700 (2026)

Hi Ian,

if the blades are not tracking, it's the links between the swash plate and the blade grips.
Either they are not equal, or the blade root is not true.
Try and error, half a turn or a turn on one link, if it gets worse, wrong direction, if it gets better, you're on the right 'track'
Also have a good look at the swash plate and bolts, everything should be tight, fit symmetrically, rotate without wobbling.

Theoretically, it could be possible that the blade grips are not equal, or that the feathering shaft is not/no longer straight (e.g. after a mishap), or it could even be the hub.
One thing you can test: leave one blade mounted, and rotate the bolt in the other blade grip (so rotating the whole assembly inside the blade grips/hub)—if the blade 'winks' it's possibly something inside the head.

If it was just the sound of off-tracking, or vibration, it could also mean that the blades are not perfectly balanced.
Here, a strip of tape to approx. one blade's center of gravity might tell tales: if it gets better, continue there, if it gets worse, try the other blade.

Good hunting!

—Eddi

Born to fly ...
forced to work.

Hi Eddi,

Thanks for the pointers. The blade tracking was a good way out on the heli's first spool up from new build. so I did not lift off.
probably about 30mm at the blade tip.
I adjusted the link to one blade and it is not perfect but could be with a little more tweaking.

What I am looking for is why.

The feather shaft must be straight on first flight, I guess but I will check it.
How could the hub or blade grip be an issue and I will check too?

At present, I'm still assuming I have built something a little wrong.

Thank you.
Ian

Hi Ian,

even though it shouldn't happen (or shouldn't skip quality control), we've sometimes seen hubs or blade grips not machined symmetrically, and even 'banana' shafts fresh from the supplier. So while it's not exactly common, it can happen.

Then, blade roots not being like parallel to the chord line has also been noticed (no idea how, either), or blades being warped somehow throughout their length.

And reading off a caliper can also be a challenge don't ask me how I know ^^

Basically, if you get the blade tracking right with adjusting the links between swash plate and blade grips, and if it remains consistent throughout the collective pitch range and throughout a flight (or many), for me it would be OK.
If not, or if tracking keeps changing, something is really off.

Everything below the swash plate has not really an effect on the static (collective only) blade tracking, so a swash plate leveler wouldn't really help here.
Of course you could try and measure the same angle of attack all around the rotor circle, with the model sitting level, and the swash plate leveled, but that is true anyway if the links have the same length, and if all the parts involved are true to dimensions and angles.
Is why I never bothered

—Eddi

Born to fly ...
forced to work.

Thank you Eddi,

All useful information.

I started again last night. Head off, all links as per manual. Swash levelled by eye.
Back together with reset links to blades.
0°, 8° settings and top/bottom stick readings now seem to give consistent readings on both blades.
I checked the feather shaft too which seems ok so maybe I did something wrong but I did not find anything.

I'll run it up again this weekend weather permitting. hope it is ok, fingers crossed

Thanks again.
Ian

Hi Eddi,

Just to let you know.

After a start again set up all I had to do was adjust one link by half a turn and blade tracking was good.
I obviously had something wrong the 1st time.

the tail seems very soft running at 1650 Head speed. Am I best fitting some bigger tail blades or do I just need to up the gain - set at 70 at the moment.

Thanks again for your assistance.

Ian



Edited 1 time(s). Last edit at 09/14/2026 03:26PM by ian Spencer.

Hi Ian,

very good!

About the tail, start with settings in that bank.
With V8, Rate, Control response and overall Gain are the main levers to work with.

But also,
. define soft weak, imprecise, with a disconnected feel, or just not LOUD?
. what tail servo are you using?
. what tail blades do you have now?
. is it much different, at higher head speeds?

Best,

Eddi

Born to fly ...
forced to work.

Hi Eddi,

yes imprecise is about right.
I have a KST HLS1535 12v servo
Kit tail; blades - RT105mm
Yes it is better at higher head speeds.

I am sure I can try things myself, Just wondered whether 115mm is the right way or have I just not set up right yet.


Thanks Ian

Hej Ian,

well, 115s would surely help, particularly if you are into flying in the lower rpm range.

But at first, here, I'd try parameters.
Start with the servo, check refresh rate and pulse.
I'm not actually sure, but I guess they can also take 1 kHz at 760 µs without overheating, or they might require some re-programming, maybe Alex could shed some light here?

