My latest RC project is a 480 mini electric helicopter called "MARS" its produced by a company in Taiwan called  Gazaur RC Design Corporation. They are new to the RC helicopter industry, they are just beginning to enter the US market. I was able to get my feet wet with a sponsorship with gazaur, and getting a mars for testing before the official US release. The Mars is unusual in design, from its interlocking carbon fiber frames, and the rubber isolated landing gear to the tail rotor that rotates in the opposite direction of most other helis. Because of these new and different design ideas (and that really unusual canopy),  I found it a fascinating helicopter. And since I have had experience with micro electrics, and larger 30 and 90 sized nitro ships, I thought a mid sized electric would be a fun project to try.

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Introduction:

This article will be covering the building and initial setup. Hopefully it will give you an idea what the quality of the kit and the finished helicopter is like. I'll try to show the unique features and give you an idea how well those things work in the real world of building and day to day flying.

I took the liberty of grabbing the images below from Gazaur's web site to give you a look at the finished product. Gazaur makes two 480 sized electric heli kits, the Mars and the Poseidon.  The two are functionally identical, with the major differences being in the styling of the canopy, frame, fins and landing gear. Look at the picture below for a comparison between the two. The poseidon is intended to look more graceful and sleek, with sweeping curves on frames, fins , landing gear and canopy, while the Mars is styled more aggressively, somewhat like a raptorial bird  (not the RC helis of the same name). The aggressive nose section, reminds me very much of HR Giger's alien.  The landing gear looks like an eagle with its talons out-stretched ready to grab some poor rodent. 

 {styleboxop float=right,color=maroon,textcolor=white,echo=no}The poseidon is intended to look more graceful and sleek, with sweeping curves on frames, fins , landing gear and canopy, while the Mars is styled more aggressively, somewhat like a raptorial bird... {/styleboxop}

Specifications:

Packaging and contents :

 The kit is supplied in a nice attractive glossy box about 8"x4½"x16". Opening the box you will find everything is sealed in clear plastic heat sealed divided bags, with white labels clearly showing the part number of the parts contained in that portion of the bag.

The individual pieces, and there are a lot of them,  are separated by part number and labeled, if you pay attention to the numbers everything will go much more smoothly than if you just start opening up bags and having at it. The Frame sets, swash plate, rotor head and all the miscellenious other items are all contained in separate  sealed bags that make everything easy to see and identify. They also keep any small items from getting lost at the bottom of the box.

 This kit includes lots of spares

 One nice touch,  There are quite a few crash / spare parts included in the basic kit, including main rotor blades, mainshaft, tail shaft, 2  main gears and 2 each of pinion gears in both 10 and 11 tooth.  Gauzar has even seen fit to include wire loom, 800 grit wet or dry sandpaper, adhesive backed velcro, zip-ties,  several small metric allen wrenches that will be needed to complete the kit, along with both red and green thread lock and even some silicone grease. 

These are nice touches. The smallest allen wrench supplied is 1.25mm which is smaller than what I need for the larger helis , so having it included really saved the day for me. We live in a very rural area and it would have been hard to locate a metric allen wrench this tiny at the local parts store.

  {styleboxop float=right,color=green,textcolor=black,echo=no} Gauzar has even seen fit to include wire loom, 800 grit wet or dry sandpaper, adhesive backed velcro, zip-ties,  several small metric allen wrenches that will be needed to complete the kit, along with both red and green thread lock and even some silicone grease. These are nice touches... {/styleboxop}

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Manual

Front Cover :

The manual is very complete with many many detailed drawings and exploded views detailing the pieces and their orientation. Rather than a Chinese version and an english version, the manual is provided with both on the same page, starting at the front cover.

Instructions: 

The items are identified in the drawings with a number that matches a small chart on each page that links the number in the drawing to the actual item number.

There is an parts list in the rear of the manual that has all of the item numbers  among with a description, dimensions and a picture of the item so that it can easily be identified.  The only down side to this is that you need to jump back and forth between the exploded view and the parts list quite a bit to make sure you are using the exact part number for the step you're working on.  This sounds complicated , but take a look at the pictures, and you will quickly see the relationship between the exploded diagrams, the chart and the parts list.

 {styleboxop float=right,color=darkblue,textcolor=white,echo=no}This sounds complicated , but take a look at the pictures, and you will quickly see the relationship between the exploded diagrams, the chart and the parts list.{/styleboxop}

Click for a larger view 

Appendix - Parts List:

Icons:

The manual also has many small icons showing where to apply the thread locking compound, grease or caution areas. So if you pay attentionion to all the information that is provided its hard to leave out something critical like applying  thread-lock to a setscrew.  

