My Custom 700N Build - PIC Heavy

[DCflyer]

All linkages threaded and ready to go........

All rods throughout the heli, except the swash to head rods which i've yet to decide on, are DaVinci 2.2mm turnbuckles with Align 700 links - they threaded very tight. Happy with them.

Quick UK FBL 28mm servo wheels, 3x8mm wheel bolts, and Align balls/nuts red loctited on. Also using Thunder Tiger metal servo plates.




I use a lot DaVinci's stuff on many of my builds and really like their machine work - the links always thread tight and they're easy to adjust.

The 500:


The Vibe:

[Jim Hansen]

Looks good. Great Job

[Glenn Goodlett]

What's the logic on the cut down Lynx tail spindle bolts? I was under the impression that stainless steel was too brittle in that sort of application. Just curious.

[DCflyer]

Originally Posted by Goodlett

What's the logic on the cut down Lynx tail spindle bolts? I was under the impression that stainless steel was too brittle in that sort of application. Just curious.

I kind of just took Fastone's experience as enough for me since he's been using them for a while and they've worked well for him.

The Lynx frame screws are quite large and beefy - the head itself is almost double the size of the stock bolts and helps to spread the surface area of the load over the washer and bearings much better - no cupping of the washer. Just a good solid bolt.

Sorry - not really a scientific explanation but I know they work well.

[DCflyer]

Originally Posted by Jim Hansen

Looks good. Great Job

Thanks Jim - its been a slow but enjoyable build - The problem with building something like this with so many varrying parts that are different from the stock design is that tolerances/clearances vary - so you find yourself waiting for specialty parts when you discover them. So far, everything thats come up has been addressed without issue so the build is turning out nicely but its taking a bit longer.

Once I have it together i'll be able to replicate it easily and future service shouldn't be an issue.

[Jim Hansen]

I here ya! lol Hey whos T Block and Grips are those i thought you were going to use Patrick's?

[DCflyer]

Originally Posted by Jim Hansen

I here ya! lol Hey whos T Block and Grips are those i thought you were going to use Patrick's?

T block and grips? You mean in the pictures directly above? Those are different heli's.

[Jim Hansen]

O They are my bad

[DCflyer]

Sunday update - installed and programmed all cyclic servos in the SK540. All trimmed to center and all linkages/bellcranks squared up to the frame. Looking pretty good.

As mentioned earlier, I was waiting on a special KDE elevator servo bellcrank, since the stock crank would not clear the large KDE thrusted bearing blocks. Once I got that I was able to do up the elevator.

The KDE arm on the right compared to stock on left:



And here they are all mounted:



Up Next:

Get all electronics (backplate sensor, sats, Switchglo Pro, and Rx battery routed and mounted - check operation - and then move on to head setup.

[DCflyer]

Tuesday update:

Got the nose cone electronics mounted. Will have to route them later.
-SK540
-Switchglo Pro
-Tail and Throttle servos


I already centered my servo wheels and bellcranks. My goal for tonight was to level the swash during its full range of movement and get the head ready for final linkage setup. Once I get my pitch nailed down I can route wires, tidy up the mainframe, and move on to installing the tail.

I got my SK540 sensing the backplate sensor for use with the Skookum governor. Great news. And I got my Switchglo Pro to work on Aux3, assigned to the knob on my DX8. The SG's servo lead is installed into the SW-A port of the SK, which is normally used for a 4-servo, multi-blade setup, but apparently defaults to Aux3 when used with a conventional head.

My main concern at this point is that I won't have enough travel in my linkages for something like Full Positive Collective AND full Left/Right Aileron - I will have to see tomorrow, but the servo travel is being hindered by the Align links hitting the servo casings. Since all links are installed on the INSIDE of the servo wheels, they can only travel so far before they contact the casing. This is just how the helicopter is setup according to Align instructions so i'm not sure how I will address this should it become an issue. Anyone have any insight here on this topic? I know i've heard guys talk about this very issue before.

Here is a few progress pics:

Just the three cyclic servos hooked up, as I had just completed swash leveling:


Head getting setup for final linkage assembly utilizing Rick Lohr's lexan Zero Pitch Tool:


An example of some of the finer points of the build: The tail bellcrank is put under heavy stresses during hard flight so I wanted to support it equally on both sides of the frame. Had a set of tail blade locknuts laying around so tried them on with the Lynx frame screws - Perfect fit. Bellcrank feels like its part of the frame now.

[DCflyer]

Thursday update.

With all the March Madness parties I didn't have time to do much tonight, but I did want get the Rail's mounted up and ready for pitch setup. I managed to get roughly 32 degrees total pitch out of the head so 13 degrees collective and 10 degrees cyclic shouldn't be an issue.

