Goblin 500 Review/Build Log

[anthony7820]

I posted this on another website that is sort of under the radar, and I wanted to post it here as well to share it with some others as well.

Welcome to my review/ build log of the Goblin 500. Oddly enough I had this thing preordered back in December and have been patiently waiting it's arrival.
Here are some specs from SAB:

• Main rotor diameter: 1136mm (with 500 mm blades)
• HPS Head (FBL Only)
• Main blade length: 470 to 500mm
• Tail rotor diameter: 226 mm
• Tail blade length: 80 mm
• Main shaft diameter: 10 mm
• Tail shaft diameter: 5 mm
• Spindle shaft diameter: 8 mm
• Gear Ratios 6.9-11 : 1
• Weight including electronics: 1900 g (excluding flight battery).
• 18T motor pulley included (other pulley sizes available)
•All pulleys are made for 6 mm motor shaft (5 mm motor shaft adapter included in kit)

Special Features:
• Full carbon fiber boom
• Quick release battery tray system
• Sacrificial breaking point for landing gear and boom
• Unique “inside the boom” tail push rod design

For this build I decided to go with the following:
Scorpion 4020-1350 motor
Scorpion backup guard
Mini Vbar
Castle Talon 90
Hitec 7245HV cyclic servos
MKS BL980HV tail servo
6s Glacier 4000mah 30c batteries


Once it showed up at the doorstep and I opened up the box, I was certain this was not your average helicopter kit.
Everything comes neatly packaged in individual boxes.



After opening the individual boxes I then laid out our parts on the build table along with various tools needed to complete the build (Blue and Green loctite, metric hex wrenches, CA, and I even used some of 3DHS new foam safe synthetic glue)


Skipping around the instruction manual I decided to build the Transmission first. After taking the main bearing block, pinion, main gear, 48t motor pulley, tail pulley, and the main shaft out of their nicely crafted foam inserts I put the assembly together using the appropriate shims to eliminate any excess vertical play in the gears. Also be sure to use blue loctite on any bolts that go into metal.

Here is the finished transmission assembly



Next, I decided to assemble the motor block. After locating the motor block, springs, bolts, and nuts I was ready to assemble the motor. Due to the size of this motor I had to un-solder the bullet connectors, route the wires through the hole in the motor block, and then re-solder the bullets. When installing the motor pinion I found that due to the design of the motor shaft (flares out toward the motor bearing), it was necessary to drill the pinion out slightly so it would fit further down on the motor shaft. (I used a prop reamer for this).


Next comes the tail and tail boom assembly. After locating the tail shaft, tail grips, dampeners, bearings, linkages, tail belt, and tail pulley. I was ready for the next step of the build. First I assembled the tail shaft and grips, make sure you grease the dampeners and spindle before assembling (use blue loctite on the spindle bolts).

Then I installed the tail pulley, tail belt, linkages, and tail fin.

After that came the tail boom. There are 2 carbon pieces with double sided tape you must install inside the rear of the boom( I did this by installing the bolts into the holes in the boom and then screwing the bolts into the carbon piece to make sure they aligned perfectly). There is also a small plastic piece you must install toward the front of the boom which holds the tail pushrod in place. I left the bolts that are holding the tail assembly in place loose because you will have to push the assembly forward later when installing the belt on the pulley toward the front of the helicopter.


Next comes the main rotor assembly. Parts needed for this assembly are; blade grips, bearings, swash arm followers, swash arms, main block, spindle, thrust bearings, and dampeners. When installing this make sure to grease the dampeners and thrust bearings, also make sure to use blue loctite on the parts. When pressing the bearings into the swash arms and and followers make sure you use green loctite on the outside race of the bearings before pressing them in.

Next I finally decided to build the frames and landing gear. Need to complete this step are the 2 frame halves, 2 landing gear halves, 6 frame spacers, and 2 plastic inserts. After installing the frame spacers inside the plastic frame halves I put bolts into the 4 front spacers and left the back 2 out for installing the landing gear and boom later. Assembling the landing gear I ran into some problems, the self taping screw provided were very weak and ended up stripping out on us while tightening them. So I opted for some heavier duty philips head screw I had laying around. After assembling the landing gear carefully spread the frame halves apart and slide the landing gear slots into the frame (yes, the landing DOESN'T bolt to the frame).


Next I installed my tail servo (MKS BL980HV). With braided wire protection on the wire, so the carbon fiber doesn't eat through the wire.


Then I assembled the transmission assembly with the servos installed onto the frames (make sure to use loctite). After that I then installed the motor block (the springs providing necessary tension on the motor belt). To get the belt onto the pulleys push the motor toward the transmission block and tighten the screws. This makes it easier to install and position the belt, when finished loosen the screws and pull the motor out slightly, making sure the belt is tight and then tighten the motor screws and nuts on the springs. Here I also installed my FBL unit and ESC.


Next comes installing the boom. Attach the tail pushrod to the ball on the tail servo arm and the tail belt onto the pulley. Now pull the tail assembly, making sure the belt is tight and then tighten the bolts holding the tail in place. Then insert the 4 screws left out of the frame from the previous step, securing the boom in place.

After this step I then routed all of the wires to the FBL unit and also installed the backup guard using a Y connector hidden underneath the helicopter


A really cool feature about this helicopter is its battery tray, the battery mounts to a carbon plate (2 are provided with the kit) and then the battery and plate simply slide on the plastic frame spacer and a metal lock pin holds the battery in place. To remove the battery, simply pull the lock pin back and the battery slides out.


http://www.3drcforums.com/attachment...3&d=1360966961


The finished product.



