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soonglim's blog
Posted by soonglim | Jan 18, 2015 @ 09:33 AM | 2,902 Views
Yup, yet another slipper clutch mod for the 180 cfx torque tube ... Torque tube slipper clutch V3 mod .

V1 and V2 uses a silicon fuel tubing to provide friction for the hold and slippage. The silicon tubing do tear on slippages. And if too thick on the V2 version, may touch the inner wall of the boom - especially the carbon fiber booms which has a slightly smaller inner diameter. The silicon tubing can also crawl along the torque tube rod if tape or some adhesive stopper is not used. So I kept searching for an even simpler solution.

I did experimented with other materials:

But those materials did not pan out since they have to be so thin they simply rub off after a few flights. I measured the OD of the stock torque tube rods I have, and they have quite a bit of variance - ranging from 2.91mm to 3.02mm. The torque tube ends also have quite of bit of variance too in its ID.

That got me thinking...well, carbon fiber rods can provide good friction contact with plastic - such as the 180 cfx torque tube ends, and can be customized to have a tight fit. So, that's what I did - made the torque tube rod out of 3mm solid carbon fiber rod and re-use the plastic stock torque tube ends. And that's it - can't get any simpler than that. And it's now so simple to make it for any length - which is what I needed for my stretch 180. There's no compromise on flight performance, just like stock and V1 and V2, and has the...Continue Reading
Posted by soonglim | Dec 15, 2014 @ 11:34 AM | 2,058 Views
Given there aren't any Blade 180 CFX torque tube replacements in stock, and I've crashed and broken mine, I made a torque tube out of the Trex 250 torque tube.

I've had the idea before I had gotten my 180 cfx. Even before the 180 CFX came out, based on the manual, and the video descriptions of the heli, I conjectured that a modified trex 450 or trex 250 torque tube would work. So when folks reported the sizing of the stock 180 CFX torque tube and confirming its fragility, I even purchase at a LHS the Trex 250 torque tube before I received my 180 CFX. Lo and behold, it is fragile, and broke it on my first crash about 10 flights in.

There has been discussions of making the torque tube too strong, and break something else. So, decided to make my adapted trex 250 torque tube with a "resettable fuse".

Turns out making it work was easy, and it's lighter at 1.7g (with bearing) versus 180 cfx stock torque tube of 2.5g (with bearing). It's just a matter of cutting it to same length as the 180 cfx stock. I made it slightly shorter to allow the "resettable fuse" to work. I dremel the ends to make the cross a bit longer. Since the trex 250 torque tube ends are screwed in and loctite, I had to use vise (with rubber grips) and a wrench to unscrew one end out. After cutting the trex 250 torque tube to slightly shorter length (about 2mm shorter), I thread the inside of the fresh cut end with a 2.5mm tap so I can screw the end back in... 4mm is enough. (...Continue Reading
Posted by soonglim | Sep 18, 2014 @ 06:41 AM | 2,077 Views
My mostly stock v120d02s going through a weight-loss program.

* Microheli tail blade grip (weight-gain? Update 9/20: It's a wash 0.1g difference, and my weight scale is +/-0.1g precision)
* Xtreme metal pitch slider (weight-gain? Update 9/20: It's a wash 0.1g difference, and my weight scale is +/-0.1g precision)
* Fusuno 130X main blades (-3g)
* Removed tail boom support struts and horizontal fin (-1.4g)
* Cut off receiver mount (receiver mounted on skids) (-0.6g)
* Cut off 3/4 of tail vertical fin (-0.8g)
* Use 1mm cf rod for tail pitch control rod (-0.6g)
* Removed motor pin connector, solder to esc wires (-0.4g)
* Removed temperature sensor (-0.3g)
* Total weight loss so far: -7.1g
* Heli weight without canopy: 72.5g
* Heli weight with canopy: 77.3g

There's more weight loss to be done, like soldering motor wires directly to esc...and also put back in stock tail pitch slider and tail blade grips, and punching holes/trimming canopy.

