Chris Walby
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Posts posted by Chris Walby
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Geoff,
I suspect your Mossie is much like all others regarding flap performance bearing in mind that the flaps are both sides of the nacelles. This just means that the wash of the props has a greater effect (good and bad) when the flaps are deployed.
Could I suggest watching The Peoples Mosquito interview with Eric "Winkle" Brown when he talks about the first carrier landing of a twin engine aircraft. There are a few useful pointers when using full flap
- Full flap, very low air speed and lots of engine power, if one engine quits the aircraft inverts very quickly (<3 seconds). Eric did this at height with his "Boffin" as passenger
- Eric's comments about the swap to 4 bladed props to achieve very low approach speed to the carrier
Of course he had the benefit of being in the aircraft to feel the approaching stall.
I am sure others can assist, but my plan would be:
- Set no flap position 1
- Set flaps at 15 degrees position 2 - use this and see how it slows up
- Set flaps at 30 degrees position 3 - not slowing at all, try this, but watch for pitch up and get on the power/down elevator to keep the speed up
- Set flaps at 45 degrees position 4 - Okay you have missed 2 or 3 landing attempts (still flying like a bullet) and time is running out. Almost full power and try this flap position or
- Plan B - Gear up, flaps 2, come in real low and belly it in on the long grass. Might cost you a set of props but not much else.
If you only have a 3 position switch then:
- Set no flap position 1
- Set flaps at 15 degrees position 2 - use this and see how it slows up
- Set flaps at 35 degrees position 3 - not slowing at all, try this - Okay you have missed 2 or 3 landing attempts (still flying like a bullet) and time is running out. Almost full power and try this flap position or
- Plan B - Gear up, flaps 2, come in real low and belly it in on the long grass. Might cost you a set of props but not much else.
IMHO the number one thing to avoid is tip stalling it with no height and the U/C down and flaps as its high drag.
The thing about maidens I don't like is the quantity of things to do in a very short space of time.
PS if you can pick a day with a reasonable wind straight down the runway it will help with any swing on take off and much needed slowing on the way in.
Hope this helps
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Jeff, following with interest and best of luck. When all finished that will produce a very distinctive sound
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As David says almost anything will fly...this pup flies on 3S800 in calm conditions.
Who said you can't take your dog onto the flight line!
C of D (dog) is in an odd place, but he will loop and roll if asked.
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Don't panic Mr Manwaring.... Okay the Seagull should weigh 6.4Kg and mine flies nice at 7.4Kg and I know the TN is a smaller wingspan, but dare I say it.....it has flaps.
If is anything like my BH Mossie and PZ Mossie (not tried the Seagull Mossie…bottled out) the flaps are very effective as long as you use plenty of power.
15 degrees is effective, 30 degrees and I need about 45% throttle as it becomes very draggy/more lift and the great Winkle Brown could effectively hang it on its props with a full size aircraft with 45 degrees!
All I would say from my experience is not to slow up too much as it has a sting if you tip stall it.
PS what is in the plastic bags? I did end up with some nice brass prop nuts, before I was about to turn my attention to the heavy non scale tail wheel!
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Hi, looking good
I found that I hand to tip the carb and exhaust together to get the cowl on.Then move them apart or the cowl will fill up with exhaust oil! Neat job...but how will you get to adjust the slow run needle...it may have to be adjusted one dayEdited By Chris Walby on 14/10/2018 09:41:51
Edited By Chris Walby on 14/10/2018 09:42:54
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Good to get the bits back and a pity its not repairable. Worth doing a careful inspection and strip down just to double check it wasn't anything else (component wise).
Apologies to ask, but you say "about 550m from where we all saw it waggling its wings and go out of sight and out of radio contact" if it was tip stall should you not have had telemetry to point of impact?
Sorry for being pedantic, but I had a model I crashed 3 times (experimental use of differential ESC control on a small twin) I sort of convinced myself it was pilot disorientation (teach me for flying in poor light and leopard spot camouflage). The last crash it didn't eject the battery and the RX was flashing (loss of signal). I have just taken it out of the naughty corner after 9 months as I found a range issue with the TX/RX combination.
Just saying its worth double checking to be sure?
PS
I think mine is repairable...honest
Edited By Chris Walby on 12/10/2018 22:35:40
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Jim,
This is absolute, contact George, take his advice as he will warrant the product he sells for the application you have discussed with him.
Any other advice for another manufacturers product is not applicable in this case.