Likes:
The simplicity and low parts count of the helicopter
The battery tray design
Boom mounting and tail assembly
Very high parts quality
Neat packaging

Dislikes:
The motor installation was a little tricky
The fact that I can only afford one!


First glance at flight performance: After I finished the FBL setup I decided to take it in the front yard for a test run, WOW! is this thing quiet, it has a special hum from the motor belt and tail belt it almost sounds like a sweeper running. It was very stable and felt very light in the air, I can't wait to get to the field and see what this thing can really do.

Is this a beginner helicopter?
I wouldn't recommend this to a beginner due to the complexity of the build, the high power it produces, and while the crash price isn't ridiculously expensive, it still isn't cheap to crash. Yet if a beginner were to get one, they wouldn't be disappointed, due to the fact that it is so smooth and stable. If you really tone down the control inputs and the headspeed, it would make a great beginner helicopter if you weren't worried about the cost.

Overall if you like the look and design of this helicopter, get one and I can assure you SAB and the Goblin 500 will not disappoint!.

Here is my second flight video of the Goblin 500. Enjoy!
[ame]http://www.youtube.com/watch?v=-Pn65531pNE[/ame]

I am sort of new to this site and forum, so hopefully I did everything correctly. Thanks and hopefully this helps a lot of people

[mwvheli]

Nice review!

[LL-Cool-T]

Has anyone else had to remove the scorpion 4020-1350 motor bullets to fit it in this heli?

[clouseau]

Originally Posted by LL-Cool-T

Has anyone else had to remove the scorpion 4020-1350 motor bullets to fit it in this heli?

I don't think SAB meant for you to run the motor wires inside that hole, it just appears to look that way in the manual. The way they cut out a relief in the carbon fiber on both sides of the motor, I'm pretty sure they had intended for us to run the motor wires along the outside the frame and down.

[anthony7820]

Originally Posted by clouseau

I don't think SAB meant for you to run the motor wires inside that hole, it just appears to look that way in the manual. The way they cut out a relief in the carbon fiber on both sides of the motor, I'm pretty sure they had intended for us to run the motor wires along the outside the frame and down.

That is what the manual showed, and after I ran them through the hole in the motor block and put the motor block on the heli, it was clear they wanted them on the outside of the frames, but I wasn't going to unsolder them again and reroute them to the outside, they are fine where they are right now and if I get bored one day I might move them.

[Napoleon_Tanerite]

Originally Posted by LL-Cool-T

Has anyone else had to remove the scorpion 4020-1350 motor bullets to fit it in this heli?

I'm running the 4020-1100 (same size motor) and just went over the frame. I don't expect any more chaffing there than I would going through the holes, and it makes it a lot easier to replace the motor if I have an issue. EXCELLENT flying by the way. Way beyond what I can do with mine, that's for sure!

[clouseau]

Originally Posted by anthony7820

That is what the manual showed, and after I ran them through the hole in the motor block and put the motor block on the heli, it was clear they wanted them on the outside of the frames, but I wasn't going to unsolder them again and reroute them to the outside, they are fine where they are right now and if I get bored one day I might move them.

Lol, the manual on that part confused the heck out of me also! Very nice build and flying

Can you give us some detail on how you got your Talon 90 mounted to the frame?

How is the Talon 90 Governor working for you?

[anthony7820]

Originally Posted by clouseau

Lol, the manual on that part confused the heck out of me also! Very nice build and flying

Can you give us some detail on how you got your Talon 90 mounted to the frame?

How is the Talon 90 Governor working for you?

Sure, I used the mount that comes with the Talon and used 4 zip ties going through the holes that you were supposed to drill in the plastic battery mount. Here are a few pictures

The governor is working great, I turned the gain down from medium to low; if you watch the video above you can hear the headspeed changes really suddenly. It seems better at the lower gain setting but I think I could probably drop it down from 15 to 12 or so.

[JPSika]

Quick question, shouldn't the ESC aluminum heat dissipator face down? The way I see you placed it seems as the heat will go up and join the battery's heat as well. Thx.

[andreansyah]

Greetings, I followed the manual why goblins would take off every tail is always spinning, but after my fox tail round the opposite direction do not matter, I wear beastx module, I see here as dimanual what's wrong with my heli. thank you all

[jdubbles]

Unplug your motor, turn on your tx and plug in the battery. Once your fbl initializes, pick your heli up and turn it clockwise, watching the tail pitch slider. If the slider moves in the direction you are turning it, your tail servo\heli rotation direction is reversed in your fbl.

I don't use beastx, so I couldn't tell you where to change that setting.

[pert]

Its in F,

[rob78]

Originally Posted by jdubbles

Unplug your motor, turn on your tx and plug in the battery. Once your fbl initializes, pick your heli up and turn it clockwise, watching the tail pitch slider. If the slider moves in the direction you are turning it, your tail servo\heli rotation direction is reversed in your fbl.

I don't use beastx, so I couldn't tell you where to change that setting.

Yes.


Another test you can do:

Rotate tail blades until they are straight up and down. Unplug motor, turn on TX, plug in battery. Fold the tail blade on top towards the canopy. Grab boom and move to the right. The top tail blade should point in the same direction of boom movement.

[Seasick78]

[ame]http://youtu.be/4FObQpyioTY[/ame]

This applies to most models. If you fly anything that has different tail mechanics (like a TDR) this will be opposite.