So i was flying and noticed my tail kicking and assumed it was belt. It ended up being my tail servo going bad. It was my first tail servo to go bad! It went bad while i was inverted and flipping but hey! it was still the original stock servo that lasted like 9 months or something!

4f200 - Beautiful skys, bad tail hold! (4 min 52 sec)

4F200 - 08-18-12 Tail servo fail & Crash! (1 min 0 sec)

Originally Posted by IntegrityHndywrk

So i was flying and noticed my tail kicking and assumed it was belt. It ended up being my tail servo going bad. It was my first tail servo to go bad! It went bad while i was inverted and flipping but hey! it was still the original stock servo that lasted like 9 months or something!

http://www.youtube.com/watch?v=XDFW1jtO33s&feature=plcp

http://www.youtube.com/watch?v=a1brMxDE234&feature=plcp

Wow....hopefully that glitch did not cause a crash...annoying that would be

Originally Posted by IntegrityHndywrk

Hey razorblade. How about an update on that tachometer you got, now that you've had it for a little bit. I'm looking at other tachometers but they seem to have a 4 blade max limitation. How is yours working out? Do you only need to put a piece of tape on one blade to get a accurate reading? Also have you determined the proper point to take a head speed reading from? Would it be the blade's CG point? or the tips? It's looking like that is an exceptional tachometer for the price. Though i'm assuming it's because it's not a hobby related product. It is actually a tool for woodworkers, lathe operators, etc. But it appears to be working accurately for heli rotors?

Below is the tach I bought. It works out pretty good. I took the main blades off and tail blades off. Applied a .5 inch of piece of reflective tape (included) to the top of one blade grip. Then raised the throttle to max and measured the rpm by pointing the red laser emitting from the tachometer at the tape for about 4 seconds. I took several measurements. This is considered the no load reading. Well its actually not a "no load" reading since there is some minimal load exhibited by the main gear and tail belt mechanics. But it works well enough.

From what I have read, a more accurate reading can be taken by using an optical tachometer (more expensive) but than that involves having a buddy take the reading while you hover the heli at around 5 feet off the ground.

http://www.ebay.com/itm/ws/eBayISAPI...E:L:OC:US:3160

Originally Posted by razorblade

Below is the tach I bought. It works out pretty good. I took the main blades off and tail blades off. Applied a .5 inch of piece of reflective tape (included) to the top of one blade grip. Then raised the throttle to max and measured the rpm by pointing the red laser emitting from the tachometer at the tape for about 4 seconds. I took several measurements. This is considered the no load reading. Well its actually not a "no load" reading since there is some minimal load exhibited by the main gear and tail belt mechanics. But it works well enough.

From what I have read, a more accurate reading can be taken by using an optical tachometer (more expensive) but than that involves having a buddy take the reading while you hover the heli at around 5 feet off the ground.

http://www.ebay.com/itm/ws/eBayISAPI...E:L:OC:US:3160

Couldn't you just do a strap down with the motor running at zero pitch and 100% throttle? Either way the optical tachs i've been looking at won't do 5 bladed. I was hoping i could use this one with a single piece of tape on 1 blade tip or something while doing the strap down thing.

Originally Posted by IntegrityHndywrk

Couldn't you just do a strap down with the motor running at zero pitch and 100% throttle? Either way the optical tachs i've been looking at won't do 5 bladed. I was hoping i could use this one with a single piece of tape on 1 blade tip or something while doing the strap down thing.

Yes you would be able to measure head speed on the bench with the main blades or without the main blades. I personally just take the blades off just to be safe. And this tachometer it doesn't care how many blades you have. In a way, it only counts how many times it sees the reflective tape. For the price, its a good tool to have.

Just wanted to report back and say that the HK-15178B Digital MG Servos I installed have been great for this heli and for $3.89 each, that's the bargain of the century IMO. Just a shame they've been out of stock for weeks now otherwise I would have bought many more of them.

Does anyone know where I can by a replacement motor pinion?
I've moved mine too often from one motor to the other experimenting that it's got too much slop now and doesn't fit the shaft tightly.

Originally Posted by BenVK

Just wanted to report back and say that the HK-15178B Digital MG Servos I installed have been great for this heli and for $3.89 each, that's the bargain of the century IMO. Just a shame they've been out of stock for weeks now otherwise I would have bought many more of them.

Does anyone know where I can by a replacement motor pinion?
I've moved mine too often from one motor to the other experimenting that it's got too much slop now and doesn't fit the shaft tightly.

Did you have to do any modifications to get the servo's to fit?
EDIT:
I can see that the mounting tabs need some trimming, but other than that it should drop in.
Unfortunately they're backordered again.

Originally Posted by BenVK

Just wanted to report back and say that the HK-15178B Digital MG Servos I installed have been great for this heli and for $3.89 each, that's the bargain of the century IMO. Just a shame they've been out of stock for weeks now otherwise I would have bought many more of them.

Does anyone know where I can by a replacement motor pinion?
I've moved mine too often from one motor to the other experimenting that it's got too much slop now and doesn't fit the shaft tightly.

http://www.shop.kkpmo.com/index.php/...2fe68649585cf1]

You can try CA or locktite too. Let it dry for 24 hours if locktite. When you get a new one, it will be round. not keyed (flat spot) so use CA inside the flat spot to lock it in place.

Originally Posted by IntegrityHndywrk

So i was flying and noticed my tail kicking and assumed it was belt. It ended up being my tail servo going bad. It was my first tail servo to go bad! It went bad while i was inverted and flipping but hey! it was still the original stock servo that lasted like 9 months or something!

