DIY: 4G6 Crash Proofing and Performance Enhancing mods! Updated 27July2010

[timewerx]

Blade Tip V5 in the works.

-Better stability
-Lighter in weight
-Improved crash survivability
-BUT less efficient than the V4, bogs a little when I get crazy on the sticks and also generated a lot more noise comparable to the stock blades (maybe efficiency is related to noise level, hmm...)
-NO graphics applied to permit customizability in looks. For example, printing in white paper, and applying strips of color with pen before coating blade tip with clear packing tape.

*Will try to design a new one incorporating both features of V4 and this V5 to hopefully combine performance, stability, and better crash survivability, stay tuned!

P.S. I actually had to use a new blade on this one. Cut it up of course. I just don't feel like flying my 4G6 anymore with the fully stock blades, too chicken to do it without the crash proof, lightweight tips! Oh yes, if I crash a stock blade hard enough, it could get too damaged to even apply my blade tip mods!

[timewerx]

The soon to be released Blade Tip V6/w and High Performance Paddles V3/w!

The 140+ sized aerodynamic and lightweight blades and when used with the new, longer paddles, raises your 4G6's performance to a whole new level! (Just reduce DR/Expo initially to avoid getting surprised!) Also offers the best blade core and rotorhead protection yet to let you re-use the blades after crashing(instead of just throwing the blades away)

Both the new mods also have the option to use weights with precise locations on the template where to place them. The weights makes the 4G6 handle easier while still taking advantage of these mod's superior aerodynamic performance!

[timewerx]

Please read this, very important:

Disclaimer:

https://www.helifreak.com/showthread.php?t=193537


Illustrated instructions are provided below the video and mod picture. Also, please look at the attachments for the template to print, thank you!

For transforming this tail blade into a more effective assymetric design, click here

These alternative, virtually free tail blades offers the following features:

-More efficient and silent - pronounced use of taper and slight forward sweep during operation reduces strength of tip vortices and reduces tip stall. Translates to better tail hold, less power drain, less noise and longer flight times.

-Improved handling, stability, and crash survivability of tail components - all these are achieved by the paper tail blade's less weight compared to stock. Less weight means less damage to tail components in a crash (completely eliminates problem of tail rotor shaft bending in a crash!!), less gyroscopic precession that could ruin those piros!

Cons:

Blade tips get ruined in ground contact easily but also easily repared by pinching with pliers (more on that later in a separate 'timewerx mods repair thread')

"Free doesn't have to be worse and in the age of Carbon Fiber and Kevlar, paper still has its place in high performance applications!"

Please skip to 4:10 if you want to view the fast piros immediately, they're so few because I had to limit doing piros in such tight space. I crashed into a wall after doing a fast piro just minutes before the video was taken. The 4G6 was fully repaired in 3 minutes, replacing just a shear pin and straightening the crumpled paper tips!

[timewerx]

Please read this, very important:

Disclaimer:

https://www.helifreak.com/showthread.php?t=193537


I discovered recently that my paper mods doesn't need to be R&R'ed all the time for things like dents. More so, even just semi-decent job of removing the dents did not compromised performance significantly at all! And it may take up to 10 crashes - quick repairs before R&R becomes a necessity.

It could take up to one hour to R&R my mods but quick repairs only take few minutes and best of all, can be easily done on the field!

Applicable to Timewerx blades and paddle mods only. Do not use on stock parts.

Warning: R&R my mods after 10 crashes or use best judgement. The tail blades for instance can take more crashes/quick repairs than that before getting too damaged to continue using. The paddles can survive way way more crashes. The main blades, usually, around 10 crashes.

[timewerx]

This is my current design progress with the 'anti-flutter' high performance crash proof blade.

I just added a forward blade area and reduced trailing edge in the inner part of the blade. Hopefully the increased area in the inner portion will improve efficiency of the blade.

The main purpose is offset center of gravity to give blade a straight or very slight sweep back angle during flight. Theoretically, this will make the blade more stable, and prevent flutter even if you have plenty of head slop! Hopefully, it will also help induce the blade to twist in the proper direction(positive and negative washout depending if you're flying upright or upside down). Proper twisting improves performance, efficiency and reduces noise.

