Build Thread: CC's Xtreme Novus 125CP FBL

[Jeff_Barrett]

Indeed, it's odd to see a 'build' thread over here in the 4G6 forums, especially considering that our little helis come 'pre-assembled' and 'test flown' from the factory.

With all the stuff I'm doing to my poor little heli, I thought perhaps I should document what I'm doing for others. So, without further ado (no pun intended my fine aussie friend!) ... CC's Xtreme Novus 125CP FBL Micro-Heli!!!



The Goal:

First, let's talk about what I am envisioning for the end product. The goal is to end up with a small flybarless micro CP heli that runs on a Spektrum 2S setup. Pretty simple, right? Right??!

Parts Purchased & On-hand / En-Route:

Novus 125CP Helicopter (aka 4G6)
Xtreme Productions CF Frame
MicroHeli CNC Tail Case
DKFuji Flybarless CNC Head
Walkera CNC Blade Grips
Walkera 4G6 CNC Swash Plate
OverSky HP08 2S Motor
XP12A ESC / BEC
OrangeRX DSM2 Remote Satellite ($14,99!!!)
Bearings ABEC-3 2x6x3 mm
Wolfgang Aluminum Front Tail Gear
uRondo Walkera-Edition Flybarless System
1N4001 Silicon Diode

I'm waiting on a lot of stuff that's incoming, so hang tight. In the meantime, here are some pictures so far:

I am still waiting on the new bearings, so I'll document their installation in detail for everyone since I know everyone is holding their breath about it ...



Xtreme Production CF Frame






Oversky HP08 2S Motor & XP12A ESC Directly Soldered




Wolfgang's Aluminium Gear

[Jeff_Barrett]

Tail Clutch Mod:

While waiting for components, I redid my tail clutch mod using some common household items. I have no way to test it yet, but believe someone else has already done this mod ... unsure who credit goes to, so if you recognize it, please let me know so that I can give credit!

CAUTION: When working with the BIC lighter, make sure it's empty so you don't light yourself or your home on fire. This can be dangerous, and so I accept no responsibility for your harm or damages that might be caused by doing this mod. Do this at your own risk!!

Items Required:

Plastic Front Tail Gear (Used / New)
Small BIC Lighter (Empty)
Stock Dampener (Used / New)
Dremel Tool / Die Grinder

Performing the Mod:

Remove the entire assembly from the tail.

Take the tail shaft and slide the rear tail gear onto it. Turn it several times in both directions about 30 times to ream the d-shape out of the hole. The gear should still fit snug, but be able to slip around the shaft.

Remove the tail gear and install the front tail gear. Using your dremel or similar tool, grind the teeth off of the gear until they are gone. Once the teeth are removed, turn the gear in both directions (approx 40 times each way) to ream the d-shape out of the hole. This one should be able to slip fairly freely, so you may need to turn it several more times in each direction. I also cut the flange off of my gear with an exacto knife.

Next, take your empty BIC lighter and disassemble the head. There are 3 springs in it. We are after the tiny spring that is under the red tab. You will need to judge how much of the spring you need by testing and cut it accordingly. It is always better to cut it longer than you think you need.

Now, let's reassemble the tail using the photo below. In order from left to right:

Rear Tail Gear
Dampener O-Ring
Ground Down Front Tail Gear
Spring



Tail Gear Mod Completed


** I will post more photos for this mod when I get time **

[Jeff_Barrett]

So, I decided to go with the OrangeRX DSM2 Remote Satellite ... $14.99!!!!

http://hobbyking.com/hobbyking/store...dProduct=13418

[Jeff_Barrett]

CAUTION: The usual. You do this at your own risk. If you screw it up, you have no one to blame but yourself.


XP12A BEC Voltage Modification:

The BEC on the XP12A puts out a constant 5 volts ... in a 2S configuration, we need to temper that voltage so as we don't fry our teeny Walkera servos that are designed to run on 1S.

To do this, we are going to use a 1N400X silicon diode (in this case, a 1N4001) to drop the voltage by approximately 0.7v to get us somewhere more akin to the output of a 1S battery (5.0v - ~0.7v = ~4.3v).

Things You'll Need:
- soldering iron
- solder wire
- 1N400X diode
- small side cutters.
- 3/32" heat shrink tubing
- third hand tool (alligator clip vise) (optional)

You can usually find the diodes in any old electronic appliance you have laying about, as long as it's black with a grey stripe and the numbering on it starts with 1N400 ... you're good to go.

Alternatively, any electronics shop will sell it, but if you don't have one nearby, I know that The Source sells them. I picked mine up there out of convenience the other day.


How to install the diode:

We're going to install the diode on the (+) positive red wire going from the BEC to the RX.