Measure the parts !

As you build you will need to have a small metric ruler or other metric measuring device handy (I use, and recommend digital calipers) Not paying attention to the manual got me in trouble two times as I was building the kit,  The first time was when I was assembling the battery keeper frames. The manual calls for 7mm long screws  to be used on the CF frame spacers and I used 9mm long screws. This caused the screws to butt together in the middle of the spacers and never tighten to the frame sides. Because the frames were slightly loose, this would have alllowed the CF frames to vibrate on the screws and possibly caused radio interference. luckily I noticed that problem and quickly replaced the screws with the correct 7mm length.

The other time I got myself into trouble by not measuring was when I was assembling the tail box, the manual calls for a combination of 3mm and 4mm wide bearings with the  bearing ID and OD being identical.  I was in a hurry and put the 4mm width everywhere.  This seemed OK at the time, but caused problems a little later when the tail case halves would not  fit together tightly without causing a bind in the pulley that the belt drives. Once I had those problems corrected things went together very nicely.  You should just always measure sizes and verify that you have the correct pieces by the manual, it will save building time and problems in the long run.

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Chassis:

The carbon fiber chassis pieces are 1mm thick material with a very shiny silver finish. They are very lightweight, and seem quite strong, while allowing some give and flex. Look closely and you can see many small slots, and corresponding tabs on the other pieces, these are Gazaur's unusual interlocking mortise and tenon system. It  is used in many places to minimize the number of bolts and screws, saving as much weight as possible.

The square holes are for a short length of rubber tube that helps hold the landing gear pieces together as well as provide some cushioning for hard landings (more on this later).  Overall the finish looks very good.

Click to view a larger picture 

There are metal grommets crimped into the tail boom attachment holes for added support in this high stress area.

{mospagebreak_scroll title=Boom, Blades, Frames} 

Boom and blades: 

The tail boom is a 12mm aluminum tube 345mm long, the main blades are  315mm long heat shrink covered wood, that are matched and balanced at the factory. The tail blades are 58mm long plastic with an unusual couterweight near the root on the leading edge. The counterweights supposedly make hovering in sidewinds easier for the tail.

Gazaur even includes a nice foam blade holder, with their name on it. 

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Starting to Build:

Lets get started building, of course you should read all the way through the manual getting familiar with the various sections before you even pick up any tools or parts... YEAH RIGHT !  But it will help you to get comfortable with the various sections. Just make sure that you actually measure any questionable parts, use threadlock where recommended, and take your time. {styleboxop float=right,color=maroon,textcolor=white,echo=no} Just make sure that you actually measure any questionable parts, use threadlock where recommended, and take your time. {/styleboxop}

{mospagebreak_scroll title=Servo Base and Servos}

Servo Base and Servos:

The servo tray is a triangle shaped assembly made out of machined aluminum (with exception of the bearings). There are 5 pieces to complete the servo hub. It also connects the upper frame halves together and contains the upper and lower main shaft bearings. The main shaft is a 5mm solid steel shaft.

The servos I used for this heli are GWS Naro HP BB on cyclic and a futaba 9650 on tail control, The GWS's  are quite fast (.09 @ 4.8v ), they have ball bearings on the output, and  should be a very good setup for 3d.

{mospagebreak_scroll title=Frames and Motor}

Motor: 

Included in the kit are presicely cut carbon fiber frame peices made from 1mm thick stock.

The motor is a Zpower 450class 3550 Kv motor, both 10 and 11t pinion gears are included in the kit. I chose the 11 tooth, to keep the head spead high for best performance.

{mospagebreak_scroll title=Main Gear and Shaft}

Main Gear and Shaft:

The main gear is made of composite nylon, and has 150 teeth. This means the main gear ratio is either 15 to 1 with the 10 tooth pinion or 13.6 to 1 with the 11 tooth pinion.  

The main shaft is main of 5mm hardened steel. It has two holes in top and  two in the bottom, the holes that are closer together are for the main gear. The one way bearing that allows for autorotations is located in the bottom of the main gear.  The main shaft bolt can be installed in either of the two holes. The manual says to use the top hole for 3d flight and bottom for beginner to light flying, I found that i couldnt get an appropiate pitch/cyclic range using the top hole(3d flight).
So for all types of flying, you would probably want to use the bottom hole.