Hopefully, it works as designed.

[hjns]

Originally Posted by timewerx

This is my current design progress with the 'anti-flutter' high performance crash proof blade.

I just added a forward blade area and reduced trailing edge in the inner part of the blade. Hopefully the increased area in the inner portion will improve efficiency of the blade.

The main purpose is offset center of gravity to give blade a straight or very slight sweep back angle during flight. Theoretically, this will make the blade more stable, and prevent flutter even if you have plenty of head slop! Hopefully, it will also help induce the blade to twist in the proper direction(positive and negative washout depending if you're flying upright or upside down). Proper twisting improves performance, efficiency and reduces noise.

Hopefully, it works as designed.

Hi Mark,

What about bogging? With broad blades, the motor will easily bog with small pitch increases due to broader blades. That's why I like the smaller blades. What do you think?

[timewerx]

Originally Posted by hjns

Hi Mark,

What about bogging? With broad blades, the motor will easily bog with small pitch increases due to broader blades. That's why I like the smaller blades. What do you think?

Hi Henk, thanks for your comment, that's true, and as much as you hate bogging, I do to.

Fortunately, making the blades wider towards the blade root does not cause bogging, in fact, it does the opposite and make the blades more efficient.

It is when you make the tips bigger or wider that bogging or general loss of efficiency is encountered.

This development stems from the apparent success of my paper blade tip mod. In response, I have also redesigned the flybar paddles with the shape of the tail blade. It's a very good example of an optimized blade design towards efficiency and performance. I did not invent the shape. It was used popularly in Supermarine Spitfire wings and later with NASA's research on MAV (Micro Air Vehicles). In kind, and in a limited fashion, I'm also trying to adapt the design to the main blades.

[timewerx]

Initial anti-flutter was a failure, made flutter worse!

This is second design, much like my tail blade shape. Flutter was eliminated completely! But efficiency was like stock which bogs the motor more easily, although transitional lift was distinctly better with more spectacular climbouts. Sounds like you can't combine 'zero flutter' foam blade and high efficiency... ...yet.

Also featured in the picture is the new high performance paddle design derived from my tail blade mod. It is longer and wider than my last and definitely more efficient. Seems more stable but more importantly, cyclic rate/agility increased without bogging the motor. Ironically, it looks like a heart cut in half... ...Make sure you dramatically reduce D/R or expo after installing the paddles.

My third design will try to focus on both high efficiency and anti-flutter properties. Will try to use lighter weight paper like 120 GSM to attempt to offset CoG so narrow blade design can be used without fluttering. Stay tuned!

[timewerx]

Okay, waiting for the glue to dry for some test flights. Pardon me for the messy workbench!

The orange portion of the blade is the 'anti flutter' mod. It is completely hollow, save for the carbon core. It uses a lighter 120 GSM board paper as promised, hoping to move CoG a little bit more forward. It is also narrower than the stock width it replaced and also much narrower than than my last one as the HP08 couldn't drive it sufficiently and bogs more as I go throttle crazy on idle up. Henk's instinct was correct!

Hopefully, this one keeps the anti-flutter characteristics of the 2nd iteration without bogging the motor.

Note that the blade tip I'm using is not V4, it is actually a V6w ('w' means it can carry weights). V6w is narrower than V4, offers higher performance and efficiency but flutters more... I've been keeping the V6w for some time now, I'm not releasing it until the flutter issue is eliminated. So far so good, V6w + anti-flutter proved more flutter resistant than both stock blades and stock + V4 tip.

[Scotty T]

wow, this is kookie thread.

How about some performance tips to help me tweak my 4g6S so I can fly it like Many Campos.

I see he tears up the stock 4g6 without any mods. I do know that he's good at programming the walkera radios.

Maybe I should just bind this to my JR 9505x and configure it from that?

[timewerx]

Originally Posted by Scotty T

wow, this is kookie thread.

How about some performance tips to help me tweak my 4g6S so I can fly it like Many Campos.

I see he tears up the stock 4g6 without any mods. I do know that he's good at programming the walkera radios.

Maybe I should just bind this to my JR 9505x and configure it from that?

