My Lovely Logo 400 SE (Build Report)

[rdlohr]

I have been so happy with the Logo 600 that I built last year that I picked up a Logo 400 SE that I plan to use as my daily flier. It is just small enough to fit through the turnstiles at work so I can fly it on my way to work and then not have to leave it in the hot car.

This is a beautiful little heli, but the build did not go without issues. I post this for the new builders to show them that how you build your heli is just as important as the heli you choose and the components you use. There are always options to decide on and problems to solve.

The parts
ESC: Kontronik JIVE 80+ LV
Cyclic Servos: Savox 1250MG x 3
Tail Servo: FUTM0521 Futaba BLS251 Brushless Heli Rudder Servo
FBL: VBAR “Blueline” 5.2 Express (Full size)
Motor: Scorpion HK-3226-1400 (Logo 400/Trex 500)
Receiver: JRPRR121 Remote Satellite Receiver DSM (Spektrum compatible) x 2
Batteries: Voltz 3300 mAh 6S 22.2V 35C x 2

All came from: www.readyheli.com



I am a minimalist when it comes to heli components so you won’t see external BECs, receiver batteries or any other frills on this heli. As it is, I used a full size VBAR (with a separate gyro pod) but would have much preferred to use a mini like I did on my 600. Chris Hansen convinced me to avoid placing gyros on the upper platform since it is prone to vibration. I was very tempted to make a Lexan mount and do it anyhow, but I trust Chris’ input. I also almost did not put on the second satellite receiver and am not sure I absolutely need it. I took a conservative approach and installed it anyhow.

My goals when building
Component placement is always critical for me so I built off of all the lessons I have learned from previous builds as well as lots of Helifreak input. Here are the rules I generally try to balance while laying out components.

1) Isolate high current noisy components (main battery, ESC, and motor) from low current parts (antenna, battery, gyro, gyro controller, and receiver)
2) Protect all components from crash damage
3) Make heli parts you replace regularly easy to replace (Bottom Plate, Tail boom, belt, tail pulleys, etc)
4) Keep wiring runs short
5) Protect all wiring

The Motor mounting tip
When I initially mounted my main gear, I noticed it was very close to rubbing on the frame. I considered using a rat tail file to shave away some frame to add some clearance, but I then realized that there may have been some movement allowed when mounting the motor mounts. I went back and was able to shift the mount down to provide plenty of clearance.


The landing gear mounting trick
One of the problems I have had in the past on other helis is that the plastic mounts that the skids attach to break off on impact. Breaking these makes the repair job much more labor intensive and a bit more expensive. This is especially true with the Logo designs since the skid mounts are part of the main frames. A fellow helifreak suggested using nylon screws to hold on the skids with the hopes that they break first. I bought a bag of nylon screws and have been using them for each build ever since.



The tail hub problem
When I started assembling my tail hub, the bearing would not slip onto the one side. At first I just figured the end of the hub had a burr or defect, but then I realized that the whole side was just a hair too big. I spun it in some 220 grit sand paper and was quickly able to take it down to the proper size. I finished it off with some 600 grit paper.



The tail rod holder nut problem
When I tried to tighten the small nut in the rod holder, it started spinning in the plastic. Upon closer inspection, it was clear the plastic had been molded for a larger nut, so this nut would spin with very little force applied. Since I didn’t have a suitable larger screw/nut combo around, I opted to epoxy the nut into place. Problem solved.



Tail boom metal insert tip
This one is annoying because I didn’t realize I was going to have a problem till it was too late. As you go to mount your tail boom, the metal inserts that you screw into tend to spin and move around inside of the frame making it difficult to align the screws properly and I’m pretty sure I stripped one of mine. I was able to turn it in tight, but whenever I go to take off the boom I’m sure I will have a problem to resolve. The solution is to put a drop or two of glue on the outside of the metal inserts when you slip them into the frame to keep them stationary. Remember to do this early so that the glue is hardened before you mount the boom.

Be very careful to mount the boom at a perfect 90 degree angle from the main shaft. I used my digital pitch gauge to confirm this.

