Fun, Learning, Friendship and Mutual Respect
START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopter Support > SAB Goblin 630/700/770


SAB Goblin 630/700/770 SAB Heli Division 630/700/770 - Goblin Helicopters Factory Support


Reply
 
Thread Tools Display Modes
Old 04-16-2012, 04:49 AM   #1
Phil777
Registered Users
 
Posts: 779
 

Join Date: Feb 2012
Location: New Zealand
Default Help with headspeed :)

Hi, ive tried reading a few things on here, but im not 100% im doing this correctly.

Could someone please calculate my head speed for me, and explain how its done, if you have time

Sab goblin
scorpion 4525 520 Ultimate
Helijive 120 v11

I will be using helijive governor, since theres no warranty with vbar using a scorp.

my helical pinion is 20t the motor pully is 22t
the maingear is 204t the main pulley gear is 37t and the tail pully is 27t


Thanks! will finally be doing my late maiden (been waiting for my replacement pully)

What rpm are you running your first flights in? and how many
Phil777 is offline        Reply With Quote
Old 04-16-2012, 05:40 AM   #2
SimStream
Registered Users
 

Join Date: Mar 2011
Location: UK
Default

Provided your throttle end points are still at 100% and your lipo is 12s 65c,your helijive set for mode 4 or 5 then

Throttle 55%: 2085
Throttle 60%: 2194
Throttle 63%: 2259
Throttle 67%: 2345
Throttle 70%: 2410
Throttle 73%: 2475
Throttle 76%: 2540
Throttle 80%: 2627

Your main gear is actually 68 tooth but as its two stage the overall gear ratio is caculated as if your main gear is 204.


SimStream is online now        Reply With Quote
Old 04-16-2012, 05:58 AM   #3
Phil777
Registered Users
 
Posts: 779
Thread Starter Thread Starter
 

Join Date: Feb 2012
Location: New Zealand
Default

Thanks, Thats what i got

Sounds about right for the jive, although i hear some are using a 21t instead of 22t
Phil777 is offline        Reply With Quote
Old 04-16-2012, 06:21 AM   #4
SimStream
Registered Users
 

Join Date: Mar 2011
Location: UK
Default

I would use a 21 tooth pulley if you want headspeeds of 2200+ or a 20 tooth if you want 2000-2200. the Hjive works best with throttle between 65 and 70,

Oh and Goblin say to run first flights at 1700-1800
SimStream is online now        Reply With Quote
Old 04-16-2012, 06:25 AM   #5
SimStream
Registered Users
 

Join Date: Mar 2011
Location: UK
Default

If using mode 5 make sure your first spool up is done with zero pitch untill gov kicks in. and you should get close to those figures.
SimStream is online now        Reply With Quote
Old 04-16-2012, 10:46 AM   #6
justindewoody
Registered Users
 
Posts: 896
 

Join Date: Jan 2012
Location: Spring, TX
Default

You need to use the 21 tooth motor pulley with a 26 tooth tail pulley (for awesome tail authority). I have the 4525-520LE motor, Heli Jive 120 V11, and I run the Heli Jive governor. My 3 head speeds are 2000, 2100, and 2200. The 21 tooth motor pulley allows the ESC to run in its sweet spot at these head speeds. If you plan to run similar head speeds, you NEED to use the 21 tooth motor pulley. And if I were you, I would go ahead and get the 26 tooth tail pulley. Good luck and happy flying!
__________________
Canomod Team Pilot | Gobline 380 | Goblin 700 Competition | Goblin 500 | Mostro 700 DFC | Gaui X7 | Gaui X5 | Trex 450L Dominator | Trex 250DFC | FlameWheel F450

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
justindewoody is offline        Reply With Quote
Old 04-16-2012, 11:16 AM   #7
SimStream
Registered Users
 

Join Date: Mar 2011
Location: UK
Default

Quote:
Originally Posted by justindewoody View Post
You need to use the 21 tooth motor pulley with a 26 tooth tail pulley (for awesome tail authority). I have the 4525-520LE motor, Heli Jive 120 V11, and I run the Heli Jive governor. My 3 head speeds are 2000, 2100, and 2200. The 21 tooth motor pulley allows the ESC to run in its sweet spot at these head speeds. If you plan to run similar head speeds, you NEED to use the 21 tooth motor pulley. And if I were you, I would go ahead and get the 26 tooth tail pulley. Good luck and happy flying!
Yes except it doesnt run in the HJive sweetspot. You have your throttle between 42 and 62. The HJive sweetspot is 65-70 it says so clearly in the manual

Decrease pulley to 20 tooth will bring your throttle up to around 58-72. Much less work for all the electronics and better results
SimStream is online now        Reply With Quote
Old 04-16-2012, 12:44 PM   #8
strokermtr
Registered Users
 

