JS Models TZ-V2 Frenzy

Wednesday, April 15, 2009

Picture taken by:
Kevin Morris
James "sparx" Kovach

Specs (as reviewed)

Manufacturer: JS Models
Distributor: A Main Hobbies

Type: 50 Size Nitro Helicopter
Flying Weight: 8 lbs 8 oz / 3,855 grams ( fueled )
Engine: OS 50 Hyper
Pipe: CY MP5

Fuel: CY 20% and 30% ( normally 20% )
Main Blades: CY Radix 600 mm
Tail Blades: Stock and KBDD 95 mm
Electronics/Radio: TX - JR x9303 2.4ghz, RX - Spektrum AR7000, Cyclic servos - Hyperion DS20-FMD, Throttle Servo - JR DS537, TJ RevMax Rev Limiter, Gyro - CY Solid-G, Tail Servo - Futaba 9253, Regulator - Align 2 in 1, Lipo - GeForce 2250 2S


I am always on the look out for good performing RC Helicopters that are priced right. I was surfing around on HeliFreak Forums
one day and saw a post about a new 50 size nitro RC Helicopter that was selling for $219.99. WOW! So I immediately headed to A Main Hobbies website to check it out as they are the distributor for this helicopter in the US. I was shocked to see what they were offering for that price. The helicopter design looked great in the pictures. The rotor head has the mixers on the grips which I have come to really like after owning other helicopters with this type of head. The servo and frame layout was nice. There is CNC aluminum bits in the head in all the right places. JS Models had pulled together some good designs from other RC helicopters and put them into one package. When talking with Chris about this helicopter, we both agreed that if the quality was there then this would be one really nice 50 size helicopter. So after a few phone calls and emails with Dan Smith at A Main Hobbies, they agreed to send me a kit for review..


Wanting to keep with the "low cost" theme, I decided to not fit out this model with a bunch of "high-end" and high priced components. With a little bit of shopping around and/or looking in various forums classified sections, you can easily fit out a 3D Frenzy for the same cost as a typical 450 class electric build. That is saying A LOT considering we are talking about a helicopter that is considerable larger then a 450 electric. The only thing I did not "skimp" on was the Gyro. With the level of flying I am doing these days, I want to have a Gyro on my helicopter that I am confident in.

There is really not much "building" when putting the 3D Frenzy together. When you open the box you will find that all of the sub-assemblies are already built at the factory for you. All you need to do is fit all the sub-assemblies together and install your engine, radio equipment and main blades. This is becoming more and more common these days.

The manual covers building the 3D Frenzy as if you were building it from a "bag-o-parts". So you will skip around in the manual a bit when putting the 3D Frenzy together. I found the manual to be pretty much on par with every other RC helicopter manual I have seen. Not great and not bad. Dan told me that they are working on a new manual for the 3D Frenzy that will be better than the one provided from the factory.

The only "issue" I had when putting the 3D Frenzy together was with the links that you install on the model, those from the servo to the bell cranks and from the bell cranks to the swash. None of them measured to the listed sizes in the manual. It is my understanding that the frame has been thru numerous revisions and I believe that the manual was printed for one of the earlier revisions. This is not too big of a deal as the sizes listed give you a good starting point to set up the head. Also, with different servos, the sizes of links can change as not all servos are built to the same specs. I have never really considered a manual's listed link lengths to be gospel anyway. I typically just set the rotor heads up on my helicopters the same and size the links as needed. While we are on the subject of the links, make sure you have a GOOD set of ball link pliers. The links snap on and off the balls with quite a bit more force then I was used to. I was a little worried that this would stretch out the links and cause some slop, but that is not the case. While removing a link with my "home made" ball link pliers, I broke one of the bell cranks. So heed my warning, make sure you have a good set of ball link pliers!

Included in the kit is an updated tail drive set. From what I have read, the original set's top bearing was wearing out prematurely. They have now put a bigger bearing in the top block and this should take care of that issue. It was nice to see that they included the updated part in the kit and did not require you to purchase it. JS Models and A Main have been very good about taking care of a few minor issues that have come up with this new model. Do not let these minor issues sway you in any way, all new kits will have a few "teething" issues crop up here and there. What is more important is how the manufacturer and distributor handle the issues. Without a doubt JS and A Main are doing a top notch job!

Servo installation on the Frenzy was thought out really well. Installing servos is the one part of a helicopter build I truly hate. Usually within 20 minutes I am screaming at the helicopter when installing servos. With the Frenzy, I was done before I knew it. They have put holes opposite the servo mounting holes on the frame so you can easily get to the bolt while installing servos. Oh, did I mention that they include nylock nuts and bolts to install the servos rather then screws and plastic mounts? They also include servo mounting plates! Very nice touch! To make your servo installation even easier, insert the bolts from inside the frame with the nuts on the outside. This way, you do not have to fight getting the nuts on the bolts between the frames. Just a little build tip!

The rotor head has adjustable ratios on the washout arms, mixer levers and flybar carrier. Out of the box, they have it setup for what I would call an intermediate setup. The manual does not touch on the different possible setups. Hopefully this is something that A Main will address when they put together the new manual. I am not going to go into detail as to what each ratio does as there is plenty of info on various forums that will explain it to you.

Installing the engine was quite easy to do. Mount the clutch and fan onto the engine crank shaft and then just slide it up into the frame. You need to do this before you install the landing gear and bottom plate. The bearing block that holds the clutch bell and start shaft is adjustable. After you get the engine in place, you can then adjust the clutch bell to get it properly lined up with the clutch. The process is really quite simple and covered well in the manual. Since the clutch threads onto the engine crank shaft, there is really no need to dial indicate anything. It is one of those "it is what it is" type of setups.

