MGJ01

Hey guys,

Chasing some advise on the way I have setup my radio equipment in my 40 size nitro trainer. Up the front I have the battery and receiver wrapped in foam next to each other, the RX antennas (main & satellite) are facing towards the back of the fuselage at right angles to each other.

Just wondering if the battery will interfere with the receiver or signal being next to it?

Radio gear is Spectrum 2.4GHz, battery is LiFe 6.6v 1700mAh

Thanks

jetmech05

Don't wrap the receiver in foam. I used to wrap the 72 receivers but I've never wrapped a 2.4 receiver. The receiver needs to be open. There is no such thing as an interference prove frequency. It 2.4 is such an improvement over 72. No need to worry about the battery it is not going to create interference.

jester_s1

We used to wrap receivers because 72mhz crystals were sensitive to vibration. Now we don't wrap them because 2.4ghz receivers don't have crystals but they are sensitive to heat.

MGJ01

Thanks guys


I will unwrap the rx as suggested. The reason i have wrapped it is to keep vibration to a minimum and also to keep the installation tidy.


Will it do any harm if i leave it wrapped?

kmeyers

Will it do any harm if i leave it wrapped?

Probably not.

I don't like your servo arms and connectors.

The adjustable length arms are a problem waiting to happen, I have seen them come loose.

The EZ connectors on the elevator and rudder I would change to Z-bends (primary controls, I guess they are on the ailerons too?).

The throttle and nose steering you can keep if you remove the set screw and replace it with a socket head cap screw that you can get some real torque on.

Just my .02

MGJ01

Thanks kmeyers

I will take your advise on the EZ connectors and will replace them with either Z bends or L bends using the nylon retainer clips. I think its too risky using the EZ connectors.

Much appreciated

Hydro Junkie

I would have used clevis's on the pushrods. They make it easier to remove the servos without having to remove the servo horns first.

kmeyers

Unless you are expert at soldering, Z bends or 90* with the keepers are the safest way to finish the ARF supplied hardware.

MGJ01

I will give the z bend a go, failing that I will stick with the 90 bend with keepers.

Thanks

TomCrump

Once you go with the z-bends, it'll be too late to use a 90 degree bend. You won't have enough length on the pushrods to do so.

rcguy59

My Feedback: (8)

2.4GHZ receivers can generate a fair amount of heat owing to their on-board processors. Cooling is more important to them than vibration isolation. Futaba specifically say not to wrap their 2.4 receivers, but I don't know about Spek.

Hydro Junkie

I personally would change out the pushrods as well, but that's me. I'm not a fan of ARF's as a rule and wouldn't trust an install that is inherently non-adjustable. Must be due to my boating background where it's always better to adjust throws using the linkages than to use the servo arm or trims. As far as soldering a clevis, if you pull the pushrod, it's not a big deal to install the clevis. I would leave one end with a threaded rod so you can adjust the length as needed

Len Todd

If you put the Rxer's antenna close to a battery, the battery can block the RF from getting to the antenna. This can cause your Rxer to be totally dependent on the Remote Rxer which defeats the purpose of having more than one Rxer. UHF is mostly line of sight communications. If there is something between Txer and the Rxer's antenna(s), the vast majority of the RF will be shielded from the Rxer.

Also, if you have CDI ignition and have not taken steps to isolate all potential CDI generated RF from the electrical system, the RF can migrate back to the battery circuit. With the Rxer in close proximity to the battery(s), the Rxer could become overloaded with the CDI's RF and not be able to work properly. I always maintain some distance (couple inches) between the battery(s) and Rxer. While the probability of this problem is typically low with today's products, the potential issue is still out there and measures should be taken to preclude it, especially in expensive Giants & Jets, etc. Such measures include fiber optic kill switches, non-conductive throttle linkage and no direct connections from the CDI module to the Rxer (e.g. using separate battery for the CDI power source.)

kmeyers

When I look at the provided picture, I saw torque tubes well anchored to former 3. It looked as if the plastic tubes were even anchored inside metal tubes into doubled plywood. This looked all very good.
For now I will assume the other end is well done too and the torque tubes are anchored half way to a former as well.

Some ARF hardware is junk. Certainly this is a good place to come and ask. Also setup is important.

I look for mechanical setup equal to flying ability as a primary driver. This means that control throws are set mechanically for 100% servo travel (at least 60* of servo rotation) to no more plane response then the pilot is ready for. This rotation of the servo is where the rated power and torque comes from.

The point here is that as the beginner pilot develops you move the clevis closer to the control surface and the Z or 90* farther from the servo horn screw. Today so many are just using the transmitter as a first set up method. I have seen planes come to the field with so much TV reduction that the torque was lost due to lack of servo motor travel. The planes would visually ground check, but, under air load the surfaces were under powered.

Setup measurements:
At cruise power and full aileron input 360* roll in 4 seconds.
Elevator just enough to flare on landing.
Rudder unable to over power the ailerons.
Nose wheel no more then about 10* at full deflection.
These are some basic ideas for beginners.

MGJ01

Thanks guys for your feedback, I have made some changes (see photos)

- Receiver has been unwrapped and placed in the servo tray with Velcro
- Removed EZ connectors on servo arms (Elevator, Rudder & Ailerons) replaced with 90 degree bends locking in place with nylon retainer clips.

The first Z bend made the metal rod brittle and snapped, so I decided to go with the 90 bends. The receiver is very close to the throttle servo and nose wheel push rod, will this cause any issues / interference?

Len Todd

If there are non-conductive components in the throttle linkage the Rxer's location to the Throttle Servo should be fine. You have a nylon servo horn. Personally I would have a nylon link or ball link connection to the throttle arm. That would help keep any RF out by the engine. But, you should be O.K.

The Nose Wheel should not be a problem unless you start developing static (e.g. nose wheel rubbing on strut, etc.). However, it takes a fairly close proximity for static to discharge. My bet is what you have would be O.K under normal conditions.

rcguy59

My Feedback: (8)

All this talk of non-conductive throttle pushrods doesn't really apply to the OP's glow engine. I would be far more concerned about the range and reliability of that HK receiver than anything else.

Hydro Junkie

I totally agree. I've heard several horror stories about HK stuff over the past year or so

jester_s1

The design of the Orange RX is probably fine. The problem is quality control. If you know a bit about electronics manufacturing you can check to see if all solder joints are made properly and then do a thorough range test with the engine running to see if vibration is going to be an issue. Of course, that's smart practice with any brand. If the receiver is built right (and that's a big "if"), it will probably perform just as well as a Spektrum branded one.

TN RC Flyer117

I have to agree about the orange receiver. I watched a plane take a plunge with my own two eyes just last weekend because the orange RX decided to go out. Everything else on the plane was perfectly operational. You typically get what you pay for in this hobby.

rcguy59

My Feedback: (8)

I've seen too many Spek-equiped planes go haywire with OEM receivers to trust the HK ones in anything that weighs over a pound or is a fast mover. I have several Orange Fast Futaba-compatible receivers in most of my 1/2A's and have never had a problem with them, but I like to restrict the amount of damage a failure would cause by not putting them in larger, faster (and more expensive) planes.

jester_s1

It's generally good practice to have a junky little foamy around to field test receivers in anyway. Mine is a Stryker. It can take a major bump and keep going.