I suggest bending the capacitor legs straight for the time being so that it's out of your way when you're soldering. It's not necessary to remove the wires from the BEC, but I did it to make life easier for myself. This is your choice.

First, I separated the red, white, and black wires ... then snipped the red wire just under half its length (closer to the BEC).

Next, snip the wires sticking out either side of the diode so that only about 2-3mm protrude from either end.

Strip the end of the red wire that's still attached to the BEC, twist, and tin it with solder. Fix it into one of the vise clips and the diode into the other. The side of the diode without the grey stripe should be facing the red wire in the vise. Set the vise clips so that the diode wire and the red wire are touching and running parallel with one another.

Once you're setup, make a good solder joint and let it cool.

Next, straighten the wires from the BEC. The red wire coming from the connector will be slightly longer because of the added length of the diode. You can keep it this way or trim it. I trimmed mine to make it neat.

Strip the end of the red wire, tin it, and put it in one of the vise clips. Put the diode in the other clip so that the end with the grey stripe is facing the red wire from the connector. Again, line them so that they are touching and parallel. Once you're ready, make another solder joint.

Cut a bit of heat shrink tube to the correct length(s) to cover the diode and your bare solder joints. Remove the red wire from the connector, position the shrink tube over the joint, and carefully heat the the tubing so that it shrinks. Don't use too much heat, the insulator on the wires melts very easily.

Put the wire back into the connector .... voila .. you're done!

For clarification, the diode has an anode and a cathode. All you need to know, is that the end of the diode with the grey stripe faces towards the connector. The side without the strip faces towards the BEC.

Here are some photos below. I have positioned the unused diode so that you can see the bias (grey end faces towards the connector) visually.





Diodes Purchased from The Source:

[eightythree]

Cool... is that uRondo going to fit well?? whats the cost on that unit?

[Jeff_Barrett]

Yes. It will fit very nicely ... I paid $200 CDN from LuftKraft for the stripped "walkera-edition" uRondo. You get a VAT tax rebate in the checkout....

http://translate.google.ca/translate...ts%2FRO-WALK-1

[fatmcnasty]

what transmitter is used with the OrangeRX?

and very nice tail clutch mod.. Ill be trying it soon..

[eightythree]

nice... Lets see some video when all finish.. expensive little heli!!

Why a need for the tail clutch?? with the front metal gear if stripping rear gears they seem easy to replace.

I crashed my 4g6 4 times at the golf dome Saturday night.. even with smashed blades it flew. changed the blades, had a bent mainshaft, stripped tail gear and i was still 3D flying it 4th crash seperated the swash.. popped it back in and had 2 more flights

[Jeff_Barrett]

Originally Posted by fatmcnasty

what transmitter is used with the OrangeRX?

and very nice tail clutch mod.. Ill be trying it soon..

OrangeRX is Spektrum DSM2 compatible. It will work with any DSM2 spread spectrum TX (ie; newer Spektrum and JR controllers).

Let me know how the clutch mod works out for you.

[Jeff_Barrett]

Originally Posted by eightythree

Why a need for the tail clutch?? with the front metal gear if stripping rear gears they seem easy to replace.

Becase it's not the rear tail gears that strip ... LOL!

Either the bevelled teeth on the main gear strip, or the gear splits where the pin goes through the mainshaft.

[eightythree]

ahh... I see... the most Ive ever done to the front gear was strip a couple teeth.
no need for clutchin my tail

[Jeff_Barrett]

If you had clutched your tail, you wouldn't have stripped those teeth ...

[eightythree]

LOL, no, if I didnt crash it 4 times I wouldnt have! the first crash hit sorta hard tail first, cant expect more than I already got!!

keep them build pics coming!

[Jeff_Barrett]

Bearings arrived for the frame today from HeliDirect. I'm going to test fit them this evening. I need to pick up some green loctite tomorrow...

[Update] Ok .. I test fitted the bearings (ABEC3 2x6x3). They fit SWEET!!! Ampdraw, my friend, you nailed it with the sizing. The main shaft is nicely solid with almost no movement at all .... just need to get me some green loctite tomorrow.

I decided to use the 2x6x2.5 on the top though, it allows the screw on the collar to line up better with the slot on the main shaft.

I'll snap a few pix for everyone tomorrow and write a brief little tutorial. Nothing to it really.

[Brett74]

Great of you to do this thread, it has inspired me to go ahead and actually start ordering mostly the same as you.
What pinion you gonna run ?
The CNC blade grips, are they from the V120D02 ?
Do I need to get a programmer of some sort for the same ESC you have ?
How do you put those pinions on ?
Brett

[Jeff_Barrett]

Originally Posted by Brett74

What pinion you gonna run ?
The CNC blade grips, are they from the V120D02 ?
Do I need to get a programmer of some sort for the same ESC you have ?
How do you put those pinions on ?

