4F200 - MKS DS470 Metal gear servo upgrade



Well, i have to say. These MKS servos are some of the nicest servos i have ever used. I even had a concrete crash and they took zero damage, meanwhile my heli broke apart all over the rotor and even bent the swash were one of the servos was attached. Really... These are pretty SOLID servos so far. Thankfully. The crash was caused by a new CC Phoenix 35 ESC. It is having startup issues and the heli suddenly jumped to full HS and tipped over. Even if it doesn't start up properly on this motor, i'm sure it's still better to have this CC ESC than a cheaper under amp rated ESC (possibly my old 20A was too low) Oh well. More on the ESC install later though.


The stock MKS servo horns are fairly rigid and strong. I don't think they will ever break. The long section of the horn is thick and strong. The stock 4f200 balls screw in directly very well! For 4f200 stock servo horn ball position, or closer to it. The tiny tab with only one hole on it should be used. Each servo comes with two identical servo horns! Pretty nice, though like i said. I don't think they will ever break. I'm going to see if my Savox 0257 servo horns will fit them. I think i would rather have a more brittle horn to save the servos from grief in a crash.. But i'll update this post later if i do that.

The servo horns must cut to fit without hitting the frame. If you use the long section you must use the first hole closest to the servo and trim the majority of the rest of the tip of the servo horn off. They are too long and will hit up on the frame on all 3 servos. The other unused branches of the servo horn must be trimmed off as well. Minimal frame modification is needed and will be explained in the pictures below.


Here is my first test flight with these servos, and also with the CC Phoenix 35. After my mishap with the sudden spool up issue and figuring out the only workaround i could

4f200 - CC Phoenix 35 & MKS DS470 testing (4 min 46 sec)

Here is a video i made with some video clips showing how durable these servos really are on this heli, when compared to the stock plastic gear servos. They also perform better. At the end of the video is a pretty good 3D flight to show their performance. Within 10 flights using the 2702V my stock tail servo gave out. I am now using a Savox 0257 on the tail as well (not in these videos though)

MKS DS470 = Major durability & performance upgrade for custom 4f200 (8 min 39 sec)

4f200 - Castle Creations Phoenix 35 ESC upgrade!



For the time being, the jury is still out on this ESC. At least in operation with my Turbo Ace 342, 4200kv 3S motor. It's not starting up very well no matter what i do. However the flight is very smooth with it and it does run the motor very nicely. It has tons of options and features. Easy PC link programmability via USB and a pretty decent governor mode. All in all, i think if the only problem i have is giving the main rotor a little push to get started, it's a small price to pay. Jumping up from my previous 20A ESC. I was worried that this 3S beast of a motor was drawing more than 20A constant, most likely spiking to around 30A easily. So I feel much more comfortable with a Castle powering my project, that's for sure. However i am very disheartened that my first Castle ESC does not function as well as i had hoped, in the manner of not starting up this particular motor. I still have some playing to do though.

4f200 - CC Phoenix 35 & MKS DS470 testing (4 min 46 sec)

Update 01-29-13:
I have had a few glitches with the CC Phoenix 35. One is a seemingly defiant will not to spool up to full head speed at take off. The other was a pure lock out when going in to a back flip, VERY similar to how my 2702V would behave. I really want to blame the 2618V for that one. But first is the video for the best flight of the day with this ESC and the new MKS servos.

4F200-Pro - Finally some decent 3D,15-25mph winds too! (4 min 35 sec)

4f200 - CC 35, MKS DS470, motor cut, crash! (3 min 35 sec)

4F200-Pro - CC Phoenix 35 won't speed up sometimes?!?! (4 min 43 sec)

UPDATE 02/02/13:

I have switched the CC Phoenix 35 to "airplane mode". It seems to be working well and the throttle "auto calibration" seems to be working okay. In this mode the throttle starts up more immediately and only throttle changes are ramped. For this motor in the 4f200, this mode seems to be working the best for startup. Also i was having problems programming the fixed end points with the Walkera RX/Gyro. It seemed like i had gotten the throttle programmed on the 2618V, but i was unable to get it to work properly with the 2702V that i am currently using. So far the ESC is much better than my previous speed controllers. I'm hoping i can manage to get governor mode setup properly, but without being able to program throttle, i don't think i will be able to use governor mode until i get a beastX or other gyro/rx. Here is a video of me ripping some 3D with the 4f200 in "airplane mode":