Main gear, belt drive gear, mainshaft and one way bearing  

{mospagebreak_scroll title=Motor mount and Chassis}

Motor Mount, Motor and Chassis: 

Motor mounting plate and motor mount 

 Here you can see the arrangement of the motor, swash anti-rotation bracket, and belt idler assembly. The frame spacers are made of nylon and have a small shoulder that fits snugly into the pre-cut holes in the frame halves. Make sure you get the shoulders on the ends of the frame spacers seated squarely in the holes on each of the frame halves to ensure proper frame spacing.

 {styleboxop float=right,color=darkblue,textcolor=white,echo=no}Make sure you get the shoulders on the ends of the frame spacers seated squarely in the holes on each of the frame halves to ensure proper frame spacing.{/styleboxop}

{mospagebreak_scroll title=Assembled Chassis and mainshaft} 

Chassis Tailboom and Mainshaft: 

 Here are some pictures that show the mostly assembled frame, tail boom, mainshaft, drive gears, and the servo mounts and servos.

Frame and boom with motor, mainshaft and servos
Click to enlarge

Right Side View
Click to enlarge

This view shows the position of the servo mounts that places the servo's  ouput arms directly below the  swashplate. Once the head and swash are mounted, this advantage will be much more clear. the links go from the servo arms to the swashplate with a short double ended ball linkage, eliminating and bellcranks or additional bearings or connections that will wear and  loosen or require more maintenance.  

Front view with servos mounted 

{mospagebreak_scroll title=Drive Belt and Tail Box} 

Drive Belt and Tail Box:

The tail drive belt is made of a high strength rubberized material and seems to like higher tensions. Pay careful attention to the bearing sizes used in this step, There is a combination of 3mm and 4mm wide bearing used and it is easy to assemble it incorrectly (don't ask me how I know this).

Top View

 Bottom View

The tail box is something else! The tail belt drives a white nylon gear that meshes VERY SMOOTHLY
with a brass gear, that drives the tail rotor away from the direction of the rotor wash. The opposite rotation of the tail rotor is just one of Gazaur's unique designs. Once I've had a chance to fly it and get used to the performance I'll post my impressions of the tail design.

  {styleboxop width=550px,float=right,color=green,textcolor=white,echo=no} The opposite rotation of the tail rotor is just one of Gazaur's unique designs.{/styleboxop}

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 Tail blades and Controls:

The tail blades are made of black plastic, and have a couterweight that supposedly makes hovering in a side-wind easier. When setup right the tail  controls feel very smooth and presise. 

Left side view of the completed tail, The "M" is for "Mars" of course !

Heres a close up of the pitch slider assembly and completed tail.  The tail rotor grips are a double ball bearing design with a sleeve spacer between the bearings using 3x6x2.5 and 2x5x2.5 double shielded bearings. they seem quite snug and slop free. 

{mospagebreak_scroll title=Landing Gear}

The landing gear use no screws to hold them together, but instead use little peices of rubber tubing or foam(depending on the kit) my kit did not have the foam to use, so i used the rubber. The skids/struts are again mortise and tenon system, very strong yet can absorb alot of impact before breaking. 

Heres a close up of the mortise and tenon attachment with the rubbers installed

Completed landing gear assembly 

Heres the gear attached to the chassis
Click to see a larger view 

{mospagebreak_scroll title=Rotor Head}

The hub and blade grips all go together fairly easy, make sure that the order of bearings/washers in the blade grips are as follows(from inside of grip, out): bearing|big washer|thrust bears assy|little washer|bearing. Be sure to use one brass micro washer (LC06) between the bell mixer arms and the blabe grip arms. This is what determines the phasing of the head. I found that using a single washer is the most correct.

Completed head and swashplate assembly
Click to enlarge image

Top view , Mixer Arms and Blade Grips
Click to enlarge image

{mospagebreak_scroll title=Swashplate}

The swash plate has a very interesting design, it can do 90 degree eCCPM, and 120 degree eCCPM, this is a very nice feature as some people may not have a radio capable of doing 120 degree mixing.  Check the manual for which holes to use for which mixing type you want to use. I'm using a Futaba 9CHPS that does 120 degree eCCPM so I put the balls on the swashplate in the inner holes.

Swash plate, either 90 degree or 120 degree eCCPM 

{styleboxop width=340px,float=right,color=maroon,textcolor=white,echo=no}The swash plate has a very interesting design, it can do 90 degree eCCPM, and 120 degree eCCPM, this is a very nice feature as some people may not have a radio capable of doing 120 degree mixing.... {/styleboxop}

{mospagebreak_scroll title=Tail Rotor Servo} 

The tail rotor servo is mounted by 4 screws attatching to 2 molded plastic fittings that are screwed directly to the lower frame. You can use a wide variety of servos with these mounts. shown here is the futaba 9650 digital micro tail servo. Mounts have to be put on the outside of the lower frame to get to fit right.

