Jon H Posted February 21, 2018 Share Posted February 21, 2018 Yea i was never able to find cone locators big enough for the 10 or 12mm hole most large spinners have in the back of them. I was going to make my own balancer at one stage but it became unimportant when i found a supply of balanced spinners. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 21, 2018 Author Share Posted February 21, 2018 Well it all held together whilst engine tuning! Edited By Ron Gray on 21/02/2018 17:04:42 Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 21, 2018 Author Share Posted February 21, 2018 And if you want to get bored here are 2 vids: Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 21, 2018 Share Posted February 21, 2018 Good to hear its still together Ron I know this is the wrong thread but just a few suggestions to help you with tuning it. You must set the main needles before the slow runs. This is true for singles as well but especially for the twins. I don't know if you did it off camera before shooting video 1 but it seemed that the mains were very lean and the slow runs rich when you first started which is why the right pot dropped out the moment you took the glow off and why it wouldn't go to full power. I suggest you run it up to about 3000rpm before removing the glows. While the slow run needles don't change the top end much the mains do influence the low end so its important to make sure they are set first. Setting the slow run with the mains out also leads you down a path where you end up with the slow run needles out of sync which does appear to be where you ended up at the end of video two as one cylinder is firing more strongly than the other. Its also important to make changes to the needles while the engine is at full throttle as you cannot gauge the change in rpm if you throttle back, tweak it, and then go again. I appreciate that its a little intimidating reaching around while its flat out but I'm afraid it is the only way to do it. if you are able to tune it on the fly you will find it much easier to find the optimum position. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 21, 2018 Author Share Posted February 21, 2018 Thanks Jon. The needle settings were straight out of the box and this was the first time I had started the tune. The mains were well out running much too lean, the engine just dying when I went to full throttle but the only time a pot dropped was when it ran out of fuel, definitely not when the glow sticks were removed! The bottom end is still too rich but at least now I’m getting 9.5k at the top but am aware that there’s more to come. The sync between the 2 pots was well out when I first ran the engine but it did sound nice like that and even though you say they’re out of sync at the end of vid 2 they are so much better than at the start! It’s actually in the mid range where the sync is at it worst hence why I was seeing if I could adjust it there. This is a wip so will be going back to it next week but ran out of time today. Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 21, 2018 Share Posted February 21, 2018 I just checked video 1 and from 49 seconds until it stops the first time you were on one cylinder. If you listen carefully to the video you can hear it drop off after the glow stick is removed and it dies totally at about 49 seconds. I'm not trying to be critical, just pointing out what to listen for. In the last few seconds of video two you can hear a similar thing. one cylinder is tutting away strongly but the other is just putt, putt, futt in the background. That one is likely to still be rich and I think its the right pot. For the main needles I have confess to a little smirk as the instructions say to open the mains half a turn from the setting they were at when received from the factory. Its fine though, no one else reads them either We should probably kick further tuning chat over to the laser tech thread though as we are quite off topic now. Edited By Jon - Laser Engines on 21/02/2018 20:25:15 Quote Link to comment Share on other sites More sharing options...
Ian Jones Posted February 22, 2018 Share Posted February 22, 2018 Pleased to see it all coming together now Ron. Good looking model too. At least the bulkhead won't depart the airframe . Hope you are going to post a video when you have it flying. Quote Link to comment Share on other sites More sharing options...
ASH. Posted February 22, 2018 Share Posted February 22, 2018 Ron, you have a nice model there. If it were mine I would use a South Herts Intelligent Glow on it. They make one specifically for twins - around 50 quid. It will guarantee you never have a dead stick with the added bonus - you won't need to get near the prop. I know Jon is against onboard glows but I have used one and highly recommend it. I will use them on all my treasured models. It guarantees against having a flameout. Cymaz, thanks for the link it was brilliant. It's a subject I find that is always overlooked. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 22, 2018 Author Share Posted February 22, 2018 TBH guys, with all the other issues I have had with this model, the departing bulkhead had me reaching for the box of matches and it was going onto the bonfire. So this is its last chance! Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 22, 2018 Share Posted February 22, 2018 Posted by ASH. on 22/02/2018 01:09:25: Jon is against onboard glows Not just me personally, but Laser as a whole. They are never ending source of problems (the last one Ron used wouldnt even get his engine started!) and will not fix the problem. They might mask it to some degree, but the problem will still remain and the engine will quit at some point. The temperature sensing type are better than the on/off type, but if the engine is tuned correctly you dont need either. A few minutes tuning saves you 50 quid, winner winner :D This is another one that can be debated for days but it wont change our recommendation. Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 22, 2018 Share Posted February 22, 2018 Posted by Ron Gray on 22/02/2018 08:07:35: TBH guys, with all the other issues I have had with this model, the departing bulkhead had me reaching for the box of matches and it was going onto the bonfire. So this is its last chance! I will give it a home Quote Link to comment Share on other sites More sharing options...
trebor Posted February 22, 2018 Share Posted February 22, 2018 I'll buy tickets if you raffle it Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 22, 2018 Author Share Posted February 22, 2018 I will keep you guys in mind when I give it its maiden! Quote Link to comment Share on other sites More sharing options...
Brett Hoskins Posted March 9, 2018 Share Posted March 9, 2018 I've have this model, managed to get it airborne only once and had the firewall, fail on the maiden flight. I would say that it appears to be a good flyer, but it has weaknesses eg firewall. Has a high propensity to nose over at the recommended balance point taxiing on grass, and on take-off . If using factory mechanical retracts, they cannot be fixed all the way forward on the mounts, otherwise the wheels don't fully fit retracted into the wheel wells, and also interfere with the retract servo. Result, an even higher propensity to nose over. I prefer electric, but not many choices for a model this size. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted March 9, 2018 Author Share Posted March 9, 2018 Don’t start me off on retracts for this model, I didn’t want to spend out on them but after getting through 3 pairs of cheap ones I should have! In the end I’ve used HD ones from HK and converted them to twist n turn. Time will tell. Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 9, 2018 Share Posted March 9, 2018 Full size P40's had their wheels almost directly on the leading edge and had a small forward rake. THis is not replicated very well on most models. As for c/g, most are conservative to prevent a super sensitive model on the maiden. These days i tend to ignore the instructions for c/g and control movements as i find they normally recommend way too much movement, especially on elevator, and find the cg too far forward which makes the spinner a vital part of the landing gear! Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted March 9, 2018 Author Share Posted March 9, 2018 Jon - I do wish you'd keep quiet, I am now even more 'anxious' about flying this model! PS, picked up the Hurricane last night, a really nice put together and finished model, tank maybe a bit too high though (as you thought). Quote Link to comment Share on other sites More sharing options...
Brett Hoskins Posted August 1, 2019 Share Posted August 1, 2019 had many flights now with the P40. No further drama after strengthening the firewall. A very good flyer, very easy to take off and land. Any comments from others? Quote Link to comment Share on other sites More sharing options...
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