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Old Aug 19, 2009, 08:12 PM
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KCV6's Avatar
Australia, SA, Edinburgh
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How to limit flybar pivot on the 400D.

Came up with a nice simple but fairly effective method of reducing the flybar pivot.

I had some O-ring cord of varying thicknesses laying around, so I took the flybar retaining cap off. The 400 is like most Walkera setups where a cap with vertical slots in it retains the flybar and limits how far the flybar pivots. I cut a piece of cord to the same width as the slots and cleaned the cap in acetone (it is a metal head) I used the trusty Loctite Prism (CA) to then glue the cord in place. Picture to follow at some later time once I get it "tuned".

This has reduced pivot by a reasonable amount and acts as a nice bump stop type damper. This weekend should prove interesting as with a bit of luck I will get the time to put it through its paces.

Mark
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Old Aug 22, 2009, 01:05 AM
Merry xmas
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Australia, SA, Edinburgh
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Reduced flybar pivot angle seems to work

Did a quick flight this morning before taking the kid half way accross Australia for his soccer game

Reducing the allowable "reaction" of the flybar has not had a great efect on stability (it is still quite stable), but it has allowed for quicker more positive transition in direction during forward flight. Hopefully the winds will drop a bit later on thisarvo so I can tinker a bit more.
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Old Aug 22, 2009, 07:42 AM
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30 mins of flight

Got in a good 30 mins of flying off two 2200mAh packs in less than ideal conditions, which is what I was aiming for. Gusting unpredictable 0 to 20 Kmh wind and it hung in there quite nicely with effort. Reduced the flybar movement even further which provided even more response. With full extent dialed in on the standard short servo arms there is plenty of speed.

Finally got it to blade strike during a topple on landing only. Managed to do it twice and broke a lower blade both times with a corresponding nick in the top blades. Could not get it to blade strike in flight so I'm extremely happy.

I have ordered 4 new sets of standard blades and 2 sets of 3D pro blades for the big Lama and 53Q from the folk at rc711. These are shorter than the 400 blades by about 15mm, but I might give them a go. It's only a reduction of 30mm out of the 480mm diameter. If they don't work well I'll just put them on the 53Q3.

Now I wait.

P.S. I was curious to see how badly the 400 would perform with one of the broken blades, about an inch snapped off the end of one lower. It actually still flew... not very well, but it flew with control none the less.
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Last edited by KCV6; Aug 22, 2009 at 08:25 AM. Reason: PS
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Old Aug 22, 2009, 08:24 AM
It flies!!! ... so who cares ?
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Joined Mar 2009
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Quote:
Originally Posted by KCV6
Got in a good 30 mins of flying off two 2200mAh packs in less than ideal conditions, which is what I was aiming for. Gusting unpredictable 0 to 20 Kmh wind and it hung in there quite nicely with effort. Reduced the flybar movement even further which provided even more response. With full extent dialed in on the standard short servo arms there is plenty of speed.

Finally got it to blade strike during a topple on landing only. Managed to do it twice and broke a lower blade both times with a corresponding nick in the top blades. Could not get it to blade strike in flight so I'm extremely happy.

I have ordered 4 new sets of standard blades and 2 sets of 3D pro blades for the big Lama and 53Q from the folk at rc711. These are shorter than the 400 blades by about 15mm, but I might give them a go. It's only a reduction of 30mm out of the 480mm diameter. If they don't work well I'll just put them on the 53Q3.

Now I wait.
Now THAT sounds pretty promising - makes my fingers itch even more to hit the BUY button at miracle-mart and get one of these babies (even though I won't right now and slap my fingers a couple times ... )

With regards to the blades for the BIG Lama ... rather cut a set of REAL Lama400 blades down to the length of the BIG Lama blades to do this test - a Lama400 weighs about 40%+ more than a BIG Lama - and the 3Dpro blades (as much as all the others that exist) are too flexible for the much lighter BIG Lama already ... practically everybody who tried them will (at least partially) second this claim. (This is also the reason why - while I was experinmenting on the blades for the "little" Lama, I suggested in the German forum I am on to use the Lama400 blades for the BIG Lama, because they already have to lift a higher weight to start with)

Well, I am curious what your personal opinion after this test will be, but I am also convinced that it will not be considerably positive ....

Regards.
Sven
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Old Aug 22, 2009, 08:33 AM
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I agree about the flex

Hey Sven,

I pretty much expect them to flex too much (it is very evident in the 3dpro big lama video) but it will make for an intersting test at 5 bux or there abouts I figured I may as well make the postage worth it on the 4 sets of standard blades

Would have been nice to use the cam on the helicopter today but I was pushing into the unknown a bit and figured if it came unstuck in a big way at least I'd only have a helicopter to fix.

So far I am very happy, thats not to say something won't go wrong and I would like to hear from some other 400 owners as I can't really compare it to anything else I fly.