The 4F200 stock tail servo is actually okay. I still have mine which still works although I don't fly with it any more. Somewhere I was troubleshooting a AR7200BX tail endpoint programming issue and opted to try a different tail servo (Align DS420) which didn't solve the issue. It was a undocumented AR7200BX/transmitter programming side effect that was the culprit. In the end I just kept the DS420 tail servo installed and flew with it.

Originally Posted by BenVK

Just wanted to report back and say that the HK-15178B Digital MG Servos I installed have been great for this heli and for $3.89 each, that's the bargain of the century IMO. Just a shame they've been out of stock for weeks now otherwise I would have bought many more of them.

Nice to hear. I likes the price. Thanks for your feedback and sharing. Hobby King has been out of stock since 7/19/2012.

Hello!

I need to replace damaged RX2616 in my 4F200, but is discontinued. What is a spare or similar for this RX?

Thanks!

Sorry for my English...

Originally Posted by LITE

Hello!

I need to replace damaged RX2616 in my 4F200, but is discontinued. What is a spare or similar for this RX?

Thanks!

Sorry for ma English...

The RX's that work the best for this heli. are the 2618, and 2624.

The EMAX ES08MD servos are an upgrade option for the 4F200 cyclic servos. They perform better than stock and are an all metal gear digital servo. These servos are also a tad more responsive than the prior Futaba S3154 servos I had installed in my 4F200. Not a major difference, although small enough to notice from a non-pro 3D heli pilot like myself.

Here is the original manufacturer's web page for this servo: http://www.yinyanmodel.com/En/ProductView.asp?ID=171

They are priced around $12.00 each and can be purchased from the following USA web sites:

• http://www.valuehobby.com/radio-syst...ini-servo.html
• http://www.lazertoyz.com/ES08MD-12g_p_97.html
• http://www.bmkdesigns.net/emax-es08md-servo.html

But, modification of the 4F200 will be required if you want to upgrade, since these servos are taller in dimension than the stock servos. The rest of this post I have documented the steps I took to get these servos to fit securely into the 4F200 air frame.

DISCLAIMER: This post does not represent the one and only way of doing this. It only represents "a" way of doing it. If you are up-to-the-task of modifying your 4F200 then proceed and only proceed at your own time and cost. I shall not be held liable for any type of loss associated with the modifications described by this post.

1. Here is why modification is necessary. The ES08MD servos are simply taller than the stock servos.
   
   
   
   
2. Tools you will need to get the job done.
   
   
   
   
   
3. Prepare all servos. Use a file to trim away plastic. An unmodified servo is on the right.
   
   
   
   
4. Modify elevator servo insert.
   
   Use dremel cut-off bit to assist with trimming. Most important here is to relocate bottom two holes to a lower position. Use 1/16 inch drill bit to help with relocation.
   
   
   Here is how the elevator servo insert looks with the bottom aluminum support re-installed.
   
   
   Here is the elevator servo re-installed and fitting nicely.
   
   
   
5. Here are the two aluminum pieces that need to be modified. These are the pieces that are used to mount the pitch and aileron servos.
   
   
   
   
6. Modify the HM-4F200-Z-15 piece.
   
   Clamp this piece to the work bench and use a file. Grasp the file firmly with two hands, hold it level and steady moving through a consistently firm forward and back motion in order to achieve the best results. It doesn't take much force to file away the soft aluminum, so be careful and take your time.
   
   
   The finished HM-4F200-Z-15 piece. Use a 5/64 inch drill bit to enlargen the servo slots. The original is on the left.
   
   
   The pitch and aileron servos test fitted into the modified HM-4F200-Z-15 piece.
   
   
   The HM-4F200-Z-15 piece re-installed into its original location.
   
   
   
7. Modify the HM-4F200-Z-16 piece. Use a file to trim this one. Notice the two screws are filed down as well.
   
   
   
   
8. Use a 1/16 inch drill bit to help elongate the servo tab mounting holes downward.
   
   
   
   
9. Use a 1/16 inch drill bit to help elongate the holes in the fiberglass frame upward. Here also the pitch and aileron servos are test fitted.
   
   
   
   
10. Here is how the pitch and aileron servos look re-installed.
    
    
    
    
11. Last modifications are the servo horns. I use the inner most hole and use wire cutters to trim off the portion of the servo horn not being used.
    
    

The final steps are to mount the servo horns to all servos at 90 degrees as much as possible. Then adjust the servo horn to swash plate linkages. Ensure the swash plate is located in the center of its travel (pitch up and pitch down travel) Ensure the swash plate is level.

Finally go for some test flights and fine tuning of linkages and fine tunning of electronic settings in both transmitter and receiver.

Modification complete.


Sincerely,

Razorblade

Here's the first 3D flight using the ES08MD servos.

4F200 Seven Minutes Of 3D Flips Metal Gear Digital Servos (7 min 20 sec)

I am currently dealing with some AR7200BX cyclic oscillation issues.

The problem is three fold:

1. The 4F200 is a small 200 size heli
2. The AR7200BX is sensitive to input voltage and needs a BEC voltage of 5.0 volts when fitted into a small 200 size heli.
3. The HobbyWing FunFly 40A BEC is measuring at 5.3 volts (+/- 1 volt).

In my latest flight video I am flying with a different ESC, the HobbyWing FunFly 40A ESC with built-in switched BEC rated (on the label) at 3 amps and 5.0 volts. But I measured the actual running voltage to be 5.3 volts.

On the AR7200BX there is a trim pot #1 used to trim cyclic gain. I have it turned all the way down. I can't go any lower. And cyclic oscillation still appears.

So I am considering getting the Castle Creations BEC. Its $24 dollars from my LHS. The output voltage is programmable from 4.8V to 9 volts in tenths of a volt increments. From what I have read and heard is the output voltage is very accurate. Sounds like this will be "a" solution to my problems.