HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 02, 2013, 09:55 PM
Registered User
Joined Oct 2011
32 Posts
Discussion
Throttle servo question?

I have a 72" 3dhs extra with a 33cc engine i have a 645mg on throttle servo (i know this is a slow analog but i am new to this gas giant scale and wont need fast throttle response yet) my question is will this servo interfere with my ignition box thats mounted close to servo? By interfere i mean frequency or somthing on those lines.
mikesoby is offline Find More Posts by mikesoby
Reply With Quote
Sign up now
to remove ads between posts
Old May 03, 2013, 06:41 AM
Registered User
United States, FL, Citrus Springs
Joined Aug 2008
1,017 Posts
Anything's possible, but what you're asking isn't very likely. Mount it where it makes the most sense, then check it out thoroughly when you get everything up and running - just prior to your maiden flight (while doing your range check with the engine running, etc.).

Welcome to gas, and congrats on the new bird!

BTW, regarding that "slow" servo? I don't know how you fly, but for me, the slowest servo's out there keep up with what I ask of them just fine.
ahicks is online now Find More Posts by ahicks
Reply With Quote
Old May 03, 2013, 08:12 AM
Registered User
United States, TX, Leander
Joined Sep 2003
2,271 Posts
I follow the old school rules for installation, even after I went 2.4, just a creature of habit. Thats about 10" distance between ignition and radio gear and nyrod for throttle shaft. But like ahicks says, installs are much easier with 2.4. Things have come a long way since 72mhz.
Edwin
edwin1 is online now Find More Posts by edwin1
Reply With Quote
Old May 03, 2013, 03:38 PM
Registered User
Joined Oct 2011
32 Posts
10" from servos or just the rx? Im flying a futaba 8j sfhss if that helps at all
mikesoby is offline Find More Posts by mikesoby
Reply With Quote
Old May 03, 2013, 03:52 PM
Registered User
United States, TX, Leander
Joined Sep 2003
2,271 Posts
It would be a 10" separation, any radio gear to any ignition gear. Not always practical, just a target. More importantly is using a nyrod or some non-conductive throttle linkage. Metal to metal vibration can generate rf frequencies. A metal throttle pushrod can act like an antenna and radiate all inside the fuse.
Edwin
edwin1 is online now Find More Posts by edwin1
Reply With Quote
Old May 03, 2013, 03:58 PM
Registered User
United States, FL, Citrus Springs
Joined Aug 2008
1,017 Posts
Today, there is old school, and there is what works? Many of the "old school" methods of radio installation were learned/became common practice when we were running magneto ignitions and radio systems that were pretty sensitive to rf leaks. Many or most of those rules are now routinely ignored. Still, testing your rig thoroughly before flight is a great plan....
ahicks is online now Find More Posts by ahicks
Reply With Quote
Old May 06, 2013, 09:59 AM
Mulit-Platform Pilot
barracudahockey's Avatar
United States, FL, Jacksonville
Joined Sep 2004
2,693 Posts
Agreed.

Also, fast throttle servos aren't all they are cracked up to be, you can only expect so much throttle response from an IC engine no matter how fast you yank the throttle arm back and forth.
barracudahockey is online now Find More Posts by barracudahockey
Reply With Quote
Old May 06, 2013, 10:06 AM
Registered User
United States, CA, Chula Vista
Joined Apr 2005
104 Posts
If your eng has elect ignition, not a magneto and your on 2.4, you'll probably be just fine. Don't use metal to metal on the throttle servo linkage (ever).
Always check for interference (eng off and running) before you maiden. If your throttle servo is a little slow, change the expo to a positive value and you should notice a difference.
Have someone with gas experience go over your plane with you as well. Good luck and happy flying!
rica1 is offline Find More Posts by rica1
Reply With Quote
Old May 08, 2013, 12:55 PM
Registered User
ledsled's Avatar
Louisville, KY
Joined Mar 2009
2 Posts
The worst case of ignition interference I ever saw was from a lose plug cap. Most of my throttle servos are a little short of 10 "s from the ignition wiring. Double check it all on the ground!
ledsled is offline Find More Posts by ledsled
Reply With Quote
Old May 08, 2013, 06:29 PM
Registered User
Joined Oct 2011
32 Posts
Thanks guys appreciate the info. Does the ignition box need to be wrapped in foam??
mikesoby is offline Find More Posts by mikesoby
Reply With Quote
Old May 08, 2013, 06:58 PM
Registered User
United States, FL, Citrus Springs
Joined Aug 2008
1,017 Posts
No. It's a big block of epoxy inside, pretty durable.
ahicks is online now Find More Posts by ahicks
Reply With Quote
Old May 08, 2013, 08:44 PM
Registered User
Joined Oct 2011
32 Posts
Thanks once again ahicks haha ur a big help! Im getting excited its almost done! Hope it flies like my 57" extra
mikesoby is offline Find More Posts by mikesoby
Reply With Quote
Old May 09, 2013, 07:46 AM
Mulit-Platform Pilot
barracudahockey's Avatar
United States, FL, Jacksonville
Joined Sep 2004
2,693 Posts
I mount mine on a foam pad then secure it with a pair of tie wraps in a plus pattern. I wouldn't wrap it but I lay down to strips of 1" foam insulation tape from Home Depot, its got adhesive on one side and comes in a roll.
barracudahockey is online now Find More Posts by barracudahockey
Reply With Quote
Old May 09, 2013, 05:07 PM
Registered User
Joined Oct 2011
32 Posts
Thanks baracuda
mikesoby is offline Find More Posts by mikesoby
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion electric heli throttle sub trim question wc_wickedclown Mini Helis 2 Apr 08, 2013 07:08 PM
Discussion throttle lift off question Charlie6017 Multirotor Talk 6 Mar 29, 2013 12:57 AM
Discussion DJI Naza throttle 2 questions before first lift-off kakemann Multirotor Electronics 8 Mar 27, 2013 09:31 AM
Sold HPI Baja 5b throttle servo , DS1313 Hi Performance Digital Throttle Servo ronzer Cars - Trucks and Parts (FS/W) 0 Jan 16, 2013 09:32 PM
Poll Throttle question.. detent setting..and a few other questions... DGrant Electric Heli Talk 15 Jan 12, 2013 09:53 AM