Multiplex Heron - Now a Build Thread

[Konrad]

Next time try to use a heat gun to "train" the motor wires rather than cut the strain relief.

I go into detail about the use of Futaba servo leads in my HIP thread. I also give a value as to lead length. I also give some advice about the general build.

Multiplex Heron - Now a Build Thread

I bought a Multiple Heron kit from a local club member. I'm looking at things I need. I had the following things planned now. Any suggestions welcome. This is my first sailplane, but not my first plane. Motor: Turnigy Aerodrive SK3 3542-1000kv. Mentioned on RC Groups as a good upgrade to the...

forum.alofthobbies.com

I've never seen duct tape work as a pottting compound. Well, other than on a U-Tube gag video.

@gp49 what is gained with the PCB on the connectors? I see the same risk of over heating pins in the plastic housing.

PS,
I like GP49's potting fixture. I have some aluminum ones and find that it acts as a heat sink making the the hot glue cool down a bit too fast.

 

[jure]

... what is gained with the PCB on the connectors? I see the same risk of over heating pins in the plastic housing.

the connector pins are strain/stress relieved, as the strain now is transfered to the six wire soldered connections on the small PCB.

 

[Konrad]

But the wires are still unsupported at the PCB. And it has been these wires that fail not the pins.

Also the PCB adds a lot of length to leverage the pins out of the plastic housing. and the added length can/will make it difficult to install in a lot of application.

 

[jseyfert3]

Next time try to use a heat gun to "train" the motor wires rather than cut the strain relief.

That makes sense. I'll make sure they are sufficiently protected from the motor casing still though.

I go into detail about the use of Futaba servo leads in my HIP thread. I also give a value as to lead length. I also give some advice about the general build.

Yeah, I read your thread again last night. I saw you point out this issue, but I missed it the first time I read that thread. There's a lot of info there to take in in a single read.

I've never seen duct tape work as a pottting compound. Well, other than on a U-Tube gag video.

Sorry, not as a potting material itself. But if potting with epoxy or any other two part potting compounds, you can wrap duct tape around the connector, and it works great as a very simple mold. I didn't realize you were potting these with hot glue. Duct tape may not work great as a mold for hot glue.

 

[Konrad]

Ok, as a mold duct tape should work fine, if not elegant.

 

[gp49]

But the wires are still unsupported at the PCB. And it has been these wires that fail not the pins.

Also the PCB adds a lot of length to leverage the pins out of the plastic housing. and the added length can/will make it difficult to install in a lot of application.

That's the point of the PCB's I think: the pcb make the install easier OR 'difficult'. It all depends on the application. The PCB are easier to solder into the MPX connector then the wires direct. That's why I use the female pin method for most of my installs followed by the 'hot glue' cover.

For the skinny fuses in the current F3F/B gliders i now use PCB'S below. They nicely relocate the wires to a different position in the compact fuse....

As I mentioned before, there are many ways to skin a cat, but for me it's a lot better/ easier to use a MPX +/- PCB board then to use a JR/Spektrum/Futaba servo plug as a connector for the wings.

 

[Konrad]

I like that 90 degree board. I can see applications for the 90 degree board.

 

[gp49]

Here is another option with a tab for a plastic tie wrap to keep the wires somewhat is check. I have seen others as well, each one unique for a different application:

 

[gp49]

I like that 90 degree board. I can see applications for the 90 degree board.

@Konrad - I got mine from the pcb print place.. Paid under $30 for lifetime supply - that's including shipping. You can get the files and the website where to get them here: https://www.rcgroups.com/forums/showthread.php?3648359-4-servo-wing-connectors

 

[Konrad]

To save anyone from having to go through RCGoofs and giving Google a false impression as to RCgroups relevance here I eliminate the middle man with a direct link.

PCB Prototype & PCB Fabrication Manufacturer - JLCPCB

Instant online PCB quote, get PCBs for only $2. Check design with the online gerber viewer, Easy and quick PCB Price Calculator from JLCPCB

jlcpcb.com

 

[gp49]

To save anyone from having to go through RCGoofs and giving Google a false impression as to RCgroups relevance here I eliminate the middle man with a direct link.

PCB Prototype & PCB Fabrication Manufacturer - JLCPCB

Instant online PCB quote, get PCBs for only $2. Check design with the online gerber viewer, Easy and quick PCB Price Calculator from JLCPCB

jlcpcb.com

Just to clarify you will need the 'files' from the rcgroups link to upload into the 'jlcpcb.com' website. They are only a 'print shop' and do not design the pcb boards for you..

 

[Flying Dutchman]

When soldering onto the MPX connectors, be sure to have the male/female pieces engaged. This keeps the pins aligned when things get hot. I picked up that tip on this forum long ago, and it helps a lot.