....I am off to the shed to fit a remote glow to my Laser... why bother listening to the manufacturer and expert if you just ignore them.
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Jim,
Looks good and if George suggests it with his experience I am sure he's spot on. His advice to me (twin IC with flaps and retracts) was to have one RX battery and a high power UBEC. His rational was that if a retract servo failed the UBEC voltage would not drop as the servo failed due to the high current performance of the UBEC.
As you have two batteries you might as well spread the load for the cost/weight of another UBEC so I can see that logic.
Only issue with UBEC's was with a HK one and some digital servos where if all three were used at the same time it "browned out" the RX voltage. Fortunately if found it on the bench and just bought a 4-max UBEC to solve the issue. It would have been a real gutter if the plane had been flown as my normal control checks are individual and slow so I would not have found the issue until a time of
high stresspanic which is not when you want to test the re-initialisation time of the RX!Be great for the rest of us if you set a build log up and post a few pictures
PS all the best with the build
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NiCad's for planes...it will never take off
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Allan, any news on finding your mossie as the leaves seem to be dropping off the trees around our area it might be easier to spot?
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Hi, would a Laser 80 pull it ok?
Cheers
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Hi, Best suggestion is to talk to George at 4Max, I have always found him very helpful + there are a few help guides on his website.
IMHO it won't make any difference either having longer battery leads or motor leads (tin hat on!) however other ESC manufacturers state that if battery leads are extended then additional capacitors are to be added.
If its a small model then option "a" is okay (although if you have a spare channel you could have differential throttle if you want (very helpful if you have no rudder control)).
I don't think option B helps unless diodes are used so the UBEC can be fed from either ESC (in case one battery goes flat). There are dual fed switches that can supply an RX from either battery so that's an option.
I have a couple of 62" models that use only 1 lipo 4S5000 for both ESC's and a separate 2S1000 lipo for the RX (via UBEC). That way you power up the RX first and can check controls, then power up the ESC's when ready to fly
Is there a reason why you want 2 main batteries?
Do you have spare RX batteries for your IC models you can use?
Tin hat on again! You may have a start up sequence issue with option A if you power up the lower ESC and don't have the RX powered up (check with George, as other makes have caught me out).
PM me if you want a wiring diagram
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Hi, what lemon rx was it ?
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Another vote for Titebond... the most things I glue together with CA is my fingers + making a mess of coverings when it tracks along joints/seams
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My 2p worth. I went from Riot post A test and wanted something good in windy conditions + cheap (at the time) so picked (well advised by my LMS) to go for a BH Speed Air (electric). It had no vices, was tough as old boots and got me through my B test. I later put a Laser 70 in it as the covering started to fade and fall off. It was only my stupidity that killed it off. Stripped it and scrapped it only to find I could have bought a fuselage for it!
I have a wots wot (electric) and acro wot (Laser 70) and yes they are nice, but both have a bite if provoked so a bit of a steep learning curve.
As others have said the T28 and other park flier foam warbirds have very benign handling so good choice if you want to go straight there. Just my experience, but be warned benign handling foamies can get you into bad habits when you move on to something a bit more feisty and unforgiving.
Lots of routes and depends where you want to end up eventually so just keep asking questions, hope this helps
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Ronos and anyone else who is interested, last Saturday I flew her a couple of times and the wind was not straight down the runway.
I needed a fair bit of rudder in to keep her straight, made a right mess once and aborted a take off, so that might explain others issues with a swing to one side.
Bottom line, keep your cool add a bit in and bear in mind once the motors are at 3/4 throttle she will be more responsive to rudder input (I over corrected)...failing that just take off into wind!
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Hi,
Well done I am sure you won't regret it although Jon would have seriously considered keeping them for himself as I think he can't scratch that twin itch!
The issue for me was with the existing mounts is everything ends up very tight like throttle linkage etc. I just prized the bulkhead out, measured back the same amount on each side plate to maintain the offset and glued a new one in (without all the holes in it!). The tank sits below the bulkhead in line with the carb just in front of the retract.
I retained the throttle servo position and re-angled the linkage + put a reinforcement braces in.
PS IMHO I would really suggest running them in for a bit (I ran mine in the Dual Ace first as I have not flow IC twins) + I really wanted them ultra reliable + the 70's have to work for their money to get 7.5kg of model up to speed (and it really starts to shift when it get going). Jon suggested not trying to take off on full power for a couple of reasons, most likely time to find out you haven't quite got the set up and one dies + there is not a lot of rudder authority at low air speed so you end up with a bit of tail wagging if you don't take your time.