9650, mounts outside frame screw on from inside 

With a Hitec HS-55 or similar sized servo, put the mounts inside the lower frame pieces as shown here.

HS55 Mounts inside frame, screw on from outside 

{mospagebreak_scroll title=Setup}

Normal:  10/1.5  cyclic 6 degrees (this way you can drop the throttle fast and the heli wont be a brick)

Idle up 1: 11/0  cyclic 7 degrees (i like to set it up so it still acts as a normal with a little bit higher RPM but i can still drop the throttle and it still goes to 0 throttle)

Idle up 2:  10/-10 cyclic 7 degrees(this is for mild 3d)

Idle up 3: 9chps) 12/-12 cyclic 8 (this is if your only doing 3d, if your a beginner setup idle up 1 and normal.

Links: From servos to swash: 45.5mm

           From swash to Flybar control arms: 49.7mm  

           From swash to Bell mixers (hoops): 64.5mm

           From Bell mixer to flybar: 28.3mm (or 25 for 3d)

**NOTE** Gazaur's manual shows the links being measured from the end of the plastic links, do not measure from the middle of the links...but as they show (from the ends)

Also, in the manual it says to use the upper hole on the main shaft for 3d, and the lower for smooth flight, i found that i could not get the right cyclic/pitch range in the upper hole, so for all purposes, you need to use the lower hold (putting the head higher on the heli)

 

Tail: Use the outer hole on the tail blade grips, this will allow the heli to piro equal speeds both ways. set up the gyro/tail servo according to your gyros manual. I used the GY-401/futaba 9650 for crisp response. The 401 features a "limit" and a "delay" feature for perfect tail control. set the limit so that the tail doesn't bind on either side. In order for the tail to be perfect, it needs to be setup mechanically as well as with the electronics. With using the 9c there are great gyro programming features, i used the "C" switch for optimum holding settings. Make sure to setup at least one rate mode on the gyro, and of course a heading hold. The tail should hold without correction in rate mode if the tail is setup properly. DO NOT add trim to make the tail still, adjust the tail control rod. if there is trim applied, the heading hold mode will go nuts. 

{mospagebreak_scroll title=First Flight}

Your first flight should be little hops, unless you are an experienced enough pilot to do otherwise, check directions, set the controls how you like, make sure the tail will hold in rate mode(if using a GY 401) 

I dont want to tell you what you already know about first flights, but some begginners might have problems, so here goes...

Spool the heli up slowly, letting oil soak into the bearings, then bring the heli up to a hover slowly. The first few flight should be nothing but hovering and FF, just for the helis sake, to let thing work into place.

My first flight was very successful, I only had 2 clicks of left trim, the tail response was great thanks to the 401/9650 combo. If you plan on doing hard 3d with the mars, i reccomend that you get a decent set of CF blades. The Gazaur wood blades hold up to the RPM fine, but they are flexible enough to not allow the fast and snappy control you will want for 3d. 

{mospagebreak_scroll title=Flying Impressions}

The mars 480 is one of the smoothest mini helis ive ever flown, I have a T-rex Se, and it doesn't compare for smoothness, or fastness on the cyclic. There was a few things i think could use a little bit of improvement, for one, unless you build the head perfect, there will without a doubt be phasing problems, also the tail control links (little tiny links), couldnt be tight, otherwise it pinches the control arms and wont move, you need to back the screw out to where its free, but only that much...And one last problem, the anti-rotation arm(in the upper frame) is a little bit to far away from the swash plate, i had a crash due to that coming out, i put a small washer between the bolt and the spacer, and the problem was gone(easy fix!)

With Century Rotortech 320mm blades, and a good lipo, and the Zpower 3800kv motor...3d power is insane, and flying characteristics are phenominal.  As long as phasing is correct, and the swashplate stays level through the whole travel, there should be no pitching or rolling when hitting a flight comand.

{mospagebreak_scroll title=Conclusions}  

The kit is very well laid out, and the heli is definately a builders kit!! the few things that needed improvment are:

The Antirotation arm needed to be longer or the CF peice closer to the swash, or use an align bolt with flat, wide screw.

The tiny tail links needed a spacer in them to make it so you can tighten the tail down without worries, but the way it is seems to be holding up great!

Gazaur should include a few extra tiny brass washers used for the mixer arm spacing on the head...otherwise, this heli is spotless. None of the Cf peices were miss-cut, and every lined up perfect...

Great Job, Gazaur!!

more to come as we get pictures posted