Hey Brett.

- Likely a 15 / 16T pinion. I'll have to do some testing to find the best result.
- I used 4G4/4G6 cnc grips. The V120D02 ones do not fit the DKFuji FBL head.
- You can program the XP12A via the transmitter. I believe TomZ posted a copy of the manual on RCG. When you're ready, send me a PM with your email addy and I'll send it to you in PDF.
- Pinions slide nicely onto the shaft. Put a dab of CA on the shaft and quickly press / position the pinion. To remove it. take a thin long strip of paper and wind it around the pinion. Pull it straight off with a set of pliers. I believe timewerx documents it somewhere in his stickied mod thread. Alternatively, buy a pinion puller for this sized heli.

[eightythree]

Since ya know every which way mod for this heli, can the diode step down mod be done with a stock ESC as well??

[Jeff_Barrett]

Originally Posted by eightythree

Since ya know every which way mod for this heli, can the diode step down mod be done with a stock ESC as well??

I can't take that kind of credit ... I'm standing on the shoulders of giants here.

Yes. The diode will work on any ESC setup. Simply put it in line on the postive wire from the ESC to the RX with the same biasing that I used (grey stripe towards the RX).

[Jeff_Barrett]

Purpose:
Replace the crappy radial and thrust bearings that come with the Xtreme frame. The stock bearings allow for a lot of side to side movement on the main shaft. That's bad, especially on a tiny heli like this where everything needs to be setup just right.

Required Supplies:
- Q-Tips / Cotton Swabs
- Green Loctite/Permatex
- ABEC-3 Bearings (2mm x 6mm x 3mm)
- ABEC-3 Bearings (2mm x 6mm x 2.5mm)

My bearings were super cheap at HeliDirect. Lots of other online vendors carry them, but careful, some of them are overpriced.

* You can get away with only 3mm bearings if you so choose.


How to replace the bearings:

Let's start with the obvious, remove the main shaft and related items from your frame, leaving the bearing blocks exposed.

Carefully, remove the thrust bearings first. Under the thrust bearings, there's a small shim / washer. Set these washers aside as you might need them later to set your gear mesh.



Next, we're going to carefully remove the radials bearings from the blocks. Use an old main shaft or a small phillips screw drive and gently push them from them middle of the frame outwards.



With the end of a clean swab or q-tip, clean the inside walls of the bearing blocks where the bearings will sit.

We're ready to install the new bearings! Let's start with the top side ... you can either use the 2x6x2.5 or 2x6x3 bearing here. I used the 2.5mm bearing to expose the notch in the shaft better. Ampdraw is using the 3mm bearing here and is using two screws on his retaining collar. Either bearing will work.



First, from the top, place the bearing into the top of the bearing block. Once you're sure it's hit the bottom of the block, break out the green loctite.

This is a wicking version of the loctite, so be very careful not to get any into your bearings. If you do, rinse it thoroughly in water and dry it out with a hair dryer.

My suggestion is to place a drop of loctite onto the the crossmember of the bearing block, then use a toothpick to draw it to the edge of the bearing. You'll know it's good when the rim turns green....

(yah yah, I know the photo is of the bottom bearing block!)



Next, you will likely want to clean up the excess loctite with a swab / q-tip. Careful not too clean too much away, as the cotton will wick the fluid up quickly.



Flip the frame on it side with the bottom bearing block facing you and repeat the steps you took to install the top bearing, only this time, using the 2x6x3mm bearing



We're almost done now ... if you want, you can install the main gear, main shaft, and retaining collar and let the heli rest overnite while the loctite cures.



The final step is to check your gear mesh. Ampdraws meshed almost perfectly. Mine didn't, and so I had to shim my main gear. I used the two shims / washers that we set aside while removing the original bearings from the frame.



My drive train runs smooth as silk now, with almost no play at all on the main shaft.

[Jeff_Barrett]

Worked on the heli again this evening for a bit. The bearings are fixed nicely into the bearing blocks now, and they still work great, so I guess I didn't get any loctite in them.

I fit my 14T pinion to the new HP-08 2S motor and installed it into the frame. I'll have to order a 15T and 16T pinion as well (anyone got a good source for 15T?).I'm waiting on the uRondo, so I hooked up one of my AR6300's (Anyone looking for one?? or two?? Shoot me a PM) to test both my diode mod, and my motor.

The diode mod works like a charm and is doing exactly what it's supposed to ... keep the smoke inside those servos.

The motor works great, but it was poorly balanced, so I had to balance it. I don't think there's a really well done tutorial on it, so I'll do a write up tomorrow on how I did it. I will say this though, it's amazing how much vibration a poorly balanced HP outrunner can produce....