Goblin - Project details and Build issues

[windwizard]

Hi Goblin fans and all 700 class Noobs!

This is a summary thread for 700 class noobs (experienced pilots building their first 700 size fbl heli ) people like me, that would like see a complete project list of componants and costs to build a Goblin without cutting corners in quality. (this is my project, many variations exist that are just as good - maybe better)

Following is a "summary list" consolidating issues that have arisen surrounding the Goblin build for the benifit of any "Johny come latelys" venturing to build a Goblin. (The list is current to the best of my ability, but Im sure it will grow with time)

Let me say at the onset that MANY people here in the SAB forum have contributed with valuabe insight both for my equipment choices as well as the flagging various build issues. Many thanks to all of you!



Last bit if information - I started this project with a Spectrum DX7, some tools and soldering iron. Thats it! Everything else needed is listed below.(so far)

Everybody needs a Goblin! I hope this post is fun and useful to ya!


WIZ

[TomC]

Wiz,

I'm not sure that this Noobie idea thread (or sticky) is a good thing, but I could be wrong.

The Goblin 700 is advertised by SAB as a heli only suitable for advanced flyers/builders. I'd probably also add that some previous FBL experience is highly recommended and this should include 50-90 sized electric heli's.

This heli may be a potential lethal weapon in the wrong hands imho.

Cheers,
TomC

[windwizard]

SETUP DETAILS

Flight Style: Sport, Big Air n/a
Headspeed: 2075 power / 2175 general /2225 cruising
Motor: Scorpion 4525-520 (92.8 % eff.) $349.99
Motor lube Scorpion Motor Bearing Lubrication Kit $5.00
Pulley: 21 Tooth (optional Pulley = 9.71:1) $16.00
FBL System: V-BAR Full size (blue) ver. - 5.2 $319.99
Hyperion phase sensor $ 9.00
Governor: v-bar


BEC: Western Robotics Hercules Super BEC $100.00
Bec Adaptor (WR) Used for back-up battery pack $12.00
RX: (2 remotes) Spektrum DSMX Remote Receivers $70.00
BEC Backup Pack: 800 mAh NiMH buffer pack & charger $30.00
ESC: KONTRONICS Heli Jive 120+ HV(v11) $539.99
Kontronik Pro-disk Programming Card $128.00
Cyclic Servos: Outrage BL9180 (8.4v)$380.00
Tail Servo: Outrage BL9188 (8.4v) $138.00
Futaba replacement arms for Outrage servos # 04021 $17.00
(arms replaced due to tight fit next to servo support frame)



Servo Extension Tail servo $2.00
Main Blades: 690mm Stock SAB n/a
Tail Blades: 115mm Stock SAB n/a
Lipos: 2nd choice Turnigy 35C 6S 5000mah(x2)$120.00
Wire red 10 guage $4.00
Wire black 10 guage$4.00
EC5 connectors For Battery Harness (4 set) $6.00
EC3 connectorsFor BEC (2set) $2.50
M2.5x10 Screws (1bag) $4.00
(longer screws needed for mounting Torq servos)

Shrink tube (green) $15.00
Tri Flow synthetic grease with teflon $10.00
Glue gun $9.00
Shoo Goo $6.00
Swashplate leveler (true-blood for trex 700 nitro) $25.00
SAB GOBLIN 700 Flybarless Electric Helicopter Kit $1000.00
MISC. COST FOR EXTRAS AND SHIPPING TAX $75.00
___________
TOTAL $3422.00

[windwizard]

Tips and tricks video thread - HF

• belt tensioning –SAB thread
• blade grip arm assembly – SAB thread
• gluing bolt to main gear for easy assembly –SAB thread
• Mr Mels vbar video series in Mikado support area of Tech Forum

HEADSPEED CALCULATIONS:
Includes the update/repair for the wrong gear ratios listed in the manual
due to the pinion drive gear having 20 teeth not 19.