Cheers... Mark
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Old Aug 22, 2009, 08:54 AM
It flies!!! ... so who cares ?
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Quote:
Originally Posted by KCV6

So far I am very happy, thats not to say something won't go wrong and I would like to hear from some other 400 owners as I can't really compare it to anything else I fly.

Cheers... Mark
Believe me Mark, if I had one, you WOULD hear from me ... but as I said, right now it would not be a prudent decision to spend the money for it - as I can barely afford the money I just spent on a lot of parts for my "little" helis

But I definitely DO READ all your posts here with great interest and ... comes time, comes money ... hopefully by christmas (the latest next year for my vacation to Germany) I'll be able to call one of the 400D's my own ...

Regards,
Sven
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Old Aug 22, 2009, 10:16 PM
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Understand fully..

Sven, fully understand. I have already blown my budget this year! Fortunately I am that busy at work that I have no chance of a vacation so luckily in Aus we can cash in up to 50% of our Long Sevice Leave with management approval.

By the way, if there is anything in particular you would like me to try, by all means don't hesitate in asking, I'm hoping this thread will help out others as much as possible up front, especially helping them make the decision thats right for them. I enjoy the 400D but fully understand that it may not be eveyones cup of tea .

I have come soooooo close to getting a big lama.....

Back to the shed for me for some more zinc plating.... car restoration

Cheers... Mark
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Old Aug 24, 2009, 08:35 AM
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Originally Posted by KCV6
Back to the shed for me for some more zinc plating.... car restoration

Cheers... Mark
Car restoration?!!!! What have you got there, mate? While you're at it, can you send over a Ute for me? Pontiac was on the verge of bringing them in and selling them as a Pontiac version of our El Camino, but now Pontiac is a dead GM division. Our G8 is a Holden unit that did make it into our showrooms, but alas, that will be gone now too.
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Old Aug 25, 2009, 05:58 AM
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Australia, SA, Edinburgh
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Ute.

Yeah it's a shame the whole export of commodores has ceased. Not a bad vehicle.

They have a whole class of circuit racing here called V8 Brutes using the Falcon and commodore Ute’s.. damn fun to watch, always full of biff and barge

Just helping my brother out restoring his Mk II Cooper S. Now there’s a heretic of a car if ever.
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Old Aug 25, 2009, 09:52 AM
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KCV6's Avatar
Australia, SA, Edinburgh
Joined Aug 2009
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shortened flybar.

Well I made up a 1.7mm thick x 15mm wide plate to re-bend and shorten the flybar by 15mm off each end. This is an old trick I learnt a while back. The flybars have a "hook" bent in the end. Measure the inside radius of the bend, or use a feeler gauge to measure the distance between the bar and the parallel return part of the hook. In this case it is 1.7mm. Grind a piece of mild steel or stainless plate to this thickness and a width matching the amount you want the flybar shortened by. Place this plate in a vice and put the hook over one side. Carefully bend the flybar using a soft metal rod (copper, aluminum etc.) back around the other side. Slide this off the plate and do the same for the other end. Trim the old hooks off and using a plastic or copper mallet close the new hooks up that bit extra so the two parts of bar are parallel. This will shorten both ends the same distance. Pics of the bend plate and how to dampen and reduce the flybar pivot to come soon.

This has made the 400D super responsive now, almost to the point of being scary to fly inside my lounge room for fear of over correcting (many things to break). It flies more like a single rotor now and requires far more control input. Personally this is what I was aiming for so it will respond quicker to outdoor wind conditions. This has also eliminated any chance of the flybar ever collecting the lower blades and wrapping itself around the shaft as has happened to at least one other 400 owner (see "Walkera Lama 400" on youtube by technoelect).

Now I just have to wait for the severe storms we are having this week to subside so I can get it outside.

In the mean time I have been working on the two dies for making press molded CF blades. This is progressing well and looks to be a fairly straight forward process.

Cheers. Mark
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Old Aug 29, 2009, 09:14 AM
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I'd be interested in your evaluation of the 3D Pro blades as I was very disappointed with the ones I put on my Lama 4. Along their length, they had actually curled up. I know they were straight when I got them, but the curl was noticeable after a while.
If you have this BIG 400 size heli and have to power it with 2200mah batteries, I'd hate to ask how much it weighs.
I'd like to fly in my 1/2 acre lot and not have to go anywhere every time I want to fly. My problem is that we ALWAYS have a stiff breeze or more until just about an hour before dark, if it decides to calm down at all. Most houses are too small for a 180 size heli, so, that leaves a palm size heli for almost 7 months of the year. I can fly my 180 size Lama 4 outside, but it is affected by the wind. The videos of the 400D have been less than complimentary. IMHO, they have hurt their sales with those videos and shouldn't have bothered. From what I'm reading about the Esky Big Lama, that's nothing to write home about unless you modify the heck out of it. I think there are MANY of us out there who are looking for that right heli and spend a heck of a lot of time and money chasing around trying to find it.
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Old Aug 29, 2009, 09:34 AM
It flies!!! ... so who cares ?
erdnuckel2's Avatar
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Quote:
Originally Posted by kodak_jack
I'd be interested in your evaluation of the 3D Pro blades as I was very disappointed with the ones I put on my Lama 4. Along their length, they had actually curled up. I know they were straight when I got them, but the curl was noticeable after a while.
If you have this BIG 400 size heli and have to power it with 2200mah batteries, I'd hate to ask how much it weighs.
3Dpro blades are already too flexible for the BigLama, Jack. THey are not made to be used on the Lama400 (they are MUCH softer and about 1" shorter than the Lama400 stok blades - you can surely cut them down to fit s BIGLama, but the other way round ?

