McG 6969 Posted February 6, 2018 Share Posted February 6, 2018 A real cracking aeroplane there, Tim. Congrats & you'ill be fine for the maiden at 80+ W/lb. Cheers Chris Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 6, 2018 Share Posted February 6, 2018 First off that's a cracking job again Tim. Secondly I would want more power for this type, can you do it without much work on it, and will flight times still be o.k ? Having said that I would fly it first. Quote Link to comment Share on other sites More sharing options...
J Moyler Posted February 6, 2018 Share Posted February 6, 2018 Well done, it looks great. It puts me to shame as I have not even started mine yet. I think it should fly fine on that power. I used to fly a 80 " Piper cub with less than 80W/lb. With my twin I find the two engines seem to produce more more power than you expect. This could be because twins or other multimotors require less power because the prop is not being blanked nor does the prop-wash create as much turbulence over the fuselage. And motors on the wings actually give you better low-speed lift and aileron control due to airflow over the wing. In summary you should be fine with 83W/lb. I would double check everything first and check the prop speed with each motor just to make sure everything is working as expected. Good luck with your first flight, we would like a full report. JM Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 6, 2018 Author Share Posted February 6, 2018 Thanks for all the nice comments guys and I will take the advice and try it on the power I have for the maiden. Should be dead easy to change motors if I decide to as they just bolt onto the motor cage using the new x mount as the outer holes are the same pitch and the x mount obviously has a bigger pitch for the slightly larger od motor. All goes through the front of the large cowls fairly easily. Decals were easy Richard I found that Flighline RC (USA) did a range of decals for their ARTF Tigercat so acquired a set as it is a 63 span. Only took a week for delivery ! CG came out slightly aft so rather than add inert ballast I will swap out the BEC and use a NiMh Rx battery. Plenty of space up front and I can then have a switch independent of the LiPo. (That’s already in the weight budget above btw) weather and field are going to have get a lot better before I take the plunge..... Tim Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted February 6, 2018 Share Posted February 6, 2018 Come to think of it, two motors are more effective that one. Consider the amount of air being pushed back from the much greater area of the prop discs. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted February 6, 2018 Share Posted February 6, 2018 I wouldn't worry about the power. That 100 watts/lb rule of thumb was established when people were using heavy and ínefficient brushed motors and heavy, usually low voltage, NiCad batteries. My Ballerina is quite aerobatic on around 80 watts/lb and I fitted a smaller prop to draw less current and give me better endurance without compromising my enjoyment of its performance. It'll certainly fly with authority with the power you have. It certainly won't be staggering about the sky on full throttle all the time and threatening to stall. It looks terrific btw and don't we all underestimate the weight of a model before we finish it. I know I do. I was hoping to keep my Mew Gull down to 4kg but its around 4.5kg, perhaps a bit more and the maiden went OK using a smaller prop than I intended (because that's what I had in stock ie a 14x7 rather than a 16x8)) and consequently less power. Geoff Quote Link to comment Share on other sites More sharing options...
Lucas Hofman Posted February 7, 2018 Share Posted February 7, 2018 Congratulations Tim, this looks really good. You should have no problem flying it scale. If you want near vertical performance (which the original does not have) you have to add power. Regards, Lucas Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 7, 2018 Share Posted February 7, 2018 @Tim - I did check my stock of 3 bladed pros and they are all 8" not 10"! Great looking finished model the big round nacelles and extended nose improve the looks no end. Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 7, 2018 Author Share Posted February 7, 2018 Thanks to all for help and advice. Almost wishing I had covered in solarfilm now that sad news is out. Be sure I will get you a flight report as and when but I will be waiting for close to ideal conditions for the maiden ( that includes being above 5 degrees C !) so I would not mind betting one of the other GTC’s get airborne before me ! Tim Quote Link to comment Share on other sites More sharing options...
Lucas Hofman Posted February 7, 2018 Share Posted February 7, 2018 Having retracts does add weight but decreases drag a good deal. I would not be surprised if the latter has more effect then the former. Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 13, 2018 Author Share Posted February 13, 2018 Hmmm, I knew I would eventually have trouble with the retracts but one unit has failed after my first taxi trial. Never went more than walking pace across the back garden but when I came to put it all away and raised the gear only one leg came up. Glad it was only a shakedown run or I would have been even more peeved. Took it apart and saw nothing untoward other than the gear train was no longer consistently meshing properly. Bin. Certainly not been stressed but has had a fair few cycles since I started testing last November. Not expensive per se but looked one of the more robust HK units. QC issue perhaps , either way another pair on order.... Tim Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 13, 2018 Share Posted February 13, 2018 Over the last couple of years since my return to this building / flying lark, the biggest problem I've had (next to having too many models) is to do with retracts and their failure. I've come to realise that the old adage of 'you pays your money and takes your choice' is very true and that 'cheap' units tend to be exactly that. And it's not just me, others in my club have had the same experience too. Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 13, 2018 Author Share Posted February 13, 2018 Ron, Could be right Ron. This is my first foray into retracts and didn’t really get good vibes from anything I looked at so settled for HK. What do you recommend? Tim Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted February 13, 2018 Share Posted February 13, 2018 I bought some cheap HK retracts a while ago. Yesterday I started playing with them for a possible idea I had. Well they worked but needed 6 V nicad. They did sound and feel a bit Micky Mouse. I have decided to change my plans. Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 16, 2018 Author Share Posted February 16, 2018 Replacement retracts arrived today. They sound a lot smoother than the first pair so 🤞 Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 21, 2018 Author Share Posted February 21, 2018 Absolutely fantastic, many thanks Peter for such a great design . I have never flown such a smooth flying aeroplane. Needed some up elevator trim wound in on the first circuit and that was it. I love it. You may have gathered I took Grumpy out for his maiden today. Wind was down to 5 mph and straight down my strip and looking at the 10 day forecast the winds are set to increase again. In the end by 1600 it was perfect conditions so I had no more excuses. There is a slight nose up trim change as the gear comes up and the cg moves rearwards a little which I was sort of expecting. Expect I can mix that away. First landing without flap was deceptively fast but on the money. Flaps slowed him down nicely with little or no trim change at slow speed. Second landing was at half flap , no issues. Only on low rates for these 2 flights but while roll rate was sedate it looked brilliant. Couple of reversals , 1 loop and that was it. Set the timer at 7 minutes for these first flights to be safe and I think I have a fair bit left. Will find out when I recharge. Could it cope with more power? Sure but it flys great and looks so realistic atm I am well satisfied. I have got video but this site did not like IPhone format it seems so I may put them on utube. Thanks again to Peter for a great design. Tim Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted February 21, 2018 Share Posted February 21, 2018 You model looks great. So glad that you are happy with the performance. Mine is the best twin that I have ever flown. and this proves that mine isn't a fluke Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 21, 2018 Share Posted February 21, 2018 Hi Tim. Sorry for the delay but with retracts you really do need to spend a bit more to get decent ones, it's hit and miss with HK so you may be luck. eFlite ones are good! Glad you got TC out for its maiden and looks really good, re the vid, you have to upload them to YouTube then use the YouTube share function>embed and copy and paste into your message via the Youtube icon on the header rail. Quote Link to comment Share on other sites More sharing options...
Rob Ashley Posted February 21, 2018 Share Posted February 21, 2018 Tim. Many congrats mate. Very pleased for you and glad to hear the GTC flew brilliantly. Interesting to note your comments about the power available too. BestRob Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 21, 2018 Author Share Posted February 21, 2018 A little bit of indulgence. Videos from todays GTC maiden Edited By Tim Ballinger on 21/02/2018 22:47:27 Edited By Tim Ballinger on 21/02/2018 22:49:05 Quote Link to comment Share on other sites More sharing options...
Concorde Speedbird Posted February 21, 2018 Share Posted February 21, 2018 Superb, looks just like a Tigercat! Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 21, 2018 Author Share Posted February 21, 2018 Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 21, 2018 Author Share Posted February 21, 2018 Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 21, 2018 Author Share Posted February 21, 2018 Quote Link to comment Share on other sites More sharing options...
Tim Ballinger Posted February 22, 2018 Author Share Posted February 22, 2018 Ok last one and then I promise no more ! Quote Link to comment Share on other sites More sharing options...
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