Nice build, flies well with the Lasers and just sounds superb!
The guys before me with electric and IC have been invaluable with their help, so if you have any questions fire away.
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If you have a simulator try flying a twin with one on full power and the other cut (set it up to fail it sometime into flight)....hard work with good air speed and rudder control....low air sped and it is very tricky to recover from the spin, even if you kill the other motor I normally end up in the ground!
I suppose if you can cut and restart the motor recovery might be easier, but never have tried that.
PS the only twins that that have done that were both electric, one ended up spinning in from 25ft the other dead stick in after the spin (I just got lucky) and did no damage.
Good luck and let us know how you get on with the build and the flying.
PPS Yes...just look out for the ground..it will come up all to fast
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Hi, you could well be right and with the gear down it will be quite draggy. No consolation but my flights I have had to drop in over trees and fly into a light/moderate wind with a long runaway so powered in all of the way.
The rudder on mine seems to have little authority so even if you had kept the wings level it would have been a big arc to get it around.
I am trying to help the best I can with working out where it is, if the school have not seen it, then it might be worth a look further afield. We had one that went a very long way assisted by its glide angle and ground sloping away others far shorter than originally thought....I am not helping am I
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Double guessing isn't really going to help, but perhaps a process of elimination will.
- Loss of signal - looking unlikely as you mentioned no loss of signal until it went behind the trees (how quick does it report, can that help in location assuming the signal loss was the point of impact)
- ESC overheating where both shutdown at the same time, very unlikely and at low air speed on one motor it would have spun in
- Is it twin lipo (one for each motor, or just one), if its one the both ESC's might have shutdown on low voltage - odd as you weren't in a high power situation. if its two lipos the changes of both cutting out at the same time is very small - again it would have spun in.
- Had you put the flaps down?
- I would have expected a loss of elevator authority if you were getting close to stall + loss of height, tricky to try and remember what you were doing at the time but worth a think about if its attitude (AOA) changed or not.
Might be worth asking any other TN Mosquito owners how their performs on very low power settings do they glide/spin in?
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Allan, So sorry to hear about your loss, maidens are always (for me anyway) high pressure, tricky events where you don't get a second chance.
I have hunted for mine and others models and am still surprised as to how far out you can be + how far it can travel when out of view.
All the best and hoping you manage to find her before too long.
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IMHO it could be a number of reasons
- Different batch from the manufacturer slight change in spec
- Different version (the Prodrive range changed version and the spec's changed, but it was hard to see in the sale blurb, oh and the mounting spacing changed
- For the same motor some suppliers independently test (not in this case admittedly) and their own results are different to the manufacturers spec
Do you really need the 40A continuously as opposed to 34A? if you are flying (just) with that sort of margin then it might be worth a recalculation!
Just had a look at the Rucus and Century use the little RIOT pancake motor.. I don't think you will have an issue. Install everything and do a few power tests with different props to get a prop pulling 32A and fly.
Edited By Chris Walby on 30/09/2018 08:16:35
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Cracking good day at the flying field. People learning to fly, WW1, WW2 and a hole host of other craft flying. Even had a master class of how to maiden a very "challenging" model and importantly everyone left with as many bits as the turned up with!
All worth the many walks to the other pits and boy I need to get better organised
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Tony, commiserations for your loss and yes you are spot on when it comes to checking the Velcro baseplate is fully attached especially after lots of flights. While fitting a battery on my Carbon Yak I noticed the end of the tray lift a bit. Further investigation and it came out with little difficulty (originally glued in with silicone sealer).
IMHO I would change battery fixing system/prevent the Velcro detaching and leave it at that.
UBEC and lipo add complexity and weight and one day you might want to disconnect the lipo very quickly without undoing the locking system.
PS My Wots wot tray fell out (yes there are people that have never had this issue, but when its does) and before I landed the lipo disconnected from the EC5 connector, the massive change in C of G would have probably made it un-flyable anyway.
Laser Engines - Technical questions
in IC Engines
Posted
Rocker, with my limited experience I would say its a case of moving the engine or the tank to get them to line up.
There are a few threads where you can use a small tank in the correct position fed from another tank in a less optimal position.
Sort of depends on how much wood work mods you want to do, but there have been a few issues with build quality and my seagull Mossie came apart a bit to easily (to move the bulkhead back). Made the mod easy and once beefed up all has been ok.