The Rail 716's are amazing. Nice wide blades and beautifully constructed. I had to get a side by side with my 550E running 550mm Rotortechs to give a reference on how big this thing is.

The head itself spins so smoothly its ridiculous - I gave it a light push and it spun for over a minute.

Side by Side:


The linkage setup for the swash-to-blade grips I decided on was a Synergy setup. I had some links/balls left over from my Synergy head conversion on my Vibe and settled on them. They are 6mm balls and 6mm links on the inner swash ring and the grip arms - much bigger/beefier compared to the Align's and will do the job for a heavy duty setup.

The linkages themselves are Lynx 2.7mm rods that are 65mm long. I had to drill out the inside of the links to 2.5mm and they threaded on very tight with plenty of material left along the outside edges.

Final Head Setup:

[abit late]

Thanks for the updates, keep them coming - this has become a work of art.

Sent from my Nexus 10 using Tapatalk

[DCflyer]

Originally Posted by abit late

Thanks for the updates, keep them coming - this has become a work of art.

Sent from my Nexus 10 using Tapatalk

Will do thanks bud. This has sort of turned into my own personal blog. But its getting there

Upon final head assembly, I noticed that the swash follower arms had a bit of play in them - they are from a previous 700N so I think the inner bearings have worn out the bores inside the arms and have axial play - no good.

So i'm now waiting on a set I ordered yest to get here so I can do pitch setup. I guess I can do it without them, but i'll just wait and do it once - My OCD won't allow anything else and i'll just end up doing it twice

This actually started out as a mild build with a few upgrades, but has morphed into what it is today. Eventually she'll get some airtime but I suspect i'll be quite careful with it considering the time and effort thats gone into it.

[DCflyer]

Sunday Update:

Did head pitch setup. Perfect 0 on both blades at mid stick. 12.5 degrees collective and 10 degrees cyclic to start out. Good range in servo throw for the FBL geometry as well thanks to the shorter balls, servo wheels, and KDE grip arms, without having to use the inner hole on the aileron bellcranks and elevator arm ( I really didn't want to do that since the angles of the rods are slanted to the swash and it looks really funky).

Fuel system rigged up and plumbed tonight. Using this as a guidline:

http://www.heliproz.com/articles.asp...cks&article=15


YS check valve rests just behind the frames (100mm distance from crankcase)
Using a JR metal fuel filter
OS 3-way valve for tank pressure relief
All Lynx Nitro fuel tubing
Great Planes fuel plugs (2)

Turned out to be a very clean setup.

[DCflyer]

Monday night update.

Wanted to get wiring routed and done tonight. I'm 95% there. Just have to adjust a couple little things to get it just right but for the most part, wiring went well.

Few things to note:
-Switchglo Pro is on a Y-harness with a secondary power lead
-Backplate sensor is passing through a Futaba 7.4v to 5.5v regulator to prevent potential failure.
-Pulse 3600mah Lipo Rx pack has two power leads, one going directly in Skookum and the other into the Y-harness with the Switchglo and then into the SK540, so the FBL has power redundancy.


Pics:





My busy backplate, complete with pressure outlet, backplate sensor, and Switchglo ground.



The final result. Again, not quite done yet - have to do some trimming on some of the servo tabs themselves (I hate Futaba tabs) to get everything to sit flush and even before I lay some hot glue over it.




Up Next:

Throttle servo setup. Hatori Pipe Install. DSMX sats install.

[DCflyer]

Weekend update:

Spent most of the day inside working on it since its been raining nonstop. Got a lot done though.

-Completed throttle servo setup
-Got main gear in
-Mounted and routed Sats (one on each front lower frame support perpendicular to each other)
-Mounted canopy supports
-Got the entire DFC boom and tail system on - final mount

Notes:

- The main gear mesh is a little tight so I massaged a 1/4mm out of each screw to shift the clutch stack and motor as forward as I can, giving good mesh on the KDE main gear.

-Am currently figuring out some programming issues with my Switchglo Pro - Can't seem to get it to activate on any Aux channel - i'm sure its my error so need to do more research.

-The throttle servo setup - holy cow. I spent prob two hours on this. The main issue here (as i'm sure other guys with Aligns and YS motors know), is that the carburetor arm that the actual horn attaches to is MUCH shorter compared to an OS motor. This, then, causes the linkage geometry from the carb horn to the servo horn to be at quite an extreme angle. It would cause the ball link to bind against the servo casing - I tried running the link on the outside of the servo horn, but it made the angle even worse - i'm talking a 15 degree angle relative to the heli.

In my attempt to prevent it from binding, I tried different ball link spacing, but my endpoints for throttle were nowhere near 100, which is bad news since i'm planning on running a governor. After trying 10 different combinations, it was clear that the ball link spacing needed to be on the second hole out on both horns in order to get proper endpoint setup. It was now a matter of getting proper linkage geometry.