The quality of the parts is very good. Much better then I expected when considering the price of the kit. The aluminum parts are not polished, but they do not look bad at all. The plastic molded parts are very nice as well. They are also very "stout" to say the least.

Flight Report

For the first few flights I left the 3D Frenzy in its stock "out of the box" form. Out of the box the 3D Frenzy flies great! The collective and cyclic response is very good. The cyclic is not super fast, but more than adequate to pull off just about any 3D maneuver you can throw at it. It tracks very well in both forward and backwards flight. The 3D Frenzy settles into a hover very nicely from both take off and forward/backward flight. It is a very stable and smooth helicopter. I had no problems performing smooth loops and rolls as well as doing quick flips out of the box. For the beginner or intermediate flyer, I see no reason to make any changes to the 3D Frenzy out of the box. You will have a hard time "out-flying" it.

For my head speeds, I setup FM1 at 1950 rpm and FM2 at 2100 rpm. In flight mode one, I found when doing maneuvers that required a lot of pitch or cyclic that the engine would bog a bit. This is due to the 8.5:1 gear ratio of the 3D Frenzy. At 1950 rpm, the OS 50 is running below its optimal rpm. Switching to FM2 took care of this as now the OS 50 is running just above its optimal rpm. Now when you load up the head, the engine will fall into the optimal rpm and maintain head speed better. I kicked the head speed up to 2200 rpm for a couple of flights and the 3D Frenzy maintained head speed even better. If you are looking to do some hard 3D, then I would suggest you run the head speed above 2100 rpm. For general aerobatics and forward/backward flight, 1800-1900 rpm will be just fine as you will not be loading the up the engine.

The stock tail blades are more than adequate and handled just about anything I could throw at the tail. I could not get the tail to blow out even once. The winds were blowing around 10 mph with 25 mph gusts on this particular day. Doing tail slides from 100+ feet with a cross wind did not even phase the tail on the 3D Frenzy. You will see in some of the pictures and the flight video that I swapped out the stock tail blades for a set of KBDD yellow tail blades. I did this because I like how visible the tail is with those particular tail blades. I also swapped out the stock landing struts for the same reason.

After a few flights with the stock setup, I then put on a set of KBDD paddles. I was looking to increase they flip and roll rates a bit. These paddles did just that. They are lighter and smaller then the stock paddles. So with a few inexpensive changes, you can turn the 3D Frenzy into a quick 3D machine. A longer flybar and changing the mixing ratios will improve the flip and roll rates even more. I have not experimented with these two things yet, but will update when I do.

To sum it up, it did not matter if I was flying slow, precise, fast or hard, the 3D Frenzy performed great.


There is really only one thing I would change on the 3D Frenzy. The gear ratio. For the "3D Monsters" out there, the 8.5:1 ratio is perfect. They can run up the head speed to 2200 rpm and let her rip. But for the "mere mortals" such as myself, a ratio of 8.7:1 would be better. This would allow you to run the head speed around 2000 rpm and provide more than enough pop and keep the engine running just above its optimal rpm. Being that the clutch system is pretty much a Raptor 50 setup, I am going to try the optional 8.7:1 gearing that can be purchased for the Raptor 50. Again, I will update later when I have chance to install them..


The JS Models TZ-V2 3D Frenzy is a very well rounded helicopter. Out of the box, it will be a great machine for the beginner as well as the intermediate flyer. With a few changes to the mixing ratios and swapping out the flybar and paddles, it will please even the best of the 3D flyers out there. With the low purchase price and replacement parts cost, the 3D Frenzy makes a wonder model to train on. A typical crash, if there is such a thing, will not cost you much more than crashing a 450 size electric helicopter. So if you are a beginner looking for a good trainer or an intermediate/advance flyer looking for something to learn new maneuvers, then look no further then the 3D Frenzy.


Since originally writing this review, I have a few updates that I would like to address. The first one is the lengths of the links as supplied to me by the factory. Dan has informed me that this issue has been addressed at the factory and that now all links are coming in the kits sized properly. He mentioned that he is hearing from many customers that when they put their Frenzy together, they do not have to adjust any link lengths. Just snap it all together and fly with proper blade tracking and pitch ranges. This will save you some time as well as sore fingers! Another nice touch with this kit.

Also, I got around to installing the Raptor 50 Optional 8.7:1 gear set into my Frenzy. This is just what it needed if you are wanting to run your Frenzy around 1900-2000 RPM head speed. This now had the engine running just above it's optimal operating RPM and will fall into that range when you load up the head. Before this change, when I would do anything that loaded up the head, the head speed would decay throughout the maneuver and I would have to back off my collective to let the head speed build back up. I am no longer having to do this. If you like to run a 2200 RPM head speed, then you would not really need to be looking at doing this change.

You can hear more about the Frenzy by tuning in and listening to our show. Currently the following shows we talk about the Frenzy and there will be more later as I spend more time with the Frenzy.
Episode 52
Episode 51

Picures and Videos

Pictures of the build can be found in my
Picasa Picture Album.

This is the Walk Around Video

Here is one of my Flights at the Austin Fun Fly, man was it windy!

Here is a video of Ben Storik working the Frenzy HARD! A Main has signed Ben up as Sponsored Flyer for them.


RCHeli.DK said...
This comment has been removed by the author.
RCHeli.DK said...

Just did a review of the new Frenzy 90 TT version check it out here http://rcheli.dk/frenzy-90-tt/

Leonard said...

I'm going to start my Frenzy build. I'm using the same motor ! Did you have to disassemble any of the motor to install it? Also did you use Thread lock anywhere on the build?
Your pics where great and walk around video.
My Frenzy arrived with a all white Canopy with no tinted windshield?