Official Eflite UMX Mig 15 DF Owners Thread - Page 154 - RC Groups
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Nov 20, 2012, 02:03 PM
pǝʇɹǝʌuᴉ sɐʍ I ǝsnɐɔǝq
LowlyElevated's Avatar
Its a good thing the mig can do wind.

Its the beggining of a florida winter, which is like spring for most of you, and you can't buy a calm day. (just the opposite in the summer) Yet the mig will fly in more wind than most of my other planes, except the giant scale. (And i would be worried to fly it in that much wind) It just cuts right through most of the wind.
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Nov 20, 2012, 02:24 PM
I'd rather be flying!
turboparker's Avatar
Quote:
Originally Posted by Kevin Greene
Hmm---JR/Spektrum RX's and satellites are all plastic coated...As well as Orange RX's/satellites...And guys have been putting heat shrink over them for years to keep the wires straight...

But hey, you tested the plane before and after so it's hard to argue with your results......

Just mentioning this for a good discussion and to learn......

Kevin
Antenna design is complex & non-intuitive, as RF does not behave at all like DC. The higher the frequency, the more critical everything becomes. What may be a good insulator at DC or low frequencies may be very lossy at high frequencies. Also, putting anything over the actual antenna will de-tune it. Antenna coatings need to be accounted for during the design process, as the dielectric properties of the insulation or coating will have an effect on resonant length. In Vadimpelau's case - he used bathroom silicone caulk on the antenna connection right at the board. Bathroom caulk is not intended to be used on electronics for two reasons. 1) Acetic-cure silicone will eat copper wiring & circuit traces. 2) It is often lossy at high frequencies.

Electronics-grade neutral-cure silicone adhesive is the only type of silicone that should be used for electronics work, but it can still de-tune a circuit at 2.4 GHz. Putting even a low-loss dielectric over an otherwise bare antenna connection at these frequencies can change the capacitive reactance enough to matter, which changes the antenna's impedance. And at RF, impedance-matching is the name of the game.

Joel
Nov 20, 2012, 09:13 PM
ChuckTseeker Super Fan
Aphro's Avatar
How about clear Scotch tape? I use it with all my park size aircraft (AR600/6210/8000 etc...). Safe to secure antenna leads with? Or will that also mess with the 2.4ghz signal? I have never had any drop outs, just curious if tape could also interfere...
Nov 21, 2012, 01:37 AM
I'd rather be flying!
turboparker's Avatar
Quote:
Originally Posted by Aphro
How about clear Scotch tape? I use it with all my park size aircraft (AR600/6210/8000 etc...). Safe to secure antenna leads with? Or will that also mess with the 2.4ghz signal? I have never had any drop outs, just curious if tape could also interfere...
A small piece of Scotch tape won't affect things enough to notice.

Joel
Nov 21, 2012, 10:54 AM
Registered User
Valkpilot's Avatar

Nosewheel Experiment


Has anyone tried to use the nosewheel off of the UM T-28 on the MiG? Or is the wire too thick?
Nov 21, 2012, 12:53 PM
Registered User
Quote:
Originally Posted by Valkpilot
Has anyone tried to use the nosewheel off of the UM T-28 on the MiG? Or is the wire too thick?
I don't know about the T-28 gear. I picked up some 0.032 music wire from my LHS and I have been using that after bending up my own gear. The stuff might be a bit thicker than the factory wire, but it fits snugly, holds its shape well, and won't snap if bent back into shape after a bad landing.
Nov 21, 2012, 01:42 PM
when down=up, up=expensive
whichwaysup's Avatar
Quote:
Originally Posted by Valkpilot
Has anyone tried to use the nosewheel off of the UM T-28 on the MiG? Or is the wire too thick?
I have used the mustang LG, which I think is the same diameter as the T28. It's a bit tight, but it does fit into the slot. Just be careful - bend SLOWLY - that wire will break if bent too quickly or too far.
Nov 21, 2012, 06:13 PM
Registered User
Quote:
Originally Posted by turboparker
Antenna design is complex & non-intuitive, as RF does not behave at all like DC. The higher the frequency, the more critical everything becomes. What may be a good insulator at DC or low frequencies may be very lossy at high frequencies. Also, putting anything over the actual antenna will de-tune it. Antenna coatings need to be accounted for during the design process, as the dielectric properties of the insulation or coating will have an effect on resonant length. In Vadimpelau's case - he used bathroom silicone caulk on the antenna connection right at the board. Bathroom caulk is not intended to be used on electronics for two reasons. 1) Acetic-cure silicone will eat copper wiring & circuit traces. 2) It is often lossy at high frequencies.

