john stones 1 - Moderator Posted February 21, 2020 Share Posted February 21, 2020 Bought a model of someone, the servo screws have been threadlocked, doesn't appear to be a solvent, what's the thinking ? soldering iron tip, would I ruin the servo with the heat ? Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 21, 2020 Share Posted February 21, 2020 john I presume you mean the screws holding the servo. I doubt if touching the screws long enough to soften the thread lock would damage the servo. It might damage the grommet, if there is one, but that is replaceable. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 21, 2020 Author Share Posted February 21, 2020 Screw holding the horn on Simon, it's well stuck. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted February 21, 2020 Share Posted February 21, 2020 If John Stones comes on here asking for help, then it has to be a real problem You are almost doomed to damage the servo, as you well realise John My own desperate measure would be to sacrifice the servo arm Cutting slots down to split the arm off, then fit a new arm Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 21, 2020 Author Share Posted February 21, 2020 Yep I feared the nurse, it's a top servo and a great big metal horn, dreading looking at the ailerons. Quote Link to comment Share on other sites More sharing options...
J D 8 Posted February 21, 2020 Share Posted February 21, 2020 Shock loading, tapping the screwdriver with a small hammer as you try to turn the screw may make it release if it is threadlocked and not fixed with something else like super glue. Quote Link to comment Share on other sites More sharing options...
wingcoax Posted February 21, 2020 Share Posted February 21, 2020 Hopefully it will be 242 (blue) and should move with only a bit of shock. Quote Link to comment Share on other sites More sharing options...
PatMc Posted February 21, 2020 Share Posted February 21, 2020 If the servo is out of the model or you can remove it, try leaving it in the freezer for 30 mins or so then heat the screw with a soldering iron for just a few secs or carefully hold the servo arm in a cup of boiling hot water. The sudden changes in temps may give enough variation to do the trick. Quote Link to comment Share on other sites More sharing options...
Nigel Dell Posted February 21, 2020 Share Posted February 21, 2020 Posted by PatMc on 21/02/2020 16:00:26: If the servo is out of the model or you can remove it, try leaving it in the freezer for 30 mins or so then heat the screw with a soldering iron for just a few secs or carefully hold the servo arm in a cup of boiling hot water. The sudden changes in temps may give enough variation to do the trick. I concur have done it this way with success, sometimes just a few seconds of the soldering iron without the freezing works fine, is it a metal geared servo? You can afford a little more time with the heat, also a small point but using a pointed bit seems to work easier than a flat blade bit but only in minimising the damage done to the horn for me. Quote Link to comment Share on other sites More sharing options...
Andrew Calcutt Posted February 21, 2020 Share Posted February 21, 2020 Hold the arm in a vice and use an impact driver on it,make sure it is the right screwdriver bit. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted February 21, 2020 Share Posted February 21, 2020 If they've used threadlock then I'm assuming it's a metal geared servo? Localised heat from a soldering iron on the screw head shouldn't hurt the servo unless you leave the iron on for a very long time. Quote Link to comment Share on other sites More sharing options...
Joe Beavis Posted February 21, 2020 Share Posted February 21, 2020 I am guessing that the thread is M3 ish, and the screwhead socket is now in less than new condition. I would favour Dremelling a new screw slot, preferably inline with the arm - you may be able to save it, select a screwdriver with the widest blade that will fit, grind it if necessary to really fit the slot, and apply steadily increasing torque. If you can hold it in the vice, that's good. If it is Loctite, then any heat will help. Also, if it is Loctite, I would not use an impact driver. It yields best to steady and overwhelming force! Good luck! Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 21, 2020 Author Share Posted February 21, 2020 Ground a dremel wheel down first then slotted it, out it popped and I can't see any threadlock on it, all the others had and they came out easy. Quote Link to comment Share on other sites More sharing options...
Stephen Smith 14 Posted February 22, 2020 Share Posted February 22, 2020 Always use socket head screws on metal geared servos, can tighten them to the correct torque easily and are easy to remove. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 22, 2020 Author Share Posted February 22, 2020 Posted by Stephen Smith 14 on 22/02/2020 18:59:26: Always use socket head screws on metal geared servos, can tighten them to the correct torque easily and are easy to remove. Agree, replaced em. Quote Link to comment Share on other sites More sharing options...
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