David Davis Posted August 12, 2021 Author Share Posted August 12, 2021 I have now got to the stage of installing the engine. For a throttle servo, I have three possibilities: a Hitec HS55, a Hitec 5055MG which are both micro servos or a standard size Hitec HS 311/Futaba 148 servo. The throttle servo only has to push a little lever forward and backwards so the HS55 should cope but will this little servo be strong enough to withstand the vibration? Not that Lasers vibrate very much! Incidentally, I started up the engine, a Laser 70, in the test stand yesterday. I had fitted a 16x4 propeller. It fired up staight away with a single back-flip! 1 Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted August 12, 2021 Share Posted August 12, 2021 hello David, I would go for a servo slight meatier that the HS55.....if the light weight servo dies due to the vibrations you may end up flying around for a while. ken anderson...ne..1...meatier dept. Quote Link to comment Share on other sites More sharing options...
David Davis Posted August 16, 2021 Author Share Posted August 16, 2021 Apart from fitting the top sheeting forward of the wing seat and a little making good, all of the woodwork involved in the fuselage construction is complete. I have left off the sheeting below the engine for the time being. The engine currently fitted is a Laser 70. I have three Laser 70s but I have plans for all three! My Laser 62 seen running on the test bed in Post 83 is being professionally repaired. If it comes back before I'm ready to fly the Big Guff I'll fit it. If not, I'll use the 70, then see whether the 62 will fly it. The next stage is to fit the throttle servo, rig up the rudder and elevator actuation and cover the fuselage, fin and rudder. The nose is about 1.75" (4.45 cms) longer than it should be because I forgot to mount the engine further back in the structure and a Laser 70 with a modern engine mount is much longer than a Brown Junior! There are precedents for this in full-size avaiation! Quote Link to comment Share on other sites More sharing options...
David Davis Posted August 21, 2021 Author Share Posted August 21, 2021 Some progress has been made. Still some way to go yet. It does not look too bad at a distance! Note the usual immaculate workbench! 3 Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted August 21, 2021 Share Posted August 21, 2021 Coming together nicely. Quote Link to comment Share on other sites More sharing options...
David Davis Posted August 24, 2021 Author Share Posted August 24, 2021 I have just weighed the fuselage and tailplane with all of the accessories installed. It weighs 2980 grammes or 6lbs 9ozs. As the wings, which escaped the conflagration, weigh 795 grammes or 1lb 12 ozs, the total weight of the model will be 3.77 kgs or 8lbs 5ozs which is 114 grammes or 4ozs lighter than the first one. The next job is to connect up the rudder and elevator controls and to fit the plywood section between the firewall and the wing's leading edge. I hope to fly it on Wednesday afternoon, weather permitting. 2 Quote Link to comment Share on other sites More sharing options...
David Davis Posted August 26, 2021 Author Share Posted August 26, 2021 It was too windy for flying the Big Guff yesterday. I'm waiting for a calmer day. Pictures of the finished model below. It is not as well-built as the red one which was destroyed in a fire, partly because the 1mm balsa which clads the fuselage was rather soft and I was unable to remove some of the ripples however much I sanded it . Towards the end of the construction process I also began to lose interest, something which often occurs as far as I'm concerned. It is unsurprisingly nose heavy with the centre of gravity at about 30% of the root chord instead of the 40% recommended. I plan to move the receiver battery backwards. I have also lost the vinyl graphics sent to me by Pyramid Models similar to those which adorned the fin of the red one. I expect that they'll turn up sometime when I'm looking for something else! The tail surfaces were built for me by my club colleague at Berry Marche Modelisme, Guy Auxvieux. 3 Quote Link to comment Share on other sites More sharing options...
David Davis Posted September 5, 2021 Author Share Posted September 5, 2021 Well I flew it for the first time yesterday afternoon. I had balanced it at 40% of the wing root chord as suggested on the plan but it was too far back as evidenced by the steep take off. I managed a circuit and a good landing on the grass flying the model with very little throttle and full down trim. I will move the rx battery forward to bring the CG further forward. Thanks to Bertrand Viol and all of my collegues at Berry Marche Modelisme. 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 18, 2021 Author Share Posted October 18, 2021 Great day out at the Gueret club's fly-in yesterday. Perfect flying weather. I managed four flights with the Big Guff which attracted considerable attention especially from the camers enthusiasts . 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 19, 2021 Author Share Posted October 19, 2021 An American modeller over on RCG has offered me a Brown Junior for the Big Guff, the same as originally fitted by the Good Brothers. I'll be getting it for the cost of the postage from the states! I've no experience of vintage spark ignition engines but I did used to ride a BSA Bantam in Pre 65 trials! I will let you know when it arrives. As always the views of the cognoscenti will be warmly welcomed. 3 Quote Link to comment Share on other sites More sharing options...
Geoff S Posted October 19, 2021 Share Posted October 19, 2021 Not quite the same thing, David ? I used to ride a 350cc 1932 Ariel Red Hunter in the same type of events and was preparing an HT5 before a cat in my pedal cycle front wheel put paid to my trials riding but I doubt if it's helped my fooling around with glow engines. The Big Guff looks stunning btw. Glad you've managed to resurrect it. Be interesting to use a contemporary engine just to add verisimilitude to its aerial excursions. Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 1, 2021 Author Share Posted December 1, 2021 On 10th November a clubmate filmed my Big Guff in flight but the video is too big to show on this site at 157MB. Anybody know how to reduce it to less than 48.83 MB? PS. The Brown Junior arrived safe and sound but I haven't got round to running it yet. Life is getting in the way. Quote Link to comment Share on other sites More sharing options...
MattyB Posted December 1, 2021 Share Posted December 1, 2021 (edited) 13 minutes ago, David Davis said: On 10th November a clubmate filmed my Big Guff in flight but the video is too big to show on this site at 157MB. Anybody know how to reduce it to less than 48.83 MB? PS. The Brown Junior arrived safe and sound but I haven't got round to running it yet. Life is getting in the way. Just upload it to Youtube and post the link, that’s far quicker and easier to do than pithering with file conversion and editing to get below that limit. Edited December 1, 2021 by MattyB 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 3, 2021 Author Share Posted December 3, 2021 (edited) The Big Guff in flight 10th November 2021. Video by my friend Frans Cooremans. It is an amalgation of three flights which I had with the Big Guff that day, hence, sometimes I am wearing a blue fleece and sometimes I am not! French scholars will forgive me for using the femine "la" when referring to the engine, I should have said, "le moteur." 927767862_----DavidAndTheBigGuff.m4v Edited December 3, 2021 by David Davis 6 Quote Link to comment Share on other sites More sharing options...
Basil Posted January 12, 2022 Share Posted January 12, 2022 On 23/07/2021 at 15:27, David Davis said: Yes and I've got a set of orange overalls to match! David, sorry that this will seem very much out of date but every time I've seen this I keep meaning to ask you what is this model please? Bas Quote Link to comment Share on other sites More sharing options...
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