Custom 4f200 - 80% throt. You'll wish your's flew like this! (3 min 53 sec)

4F200 - 2702V Gyro/RX Upgrade / Savox tail Upgrade





I got tired of fighting tail holding, or the lack of tail hold on the 2618V. Without separate end points to set for the tail travel. It leaves the travel asymmetrical. Most of the time i had to adjust for a few degrees of counter torquing pitch to help mechanically hold the heading with the 2618. The 2702V has separate end point programming (not a single pot for both ends) so it does fly much better than the 2618V. The 2702V came off of my V450 and the previous dip switch settings were just about right. You might need to play with the gyro reverse switches on the RX as well as the TX reverse switches to get gyro correction and stick movements to work correctly. You will have to use 120° servo mode on the TX in "swash". I also, for my current settings, had to set the TX mixing for -100 on pitch and +60 on elevator and aileron mixing. This reversed the pitch servo control direction. Everything seems to be working fine now. But within 10 flights, my stock 4f200 tail servo burned out!! This was no surprise. The 2702V is notorious for burning out tail servos. But i am not sure the 4f200 tail servo is spec'ed to handle the 2702V's output. I installed a Savox 0257MG, which adds some weight to the tail. I actually need this because i plan on using slightly bigger batteries later on. The Savox servo actually dropped right in the stock servo mount. I used the same screws, i just added a silver "C washer" to each screw so the head didn't pull though the plastic. The rudder gyro had to be reversed and so did the TX control. Also gyro gain had to be turned way down. To about 65% or 70%. Previously, i was using 90% with my stock tail servo. The heli seems to be flying well now. I will post more video when i have had a chance to shoot some with the 0257MG servo installed.

CB180Z Tail Fins on the 4f200



Okay, this is a simple mod that ends up being both for looks and for function. The horizontal tail fin on a gyro stabilized RC helicopter is almost pointless. The only main function i believe it serves is protecting the tail rotor in a roll over. The vertical fin also has lost nearly any function on a RC heli. Except for maybe to protect the tail rotor.. The 4F200's vertical tail fin was not as tall as i would have liked. Especially since it was only FRP and ended up being fairly flexable. So if the tail did slap down on a landing, between it's flex and shorter length. It would allow the tail rotor to hit. Especially with the bigger tail blades. I am back using shorter tail blades now. But i had already ordered the CB180Z tail fins. Stupid me... For some reason i thought they might be CF, but they are only painted to look like CF... They are actually a little bit thinner than the 4f200's fins but the outlines are cut fatter and the horizontal fin is just bigger.

Since i didn't like the way the painted CF looked. I also don't really want black fins. I went ahead and sanded off all of the paint. Painting over it was a failure, something on the surface or the painted CF stuff it's self was causing my paint to bead up like wax. So i had to clean it with mineral spirits and sand the rest of the paint off. I think the look of the fins will stand out more in the air, for sure. So i think it looks better. The design of the cuts is not horrible and after painting. I think the heli looks damn good. It will look even better when i start painting my canopies again! Though i do like the stock 4f200 canopy colors. Black is just not as stand out as most would like.

A small modification was needed. I had to use a drill bit and bore the two holes on the vertical fin over some. They are just shy of being in the same positions to line up with the 4f200 screw holes. The back screw will line up, you just have to ream out the existing other two holes so they are more like short slots. Hopefully that makes sense.





UPDATE 02-13-13:
The new tail fins look great, i think. They are fatter looking from the side, so they stand out more on the profile. But the are honestly half, or less than half the thickness of the stock tail fin. Because the vertical fin is so thin. It tends to vibe around at the tip more than the stock fin did. I was going to get the V200D03 fins instead, but they didn't look as thick on the profile side. The fin is not vibrating. The heli is. It is just much more visible at the bottom tip of the fin now. Though most of the time it's hardly noticeable at a distance. I only really see it when i hover close and look. Unless there is an actual vibration problem. Then the fin wags back and forth with the vibe.

