HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 06, 2012, 12:44 AM
Just gotta mod. it
canadianufo's Avatar
Northern British Columbia
Joined Dec 2006
936 Posts
should be interesting

now, if it would stop snowing.
canadianufo is offline Find More Posts by canadianufo
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 06, 2012, 03:32 AM
Registered User
xmech2k's Avatar
United States, CA, San Diego
Joined Jun 2007
1,791 Posts
LOL! That's gonna be awesome!
xmech2k is online now Find More Posts by xmech2k
Reply With Quote
Old Dec 06, 2012, 10:41 AM
Fly and let Fly!
Cocg's Avatar
United States, CO, Grand Junction
Joined May 2010
1,825 Posts
Quote:
Originally Posted by canadianufo View Post
now, if it would stop snowing.
Thats Fkn Cool.!
Cocg is online now Find More Posts by Cocg
RCG Plus Member
Latest blog entry: Updating Hangar (a little)
Reply With Quote
Old Dec 11, 2012, 02:13 PM
Registered User
Joined Dec 2007
1,059 Posts
Do most Turbo Jets arrive with the back of the fuse bent like this? Did it straighten and look OK using hot water?
The package is lacking anything to keep the back of the fuse from hitting the box.
BrianL is offline Find More Posts by BrianL
Reply With Quote
Old Dec 11, 2012, 04:35 PM
Mach One
captain MoMo's Avatar
Joined Apr 2011
1,978 Posts
Quote:
Originally Posted by BrianL View Post
Do most Turbo Jets arrive with the back of the fuse bent like this? Did it straighten and look OK using hot water?
The package is lacking anything to keep the back of the fuse from hitting the box.
I have three delivered and ALL three had this bend. Just straighten out carefully and it will be just fine. Be careful not to break it off. Either case I did not see any issues fixing it. Its due to bad packaging by Dynam.
captain MoMo is online now Find More Posts by captain MoMo
RCG Plus Member
Reply With Quote
Old Dec 11, 2012, 05:05 PM
Registered User
United States, CT, East Hartford
Joined Jul 2008
432 Posts
Same here, except mine came unglued. Slowly bent it past straight and glued it together again, looks good as new. Too bad they did not protect the back of the plane as well as the sides.
handyman 220 is offline Find More Posts by handyman 220
Reply With Quote
Old Dec 19, 2012, 07:18 PM
Registered User
Eric Henderson's Avatar
United States, NV, Las Vegas
Joined Dec 2005
1,308 Posts
Early Xmas???

December Birthday gift -- one Dynam Turbo Twin.

I had wanted one of these for a while and Nitro Models delivered in a couple of days. Many of you have gone before me with this nice looking exec jet. I fully intended to build her as stock as possible using what I had learned from this thread. Initially I only changed the color scheme to my current high-vis scheme. (old eyes thing) That was until I had it finished.

Problem one, was that he wings were flexing too much or better said too easily. Added some blade type CF spars to underside with thick and then thin CA. Two main spars and a sub spar at the center to address the dihedral and sweep of the wing. The Sub spar keys into the main spars in a sort of triangle. Seems to have made the wing nice and firm, but not too stiff.

Problem two, she was pretty nose heavy. I pulled the ESCs and with my partner, captain-carving-knife, I opened up the area behind the wing where the fans are held with four bolts. Went down and though to create room and an exit vent in the lower side of the fuselage. Also added more vents on the fuselage part of the fan assembly. (Fresh air now comes in through canopy and nose-wheel well to cool the battery and the ESCs). Added a new and longer battery (heavier-rated) lead to reach the front. Fitted a BEC while I was soldering all these wires back together. Boy, you need a pretty heavy soldering iron to handle all of the heat dissipating through four wires!

Amazingly, to me at least, I did not have to build a new battery box. I can now fit a 3300mAh 3S pack in the front and I am right on 60mm for the CG. So I am now happy --- wrong!

Running up the fans saw nasty vibration and blade scraping. Aaagh! I quickly pulled the fans off and found that neither motor was centered nor tight (four screws just finger tight). Also one fan was wobbly on the Ali fan hub. All four supplied fans were loose on this component. Fixed it by adding some more diameter to the hub using packing tape. Centered the motors and put it all back together. BIG difference—ran all the way up and was smooth.

Finished just in time, because my “Xmas Vixen” arrived at the front door as I tested the fans for full bore……All I need now is more time and some sun…

Happy holidays,

EDF-Eric.
Eric Henderson is offline Find More Posts by Eric Henderson
RCG Plus Member
Latest blog entry: Mental hang-nails
Reply With Quote
Old Dec 19, 2012, 07:33 PM
Registered User
xmech2k's Avatar
United States, CA, San Diego
Joined Jun 2007
1,791 Posts
Looks good, Eric! You'll like this one. She flies real sweet, and looks great in the air!
xmech2k is online now Find More Posts by xmech2k
Reply With Quote
Old Dec 19, 2012, 08:00 PM
Mach One
captain MoMo's Avatar
Joined Apr 2011
1,978 Posts
I crashed mine last week and now in the process of replacing the fuselage. But this time I am going to paint her a Cessna off white color with WBPU gloss coat afterwards. I recently changed all the stock retracts to pz servoless retracts (from HK) and they work like a charm when cold.... unlike the stock ones, that always stopped working in ambients less than 60F.
captain MoMo is online now Find More Posts by captain MoMo
RCG Plus Member
Reply With Quote
Old Dec 19, 2012, 08:52 PM
Fly and let Fly!
Cocg's Avatar
United States, CO, Grand Junction
Joined May 2010
1,825 Posts
Quote:
Originally Posted by Eric Henderson View Post
December Birthday gift -- one Dynam Turbo Twin.