Electronics-grade neutral-cure silicone adhesive is the only type of silicone that should be used for electronics work, but it can still de-tune a circuit at 2.4 GHz. Putting even a low-loss dielectric over an otherwise bare antenna connection at these frequencies can change the capacitive reactance enough to matter, which changes the antenna's impedance. And at RF, impedance-matching is the name of the game.

Joel
Good job, Joel!!!...I'm doing "I'm not worthy" bows in your honor......THANKS for the explanation!!!...On one RX I had the antenna break loose and I resoldered a new one from a bad RX...I placed one drop of hot melt glue over the solder connection and so far no reduction in range...I do have a tube of electronics grade silicone (no acetic acid) and glue my RX's in with this...

I now have about 15 flights on the MiG...What a saaawwweeeeet little plane!!!...However, the last two flights I did notice some aileron rocking...The fan feels out of balance at certain RPM ranges so I'm sure that the out of balance conditon is causing the aileron rock...I'm also suspect of the motor's bearings which have been known to fail prematurely...

The last flight I flew without the landing gear...The plane has MUCH more speed and vertical punch...I'm going gearless unless I have no option but taking off/landing on hard surfaces...The plane belly lands very easily, skidding over the grass like a greased plane....I don't have the guns in place as I don't want to rip them off...I'm flying this plane so much that my other micros are screaming, "What the heck???"...............

Kevin
Nov 21, 2012, 08:15 PM
Registered User
Valkpilot's Avatar
Quote:
Originally Posted by whichwaysup
I have used the mustang LG, which I think is the same diameter as the T28. It's a bit tight, but it does fit into the slot. Just be careful - bend SLOWLY - that wire will break if bent too quickly or too far.
Yes, I too have been using the "mustang mod" but was thinking of trying
the T-28 gear WITHOUT bending it. Or would it raise the nose too much and cause a tail scrape?
Nov 21, 2012, 08:28 PM
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LowlyElevated's Avatar
The mains wouldn't even be touching the ground if you did that.
The stock gear has a high angle of attack as it is, and the t-28 gear is much longer.
Nov 22, 2012, 01:02 AM
Wandering IT geek
ronin4740's Avatar
Have looked through the thread and have noticed that several folks have had binding problems.

Just took mine out of the box, put the battery in and bound using my JR 9303 transmitter. Bound fine. Realized that flapperons won't work, disconnected battery, reprogrammed the JR 9303 to normal wing, set JR 9303 back to operational mode, put battery into MIG and it was in searching for TX mode.

Powered off JR 9303, powered on holding bind button, MIG bound.

Disconnected battery, reconnected battery, MIG in search mode...

Is this normal? Is it normal for only DSM2 TX's? Anyone who had this issue ask HH and get a solution? I'd call them but tomorrow is turkey day... Was hoping to maiden her tomorrow... Haven't flown in soooooooooooooooooo long, jonesing!
Nov 22, 2012, 01:11 AM
Have fun
airpower's Avatar
Sadly its normal, after shes bound dont disconnect then re-connect, just fly her right after she's bound. Sometimes if you disconnect the.battery early enough when the rx light starts flashing(bind mode) and then re-connect the light will turn solid after initialization.
Nov 22, 2012, 01:48 AM
Wandering IT geek
ronin4740's Avatar
Thanks. Won't let it stop me from flying her tomorrow then.
Nov 22, 2012, 09:08 AM
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LowlyElevated's Avatar
When I power it up, I have towigglr the sticks on my radio or it will act like its not bound. Is this normal?
Nov 22, 2012, 03:32 PM
Registered User
Quote:
Originally Posted by Waffleman
When I power it up, I have towigglr the sticks on my radio or it will act like its not bound. Is this normal?
Does not sound normal. Which transmitter are you using?

I do know that you have to leave the transmitter on for a few seconds before giving power to the receiver on some radios.


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