Archive of the Yahoo! Groups mailing list for the Bug hand-launch glider 2002-2018

From: "Mark Stephen" <mark.stephen16@...>
Date: Saturday, November 19, 2011 10:29 PM
Subject: Re: Carbon rods in Dubro micro "clamp" for the servo..
John, Rick, I'll set up a few pieces of scrap and do a spring hinge on them later tonight or tomorrow and take pics to post. Would not do much good to take pics of one installed on my Bug as it is very hard to see with my own 1 1/2 eyes let alone get a good digital image of it. To answer your concerns,yes, if you get your spring tension too heavy, it can and will wear on the servo. That is why it served me well to experiment around with different dia. wire and length of the legs to get a good "TLAR" for the servos. I use .009 guitar string for my springs on my Bug and MiMi.You don't want it too weak or it will not be able to push against the airflow,but not so heavy that your servos chatter to try to keep it still. What I did was power up a servo, hook a little piece of wire to the horn and tug on it untill it started to whine. Then I SWAGed at anything that would have less than half that pull on the servo and still have enough push to move in the airflow would be shiny. So, to stretch out this long story a bit more, what I came up with was the "T" bent spring made from .009 music wire, with 1 1/4" leg (vertical part of the T) and arms that looked about right to give good anchorage into the stab and control surface. I've got dozens of hours on my servos in my Bug and not a trouble one (and their the cheap ones) 2 ea, 5g servos powered by a 150ma 1s LiPo. Get around 50 - 60 minutes flying time a charge from those little guys, so not so much battery draw from them. If their not pulling so hard that the servo wants to fight it, then it uses no more power than what it would to hold a push rod, At least that is what I'm thinking. I'll get those pics up soon. Mark --- In BugHLG@yahoogroups.com, John Gallagher <gldrgidr@...> wrote: > > I have the same concerns.  The constant pressure is considered a good thing for launching but it does sound like a strain on the servo.  The same problems occur with the pull-pull method.  Mark also mentioned that he had to modify the spring to prevent distortion at the hinge line which is another problem reported with the string/spring method. >   > Mark, > Can you upload some photos of your T spring instilation so we can see the solution you came up with? >   > John  > > > ________________________________ > From: kb11troy <kb10troy@...> > To: BugHLG@yahoogroups.com > Sent: Friday, November 18, 2011 4:22 AM > Subject: [BugHLG] Re: Carbon rods in Dubro micro "clamp" for the servo.. > > > I've wondered about the string/spring method as well. I used the wire with etched tubing because I had it left over from another DLG build. > > The thing that concerns me about the string/spring setup is that the servos will always be fighting against the pull of the spring- probably using more juice from the battery and maybe putting more wear on the servos. Any thoughts on this? > > I'm not putting it down by any means. It's a very popular technique with the competition DLG crowd. > > Rick > > --- In BugHLG@yahoogroups.com, John Gallagher <gldrgidr@> wrote: > > > > Mark, > > I was just about to ask if anyone used the string and spring method.  Any chance that you can upload some photos to the groups site? > > I also debated about using a pull-pull setup using Spiderwire (non-stretch fishing line). > >   > > John > > > > > > > > > [Non-text portions of this message have been removed] >