I had wanted one of these for a while and Nitro Models delivered in a couple of days. Many of you have gone before me with this nice looking exec jet. I fully intended to build her as stock as possible using what I had learned from this thread. Initially I only changed the color scheme to my current high-vis scheme. (old eyes thing) That was until I had it finished.

Problem one, was that he wings were flexing too much or better said too easily. Added some blade type CF spars to underside with thick and then thin CA. Two main spars and a sub spar at the center to address the dihedral and sweep of the wing. The Sub spar keys into the main spars in a sort of triangle. Seems to have made the wing nice and firm, but not too stiff.

Problem two, she was pretty nose heavy. I pulled the ESCs and with my partner, captain-carving-knife, I opened up the area behind the wing where the fans are held with four bolts. Went down and though to create room and an exit vent in the lower side of the fuselage. Also added more vents on the fuselage part of the fan assembly. (Fresh air now comes in through canopy and nose-wheel well to cool the battery and the ESCs). Added a new and longer battery (heavier-rated) lead to reach the front. Fitted a BEC while I was soldering all these wires back together. Boy, you need a pretty heavy soldering iron to handle all of the heat dissipating through four wires!

Amazingly, to me at least, I did not have to build a new battery box. I can now fit a 3300mAh 3S pack in the front and I am right on 60mm for the CG. So I am now happy --- wrong!

Running up the fans saw nasty vibration and blade scraping. Aaagh! I quickly pulled the fans off and found that neither motor was centered nor tight (four screws just finger tight). Also one fan was wobbly on the Ali fan hub. All four supplied fans were loose on this component. Fixed it by adding some more diameter to the hub using packing tape. Centered the motors and put it all back together. BIG difference—ran all the way up and was smooth.

Finished just in time, because my “Xmas Vixen” arrived at the front door as I tested the fans for full bore……All I need now is more time and some sun…

Happy holidays,

EDF-Eric.
Kinda scary having all those screws loose..!! Kinda like me.. !! Looks great..!!
Cocg is online now Find More Posts by Cocg
RCG Plus Member
Latest blog entry: Updating Hangar (a little)
Reply With Quote
Old Dec 19, 2012, 09:14 PM
Registered User
Eric Henderson's Avatar
United States, NV, Las Vegas
Joined Dec 2005
1,308 Posts
Quote:
Originally Posted by xmech2k View Post
Looks good, Eric! You'll like this one. She flies real sweet, and looks great in the air!
Thanks for the good luck wishes. It's nice not having to be on the leading edge thanks to this thread.

I did have a question about the CG. It says measure from where the LE of the wing meets the fuselage, but there is a sort of step in the foam. You could use either start point? Any info would be appreciated.

Regards,

Eric.
Eric Henderson is offline Find More Posts by Eric Henderson
RCG Plus Member
Latest blog entry: Mental hang-nails
Reply With Quote
Old Dec 20, 2012, 12:04 AM
Registered User
xmech2k's Avatar
United States, CA, San Diego
Joined Jun 2007
1,791 Posts
If I recall correctly, my cg falls right on the slot for the servo wires under the wing. Sorry, I haven't checked it for so long. Mine's 'in the hangar' now with the wing and motors off. Knowing me, I didn't use that step as a reference, I just went from where the continuous line of the leading edge of the wing stops.
xmech2k is online now Find More Posts by xmech2k
Reply With Quote
Old Dec 20, 2012, 01:43 AM
Registered User
Eric Henderson's Avatar
United States, NV, Las Vegas
Joined Dec 2005
1,308 Posts
Quote:
Originally Posted by xmech2k View Post
If I recall correctly, my cg falls right on the slot for the servo wires under the wing. Sorry, I haven't checked it for so long. Mine's 'in the hangar' now with the wing and motors off. Knowing me, I didn't use that step as a reference, I just went from where the continuous line of the leading edge of the wing stops.
Thank you for answering. I am not too worried, because it (CG) can be a little bit further back and still fly pretty good. I just did not want to be nose heavy and come in like a rocket. I have fitted the flaps, but they are not set yet with auto-elevator correction.

I forgot to mention two more little niggles with the fan. On one unit the bolt that holds the fan onto the hub was bottoming out, which meant that it could not actually tighten up the fan. The thread was not deep enough. Easy way out was to shorten the bolt 1/16"

Second item was that there was a set-screw (grub-screw to us Brits) missing. There should be two per fan-hub. this might be why some folks are getting bad noises at full rpm????