4F200 - Ino-Lab D261HB tail servo install


Well, the Ino-Lab servo is installed. This thing is pretty big. So i used a servo mount from the CB180Z fixing set, works perfectly for mounting this servo. The stock servo mount would need to be cut in half to fit this servo. Then each side would have only one fairly loose gripping set screw. I don't like the "pin sticking" "set screw" concept on a tail boom that is already obviously too narrow for this belt and a twist without poking tapping screws into the aluminum.. The CB180Z tail servo mount can be installed/replaced without having to disassemble the tail box to install it. If you cut the old servo mount off, that is. They are individual mounts for each side of the servo and clip right over the boom and have a screw which tightens the mount's grip on the boom. Just like the bigger V450 tail servo mounts, just a smaller for this size heli's boom. The servo is pretty heavy. But it actually ends up balancing the heli out almost perfectly. Previously i had to push the 1000 mAh Turnigy nano pack as far back as possible. I had to install a "wall" to prevent the battery from moving back farther into the elevator servo. Now, with the same battery installed directly square with the nose of the battery tray. The heli's CG is just about perfect. I will be going out this morning, right after this post. To do the initial test 3D flights. It hovered PERFECTLY and held the tail even in a drop out (in pitch) and then sudden pitch up for a hard climb out. The tail seemed to hold perfectly. So far the only problems i have encountered is the servo has to be orientated in a slight side angle so that the servo horn does not rub on the tail stabilizer rods. Also, none of the stock 4f200 ball links are big enough to screw directly into the Ino-Lab servo horn. The predrilled holes are too big. So there is actually enough room on a few of the servo horns to drill a small hole for the stock ball. I used a long ball from the 4f200 blade grips and had to drill the hole a little (tiny) bit bigger and put a nut on the back. I think the 4f180 ball link would fit better. The 4f200 one is a little long. But you could use two washers under the ball instead of one if the ball is loose. My hole was still slightly smaller than the ball was. So it holds tight anyway. I however found that the round horn did not provide adequate geometry for the servo rod. I ended up using the longer horn and cutting one side off. I used the second hole out from the center and with the servo tilted how it must be to avoid the tail stabilizer. The geometry is almost perfect. Though i'm still wondering if maybe i flip the ball around to the other side of the horn, the rudder rod might line up better. But it looks like it will be slightly off either way. More notes on the installation in the following picture descriptions.

4f200 Tail rocker screw upgrade to 2mm


Well, either because the Ino-Lab tail servo is so fast and has so much torque. Or because of the new higher head speeds, and very much faster tail speeds as a result, combined with the fast, powerful servo. It's a lot of stress. I don't know full reasons, but i sheered the tail rocker screw twice within about 5 flights. I feel that having a 1mm screw here is not working quite well enough. There is not much material on the aluminum rocker arm's bracket or the brass bushing either. But i went ahead and drilled them out using a few different drill bits from small to large, one at a time till i got to the right size. I tapped the bracket with threads for a 2mm screw and put a nut on top just in case. I drilled the brass bushing until the screw could move freely inside though.This way the brass will hopefully wear out instead of the 1mm screw. I actually used the 2mm screw from the main gear that stripped when the last tail rocker screw sheered... So those, or the main blade screws will work fine. I had a few test flights and noticed the tail was working properly now. I no longer had to add mechanical counter torque with the rudder rod. I could not set zero pitch and the tail was holding, a little too well. It was shaking all over. I dropped the gyro gain about 10% or 15% and the heli leveled out nice and flew great. The rocker looked real nice and tight and the bracket didn't look damaged yet. I expect that the screw will hold out, but if anything the aluminum mounting bracket will be the weak spot now. There is not much material holding that screw now, which is why i drilled to the minimum size and threaded the hole instead of making it pass through. I'll keep flying and see what happens though and update more later on what happens.

Here is the first short test flight.

4F200 - Quick test of 2mm rocker screw (1 min 56 sec)

4F200 tail conversion to V200D03, two blade tail. Assembly & modifications


Okay, so the 4F200 3 blade tail has just been completely problematic for me lately. I think the high head speeds have been giving the whole tail lots of grief. The tail belts were not lasting or flat out breaking in flight. The 3 blade tail was pretty sloppy. Surprisingly i still get a slight wag on the 2 blade tail. But i think it's all gyro gain related right now. The V200D03 tail actually has much more authority than the 4F200 tail. The piro speed is insane! You honestly don't need full pitch range on the tail! I can't explain why the 2 blade tail is so much more powerful and precise feeling. But i like it so far. Flight tests & video will be done tomorrow. This conversion took me all night.


