Cliff Bastow Posted October 29, 2022 Share Posted October 29, 2022 Hi all am hoping someone on here can help. I am restoring an old model I aquired from my club which unfortunately has no tailplane. It is a small high wing cabin style monoplane but I have no other information on the model. Does anyone know please is there a rule of thumb about tailplane size? Percentage of wing area perhaps? Many thanks. Cliff. Quote Link to comment Share on other sites More sharing options...
Robin Colbourne Posted October 29, 2022 Share Posted October 29, 2022 Hi Cliff, If you can post a photo of the model, then the likelihood is that someone can identify it and direct you to a copy of the plan. Otherwise it is likely there is a pretty similar design which could be used as a guide. If the design was originally a free flight model with a rearward centre of gravity and a lifting tail, then it could easily have a much larger tailplane than a similarly sized purely radio controlled model. Cheers, Robin Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted October 29, 2022 Share Posted October 29, 2022 1 Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted October 30, 2022 Share Posted October 30, 2022 (edited) I general terms, the size of tailplane is related to the length of tail and how much longitudinal stability required. i.e. long tail moment = small tailplane, short tail moment = large tailplane required. As Robin says, vintage designs with aft c of g and lifting tails tend to have large tail planes. Peter Miller’s book ‘Designing Model Aircraft’ had some guidance on this but I can’t locate my copy. 🥲 Edited October 30, 2022 by Piers Bowlan Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted October 30, 2022 Share Posted October 30, 2022 I can't give you figures for most designs but if it will help, with my aerobatic designs I use a CG at 25% chord and a tailplane 15% of the wing area. CG location has an effect on tailplane size. I know of one person who made the mistake with one of my designs by setting the CG at 30% and then wondered why the model was a pig to fly. Cured the problem with some lead in the nose🙄 Quote Link to comment Share on other sites More sharing options...
Cliff Bastow Posted October 30, 2022 Author Share Posted October 30, 2022 Thanks all for that useful info. the model has a 3foot wingspan and was originally rudder and elevator only. I have reduced the dihedral and will fit ailerons. It looks like it had a small IC engine but mine will be electric. Here are a couple of pics in the hope someone can identify it. Quote Link to comment Share on other sites More sharing options...
Robin Colbourne Posted October 30, 2022 Share Posted October 30, 2022 (edited) Hi Cliff, That looks a lot like a Veron Mini Robot. Even the 'lightning' zig-zag on the fuselage colour scheme matches. Here it is on Outerzone: Veron Mini Robot on Outerzone If you scroll 3/4 of the way down the Outerzone page and click on the orangey brown 'Plan File' box you will get the full size plan. Those rectangular stiffening strips on the tailplane plan look like a good way of weakening it. I would try not the have them, or just put strips on the extreme tips which you can shape to the plan outline. Cheers, Robin Edited October 30, 2022 by Robin Colbourne Quote Link to comment Share on other sites More sharing options...
Robin Colbourne Posted October 30, 2022 Share Posted October 30, 2022 Here is a Mini Robot that I saw at Old Warden in September competing in the single channel spot landing competition. Unfortunately I didn't get the owner's name. Quote Link to comment Share on other sites More sharing options...
Cliff Bastow Posted October 30, 2022 Author Share Posted October 30, 2022 Thats brilliant, many thanks Robin. Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted October 31, 2022 Share Posted October 31, 2022 (edited) 17 hours ago, Robin Colbourne said: Those rectangular stiffening strips on the tailplane plan look like a good way of weakening it. I would try not the have them, or just put strips on the extreme tips which you can shape to the plan outline. Cheers, Robin Alternatively, do as I did on my Bowman Spatman, add .4 mm narrow strips of ply epoxied to the underside of the tips. Stops it warping or splitting in ‘an arrival’. Little weight and quick/easy to do. Weight it down on a flat surface as the epoxy dries. Edited October 31, 2022 by Piers Bowlan Quote Link to comment Share on other sites More sharing options...
Nigel Grant 1 Posted October 31, 2022 Share Posted October 31, 2022 Hi I have a Mini Robot built from a plan updated by Christian Moe which was in the RCM magazine. It has been a great wee plane both at the park and also I take it to the strip to start the day with if I haven't been flying for a while. As it carry's a SLEC bomb its always popular with the granddaughters. Must of done over 100 flights. The plan I used had the more typical arrangement for the tail plane of using cross grain at the tips and the elevator tapers from 40mm in the middle to 20mm at the tip. Uses a Turnigy 2822 motor and a 3S 1000 battery. Has plenty of power to take off grass quickly and for loops etc. I see on outer zone there is a second plan and article which details some modern development's. MinRobot 1 Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted October 31, 2022 Share Posted October 31, 2022 (edited) The CM Mini Robot has been on my build list since it was published in RCMW June 2013. My grandson would love it (me too) so a build for the Christmas period is planned - shouldant take too long 😊. Nice looking example Nigel with a sharp scheme 😎 👍 Edited October 31, 2022 by Piers Bowlan Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.