(Calculator at readyheli.com)

• Result for calculation using 21 tooth OPTIONAL motor pulley
• (will keep rpm above head wobble zone)
• Estimated lowest voltage during flight: 41,16

· Lowest RPM (due to voltage and efficiency) : 2026

• For + performance, keep req. RPM below: 2075
• For target performance, keep req. RPM below: 2175
  
  
• For - performance, keep req. RPM below: 2225
  21t = 9.71:1

Tech notes:

• Longer metal bolts needed for Outrage Torq servo mounting Replacing the M2.5x8 screws with M2.5x10 screws

• Connecting harness neede to be built for battery to BEC and ESC

• Servo extension for tail servo safety break away

• Glue gun to glue servo cable to inner boom

Motor issues

· The motor shaft can be cut - required length is 28.5mm
If not cut, the maximum height of the battery is 50 mm
If you cut, then maximum height is 60mm

· Maximum motor height is 68mm.
For greater height is necessary to modify the opening in the canopy.

· Align MX 700 is perfectly compatible

Scoprion 4035-560 is listed as a motor suitable for general flight in the Goblin
manual p28. but the mounting holes dont line up for all four screws and you will
have to mount motor with only two screws!

4525-530 mounting pattern matches the 4 bolt motor plate

Warning! check resistance from shaft to motor leads - should be infinite ohms.
If not, the mounting screws could be to long touching motor windings, this could cause
ESC FIRE and failure in flight (This issue is a general warning not specific to the Goblin)

DRIVE PULLEYS WARNING (ALL 3 )

SAB Goblin 700 Service Advisory #2 (20th March 2012)
Despite extensive testing, it has come to our attention that one or two main drive pulleys (H0016) have had the pulley flange loosen from the pulley during flight. We are working to rectify this problem, and have designed a new system to secure the flange to this pulley. Replacement pulleys will be shipping soon – if you have purchased a Goblin, please contact your dealer to arrange a replacement.

Others are now reporting crashes due to this problem and the same problem being found on the motor pulley and tail pully.

Drive Belt Life?
· Depends on the type of flight ...
average is over 100 flights

Belt care - main and tail
food grade silicon spray to lubricate belts

Batteries
·Use Velcro to help hold batteries in tray – (back of tray is open)

Tech note from SAB
· Use the special washer(s), page 23, if you planning to run over 2000 HS (washer is circled on page 15 of manual)

· The head is already assembled without the H232 part.
- If the headspeed is > 2000 rpm then the H232 part has to be added (pag 33).
- In any case the blades have to be really tight (pag 33) and a small quantity of gear lube has to be added to the main gear.

· These shims increase the damper preload therefore increasing head rigidity. Please make sure your main blades are tight on the grips, you should be able to violently jerk the head in both directions and the blades should not fold. Failure to tighten the blades properly and/or run incorrect dampening preload can result in a boom strike.

· If you remove the shims on the head you won't have any wobble issues at low headspeeds. Wobble present at 1900 rpm

Boom paint
· Some booms needed to be sprayed by local body shop with a 2 pass clear coat.
I buffed with a polymer treatment wax to make the matt finish shine like it was clear coated

Tensioning Spring - (tail drive and main drive)
· spring was not symmetrical, the length of the bends on the end were different. The short end goes up and the other end goes down, (the shorter side on the support, the longer on the arm.) Sab will update the manual as soon as possible.

· spring issue is related to the orientation needs to be clarified in the instructions manual. Also, spring may need a dab of epoxy to stay put in mounting hole.

· use a tiny dab of epoxy to glue the DRIVE belt tension springs ends into the motor mount, it just makes mounting the motor unit that much easier.

Flybar sensor position
· A FBL sensor does not need to be centred on the heli, it just needs to be square to the mainshaft and centerline of the heli. it is important that leads has some flex in it so as to not transfer any vibrations into the sensor.

One Way bearing
· brass surrounding one way seized on intermediate shaft.
Took it apart and sanded/cleaned and oiled, all good now.
Another post - "one way" was dry as a sun baked bone, needed grease

Swashplate quality

· Swash has a little vertical float to the centern ball. Turns out that “I2 Swashes” are built with the same loose ball and are very good swashes

Mainshaft finishing
· Deburr the inside of the main shaft with a small rounded needle file.

Maingear fit and finish
· File the plastic away that overlaps the hole in the main gear, makes for a perfect fit main shaft.

Canopy tips
May have to ream out mounting holes to line up correctly

·Use the foam piece push out from the blade holder to make the canopy fit without sliding to one side. Measure and cut two pieces off with the rounded sides glued to the canopy.

