kiwi_craig's blog View Details
Posted by kiwi_craig | May 20, 2017 @ 02:14 AM | 15,958 Views
The 230s is a nice flier and a great trainer but lets face it, its no power house, the little 3900Kv Motor has been dumped in the new 200s for a more powerful unit and blade went with the 300x / cfx motor in the 250cfx, which shares the same rotor head as the 230s.

My 230 is destined for a huey scale shell but i wanted a boost in power so it can fly with decent authority with the weight gain. The 230 s chassis is pretty restricive space wise and whilst the blade 320 motor out of the 300x/cfx/250cfx is an option its quite tall and would likely stick out the bottom of the chassis and i'm betting is going to be allot harder on batteries.

By chance i have two FZW 2625 3900kv motors that where originally offered in the MJX F45 brushless kits. These motors run sweetly on 3s and provide good performance. Ive had one runnng in a v950 and it was preety decent power wise. Only odd detail on these motors is the 2.5mm shaft size, so drilling the blades pinion and or an aftermarket 12t 2.3mm pinions is required and is easy enough.

Eyeballing it, it all looked spot on fit wise so into it!

I hade to use a flat file to nudge the openings a fraction on the blades motor plate, reused the orginal motor mount screws.

Decided to drill an aftermarket 12t pinion, longer overall than the blades unit.

Due to the increased motor can height the esc is now run under the chassis like on the 200srx, this actually makes it allot easier to see the low voltage led on the...Continue Reading
Posted by kiwi_craig | Apr 08, 2017 @ 08:04 PM | 15,393 Views
The weather has been rubbish with allot of wind, decide to take the V950 down the park and get a short outdoor flight in.

Meet all expectations, flies very smoothly and has good cyclic and collective authority , and has a decent turn of speed when cranking on the throttle.

Stock motor handles the tripple blade head without worry and easy 8 minute fly times +

brushless tail is the next project then this gets loaded in an AS355 body shell as a sport flier.

V950 tri blade (3 min 30 sec)

Posted by kiwi_craig | Apr 08, 2017 @ 07:07 PM | 10,186 Views
Final Assembly

three different canopies, Rakon angry Bird for the 200 SRX is a perfect fit. FX067 canopy, I use this on my master CP, long nose, also suitable. and the stocker.

Using Blue Arrow servos, very smooth and precise.

Flies beautifully on the Walkera 4f200 LM blades, tracking is "perfect".
Posted by kiwi_craig | Apr 08, 2017 @ 06:50 PM | 10,322 Views
The New WL V950 is lovely based on the Walkera Master CP. The entire MCP drive line can be fitted into the V950 ring superior head response. A step further the 4F200 and 4F200LM three bladed rotor head and drive line can be setup into these units. the V950 main motor has no problems driving the three bladed head, the heli flies very smooth, this setup is destined for an AS355 shell as a sport flier.

Walkera Models:
4F200 is the pod n boom 3 blade heli
4F200LM is the scale heli 3 blade Lama

Parts list

Driveshaft; the original 4F200 shaft is longer than the LM version and is preferred. you will need to redrill the lower hole positions to suit the MCP main gear, this is the only part that needs major modification.

Driveshaft collar: I used the extreme clamp for the blade 200 SRX, this clamps around the shaft so no need to worry about notch heights or drill holes.

Main Gear; the master CP unit is preferred as it then get the rotor head up around the same height as stock.
Swash; 4F200

Swash locker unit: either the 4F200 or the LM version, normally comes complete with the driveshaft

Rotor Head Assembly; 4F200 LM unit (black and silver) or the 4f200 (red) is suitable. Get the main blades to match.

Linkages; The 4f200 uses a smaller 3mm ball size, you will need to get two sets of either the 4F200 or 4F200 LM links, you will need to use the longer steel shafts for both upper (swash to blade grips) and lower (swash to servo)

3mm ball ends: Rakon sell...Continue Reading
Posted by kiwi_craig | Apr 08, 2017 @ 01:33 AM | 9,567 Views
Blade 200 SRX with microheli 3 bladed head. Altered the pitch setting on the blade grips using a spacer like the rakon setup to set the clearance and the blade grip angle and used the stock 175mm long FP blades rather than the shorter 150mm CP blades.

Using the stock 11t pinion, motor has no problems spinning three blades, just goes to show how under geared they are stock.

this one is destined for a seahawk sport flier scale canopy. Bird no 2 with the Rakon setup and repowered with a higher Kv motor is the rip snort sportster. See the short blade Rakon flying here:!

