TZ 50 V2 Build Thread

[heli-c]

Control levers for elevator and aileron/ pitch levers installed next; these were straightforward enough to install requiring only minor sanding to the elevator control arm bearing holes in the frame:





Next I'll add the tail boom and pushrod guides, tail rotor assembly and fins...

[heli-c]

Before fitting the tail boom I reviewed the assembly manual as items like the horizontal tail fin mount and pushrod guides look much easier to fit first. Especially so with the tail fin mount; the manual suggests bending this around the tailboom after the tail rotor is installed but its formed from quite a stiff plastic I didn't want to overstress it.



After this I opened the bag that contained the tail rotor assembly. This comes from the factory pre-asembled with drive belt in situ. as you will see from the photos the TZ has a typical (cross between a Raptor 50 and an Airskipper 50-style) tail with a brass/ plastic pitch control mechanism. As I looked at the assembly carefully I noticed that the pitch control arms were not symmetrical...and on spinning the rotor blades by hand it was clear that the brass bushing had not been screwed into the plastic outer squarely, causing the tail rotor geometry to be...screwed? Have a look at the photos:





When I first discovered this I was more that a bit dissapointed. However the importer has agreed to replace the defective parts so at this stage I'm not too worried. Maybe I just got a model from a 'bad' batch...no matter, I am enjoying the build so much and really want to the see how the heli looks with all the tail components on, so we proceed!





Most of the build will have to be reversed while the issues mentioned are sorted out by the importer but doing it this way gives me the opportunity to learn how everything goes together, and adress any issues with the kit at the same time.

The TZ is really starting to take shape now...'must admit, even at this early stage I am really pleased with the way it looks. I'm the type that enjoys looking at helis as much as building and flying them and so far this model is ticking all the right boxes visually.

Main gear and rotor head installation next...

Cheers

[Mart61]

Nice write up! Many thanks!

[heli-c]

'Bit of a break from the TZ while I built and setup a CX450 for a mate...we proceed!

Next up is to fit the main gear, tail drive gear and main shaft. The components arrived as shown:



I carefully installed the one-way bearing into the main drive gear, sequencing the 4 bolt tightening procedure to minimise distortion. On spinning the gear by hand I noticed a rather severe run-out - severe enough to make the gear wobble in my hands as it was turning. This is the 4th issue I've had with this heli...I'm beginning to wonder why me! Maybe I've been sent the Friday afternoon build kit, or am just plain unlucky...I have read several build threads on different heli's and while many heli's have issues straight out of the box, I don't remember reading any as problematic as mine! Oh well another item to be returned to JS Models...additionally something I should point out is that the nut which secures the jesus bolt is slightly too large to fit comfortably between the lower bearing block and tail drive gear unless you make sure the flats on the nut are horizontal top and bottom...I found this out the hard way and now have deep score marks on the bearing block. Not too much of an issue, just something to be aware of.

In order to complete the thread I'll press on regardless. Incidentally TZ Heli have agreed to replace all defective parts I discover so provided these are returned fairly soon (parts sent Monday, arrived there today, expected back by the end of next week) there shouldn't be any more angst on my behalf! A 2 week delay is a bit off-putting mind - I wonder how it will be getting spares?

I digress...the main gear and tail drive gear slide easily into the frame and just require the main shaft to be inserted through. Aside from the jesus nut thing, no further issues to report...





Next I'll go through the rotor head installation, and also some radio choices I've made. The jury is still out (apparently...) on the Align DS610s for cyclics though...I read with interest a recent thread on here about the cases breaking up, even on non-crashed heli's, as these were my 1st choice cyclic servo. Would anyone care to recommend an alternative?

Cheers

[Brian Gifford]

Brilliant build thread, thanks. Keep up the good work!

[nowinkk]

Pls update us on the build. It seemed to have stopped for quite a while, any problem encountered?

[heli-c]

Hi nowinkk - yes I encountered several problems with this build, hence the lack of updates in the build thread.



The next section I had intended to write was the head setup. The main issue lies with the mixer block locating pins and the headblock itself. In order to allow free movement between these 2 components would require at least 2mm of material to be removed from the headblock. This is mentioned in the Model Helicopter World review I mentioned earlier so you could say I was warned...however when I approached the importer and manufacturer about this i was told that I had to (quote) 'adjust the head and mixer correctly'. The locating pins are fixed; no room for adjustment there - perhaps the adjustment ther refer to is the machining of the headblock! In fact I approached the importer with all the aforementioned issues, and the final straw for me was to send the defective parts to them for replacement, only to have the exact same components back to me! (Yes, I marked them all with my initial. TZ heli said they could find no defects on the components I returned to them e.g. the notchy bearings were, according to them within 'range' as was the tail rotor assembly pictured. However they only mentioned this after I waited 10 days for the parts to come back to me...and charged 15-odd Euro postage for the priviledge! That was the last straw)

Like I said before this is my first nitro build, but I'm no stranger to engineering principles and could probably overcome most of these issues myself. My question is, should I have to? After waiting 10 days for parts, dissapointing responses from the manufacturer and an overall loss of confidence in the model I sold it. No doubt all heli's require some tweaking to get them flying and this is half the fun for me. However, I'm simply not willing to install 1200 pounds worth of RC gear in an airframe I have no confidence in.

But this is just one personal opinion - I know many TZs are being flown successfully and good luck to those who enjoy them and can get parts quickly. For a first nitro heli its just not my cup of tea

Thanks for your interest guys,
Carl