Servo mounting and geometry
When I first looked into mounting the servos using the stock horns (from Savox), I was not at all pleased with the resulting geometry. The links were at quite an angle unless I used two nuts to shift them inward and the horns seemed to flex really easily. A fellow helifreak suggested I use the Mikado horns and they worked out much better. They are much more rigid and they sit closer to the servo which removed the need for any extra nuts.
Before (2 nuts):


After (1 nut):


The Mikado plastic frames are perfect for screwing servos into. For the aileron servos, I opted to make some Lexan spacers to center the screws and provide flat surfaces for the screw heads.


For the elevator servo, I used a thicker Lexan spacer to shift the servo back to center the linkage between the frames. I didn’t really want the pointy end of the screws sticking out where I could see them so I drilled the frames and screwed it from the outside with a plastic nut mount in back.


I also carved away to the right side of the servo mount area to allow easier insertion of the servo and to give me the option to shift the servo back if I ever needed to. It turns out the geometry was good enough with the Mikado horns that I didn’t need to shift it back.


Wire placement and shortening
I shortened the servo wiring by cutting the connectors off to proper length and putting on new contacts/connectors. I left enough slack so that I could remove the ties and shift the VBAR back for maintenance if necessary.




Connectors and crimping tool came from here:
http://www.hansenhobbies.com/product...orkits/ck_sck/
Wire sheathing came from here: (ReadyHeli also has some)
http://www.techflex.com/prod_CCP.asp

I also shortened the sat receiver wiring by splicing the wires and hiding the splices with braid.


I considered just folding the wires under the braid but I liked the shortened result better.


As always, be careful to retain the integrity of any wiring you opt to shorten. Shortening a wire and then having a problem with it is just not worth it.

Zero everything
Zeroing the head is quite easy with an FBL head.
1) Use the VBAR to trim the horns to 90 (use a tool if you want perfection)
2) Lock the blade grips at zero. (again, a tool helps, but you can swing the blade tips together to get 90)
3) Level the swash by changing the upper mechanical link lengths as necessary. Assure that the swashplate driver keeps the links parallel to the main shaft. With both links at the stock 37 mm length, my swash was perfect.
4) Now adjust the lower mechanical link lengths to match the swash
5) Last, shift the swashplate driver so the base and its arms are all in line while still at zero pitch.
You can also start at the bottom and work your way to the top with similar results. As long as you end up with your horns at 90, grips at zero, swash level, and swash driver arms lined up, you can’t go wrong.


Zero Pitch and Under Swash Leveling Tools came from here:
http://www.readyheli.com/RDLohr_bymfg_23-3-1.html

Rudder direction trick
I’ve always worried that I’m going to have the rudder direction reversed and start my maiden flight with a spinning heli, or worse a chicken dance. Since I learned this trick, even I can’t get it wrong. Just position the top tail blade straight forward as shown in the picture, and the tip of the blade will track the direction the heli will turn. The picture shows full left rudder.



Final product

We solved a number of problems along the way, but ended up with a nice looking, mechanically sound, well tuned, great flying heli. I just maidened it today and I didn’t have to touch a thing, not even tracking. It flies awesome. It flies much more like my Logo 600 than my TREX 500 that it will be nudging out of my daily flying ritual.




I hope the detail I provided helps the next guys build go easier!

Rick


My other build reports:
https://www.helifreak.com/showthread.php?t=69894
https://www.helifreak.com/showthread...highlight=sexy

[Kalpazan]

Great report! Glad too see I did it almost the same way only that I grounded the boom to the motor mount in addition.

I know it is individual, but do you mind to post your vbar config file just for reference ?

[Bigugly]

Thats a nice clean build.

[ChrisH]

NICE Rick! Looks great. Two sats is definitely the way to go on anything swinging 425mm blades and up, IMO. And it looks like you did an awesome job of doing clean wiring even with the fullsize

[Laurens]

Thanks for sharing Rick! After about 20 months I'm starting to develop some play in the tail housing. I just glued the bearings in the housing, and I'll put some green loctite between the tailshaft and inner bearing races. Lets see how that works out.

I just stretched my 400 into a 400SE too, I also use it as a daily flier.

Are you going to make those lexan spacers for 9650 servo's too?

[pgleesonuk]

One thing I did regarding the landing gear was to install a pair of these carbon fibre parts
http://www.helishop-online.de/epages...lle%20Logos%22
Should protect the tabs in a heavy landing.

Also, by changing the motor I managed to arrange for a driven tail during autos.
https://www.helifreak.com/showthread.php?t=397310

I'm don't fly hard 3D, so maybe the motor power is not so critical. But at 1950rpm the Kontronik as all the power I need, and is very efficient. 300W to hover at 1950rpm

Getting really good results from a Fusion Hawk 60A ESC and the mini vbar governor.