 

[jseyfert3]

Going slow here. Messed around just a little tonight. As I knew, the HS-5065MG would be just a tad bigger than the HS-55 this was molded for. To fit the rudder servo, it seemed I could just cut the servo tab slot a little wider, so I did.

I also had to trim the foam a tad near the servo wire exit. Then the servo fit in, even though it’s slightly wider that the HS-55. Like a light press fit.

Out of curiosity I grabbed one of my NIB HS-55s, and sure enough it slides in without pressing or cutting (besides a thin lip of foam from the molding process over the tab slots). With one glaring exception…the elevator servo wire outlet is molded into the wrong spot! Like these are supposed to be identical servos here, why are the wire spots in different locations!? In any case, easily remedied. I need to trim for the HS-5056MG servos anyway.

At this point I also noted the head of the 5056s was higher than the 55s. They do still fit with the bigger head and servo arms…just barely. But I don’t think I’ll need to trim the foam.

Comparison of the HS-55 and HS-5056MG servos. The 55 is on the bottom in the top photo, and on the top in the bottom photo. Just to be confusing…

 

[tic]

It's nice to see a thoughtful assembly with good components

 

[Konrad]

Nice photo of just how slow a Heron can land. Look at the short skid marks behind the Heron. This is Tic's well used, suntaned Heron. (note the cream color).

 

[northcave]

I’m just beginning a Heron build also. I think I’ll also go for the HS-82MG but perhaps the HS-65MG for the tail rather than the digital versions.

I was considering a more powerful motor but I begin thinking it’s a bit of a cheat and takes away some of purity of the motor glider if you can just crank the power on and fly vertically up. So I think I’ll stick with the standard motor.

 

[Konrad]

Ok, just so you know Multiplex and Hitec are owned by the same guy (Mr. Parks). I say this because I don't think the Hitec servo is the best choice for this bird. (that having been said, my Heron is still going strong with the Hitec servos I installed 6 or 7 years ago. I don't have as much time on my Heron as Tic, but I do fly her hard at times.

Do go with the metal geared servo. Today I can't think why one would want an analog servo. Unless one is concerned with the the power (heat) limit of the BEC. (If so get a better BEC)

I like the Emax servo line for high marks when it comes to value and performance.

Not sure what you are thinking when you state "the Purity of the motor glider". I like the short time on power of a rocket like climb. This allows me more time to search for lift rather than plod along waiting to reach altitude. (Yes the stock motor is adequate, but for near the same cost (price and weight) one can get a better performance unit).

Are you looking to get the Heron in a kit or as an ARF? I recommend the kit and sourcing the other components to meet your needs.

 

[jseyfert3]

Well, this ended up sitting for like a year. Time really flies. Just broke it back out and continued assembly this weekend. Plan is to continue working on it and get it flying shortly.

Unfortunately, after a year and a move, I can't locate my motor or my ESC. And that was a $70 ESC too...hopefully I find it, otherwise I'll need to get a replacement.

I see the Neuron series was discontinued too. FrSky replaced it with the Neuron II, but Aloft doesn't list that for sale. Google only appears to show three shops selling it, none in the US. Also price went up to $100.

 

[Konrad]

I too have a lot of stuff in a safe place, never to be seen again.

 

[jseyfert3]

Well, that prior post, where it sat for a year, was just a prelude. Things changed yet again and it ended up sitting for over two more years.

The good news is in that interim I found my motor/ESC I mentioned went missing back in 2023.

Current state of the build, as I pulled it out of the box since I last touched it in 2023:

• 5 of 6 servos glued in place
• All stiffeners glued in place except the two fiberglass stiffeners for the vertical stab (I appear to have lost these) and the 4 metal aileron/flap stiffeners (I did not loose these)
• Wheel, motor mount, canopy clips all glued into place

Looks like I was intending to solder the tail servo extensions to the servo leads:

My Rx, ESC, motor, 3 sizes of props, and a pitot-static airspeed sensor (may or may not install that).

Finally, I have a question about the control setup. Everything made sense until I got to the flaps. The manual says this:

Under the “Ailerons” section, when it said flap +2/-2 I took that to mean if you have full right aileron, you should have 2 mm up deflection on the left flap and 2 mm down deflection on the right flap. Is that correct?

However, under “Flaps”, it says aileron should be +10 mm. What does that mean? When are the ailerons deflected up by 10 mm? Does that mean they should be up for either of the speed or thermic mixes? That doesn’t seem to make sense, I thought in the speed and thermic mixes you adjusted both the aileron and flaps up or down to change the camber of the wing.

Everything else I understand. Elevator is full range +/- 10 mm, trim it down 0.5 mm when throttle is on, trim it down 1.5 mm in either speed or thermic mixes.

Spoilers is just mega up on ailerons and mega down on flaps, along with down deflection of elevator.

So it’s just this aileron/flap mix I’m slightly confused on. If someone can point out what I’m missing here I would greatly appreciate it!