This flight is with old 450mah (or 500mah) 20c lipos - don't recall as these are 2+ years old and had been used heavily and the marking has rubbed off.:

V120D02S Going Through A Weight-Loss Program - Test Flight (3 min 33 sec)

With the FullRiver 600mah 20c lipo (even though also pretty old), pop is even better.

Update 9/20:

* Removed receiver casing (attach with double-sided sticky foam), directly solder motor to esc, shorten power wires, and use UMX connector instead of MicroDeans (-2.7g ...WOW, those wires are heavy!)
* Total weight without canopy now at 69.8g
* Total weight with canopy now at 74.8g
Posted by soonglim | May 04, 2014 @ 07:34 AM | 2,959 Views
I've mod my custom v120d02s to be virtually crash damage proof - except for the stock main gear. Two problems I have with the main gear: (1) the teeth gets stripped easily and gets shredded on my 2s motor setup on a crash - and it wears out too quickly; and (2) the gear mesh between the main gear tail drive part and the A-gear is never optimal and can wear out pretty quickly - or stripping a tooth on the plastic A-gear on a hard crash, even with slipper clutch, as the tail boom bends. If I use the metal A-gear, the tail drive gear on the main gear gets worn out after just a few flights - leading to tail hold issues.

Because I also have the 130X, I noticed the 130X main gear is stronger - Delrin plastic versus ABS perhaps? The 130X main gear survives crashes much better and if I don't hit throttle quick enough maybe only one or two teeth gets chewed up. But even with some teeth chewed up, it still performs good - while the v120d02s one, once there are teeths chewed up, the rest gets shredded pretty quickly.

The 130X main gear is also cheaper and more readily available (here in the US, at my LHS and online).

Additionally with the 130X tail drive design, it's A-gear and B-gears both can be metal - the v120d02s does not have a metal tail drive gear on the main gear. So wouldn't it be nice to have similar separate metal "A'-gear" on the v120d02s.

I realized it would be pretty simple to take the Xtreme metal 130X A-gear I have for the 130X and fit it onto the...Continue Reading
Posted by soonglim | Mar 20, 2014 @ 01:00 AM | 2,826 Views
After having mounts and mounts of broken stock skids on my v120d02, I finally decided to adapt the 130X skid to my v120d02s. I've found the 130X skid to be very durable on my 130X'es (especially if they've been boiled in hot water for a few minutes). The Microheli skid I got with the Microheli CF/Al frame was stronger than the v120d02s stock skid, but the CF legs still keep breaking on every crash. Sure I can CA glue them back when I can find the pieces in the grass - but it's a time waste and lost time for flying. So the 130X skid would be the best - I just needed to make an adapter to mount it onto the v120d02s frame, and have velcro for strapping the battery. Following is what I did to make this adapter.

Materials I use:
  • Hardware
    • M1.4x4mm screws x 4
      • For mounting skid to MicroHeli CF/Al Frame
      • If using the stock frame, reuse the stock skid mounting screws.
    • M1.4x6mm screws + M1.4 nuts x 4
      • For mounting adapter plates onto 130X skid.
    • M1.4x8mm screws + M1.4 nuts x 2
      • For mounting tail boom support to 130X skid.
  • 24mm x 64mm x 0.7mm Al plate
  • 15mm x 24mm x 0.7mm Al plate
  • Velcro tape
  • Velcro strap (I used the Align ones - they're decently priced and lasts)

  1. Drill two 1.4mm diameter holes in the 130X skid rear legs for mounting to tail boom support.
  2. Drill two 1.4mm diameter holes in the 103X skid 4-in-1 support plate for mounting the skid to the v120d02s frame.
  3. Drill eight 1.4mm diameter holes on the 24mm x 64mm x 0.7mm Al plate to
...Continue Reading