Join Date: Aug 2008
Location: Baltimore, MD
Default

Quote:
Originally Posted by SimStream View Post
Yes except it doesnt run in the HJive sweetspot. You have your throttle between 42 and 62. The HJive sweetspot is 65-70 it says so clearly in the manual

Decrease pulley to 20 tooth will bring your throttle up to around 58-72. Much less work for all the electronics and better results
+1 and you don't need go up on the tail pulley, as long as your 2000 head speed and up.
strokermtr is offline        Reply With Quote
Old 04-16-2012, 06:23 PM   #9
Thunder Fighter
Registered Users
 

Join Date: Jul 2007
Location: Melbourne Oz
Default

I would be worried about over speeding the tail with 2200rpm and the 26 tooth tail pulley. SAB rate it up to 2100 only.

//Dennis.

Sent from my HTC Desire using Tapatalk 2
__________________
SAB Goblin 500 x 2 : SAB Goblin 700 : SAB Goblin 770C : Jeti DS-16
Mini Protos FBL Stretch : Logo 600 : CYE Stingray

Team RCBits | SAB & KBDD Field Rep | www.rcbits.com.au
Thunder Fighter is offline        Reply With Quote
Old 04-16-2012, 06:56 PM   #10
justindewoody
Registered Users
 
Posts: 896
 

Join Date: Jan 2012
Location: Spring, TX
Default Tail Pulley...

Quote:
Originally Posted by Thunder Fighter View Post
I would be worried about over speeding the tail with 2200rpm and the 26 tooth tail pulley. SAB rate it up to 2100 only.
Where did you read this?
__________________
Canomod Team Pilot | Gobline 380 | Goblin 700 Competition | Goblin 500 | Mostro 700 DFC | Gaui X7 | Gaui X5 | Trex 450L Dominator | Trex 250DFC | FlameWheel F450

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
justindewoody is offline        Reply With Quote
Old 04-16-2012, 09:06 PM   #11
gww528
Registered Users
 
Posts: 930
 

Join Date: Dec 2007
Location: Florida
Default

Quote:
Originally Posted by justindewoody View Post
Where did you read this?
Page 33 (manual v1.3)

However, if you prefer flying at low/medium speed [< 2100 rpm], for best results we recommend changing the tail pulley for a smaller one to increase tail rotor rpm. In this way, you will have extremely precise tail control even at low RPM. This pulley is available in the upgrade list [H0049-S]
__________________
KBDD Team Pilot
Lynx Heli InnovationsTeam Pilot
gww528 is offline        Reply With Quote
Old 04-17-2012, 02:07 AM   #12
SimStream
Registered Users
 

Join Date: Mar 2011
Location: UK
Default

Quote:
Originally Posted by gww528 View Post
Page 33 (manual v1.3)

However, if you prefer flying at low/medium speed [< 2100 rpm], for best results we recommend changing the tail pulley for a smaller one to increase tail rotor rpm. In this way, you will have extremely precise tail control even at low RPM. This pulley is available in the upgrade list [H0049-S]
The front pulley now has an extra tooth as well so that adds extra speed anyway
SimStream is online now        Reply With Quote
Old 04-17-2012, 03:20 AM   #13
Thunder Fighter
Registered Users
 

Join Date: Jul 2007
Location: Melbourne Oz
Default

Quote:
Originally Posted by justindewoody View Post
Where did you read this?
I asked the question on the Goblin Forum after the new main pulley that has an added tooth was released and referred to that in the question. The answer back was that it was ok for 2000-2100rpm.

//Dennis.
__________________
SAB Goblin 500 x 2 : SAB Goblin 700 : SAB Goblin 770C : Jeti DS-16
Mini Protos FBL Stretch : Logo 600 : CYE Stingray

Team RCBits | SAB & KBDD Field Rep | www.rcbits.com.au
Thunder Fighter is offline        Reply With Quote
Old 04-17-2012, 07:00 AM   #14
gww528
Registered Users
 
Posts: 930
 

Join Date: Dec 2007
Location: Florida
Default

Quote:
Originally Posted by SimStream View Post
The front pulley now has an extra tooth as well so that adds extra speed anyway
SAB Goblin Tech states the recommendation does not change. (Goblin Forum)

Quote:
Originally Posted by Goblin Tech View Post
http://www.goblin-helicopter.com/for...ull=1#post2560

The ratio Main Rotor / Tail Rotor is: (68/20) x (37/27)
The recommended RPM does not change.
If you are flying at low rpm (less than about 2000/2100 rpm) is always recommended the pulley 26 teeth
.
__________________
KBDD Team Pilot
Lynx Heli InnovationsTeam Pilot
gww528 is offline        Reply With Quote
Old 04-17-2012, 07:36 AM   #15
emoe
Registered Users
 
Posts: 178
 

Join Date: Dec 2006
Location: Michigan
Default

Ok guys...are you using Mr.Mel's Calculator?

http://www.readyheli.com/headspeed-calculator.html

Can you answer me two questions...
1. What motor efficiency are you using?
2. Isn't the lower number battery percentage left?? Not Throttle position.

So how are you getting such exact numbers for throttle position?

Throttle 55%: 2085
Throttle 60%: 2194
Throttle 63%: 2259
Throttle 67%: 2345
Throttle 70%: 2410
Throttle 73%: 2475
Throttle 76%: 2540
Throttle 80%: 2627


What am I missing. Where did you get this info..Am I miss reading his Chart?
__________________
Trex E's 250/450's/500/600's.
Trex 600N's, Raptor 90SE, Goblins.
Thousands of Flights.
emoe is offline        Reply With Quote
Old 04-17-2012, 08:06 AM   #16
SimStream
Registered Users
 

Join Date: Mar 2011
Location: UK
Default

Quote:
Originally Posted by emoe View Post
Ok guys...are you using Mr.Mel's Calculator?

http://www.readyheli.com/headspeed-calculator.html

Can you answer me two questions...
1. What motor efficiency are you using?
2. Isn't the lower number battery percentage left?? Not Throttle position.

So how are you getting such exact numbers for throttle position?

Throttle 55%: 2085
Throttle 60%: 2194
Throttle 63%: 2259
Throttle 67%: 2345
Throttle 70%: 2410
Throttle 73%: 2475
Throttle 76%: 2540
Throttle 80%: 2627


What am I missing. Where did you get this info..Am I miss reading his Chart?
1 motor efficiancy is usually best left at 90% some pyro motors run at 92%, some odd motors at 85%

2. No its throttle percentage .....enable 'gov' and select your esc type and then enable 'extended results' to see list of throttle percentages and expected headspeeds as above

when it reads throttle 73% 2475 it means that with your setup and your throttle curve set as 73 73 73 73 73 the headspeed you should see is 2475 rpm
SimStream is online now        Reply With Quote
Old 04-17-2012, 08:11 AM   #17
emoe
Registered Users
 
Posts: 178
 

Join Date: Dec 2006
Location: Michigan
Default

SimStream. Thanks. How could I have missed that.
Thanks again.
__________________
Trex E's 250/450's/500/600's.
Trex 600N's, Raptor 90SE, Goblins.
Thousands of Flights.
emoe is offline        Reply With Quote
Old 04-19-2012, 03:37 AM   #18
Phil777
Registered Users
 
Posts: 779
Thread Starter Thread Starter
 

Join Date: Feb 2012
Location: New Zealand
Default

Throttle 55%: 2085
Throttle 60%: 2194
Throttle 63%: 2259
Throttle 67%: 2345
Throttle 70%: 2410
Throttle 73%: 2475
Throttle 76%: 2540
Throttle 80%: 2627

with 22t pinion,

Can i still use this 22t till i get my 20t?
e.g do my first flights at 2085 instead of 1900, with no issues?

And use Governor between 55-60?

without wreaking anything?
Phil777 is offline        Reply With Quote
Old 04-19-2012, 03:46 AM   #19
Phil777
Registered Users
 
Posts: 779
Thread Starter Thread Starter
 

Join Date: Feb 2012
Location: New Zealand
Default

Throttle 20%: 460
Throttle 30%: 821
Throttle 40%: 1182
Throttle 50%: 1543
Throttle 60%: 1905
Throttle 70%: 2266
Throttle 80%: 2627

just realized
with helijive mode 6,

Would this be ideal for 22t pinion?


Phil777 is offline        Reply With Quote
Old 04-19-2012, 04:52 AM   #20
MrMel
V-BAR Guru
 
Posts: 13,571
 

Join Date: Apr 2005
Location: Lidingo/Stockholm, Sweden
Default

Quote:
Originally Posted by Phil777 View Post
Throttle 55%: 2085
Throttle 60%: 2194
Throttle 63%: 2259
Throttle 67%: 2345
Throttle 70%: 2410
Throttle 73%: 2475
Throttle 76%: 2540
Throttle 80%: 2627

with 22t pinion,

Can i still use this 22t till i get my 20t?
e.g do my first flights at 2085 instead of 1900, with no issues?

And use Governor between 55-60?

without wreaking anything?
You can use lower % without issue, it's just that 1% makes so much difference there so I cannot really calculate it with good accuracy.
__________________
Gone fishing.. or hunting or something..

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
MrMel is offline        Reply With Quote
Reply




Unregistered
Go Back   HeliFreak > R/C Helicopter Support > SAB Goblin 630/700/770


SAB Goblin 630/700/770 SAB Heli Division 630/700/770 - Goblin Helicopters Factory Support

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


Copyright © 2004-2011 - William James - Helifreak.com