Flies really nicely with the "big rotor" head setup. Liking the Lionheli Parrot canopy as well, looks great. You can hear the wind at times in the video, it handles the wind far better than the stock 2 bladed version which is quite interesting.

Blade 200 SRX microheli tri blade "stretch" (3 min 5 sec)

Posted by kiwi_craig | Apr 05, 2017 @ 01:46 AM | 9,762 Views
Repower time, my stock motor has eaten another set of bearings and for some reason the magnet can is a fraction crooked ! The gap at the base opens and closes, combined equals a bad vibration, which these helis hate.....

Tested a 4100kv hobbyking motor, smaller diameter but taller can, with inbuilt cooling fan head. Has allot more power and faster response, max power rotor speed is impressive, and it runs smooth..... No more stupid priced HH motors.... the cooling fan really helps.

the stock and aftermarket stepped bore pinions go straight on, the motor has the same step arrangement right at the base.

This motor has already done allot of flying in another one of my helis, was a strong performer.

Mounting screw spacing is narrower so had to add cutouts into the alloy mount and then elongate the slots in the chassis side plate, i run a 14t lynx steel pinion.

Flight testing on the Rakon tribade head, my god does this thing haul ! pulling just over 4,250 rpm head speed and insane performance ! running the DX8 with 115% scaler on servo travel also helps the agility ! WAY TO GO.

Blade 200 RKH - EH200 power (4 min 5 sec)

Posted by kiwi_craig | Apr 04, 2017 @ 03:26 AM | 10,396 Views
okay, my two SRX 200 triblades.

bird one Rakon head, with EH200 4100 kv motor, 13t opps 14T ! pinion, rocket ship to fly

Maximum head speed, a stonking 4256 RPM !!! static thrust test 700 grams, flying weight 290 grams, thats decent thrust to weight = 2.14 times ! 150mm blades.

bird two. Microheli head with modified stock 6 degree main blades and repitched 175mm blades. stock motor stock 11t pinion (tried a 13t but the rotor is just to loaded with the 3 blades) feels smooth and fast.

Maximum head speed 3074 rpm. static thrust, hit 900 grams then pulled back to 800 grams constant !!!~ 2.71 thrust to weight !!!

currently the pitch is still a bit steep and more adjustments needed should see the rpm go up. The stock motor has good torque and thrives in the higher loads, where as the EH200 is a revver and loves the shorter blades on the stock rakon setup.......

both fly superb, not going back to a stocker now.........

with the stock drive line and 8 degree xtreme blades we saw around 3600 rpm, jumping to a 13T we saw 3800 rpm and a big improvement in how it flew. 14 T was better but the rpm gain tampered off, maybe 3875. For fp birds they seem best in the 70 to 80 efficency range, above 80 means your under geared and below 70 your over geared. no thrust test though.

See spreadsheet data below. efficiency = max thrusted loaded rpm / unload rpm (based on Kv by volts - found this to be pretty close)

The tri blades stonk! two different builds, two different machines, I like BOTH !
Posted by kiwi_craig | Mar 13, 2017 @ 09:31 PM | 11,340 Views
FY 02/03/05 etc fans

New out on aliexpress, full alloy HD differential units, these look superb, ring gear and spider housing is all one piece with bolt on end caps

under hard abuse the plastic diff housing can stretch and the spider gears can slip damaging the teeth

just need banggood to get stock and a sharper pricing and happiness filled!

a decent splined driveshaft, personally don't like the sliding pin drives as they wear like crazy............

and new adjustable steering rods, finally !

now to get my hands on some !
Posted by kiwi_craig | Mar 10, 2017 @ 12:18 AM | 10,239 Views
well after numerous late nights, head scratching and related, I have found a cure.......

the 150mm blades included in these kits are simply to short.................

I altered the pitch setting by sliding the swash locker up the drive shaft, this reduces the pitch, and trimmed the blade roots on the stock 185mm FP blades and fitted these up, and damn it, it flies as docile as.................... no death wobble, zippo, hovers happy as, STUNNED !

The tails working, just humming, with all the extra torque off the head, but no more death wooble...... I can see a longer tail tube to balance the head torque.

So the real problem is the stupidly short bloody blades they fit on these things. !!!!! waste of space.......

There is a still an odd response to the servos due to the fraction off phasing, but at least its well flyable......... I can work with this !!!

Translating this back to the stocker id bet serious $$$ if some one made a set of blades say 10mm longer than the stocker it would make a tremendous difference to the birds stability in stock 2 bladed form.....