My solution to this was to use an extra long 3x10mm carb horn bolt along with six 1mm, #4 washers to offset the carb horn further outward. This ended up being the ticket as I now have zero binding, 94/92 endpoints for throttle, and a nice straight angle for the throttle linkage.

Pics:

Here you can see my solution to the issue. Utilizing Quick UK ball links on a DaVinci 2.2mm rod. Metal servo horns and RJX HV servo for throttle.



Final mounting of the tail case assembly went very well. Held in place by 8 Lynx frame screws. The case's open design allows the use of locknuts on the inside of the frame to secure the assembly, therefore preventing the need for loctite.



What it looks like from underneath:



Moving down the length of the boom, I used all KDE hardware for the support assembly.

-KDE mount - with vibration absorbing material on the inside diameter ( + for nitro)
-KDE studs and locknuts
-KDE boom supports



And just to finish off the tail along with the CHP airframe:






UP NEXT:

-Final Wiring
-Pipe Install
-FBL final programming

[DCflyer]

Sunday night update:


Got the tail setup in the SK540. Ended up spaced out on the second hole on the Futaba metal horn - this translated to 110% travel in both directions in the software which is pretty much perfect.

Also, its strange, but both the tail servo on this build (a Torq 9188) and my 550E's tail servo (BLS251), have the same grindy operation when moved. Its only with my high quality 560hz/760us servos that I get this. None of my other tail servos exhibit this behavior. The grindy operation certainly doesn't sound pleasing to the ear, and it creates a vibration down in the pushrods.

Also used CNC endcaps on the servo to bellcrank carbon rod, which stiffened up that rod quite a bit. The original design has the carbon rod "floating" on the metal rod since the links aren't screwed on far enough to bite into the carbon piece in order to get good geometry. The metal end caps take up the extra slack and allow the links to create a contact point with the carbon rod, therefore providing for a now very rigid pushrod.

Moving back, I used the DFC carbon pushrod extending out to the tail case.




Also picked up a second canopy on ebay for more of an "old school" look - plus it was only $30. I kind of dig it.

Went ahead and installed the Hatori 3D pipe as well. Using a bit of silicone on the O-rings allowed the pipe to slip onto the header like a glove. I also used some Blue Magic polishing cream and polished the pipe for a good 20 minutes. Really pops now.




Got a lot done this weekend. Time for some rest. I have some programming and gear mesh issues to sort through in the next week. And a few more screws to loctite. Once thats done, she'll be ready for some break in tuning!

[Chanq]

Nice build and pictures

[DCflyer]

One more focus shot from the back with canopy on. Everything clears very nicely and there is so much room to work in. I caved and ordered a SICK Canopy. About an 8 week wait but should be worth it to complete this build.

[DCflyer]

Quick update. She's tuned and running well. YS120 seems to be cooperating so far. I have a small leak in the exhaust header. Need to get in there and add some RTV.

Switchglo Pro is really key to tuning these tempermental big bore motors. I can turn on the glow for 15/20 sec while the engine is running to allow it to warm up. I'm using colder Enya #5 plugs so it takes it a little bit to get going.

Running Wildcat 15% in there right now. Its 18% oil. I wanted Byron's Rotor Rage which is 21% but can't find anyone that sells it. I'd have to buy a whole case for like $140 from amain, but my LHS carries the Wildcat which is supposed to be a really good fuel so it seems ok at 18%.


Couple of changes I recently made - I tried swapping in a Lynx long mainshaft made for a 3rd bearing. Didn't like it so I went back to stock with the KDE extension.

I added an i2RC tail rotor. Much better machined than the stock unit and it has built in counterweights so I don't need to run weighted blade bolts anymore. I like this system more since the weights are built into the hub and in the toward the center, keeping centrifugal forces lower which should be easier on the blade bolts.

Speaking of blade bolts, I decided to discard the Lynx stainless frame screws I cut down so they would fit my tail rotor spindle. I order a set of the hardened Quick UK 12.9 grade 3x8mm bolts for the tail. Should be good to go there.

And finally, I caved and had to have a custom canopy done up for this build. It took over two months to get it from SICK canopies, but it turned out fantastic. These pictures do it no justice. I'll have to get some pictures of it outside in the natural light.

Running 116mm Rail tails and 716mm Rail mains. Plenty of clearance with the DFC boom. Trueblood dampeners keep the head and blades nice and stiff. The KDE head block is a perfect distance on the mainshaft. Any chance of boom strikes with this combo should be very low. Just have to keep an eye on the dampeners every 30-40 flights.

Pics: