Biggles' Elder Brother - Moderator Posted February 14, 2014 Share Posted February 14, 2014 Your confidence will build as you go through Darren. BEB Quote Link to comment Share on other sites More sharing options...
kc Posted February 14, 2014 Share Posted February 14, 2014 A couple more points on prop adaptors.....They come in different lengths so another make might be longer.They can be 3mm or 3.175mm ( 1/8th inch ) which are very similar, but not really safe using a 3.175 and closing it down does not grip well enough on a 3mm shaft.For trial fitting a prop should be fitted ( without Battery!) to ensure it clears, especially when downthrust or side thrust is used.A spinner or round ended spinner nut is required by BMFA rules. Quote Link to comment Share on other sites More sharing options...
Darran Posted February 15, 2014 Author Share Posted February 15, 2014 So prop choice as a beginner I could just look at what everyone else is proposing to use, but there is obviously some way of working out what prop should be used. Is this a black art or is they some basic guidelines to working it out. Quote Link to comment Share on other sites More sharing options...
Darran Posted February 15, 2014 Author Share Posted February 15, 2014 Today I made a bit of progress, I have mounted my motor to F1 with F1A glued in place. I have measured the height of the whole thing from the back of F1 to the front face of the prop collet. This measures 52mm. So using BEB's advice if leaving 7-9mm from the front of the fus would place the back of F1A 43mm from the front of the fus which is pretty close to the front and much further forward than I imagined. Edited By Darran on 15/02/2014 19:39:57 Quote Link to comment Share on other sites More sharing options...
Darran Posted February 15, 2014 Author Share Posted February 15, 2014 I have also created my new to plan size F4 as you can see Quote Link to comment Share on other sites More sharing options...
kc Posted February 15, 2014 Share Posted February 15, 2014 Prop selection for electric is a black art! Well without a Watt meter it is. Prop needs to match the motor to avoid drawing too much current and blowing the ESC. Follow whatever prop is recommended for YOUR motor not what others fit to this model with different Kv ratings / motors /number of cells. Quote Link to comment Share on other sites More sharing options...
Darran Posted February 15, 2014 Author Share Posted February 15, 2014 Posted by kc on 15/02/2014 19:33:21: Prop selection for electric is a black art! Well without a Watt meter it is. Prop needs to match the motor to avoid drawing too much current and blowing the ESC. Follow whatever prop is recommended for YOUR motor not what others fit to this model with different Kv ratings / motors /number of cells. It gives my two prop sizes Prop size: 7.4V/12x6 14.8V/8x4 Motor is 1100kv 313watt with a plush 40a esc and a 2200 20-30c 3s lipo. Manual (if you can call it that) suggests 12x6 for lipox2 Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 16, 2014 Share Posted February 16, 2014 As has been said prop selection is a bit of a black art. So any advice is a bit "suck it and see"! 12x6 sounds a big big for 3s on this motor - but the only way to know is with a Wattmeter. I know its more expense - but a wattmeter really is indispensable when using electric power - you simply have to know how much current your motor is drawing so you can select the right prop. The meter will pay for itself in the motors and ESC you don't burn out! With the meter you can take the throttle up gradually and be sure you don't exceed the maximum for your ESC/motor. If the motor is taking too much current you need to lower the prop load (either a smaller diameter or smaller pitch). If you are not reaching close to the max permitted current then you can fit a prop with a higher loading - either bigger diameter or larger pitch. BEB Quote Link to comment Share on other sites More sharing options...
Darran Posted February 16, 2014 Author Share Posted February 16, 2014 I had to order some servos and a receiver for this model so at the same time I ordered a wattmeter. Thanks again for the advice fella's. Hoping to crack on with the build this week. Been a little slow so far but will have more time this week to get it looking more like a plane and less like a pile of wood. Quote Link to comment Share on other sites More sharing options...
Darran Posted February 19, 2014 Author Share Posted February 19, 2014 So yesterday I added FC and my new cut F4. Next to add F1. Quote Link to comment Share on other sites More sharing options...
Darran Posted February 20, 2014 Author Share Posted February 20, 2014 And now to join the fus sides. Quote Link to comment Share on other sites More sharing options...
Darran Posted February 21, 2014 Author Share Posted February 21, 2014 Fus has been joined. All lined up but tail does not marry up despite me shaping a new F4. Will be rebuilding the tail as I managed to mark it with the clamps so I will alter the front spacer to bring it in line with the fus. Quote Link to comment Share on other sites More sharing options...
Devcon1 Posted February 21, 2014 Share Posted February 21, 2014 Darran, To avoid those marks on the wood when you use clamps try placing a bit of scrap balsa between the clamp and your work. I think some others have mentioned this little anomaly re the rear end, you could try gluing the longerons to the tub and build the rest whilst inverted on the plan, your solution will also work. Regards John Quote Link to comment Share on other sites More sharing options...
Darran Posted February 21, 2014 Author Share Posted February 21, 2014 Posted by John Milne on 21/02/2014 21:47:59: Darran, To avoid those marks on the wood when you use clamps try placing a bit of scrap balsa between the clamp and your work. I think some others have mentioned this little anomaly re the rear end, you could try gluing the longerons to the tub and build the rest whilst inverted on the plan, your solution will also work. Regards John Yes John I have been putting extra pieces in between but just for some reason didn't on this bit and managed to mark the balsa. I have plenty of this though so will redo it. i am sure I can correct the anomaly. At least it gives me chance to experience how to fix things that don't go to plan. Quote Link to comment Share on other sites More sharing options...
kc Posted February 22, 2014 Share Posted February 22, 2014 Bits of balsa or ply to spread the clamp pressure are the answer. However if you do get a dent in balsa a very good trick that often works is to put one drip of water into the dent, then one more drip right into the dent but not the surrounding balsa and leave overnight. Miraculously lots of dents will expand & disappear this way - no cost and no weight increase like filler. The old tricks are the best! Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted February 22, 2014 Share Posted February 22, 2014 Spit is even easier - and works at least as well, possibly even better! Very old tricks work well too! BEB Quote Link to comment Share on other sites More sharing options...
Darran Posted February 23, 2014 Author Share Posted February 23, 2014 Posted by kc on 22/02/2014 12:44:34: Bits of balsa or ply to spread the clamp pressure are the answer. However if you do get a dent in balsa a very good trick that often works is to put one drip of water into the dent, then one more drip right into the dent but not the surrounding balsa and leave overnight. Miraculously lots of dents will expand & disappear this way - no cost and no weight increase like filler. The old tricks are the best! I tried this and it worked a treat. Great tip. Quote Link to comment Share on other sites More sharing options...
Malcolm Fisher Posted February 23, 2014 Share Posted February 23, 2014 If you're in a hurry, the applicaton of heat from your covering iron (or even a domestic one but don't tell the wife) turns the moisture into steam and swells the balsa more quickly. Malcolm Quote Link to comment Share on other sites More sharing options...
Darran Posted February 26, 2014 Author Share Posted February 26, 2014 Ok so i have an idea in my head to make the front top cover for my model removable rather than fixed so i can gain access to the motor etc from the top. Was going to form the top sheeting as one removable cover fixed by magnets or some tiny brass fixings rather like an old car bonet possibly.Is this a feasable modification or am i just asking for issuesEdited By Darran on 26/02/2014 19:46:04 Quote Link to comment Share on other sites More sharing options...
Devcon1 Posted February 26, 2014 Share Posted February 26, 2014 Darran, Are you planning this as the battery access hatch as well? John Quote Link to comment Share on other sites More sharing options...
Darran Posted February 26, 2014 Author Share Posted February 26, 2014 The plan was to access from the top rather than the bottom and have the whole front removable from FCC to F2 So if this was possible then i would sheet the battery hatchEdited By Darran on 26/02/2014 20:18:29 Quote Link to comment Share on other sites More sharing options...
Darran Posted March 3, 2014 Author Share Posted March 3, 2014 Ok so after briefly contemplating making the top of the nose removable I decided to stick to the plan and covered it. Here's the latest pic of the fus. Not to bad a job so far. I am pleased with my efforts. Quote Link to comment Share on other sites More sharing options...
Darran Posted March 8, 2014 Author Share Posted March 8, 2014 So I took the plunge and fitted the tail section to the main fus. I followed BEB's datum line method and all appears to be in line. The body of the plane is now coming together nicely. I have avoided using cyano and stuck with aliphatic, which gives me more time to position etc, the downside of course is it takes longer to dry. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted March 8, 2014 Share Posted March 8, 2014 Looking great Darren. I think you are wise to stick basically to the plan. Small departures are OK - but a detectable front cover is a much bigger departure - maybe too big a leap for your first plan build. Keep on as you are and you'll end up with a first class model you can be proud of. BEB Quote Link to comment Share on other sites More sharing options...
Darran Posted March 9, 2014 Author Share Posted March 9, 2014 Right I have made my first mistake. I was working on the lattice work in the tail and looked at the plan I wrongly assumed that the markings for the struts that fit from bottom to top were straight ones between. The bottom runner and the top braces. In the picture above you can see the mistake. Question is do I leave them in or remove them this is the question. Quote Link to comment Share on other sites More sharing options...
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