Duct tape inside of canopy over mounting holes to strengthen
canopy from cracking when flexing during removal and mounting

Always put the swash all the way down. Grip links facing front and back. Very easy to slide on the canopy that way - otherwise it can be a real fight!

Tailboom
Warning - check clearance between 0 pitch blade and top of boom.
Min. distance is 145 cm, if less, - add tape under nylon bolts.

Shoo goo the servo lead down and tape lead to servo, (glue gun
application already being reported to not stick long term to the
inside of the boom)

· Chamfer the edges of the aluminum block with a small flat file,
so that the plastic bolt heads can easily line up and slide in.

Don't over tighten your nylon tail bolts or they will snap!

Home Depot bolts fit perfectly in case nylon bolts snap.

Ball link issues
· blank side of the ball link is pressed onto the ball- SAB stamp faces out.

· Ball links are tight will have to wear in- if too tight then ream them out

Servo installation and related issues
· Servos for swash must be installed using spacers provided (For Mikado and
Outrage servos (rubber and carbon fiber) this will require 2.5mmx10mm screws

Servo arms with Torqs servos need to be replaced with mikado or Futabas - both work perfectly on my Torque 9180s. I got the proper resolution from my Vbar and also the arm spacing put the links as vertical as I could measure them. The red also matched the servo color (futaba arms). part numbers liste on first post

Tail set up issues
· Tail rotor stallin due to over inducing pitch -…We reduced the travel to 20 deg Left and 30 deg right, which resulted in a more even VBar setting of 76 and 74.

· Please note that the tail servo endpoints are at 76 and 74 and as this is below what Mikado recommends, it still works perfectly. One cannot get the servo arm shorter due to the fixed position of the push rod guide and any shorter on the servo arm results in a push rod that binds in the guide.

· general consensus is to add pitch mechanically 3 or 4 deg. (for hover) and set servos centered and pitch arms at 90 for the rest of v-bar setup.

· there is a slight amount of radial play in the tail grips because of the thrust bearings

Tail thrust bearing (factory assembled) -dry as a bone without grease - must disassemble
factory tail to make sure all is greased and that loctite is applied properly.

HEAD ASSEMBLY
Some are reporting that the Thrust bearing is bone dry, others reported bearing installed backwards. Note: You must disassemble factory head to make sure everything is greased and loctite is applied properly.

SAB is recommending Tri-Flow clear synthetic (PTFE, Teflon) grease for thrust bearing/bearings . You should be able to get this at any bicycle shop.

PULLY SHAFT
Z60 pulley shaft must have a little up & down play in the range of 0.2-0.8 mm , confirmed by SAB Tech Dept

GEAR LUBE - opinions (Main gear break in and long term maint.)
…The best stuff I have found yet is a wax made by Track power called krytech drywax lubricant it goes on wet and drys clear it dosent fling off or attract dirt. I use it on all my heli gears main and tail.Makes everything smooth and quiet. http://www3.towerhobbies.com/cgi-bin...?&I=LXATCH&P=7

· Lithium grease on the gears. Works great, keeps gears cooler every – 12 flights

Tri flow synthetic grease with PTFE great lubricant for bearings and thrust bearings .. and gears... but some say
it gets to tacky for their liking.

GEAR RATIO ERROR IN MANUAL – REVISION BELOW
In the manual, the helical pinion (up top) is a 19 tooth gear, but in reality it is 20 tooth

Corrected ratios for calculating head speed

16 TOOTH P INION = 12.75
18 TOOTH P INION = 11.33
19 TOOTH P INION = 10.74
20 TOOTH P INION = 10.20
21 TOOTH P INION = 9.71
22 TOOTH P INION = 9.27
23 TOOTH P INION = 8.87
24 TOOTH P INION = 8.50
26 TOOTH P INION = 7.85

ESC installation (heli jive 120)

NOTE: Sideplate on heli must come off - or stall build untill ESC is mounted.

Best practice for ESC mounting: use heatsink compound or heat sink tape
and heat rated tie-wraps, Clean and simple.

Kontronics Esc…

· Heli jive 120 + (+ means more output with cooling)

· Latest version is 11.0

· KSA mode not used with scorpion motor

· Mode 8 updated to work with V-bar external governor

Disconnet red power lead (patch cable between esc and v-bar) if using a separate external BEC Approved to work with V-bar

· Home page has a support and news tab – both are useful

· Newer programming disk – available if needed

· Bail out funct. used with throttle hold set at 40% with full resume for 15 sec.