Then, up the gain and control response (try one at a time first to get a feeling what does what), and if it's imprecision around center what you feel, lower Expo.
I guess Alex could also help with insights here, they (his brother being Marik Wiehenstroth) afaik also use KST 12V.

Happy tweaking!

—Eddi

Born to fly ...
forced to work.

Hi Ian,

please use the tail servo at 500Hz, that´s for sure fast enough, Marik uses 500Hz at 760us as well.
Control response brings a lot performance in your tail, please try very high values for the low RPM.
What is your current control response? Please try values around/ above 150 for a really responsive tail

What is your target RPM range for your Logo 700?


Thanks
Alex

Hi Alex,

Thanks for your response.

Headspeed range Bank1 1660, Bank 2 1760, Bank 3 1860 but maily use at 1660
Control response is set at 70 so I guess I this is what I should be increasing?
It has been a bit windy for set up flying near me so not tried much yest.

Kind regards,
Ian

Hi Ian,

right.

Step it up in increments of 10 or 20 at a time is what I would do (safe approach, like increasing overall gain incrementally, to max it out without risking the model to explode directly ^^).

But I'd even trust Alex when he recommends 150.

Should anything untoward happen, you can always switch to a different bank with safe settings.

Cheers

Eddi

Born to fly ...
forced to work.

Thanks Eddi.

I know this is not affecting the above.
I'm sure I should know this as I built it.
After a few set up flights there is a little play in the mesh at the front of the torque tube. It is not much, about 6-7mm at the tail blade tips. Should I not worry about this?
If I should adjust, can I do this by just removing tail boom and shimming or do I need to strip further and do it from inside the chassis as per the manual?

Thanks,
Ian

Hi Ian,

I had to think hard for a moment, about what you mean, with the tail blade tips, but I think I got it

Honestly, I have no comparison.

But things add up a bit, gear mesh between the layshaft/front bevel gears, a little play in both torque tube couplings, and also at the rear bevel gears/tail rotor shaft. So you'd want to check where it begins, or where it's worst, and work on that (basically, front or rear bevel gears). Where to start, whatever works best I'd try the easy way first. With the gears lubed, it's also a bit more cumbersome to compare, unless you clean them again.

And of course it'd be good to know (or recall ...) how it was right after the build, and how it developed, if it's rather a wild goose chase or if there's really something to do.

Again, maybe Alex can shed more light on it, what amount of wear in is to be expected for example.

Best,

Eddi

Born to fly ...
forced to work.

Thanks Eddi,

Yes I think you got what I meant.
I don't think it is getting worse. There was no play when built but I was having difficulty getting the shimming at the front bevel right.

You are also right that there is a build up with front and rear bevel gears and Torgue tube couplings. Thats why I asked whether you think I'm trying to over engineer or whether it needs adjusting? I've not flown it enough to be any significant wear, it must have just settled in a bit.

Regards,
Ian

Hi Ian,

settled in, could be. Particularly bearings do that eventually.
I just went checking the demo 700 we have here, built by Alex for trade fair booths, has never seen the air.
Though I'm sure he does it right every time, not only when it counts.
It easily has the 6-7 mm backlash at the tail blade tips, and it doesn't feel off to me.

Would be curious to feel it on the heli Marik (Alex' brother) is competing with.

—Eddi

Born to fly ...
forced to work.

Thanks Eddi,

Sounds like it's nothing to worry about then. I'll wait for Alex' comment.

Regards,
Ian

Hi Eddi/Alex,

You are a good team!
105mm blades back on, 1660 head speed.
Control response slowly adjusted up to 110 and gain to 90. Tail is much more positive. I will probably increase control response a little more.
I've got to admit that i would not set it so high without Alex's input.
I did a trim flight too last night and it's looking good, more stick time required.

Thank you.
Ian

Hi Eddi/Alex,

I now have control response up to 150 now and it feels good.

Thank you both so much for you assistance.

Kind regards,
Ian

Hi Ian,

one question, if I may: after a flight, do you notice any unusual temperature rise, at the front bevel gear holder in particular?
You can feel it at the metal clamp there, for the outside.

Some pilots have reported that and asked about it, so I'm curious.

Do you recall if the aluminum bevel gear slipped in easily, into the bearings, or if there was some resistance or binding?

Best,

Eddi

Born to fly ...
forced to work.