Oddly enough, despite these minor annoyances I still really liked the airplane. I got the one with no radio system. In the end I used nine channels and still needed one more for thrust/rudder mixing - will do that when I fit a new 11ch DMSS RX.

Hope tomorrow has good desert weather? - still a bit bloody cold for the history of my ex-rugby body.

Eric.
Eric Henderson is offline Find More Posts by Eric Henderson
RCG Plus Member
Latest blog entry: Mental hang-nails
Reply With Quote
Old Dec 20, 2012, 11:52 AM
Registered User
xmech2k's Avatar
United States, CA, San Diego
Joined Jun 2007
1,791 Posts
Eric,

I found I didn't need any flap-elevator mixing, she only pitched up a little if I extended the flaps with too much airspeed, but once at a reasonable speed, I didn't notice any trim change. I will say, though, due to my inexperience at the time, when I installed the flaps, I wound up with probably less than 40 degrees at max deflection. And I think it's more trouble than it's worth to rip the servos out to correct it.

I'm only using 6 channels. I was able to add a little differential aileron mechanically, since the aileron servos were so loose. One fell out during a taxi test! Speaking of which, give those aileron servos a good tug to make sure they are secure, if they're installed from the factory! (Hope you read this before the maiden!)

Anyways, I wonder if differential thrust is really necessary. The rudder seems to work well, and seeing that the motors are close-set to the fuselage, I wonder how effective it would be? I guess it's a good idea for something like their A-10, that doesn't have rudder control. I never thought of doing that on a model like this.

Good luck with that maiden!
xmech2k is online now Find More Posts by xmech2k
Reply With Quote
Old Dec 20, 2012, 02:59 PM
Registered User
Eric Henderson's Avatar
United States, NV, Las Vegas
Joined Dec 2005
1,308 Posts
Quote:
Originally Posted by xmech2k View Post
Eric,

I found I didn't need any flap-elevator mixing, she only pitched up a little if I extended the flaps with too much airspeed, but once at a reasonable speed, I didn't notice any trim change. I will say, though, due to my inexperience at the time, when I installed the flaps, I wound up with probably less than 40 degrees at max deflection. And I think it's more trouble than it's worth to rip the servos out to correct it.

I'm only using 6 channels. I was able to add a little differential aileron mechanically, since the aileron servos were so loose. One fell out during a taxi test! Speaking of which, give those aileron servos a good tug to make sure they are secure, if they're installed from the factory! (Hope you read this before the maiden!)

Anyways, I wonder if differential thrust is really necessary. The rudder seems to work well, and seeing that the motors are close-set to the fuselage, I wonder how effective it would be? I guess it's a good idea for something like their A-10, that doesn't have rudder control. I never thought of doing that on a model like this.

Good luck with that maiden!
I will check the servos. I already tested the retractable landing gear and one main had no glue on it at all. Reglued them all with gorilla......

I have been using thrust balancing with multi engines and motors for about ten years. Apart from taxi fun, I was also able to use a TX "trim feature" to get straight-line flying with the rudder set straight. The same design of mixes that the rudder uses can be used to bring down the appropriate motor a fraction, while flying. Then you lock that % in and switch (with a switch) back to normal rudder or thrust mixed rudder.

Some might say "unnecessary", but it is so much fun to do what real airplanes do from your TX. I can't get dual motor rpm telemetry yet so I trim with straight-line tests and look for crabbing etc.

As regards the Dynam Turbo Twin. I need an 11 channel RX--so that will have to wait - the DMSS stuff costs more than the Sea Vixen :-( I will eventually try it just to see if rudder controlled thrust does have an effect with the pods so close together.

I am using two channels for the flaps, because the servos are laid out wrong in the SR Trainer and the Turbo twin. They should lay in the same orientation for both panels.

If you think this is anal retentive you should see my A-380 programs. One version has individual control of all four motors. Not one of them is plugged into the throttle channel either! This airplane (A-380) had a V-tail program as stock and no rudder. Once the steerable nose-wheel left the ground it did what it wanted until fully flying. Was not long before I fitted a rudder, but the variable thrust using the rudder-channel saved the day more than once.

Played with the outer motors and inner motors and setttled for "gentle" mixes to the outers for flying and bigger amounts for taxiing.

Regards,

Eric.
Eric Henderson is offline Find More Posts by Eric Henderson
RCG Plus Member
Latest blog entry: Mental hang-nails
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Lifelike Turbo Jet 2000 conversion budgetfly Foamies (Kits) 22 Feb 25, 2006 07:02 PM
TJ3D... (Wal-Mart Turbo Jet 2000 conversion) ScottChase Foamies (Kits) 10 Sep 11, 2003 02:27 AM
Turbo Jet 2000 EDF thelocust Foamies (Kits) 1 Mar 05, 2002 09:28 PM
Twin Jet and Permax turbo 450 setup geoff.sim Foamies (Kits) 3 Jun 08, 2001 12:25 AM