Mikado V-Bar

· full size 5.2– (blue) – more resistant to vibration than the black one

· Requires 2 spectrum satellite receivers

· Small emergency battery suggested (5 cell NiCd/NiHM 6v) charges off BEC

· Pro software upgrade (after purchase – later on)

· Western Robotics is about to release an adapter that will allow their super bec to work with emergency battery pack

Mikado and Kontronics have partnered togather to allow programing
VBAR v5.2 and heli jive v11.0 setup to be very straight forward - yea!

Build thread short-cut

Thunder fighter did such a great job I didn't want all his valuable work to get lost in the obscurity of post dated threads forever moving deeper into the archives - Check out his build proceedure below...

https://www.helifreak.com/showthread.php?t=391487

[windwizard]

Originally Posted by TomC

I'm not sure that this Noobie idea thread is a good thing,

Hey Tom

This thread made mention that it is for people that are new/noobs to a larger heli class (.ie. "700 class noobs" ) people just like me... profecient in the hobby, (more or less), but now ready to build a large heli with fbl setup for the very first time.

This is my target audience - and with 4000 plus views on my other Goblin noob thread there must be a lot of us out there. LOL

Thanks for your concern, point well taken.


WIZ

[RUN4COVER]

+1

Hey thats a lot of good info in one place

[SimStream]

Check your pinion size (transmission pinion not motor pulley) its now shipped with a 20 tooth and the manual head speed table is incorrect

[windwizard]

Your absolutely right Simstream.

[Luisito]

Awesome summary WindWizard.

Can you provide a link to Western Robotics adapter? Can't seem to find it on their web site.

I'll be using a HV setup with Torque servos at 8.4V with WR Super BEC since Kontronic ESC BEC output is 6V. Thinking of using a 3S receiver pack to keep voltage at 8.4V instead of the 7.4V of a 2S pack.

Luis

[justindewoody]

SimStream...I thought they are shipping with a 22 tooth pinion? My Goblin came with a 22 tooth pinion...and I just got it last week.

[justindewoody]

Can other Goblin owners confirm that they have a 22 tooth pinion and not a 20 tooth?

[SimStream]

Intermediate gear pinion is 20 tooth not 19. The motor pulley is as you say 22 as supplied
The confusion arises because the gonlin uses a motor pulley not a pinion. The only pinion used is the main gear driving pinion.

[justindewoody]

OK, my motor pulley is 22 tooth, and the pinion that drives my main gear is 20 tooth. Got it.

[windwizard]

n/a

[windwizard]

Originally Posted by Luisito

Awesome summary WindWizard.

Can you provide a link to Western Robotics adapter?
Luis

No news on the adapter yet - still not released for retail. Soon I hope!


WIZ

[windwizard]

motor issues updated march 18

[rcflyerheli]

As far as the Western Robotics BEC, if one uses a 2S lipo for Vbar power and HV servos, it should not be needed, right?

[gww528]

Originally Posted by rcflyerheli

As far as the Western Robotics BEC, if one uses a 2S lipo for Vbar power and HV servos, it should not be needed, right?

Correct, no need for a BEC with 2s lipo... make sure you tail servo is HV also.

[windwizard]

The bec just allows the 8.4 volts for the servos that you wont get with a 2s lipo, but that isn't any big deal for the average flyer I wouldnt think.


Wiz

btw - there have been more issues added to the "build issues" list recently on p.1

[gww528]

Originally Posted by windwizard

Tips and tricks video thread - HF [LIST]

<snip>

Mikado V-Bar

· full size 5.2– (blue) – more resistant to vibration than the black one

· Requires 2 spectrum satellite receivers

· Small emergency battery suggested (4 cell NiCd/NiHM 8.4v) charges off ESC

· Pro software upgrade (after purchase – later on)

· Western Robotics is about to release an adapter that will allow their super bec to work with emergency battery pack
]

@windwizard, the buffer pack - Small emergency battery suggested (4 cell NiCd/NiHM 8.4v) charges off ESC, for NiHM should be less than what your BEC is set for. i.e. Bec = 8.4 or 7.2 the Buffer Pack = NiHM 6v *(5 cell )