.com/98p-mars-b...90a-combo.html
Al
I ordered two of those motors with 44 pounds of thrust ! I'm going to buy two 4x8 sheets of 1/4" plywood and make ULTRA SUE.

Well, maybe not. Not enough money in the piggy bank.

But I did order three of these - http://www.hobbyking.com/hobbyking/s...ess_Motor.html and the appropriate ESCs, a new battery to replace the one that looks like it met Inigo Montoya, and a HERD of 9 gram servos. It should all be waiting for me when I get back from my week long trip.

So, my current thought is to make MEGA ME SUE with the rectangular center panel... put two motors on each dihedral line... and make two fuselages to protect the motors. Since I'm going to have a fancy dancy 9 channel radio and a 8 channel receiver, I am thinking of putting two rudders, two ailerons, and two flaps on it. I can use various combinations to get greater control authority if working together, or independent flap and aileron behavior, or CROW, or with two rudders working in opposition ... ultra CROW. However, first thing I'm going to do is make a multi control surfaces SUE... That way I continue to practice with a regular SUE (I have two ready to go when the darned rain stops), then spend time with a regular sized multi control surfaces SUE, then go to MEGA ME SUE.

Change one variable at a time.
Dan_D is offline Find More Posts by Dan_D
Last edited by Dan_D; Dec 04, 2012 at 04:05 PM.
Reply With Quote
Old Dec 04, 2012, 04:34 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
Quote:
Originally Posted by Dan_D View Post
I ordered two of those motors with 44 pounds of thrust ! I'm going to buy two 4x8 sheets of 1/4" plywood and make ULTRA SUE.

Well, maybe not. Not enough money in the piggy bank.

But I did order three of these - http://www.hobbyking.com/hobbyking/s...ess_Motor.html and the appropriate ESCs, a new battery to replace the one that looks like it met Inigo Montoya, and a HERD of 9 gram servos. It should all be waiting for me when I get back from my week long trip.

So, my current thought is to make MEGA ME SUE with the rectangular center panel... put two motors on each dihedral line... and make two fuselages to protect the motors. Since I'm going to have a fancy dancy 9 channel radio and a 8 channel receiver, I am thinking of putting two rudders, two ailerons, and two flaps on it. I can use various combinations to get greater control authority if working together, or independent flap and aileron behavior, or CROW, or with two rudders working in opposition ... ultra CROW. However, first thing I'm going to do is make a multi control surfaces SUE... That way I continue to practice with a regular SUE (I have two ready to go when the darned rain stops), then spend time with a regular sized multi control surfaces SUE, then go to MEGA ME SUE.

Change one variable at a time.
Sounds like a good plan !

You started this thread flying a store-bought plane and building a store-bought kit , now you're a scratch-building maniac ! AWESOME !

Al
balsa or carbon is offline Find More Posts by balsa or carbon
Last edited by balsa or carbon; Dec 04, 2012 at 04:41 PM.
Reply With Quote
Old Dec 04, 2012, 04:52 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
Night time slow flyer

I just watched this video , looks like it would be a GREAT plane to build for LED night flying - or anytime flying . It says in the info below the video that they'll post a build video soon .


Flite Test - Old Fogey - Review (8 min 55 sec)


Al
balsa or carbon is offline Find More Posts by balsa or carbon
Reply With Quote
Old Dec 04, 2012, 09:18 PM
Registered User
United States, WA, Moses Lake
Joined Feb 2012
416 Posts
Thanks for the link Al. I like the way those planes are made. I was going to build that dart but they call it ft flyer I think. Anyway I like this plane better I have to have one. I already have the parts.

I also like that trough cut fuselage idea using the paper as part of that glue joint. I made one using that method it was nice and square and strong. Like a cigar box. I'm not a big fan of the paper but it works well for those. What do you think that plane would weigh 10 oz range?
Low and Slow is offline Find More Posts by Low and Slow
Reply With Quote
Old Dec 04, 2012, 10:09 PM
Hot glue held together by foam
United States, WA, Vancouver
Joined Aug 2010
2,467 Posts
Quote:
Originally Posted by Low and Slow View Post
Thanks for the link Al. I like the way those planes are made. I was going to build that dart but they call it ft flyer I think. Anyway I like this plane better I have to have one. I already have the parts.

I also like that trough cut fuselage idea using the paper as part of that glue joint. I made one using that method it was nice and square and strong. Like a cigar box. I'm not a big fan of the paper but it works well for those. What do you think that plane would weigh 10 oz range?
10 oz is a good guess - we'll know for sure when they post the build video .

It kinda looks and flies like my Electrifly Flylite with the high under cambered wing , although it has polyhedral instead of dihedral . And it has the same motor as my Flylite , the 24 gram HexTronik/Blue Wonder/HURC2712/etc.

Be sure to show us the photos/video when you're done !

Al
balsa or carbon is offline Find More Posts by balsa or carbon
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Newbie with Two Year old 8S lipo's, Pictures (edit, its also an e-bike) drebsdorf Batteries and Chargers 10 Sep 02, 2012 02:08 PM
Question Reincarnating an old Digi-Trio with new innards? Rabbit5487 Radios 13 Aug 27, 2012 06:10 AM
Discussion Teaching an old car new tricks?..... WhtSpirit01 Off-road Cars 2 Apr 21, 2012 10:17 AM
An Old NEWBIE... HarshaDS Beginner Training Area (Aircraft-Electric) 10 Mar 30, 2004 07:54 AM
Newbie question from an old airhead... randall1959 Beginner Training Area (Aircraft-Electric) 6 Feb 16, 2004 09:43 PM