BTW, the AUW for a truly "ready" to fly Lama400 is about 700g!! So the only thing that comes to my mind is that Mark is on the right way in building those CF blades ...

Regards,
Sven
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Old Aug 30, 2009, 02:08 AM
Merry xmas
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Australia, SA, Edinburgh
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blades

After yet another on ground topple resulting in a snapped upper blade I can't agree more. LOL I am pushing it too it's limits in wind now and it is handling it very well so long as I'm quick enough. Today is overcast with showers with 15Kmh winds gusting to 20kmh. It holds it's own well in these conditions with moderate effort.

CF is definately going to be a good thing. The standards just don't like hitting anything hard.

Jack I'm at 722 grams all up for 15 + mins of flight time with cam fitted. With the 1500mAh pack and no cam I am back at stock weight at around 640 grams and a good safe 12 mins of flight time.

I am trying the 3d pro hardened blades more to see current draw and lift with a shorter blade fitted. This will give me some direction in blade shape for the CF ones rather than just copying the standard blades. I will run a set for as long as possible and take before and after pics to see how they go with developing bends.

I had a bit of a vibe problem at hover today.. LOL turns out one of the standard blades was .4 grams lighter on the top set. I added some alluminium tape to ballance and the vibe was gone. Shame I toppled the darn thing about 2 mins in...... grrrrrrrr

Hey Sven I was looking at the bling.... I did exactly the same with a second flybar link.... has killed some play in mine for sure.

Mark
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Old Sep 06, 2009, 05:05 AM
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Between yesterday and today I managed to fly 4 2200mah, 4 1600mah and 2 1500mah packs through the 400D. Thats about 2.2 hours of airtime.

I have developed a love hate relationship with it.

The love being the flexibility of the 400D, the fact you can just potter around, do nice tight flicking in a small area outside with plenty of speed or get half decent FFF and do nice big circuits and naturally a combination of the above.

The hate.... The damn blades breaking too easily causing interruption too the fun, they are simply too brittle and snap way too easily albeit due to operator error. I went through 4 sets and every single break was due to clipping either the ground or foliage causing blade strike (CX blade strike). Note these were not all outright breaks, I have 2 complete sets with large chips out of them that can still be used for flight. I could just get the upper and lower blades to clip each other in flight so I ended out backing the extent off on the servo travel to about 3/4 and havn't heard a click since.

I have been flying with a combination of 1 and 2 flybar links. With 2 it can be a bit too responsive and requires stick input to pull it back into line. This will be something that is up to personal preferance and in my case will be on some times and off others.

All in all for me it's great fun and has proven to be durable and reliable taking many hard knocks in the 14 hours of flight time I have logged so far with the exception of the Blades. Motors are great. Plenty of power, good brushes, smooth and never get hot. Very simple and cheap mods transform it into a much nicer helo.

Mark
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Old Sep 06, 2009, 08:32 AM
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Quote:
Originally Posted by KCV6
Between yesterday and today I managed to fly 4 2200mah, 4 1600mah and 2 1500mah packs through the 400D. Thats about 2.2 hours of airtime.

I have developed a love hate relationship with it.

The love being the flexibility of the 400D, the fact you can just potter around, do nice tight flicking in a small area outside with plenty of speed or get half decent FFF and do nice big circuits and naturally a combination of the above.

The hate.... The damn blades breaking too easily causing interruption too the fun, they are simply too brittle and snap way too easily albeit due to operator error. I went through 4 sets and every single break was due to clipping either the ground or foliage causing blade strike (CX blade strike). Note these were not all outright breaks, I have 2 complete sets with large chips out of them that can still be used for flight. I could just get the upper and lower blades to clip each other in flight so I ended out backing the extent off on the servo travel to about 3/4 and havn't heard a click since.

I have been flying with a combination of 1 and 2 flybar links. With 2 it can be a bit too responsive and requires stick input to pull it back into line. This will be something that is up to personal preferance and in my case will be on some times and off others.

All in all for me it's great fun and has proven to be durable and reliable taking many hard knocks in the 14 hours of flight time I have logged so far with the exception of the Blades. Motors are great. Plenty of power, good brushes, smooth and never get hot. Very simple and cheap mods transform it into a much nicer helo.

Mark
That's one heck of a lot of batteries you seem to have. Do you think the kind of blade strikes you're having would be taken care of by more separation between the blades as in an extended shaft or are they just something that you won't be able to get away from?
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