Bloody helll..... What a journey this has been..... And i ordered a rakon head yesterday in frustration, arh well. Twin tri blades ....

This is my take on the situation: for the 200 the rx is tuned to suit the response from the stock rotor diameter, at around 400mm, The tri blades, they reduce this to 350mm and put in more pitch...... The rx senses an out of sync aileron roll and puts out...Continue Reading
Posted by kiwi_craig | Feb 10, 2017 @ 05:39 PM | 10,703 Views
Lots of choices out there, its really important to get the motor KV / battery / gearing all matched.

there seems to be allot of high Kv "kits" that basically cog like hell and are rubbish to drive,

here is my spreadsheet figuring kv. batteries and gearing compared to the stock setup running a 2S lipo as the base line 100% value.

basically around 30% speed increase is the practical limit - gain

I went to the effort of hunting out the 2845 - 2600kv motor, it works nicely, excellent torque and stellar top end speed on 3S.

2S - the 3100 motor is the pick, 3S the 2600 or 2800 motors are the go.

gears the robinson racing gear sets are the way to go 16t through to 26t works on these setups.

get the bigger 2845 can motors, forget the smaller 2838 motors, gutless in comparison. and anything higher than 3600kv just wont work worth a damn.......
Posted by kiwi_craig | Jan 24, 2017 @ 05:11 AM | 9,086 Views
test flights: lots of them, bottom line, flies like crap............

I cant believe how poor this flies. forward flight, okay but vastly different left aileron vs right right, very slow to turn left with allot of lag, right, rolls over nicely and turns 3 times faster,,,,,,,,,,,,. static hover is good and allot of fine tuning on the servo links to get this spot on. very slow on left turn, fast on right aileron.

if I fly in reverse this is where it goes totally pear shaped, heli starts to roll to the right, aileron left to counter response is very poor, wont respond, several near misses. I'm not talking fast flight here just gently bringing it back toward me. stock is fine as doing this. this was a real eye opener, something wierd is going on with the cyclic on the head for sure...........

on spool up and initial hover it can get into a wobble then stablises.

Gains set according to the instructions and fine tuned the tail and filter settings. tails was twitchy at 180 and improved as the gain value was bought back to around 150. definite improvement with tweaking the gains

seems to have allot of pitch, collar is set correctlyin the recess on the driveshaft, moved the collar to the top of the recess notch to takes some pitch off, still seems excessive. might just try locking it higher up.

been right through this several times. Drive shaft bearings and frame are new, servos good, was flying fine in stock form.

observations are - blade grip feathering...Continue Reading
Posted by kiwi_craig | Jan 21, 2017 @ 08:00 PM | 9,488 Views
Blade comparision, the microheli blade is a proper symmetrical cp type blade where the stock unit is a typical assymetric profile to generate lift and has the pitch set into the blade root.

The rotor head is a smaller diameter, the blade grips are longer by 10mm versus stock, but the blades are shorter, 150mm vs 185mm stock. Taking into account the difference in blade grip length the rotor dia is 50mm less than stock.
Posted by kiwi_craig | Jan 21, 2017 @ 07:35 PM | 9,188 Views
The stock canopy grommets are a right pain in the rear, tend to pull through the canopy and tear with use and fiddly to get on, ive been flying with out the grommets but the canopy vibrates on the mounting pins.....

Microheli grommets have a larger flange and outer diameter to prevent pull through, and the canopy mount pin hole is
larger, rubber is noticably harder. Fit is still tight, and a bit of silicone grease works wonders. 4 in the pack also.

Posted by kiwi_craig | Dec 26, 2016 @ 02:40 AM | 7,965 Views
attached is my xls spread sheet comparing the stock motor to various aftermarket brushless motors at 2s and 3s and varying pinion sizes. the values are approximate but give good guidance on relative performance vs stock.

This is based on the blue can 2845 motors that are readily available on aliexpress

Currently running the 2845 2600kv on 3s with the 22 pinion, FAST. Yet has good low speed manners and no cogging.
Posted by kiwi_craig | Dec 14, 2016 @ 03:26 AM | 7,807 Views
After allot of searching i have found what has turned out to be a perfect upgrade shock. Price is resonable for an all alloy body rebuildable shock.

Excellent build, and prefilled from the factory, so bolt on and go.

A fraction shorter than stock by about 2-3mm, certainly not an issue. Springing and damping seems good , needed a small amout of preload, spot on. Good shock, good price.