Manny used really aggressive pitch curves (I think +- 12 to 16 degrees) and 100% on the D/R to make the stock 4G6 rip. The problem with that is that setup require very fine collective and cyclic management skills or else, you'll bog the weak motor quite easily.

With extensive modding, the 4G6 could definitely do more especially if flown by a very good pilot such as Manny.

Update regarding my latest anti-flutter mod:

-Narrower-than-stock anti flutter, did no better than the wide one. Bogging was similar but noise was louder, equivalent to stock blades. Efficiency was comparable to stock blades.

-However, this 'lightest of them all' design on a positive note was very easy to balance. Not only flutter was eliminated but vibration too! This blade could be operated at a higher HS without vibrating, especially when the plastic head is used. Note, that my 4G6's rotorhead had plenty of slop.

-The 'no-flutter' blade seemed to dampen cyclic which makes the 4g6 appear more stable.

Will redesign the anti-flutter again with slightly wider chord, a littler wider than stock to try to reduce noise and bring back the original efficiency that was lost. Maybe a more stable blade is less efficient? Hope not!

[Scotty T]

Originally Posted by timewerx

Manny used really aggressive pitch curves (I think +- 12 to 16 degrees) and 100% on the D/R to make the stock 4G6 rip. The problem with that is that setup require very fine collective and cyclic management skills or else, you'll bog the weak motor quite easily.

Well to do those tricks you have to have good collective management anyway.

But 100% D/R? I'm not sure that makes sense.

[timewerx]

Originally Posted by Scotty T

Well to do those tricks you have to have good collective management anyway.

But 100% D/R? I'm not sure that makes sense.

Nah, I don't think it would make sense to everyone anyway. I actually find it bit lacking. I went as far as modding my flybar, getting rid of the weights and replacing the paddles with something bigger and lighter like paper. With all the mods currently on my 4G6, gives it twice the cyclic rate of stock at same HS. Picture below show my current custom flybar.

Update on blade mod:

-Shown below is my latest design. Flight tests have commenced and gives the highest performance of all. It looks like my second design but this is narrower and only slightly wider than stock and uses lighter weight materials.

-Solves vibration and flutter issue. Allows higher HS with plastic head before vibrating to oblivion compared to stock and all blade mods I did so far. The secret is reducing the weight of the blade. Improves cyclic performance and reduces bogging in cyclic. When balanced and properly tracking, blade is silky smooth in operation

-Prevents bogging better than any of my blade mods so far. Still waiting for the new LiPos to see if more aggressive maneuvers can be attained without bothering with cyclic/collective management skills(so you can fly ala Manuel Campos without sweating!)

-Improves crash-survivability. Less weight of rotorhead components, I think that's self-explanatory. The mod itself is highly crash-survivable and escapes damage far most of the time!

This maybe the final 'mid blade' enhancement mod for offering higher performance and solving vibration issues.

Will also test this mod with stock motor to see if bogging is also reduced with stock motor (HP08/07 performance on a budget!)

[timewerx]

Did a bit of tweaking to my latest blade mod on a brand new blade but otherwise, looks exactly the same. Weighed the newly built blades and they weigh only 2.25 grams per blade compared to stock foam blade's 3.1 gram per blade weight. This is very good for reducing collateral damage and damage to the heli itself!

The tweaks were done to move blade's center of gravity closer towards the leading edge. Initial test flights demonstrated silky smooth operation which was a dramatic improvement over the stock blade and any of my previous blade mods. Not even ground-blade resonance was seen. Only minor drawback was noise. Blade seems to be even noisier than stock blade, louder buzzing sounds for instance but surprisingly, it's still more efficient than my quieter blade designs. So one would think, noisier doesn't necessarily mean less efficient.

I think that is all and this blade might be it! My 4G6 certainly felt amazing with it!

[edit]It wasn't actually noisier, aggressive collective tests has shown it is still much quieter than stock blades.

The new blade will be given a nick called 'Swiss Army Knife' guess why?

[hjns]

Originally Posted by timewerx

Did a bit of tweaking to my latest blade mod on a brand new blade but otherwise, looks exactly the same. Weighed the newly built blades and they weigh only 2.25 grams per blade compared to stock foam blade's 3.1 gram per blade weight. This is very good for reducing collateral damage and damage to the heli itself!