It's pretty simple really. The V200D03 frame pieces needed to do this conversion are not sold separately. So you would actually need to buy a whole V200D03 frame to get the 2 pieces needed. Otherwise you will have do to some frame modification yourself. Mainly, the frame/ bearing block below the pit. & aile servos needs to be replaced with the V200D03 one or grinded down and cut up. Also, you will need to install the second bearing block from the V200D03 for the torque tube power take off assembly. If you don't have one, you'll have to make one yourself. Which is what i did, out of another frame / bearing block from under those same servos.


In the photo below you can see how i did it. I used that servo tray/ bearing block piece as my second bearing block to stabilize the torque tube gear shaft. I lined the block up with the frame and marked it though the holes in the frame. I then drilled holes for the screws and tapped in some threads for them. If you can't tap the threads on. You can put a nut on the back here. One of the brass ones out of the 4f200 screw kit, or off your old 4f200 tail grips should fit.






Like i was saying. The servo tray & bearing block piece installed already in the 4f200 needs to be modified in some way to accommodate the new TT gear that will be protruding out of the tail boom to meet with the main tail power take off gear. I did a sloppy job and was getting tired, so the pictures also came out a little blurry. But the photo below shows what the tray looked like BEFORE modification. (looking at the bottom of the heli, it's upside down)





The following photo shows AFTER modification. It's sloppy, but it works. I removed the bearing, cut the middle of the frame away, and used the dremel to grind the edges semi-cone shaped. There is plenty of clearance now.






More photos below from the assembly of the tail section. I'll update this post later and update the photo comments too. Flight videos will be coming very soon also. The heli definitely sounds different now, thats for sure.

V200 - Dampening tail vibes i can't get rid of


Well, shortly after installing the V200D03 tail on my 4F200 i noticed a rather wicked vibration that was rather violent but high frequency coming from the tail. The whole rudder push rod was dancing all over and so was the vertical tail fin. I tried all different kinds of tail blades, including 130X micro tail blades. The smaller blades had the least vibration. With no tail blades on the vibration seemed to be absolutely non existent. I even replaced the tail shaft and tail blade grip spindle hub. Nothing was getting rid of this vibe. So i went ahead and did what i could to dampen the vibes in an effort to prevent screws from coming loose and from giving the gyro grief too.


The first thing i did was follow Viking's example and advice with his V200 and i was going to build my whole rudder push rod purely out of a CF rod or V120 tail boom. But i didn't have a sufficient epoxy to build it properly. So i ended up using some heat shrink over the stock rudder push rod. The rubber/plastic heat shrink tightly squeezing the metal shaft, i was hoping would dampen any vibrations. But then to top it off i slid a 4f200 tail stabilizer rod over top of that. It fit pretty tightly so i ran some CA glue down the side of the heat shrink on and very quickly slid the CF tube pipe from the stabilizer bars set over top. This did seem to prevent the vibes from traveling to harshly down to the tail servo. With any luck it will extend the life of my tail servo. Which is already WAY over spec, so i don't think it will be a problem. More pictures below.



The second thing i did was cut and trim the vertical tail fin. The vibration was being greatly exacerbated by the FRP tail fin. The fin would take on resonating like a tuning fork and that vibe was a fair bit worse than the vibe on it's own. So cutting the tail fin actually resulted fairly well at negating the vibe. It changed the fin's harmonic resonance frequency and so the now much narrower fin didn't vibrate around as much. Or at least didn't conduct that vibe farther along. Unfortunately the narrow and now weaker tail fin broke in my first hard landing on the skids.


The third thing was to coat the vertical fin with a rubber spray. I am not sure this did anything at all to dampen the vibes. But i thought i would try it anyway.

V200 - Tail vibe solved??

V200D03 - Tail Vibration Solved (0 min 0 sec)

Okay, well unfortunately this didn't solve the tail vibe 100%. But with the CF reinforced rudder rod and the regular, uncut vertical tail fin installed. There is significantly less vibrations now than previously. Changing the TT shaft out is a total pain, just FYI.


UPDATE:
It appears the vibe is becoming worse as time goes on.

4F200 / V200 - Physical Installation of uBeast & SRX


A picture is worth a thousand words. This is how i installed my Microbeast V3 with a Spektrum Satellite Receiver. So far it's all working great when it's not blowing 30 mph winds

It's kind of a wiring mess... But imagine if i had to fit a whole regular RX in here! The satellite rx is not so bad.