[rdlohr]

Originally Posted by Kalpazan

Great report! Glad too see I did it almost the same way only that I grounded the boom to the motor mount in addition.

I know it is individual, but do you mind to post your vbar config file just for reference ?

I didn't realize this heli had a static issue. As far as my VBAR setup, I have everything initially set at the recommended Logo 400 values.

Originally Posted by Bigugly

Thats a nice clean build.

Thanks much.

Originally Posted by ChrisH

NICE Rick! Looks great. Two sats is definitely the way to go on anything swinging 425mm blades and up, IMO. And it looks like you did an awesome job of doing clean wiring even with the fullsize

Thanks much. I figured better safe than sorry.

Originally Posted by Laurens

Thanks for sharing Rick! After about 20 months I'm starting to develop some play in the tail housing. I just glued the bearings in the housing, and I'll put some green loctite between the tailshaft and inner bearing races. Lets see how that works out.

I just stretched my 400 into a 400SE too, I also use it as a daily flier.

Are you going to make those lexan spacers for 9650 servo's too?

I'll keep that in mind for the tail.

Laurens, I didn't really intend to market the spacers, but if you send me a 9650, I'll make you some.

Originally Posted by pgleesonuk

One thing I did regarding the landing gear was to install a pair of these carbon fibre parts
http://www.helishop-online.de/epages...lle%20Logos%22
Should protect the tabs in a heavy landing.

Also, by changing the motor I managed to arrange for a driven tail during autos.
https://www.helifreak.com/showthread.php?t=397310

I'm don't fly hard 3D, so maybe the motor power is not so critical. But at 1950rpm the Kontronik as all the power I need, and is very efficient. 300W to hover at 1950rpm

Getting really good results from a Fusion Hawk 60A ESC and the mini vbar governor.

Nice!

Rick

[Rollin_3z]

Good job, very nice build...You could get more space for motor by heating up frame with a hot air gun and holding the new shape till it cools down. Flew mine all day, luv mine.

[rdlohr]

Originally Posted by Rollin_3z

Good job, very nice build...You could get more space for motor by heating up frame with a hot air gun and holding the new shape till it cools down. Flew mine all day, luv mine.

Nice idea. I didn't seem to have any problems with this motor.
Rick

[BennyTRD]

Nice build Rick. Just got a 400SE myself that I'm building at the moment. Some great little tips here that I'll keep in mind.

[rdlohr]

Originally Posted by BennyTRD

Nice build Rick. Just got a 400SE myself that I'm building at the moment. Some great little tips that here that I'll keep in mind.

Thanks Benny. Enjoy that build!
Rick

[Big Fil]

Great job Rick! Like usual you always have the cleanest builds I've ever seen.

Now that your 400se is going to be your daily flyer, will it be transported in the bag like your 500 was?

[rdlohr]

Originally Posted by Big Fil

Great job Rick! Like usual you always have the cleanest builds I've ever seen.

Now that your 400se is going to be your daily flyer, will it be transported in the bag like your 500 was?

Thanks Fil. haha, yes, that is part of the game. If I tote it in a stop and shop bag, I can stroll right by the guards. It just fits.

Rick

[rdlohr]

People have been asking me where I got components, tools, etc so I went back and provided links.
Rick

[rdlohr]

Originally Posted by Kalpazan

Great report! Glad too see I did it almost the same way only that I grounded the boom to the motor mount in addition.

[Bullfrog98]

Crap!!!! Was it this beautifully built 400SE than crashed!!!

That's just a crying shame man.

[rdlohr]

It was but she is good as new now!

https://www.helifreak.com/showthread.php?t=413674

Rick

[rdlohr]

It took a new VBAR controller but she is flying flawlessly now.
Rick

[BakedMopar]

Originally Posted by rdlohr

It took a new VBAR controller but she is flying flawlessly now.
Rick

That's great to hear. I have yet to do the stretch and tail servo mount. Hopefully I can find some time soon!

[rdlohr]

Many flights later and into the next season, I have to say I'm loving my Logo 400. It has surpassed my REX500 as my favorite bang around heli. It just flys great and its small enough to take to work with me. Having a single battery is convenient as well.

Rick