The tweaks were done to move blade's center of gravity closer towards the leading edge. Initial test flights demonstrated silky smooth operation which was a dramatic improvement over the stock blade and any of my previous blade mods. Not even ground-blade resonance was seen. Only minor drawback was noise. Blade seems to be even noisier than stock blade, louder buzzing sounds for instance but surprisingly, it's still more efficient than my quieter blade designs. So one would think, noisier doesn't necessarily mean less efficient.

I think that is all and this blade might be it! My 4G6 certainly felt amazing with it!

[edit]It wasn't actually noisier, aggressive collective tests has shown it is still much quieter than stock blades.

The new blade will be given a nick called 'Swiss Army Knife' guess why?

Hi Mark,

Can you give us a nice manual/template to make these blades?

Looking forwards to it!

[timewerx]

Originally Posted by hjns

Hi Mark,

Can you give us a nice manual/template to make these blades?

Looking forwards to it!

Hi Henk, Will do that tomorrow, just posted the video.

I owe this one to you guys!

https://www.helifreak.com/showthread.php?t=227756

[timewerx]

Originally Posted by timewerx

Hi Henk, Will do that tomorrow, just posted the video.

I owe this one to you guys!

https://www.helifreak.com/showthread.php?t=227756

Sorry, I think this will take another week. Running things on my mind, I think this mod will be a little bit complex to make.

So instead of two-piece paper surface, I will turn this into one-piece paper surface with same 'wave' trailing edge as V6-7. Hopefully weight will be the same or even better, reduced.

Blade will be renamed to V7 and should be almost easy to do as V4 and hopefully not as difficult to quality control as V6-7.... ....Quality will be crucial in this mod, after all, vibration, fluttering, and tracking issues we are trying to solve. It's these quality issues that sometimes causes the noted problems with the stock foamies.

[timewerx]

This is what's coming. Now in one piece! The Blade V7 Should have done this earlier. I have fears that will be much more difficult to install rather than just the tip in the previous blade. My fears were unfounded, just have to do some flight and crash tests to see if the blade holds up under abuse.

Hopefully, the one piece and flush geometry will improve efficiency and performance even further.

[timewerx]

New blade offered even higher performance and efficiency!

Crash test with new stock main shaft from Clubheli did not bend the mainshaft. Obviously due to the less mass of the V7 blades and also due to the new lightweight paddles.

This is probably the best blade for 4G6 now, no lies. After all, I'm not selling it anyway. Paper and inexpensive doesn't have to be cheap or incredibly primitive and unsophisticated. It could be carbon fiber but a distinct lack of innovation in aerodynamics or significant performance gains. Inexpensive, isn't always inferior unless the only motivation is profits and more money.

[timewerx]

In the undamaged state, the V7 blade demonstrated a factor of safety of 2.67 @4500 head speed based on forces.. But based on head speed, the factor of safety is 1.67 or the equivalent of 7500 rpm headspeed before the paper blade mod will start to lose adhesion to the graphite core and eventually fly off the blade.

The situation above is quite safe but, I also did impact tests on the blade separately. In fact, worse damage was inflicted than normally encountered in crashes, enough to damage the graphite core. What was discovered is the white glue completely lost adhesion in these situations. See picture below, after impact tests, the paper blade easily separated from the graphite core. This is going to go against the blade's intended re usability after a crash.

In response to that, I will change the adhesive used to secure the board paper to the graphite from white glue to double sided tissue tape - same material Walkera used to bind the foam material to the graphite core of their blades. This was not an issue with my previous blade mods. But due to near complete replacement of the foam material with V7 Typhoon blades, it's going to be a safety issue if white is to be used. Safety tests with the new adhesive will commence tomorrow.

I have actually previously considered double sided tape but they tend to be messy to remove, especially to those very sticky types. Good news is, I found that carburetor cleaner spray or lacquer thinner will cleanly and safely remove the sticky residue from the graphite. The liquid could melt the remaining foam material though, so be careful. Best practice is to apply liquid to tissue paper first and rub that tissue paper against the graphite and avoiding the foam.