RE: Pitcairn PCA-2 Autogiro by Whirlybird Aviation
Love what you have done - I gotta build one of these things for myself!
Posted on: 6/20/2012 2:25 PM by Author "fledermaus" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11125635

RE: Are all RC forum's activity in decline?
I have not encountered any of the major site problems people are talking about, although on rare occasions the site has been painfully slow. I monitor a small number of selected forums that cover my interests but I have to say that I find less and less that really interests me on the site. A lot of the content is repeating what has already been said - and of course this might be what newcomers need to hear, so I am not really objecting, just that this doesn't encourage me to come back as often as I once did back when I was a newcomer. I got a lot of info from RCU when I started out about 7 or 8 years ago, for which I am grateful, but now that I am connected to the local clubs and the LHS, I don't need RCU as much as I used to, so I don't come as often.
Posted on: 6/20/2012 2:23 PM by Author "fledermaus" in the forum "The Clubhouse"
http://www.rcuniverse.com/forum/fb.asp?m=11125631

RE: CG location when fuel is burned
Perhaps the problem here is the assumption that the CG is a fixed point during flight. It isn't, not in models, not in full-scale. The "optimal CG" is determined by the centre of lift (among other things) and this is the point modelers usually are trying to get their planes to balance at. We do this when the tank is empty. Thus, at take-off, our "actual CG" will be somewhat forward of the "optimal CG". As fuel is consumed, the plane will balance further aft, but it will never reach a point where the "actual CG" is behind the "optimal CG". This is good, since having the "actual CG" too far aft leads to pitch instability. The changing point of balance is one reason models and full-scale planes have trim adjustments.
Posted on: 6/16/2012 5:31 PM by Author "fledermaus" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11120581

RE: Planning 130 inch Bellanca Aircruiser
Thanks for the input. I am using the same set of drawings as the basis for my plans. They come from the local historical aviation society, and the Western Canada Aviation Museum is restoring CF-AWR, "The Eldorado Radium Silver Express". I've had a lot of opportunity to examine the airframe over the last several years as they have worked on it. The Aircruiser still had the radial air-cooled engine - as you can see in your drawing of CF-BTW it had a Pratt&Whitney Hornet R-1690-SIEG supercharged engine (750 HP), while the Airbus used the Wright Cyclone R-1820E (575 HP). CF-AWR was fitted with a Wright Cyclone R-1820 F-32 that delivered 760 HP at 2100 rpm.
Posted on: 6/16/2012 10:27 AM by Author "fledermaus" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11120254

Planning 130 inch Bellanca Aircruiser
Starting to work on some CAD plans to build a large Bellanca Aircruiser - 130 inch span, to be powered by a DLE 55. This is the first really large plane I have considered building. Question about sizing the structural frame members. The fuselage is a typical box truss design. If I use spruce square stock for the truss members, will 0.25 inch be strong enough for this size of airframe, or would I be better to base the design on 0.375 inch square stock?
Posted on: 6/15/2012 2:09 PM by Author "fledermaus" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11119488

RE: How to scale up from 1/72 to 1/6 scale?
72 = 6 x 12 so if you multiply any measurement from the 1/72 model by 12 you will have 1/6 scale.
Posted on: 6/15/2012 2:01 PM by Author "fledermaus" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11119478

RE: Is this a good field box set?
[quote]ORIGINAL: DMalyuta  P.S. Just how dangerous are lead acid batteries and what precautions should I take? I've done a fair bit of environmental chesmitry for exams recently, and it had scary stuff about lead and its health effects- going from stomach burns to cancer. [/quote] Don't worry about the contents of the lead acid battery UNLESS you foolishly try to cut it open. The contents won't jump out of the casing of the battery and bite you. Lead is indeed toxic, but it has to get inside you in order to affect you. If you don't expose yourself (or others), it won't hurt you (or others). You can handle lead metal without any hazard, but you have to avoid ingesting it - for example, indoor gun ranges often have microscopic lead dust in the air that people can inhale. That's not good. BUT: your starter battery should not produce any lead dust.[:)] The acid gel in the battery can indeed cause skin burns, but again only if it contacts your skin. Don't break open the battery. And, when the battery is dead, take it to someplace that can recover the lead and dispose of it properly, don't just throw it in the trash.
Posted on: 6/13/2012 6:39 AM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11116633

RE: Is this a good field box set?
Speaking of LiPo powered engine starters - I have a 12V Torquemaster 90 starter that I have been running off a Pb/acid battery and I'd like to make an integrated battery pack for it. It only has to start engines in the 0.35 - 0.91 size range, no really big monsters. Question: If I run it on a 4S (14.8 V) pack it should be ok, but what battery capacity should I aim for?
Posted on: 6/12/2012 1:26 PM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11115861

RE: First Kit
prgonzalez has discussed the big picture issues, and I think he's got it right. HOWEVER: if you want a straightforward suggestion for a first kit build, I like the SIG 4-Star 60. It is a typical SIG construction, the parts fit very nicely together right out of the box (at least mine did), the plans and instructions are crystal clear, and the plane is a very nice flyer. The design is also very easy to modify if you find you like kit-bashing. Lots of people fly 4*60s with Saito 91s in them. When I built mine, I couldn't afford the extra $ for a 4-stroke so I put in a SuperTigre G75 which is also a very lovely engine in this plane. [8D]I see over on the other thread that they are also fond of the 4*. It's nice to have one's opinion backed up[;)]
Posted on: 6/8/2012 2:11 PM by Author "fledermaus" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11111568

RE: Thinning out epoxy with isopopryl alcohol
You can also thin epoxy with acetone, which is usually available with much less water. It evaporates more quickly however, so if you are taking a long time to get coverage the viscosity of the epoxy will change during application.
Posted on: 5/28/2012 4:34 PM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11097805

RE: Once on step plane whips around and dunks
Looks like you have it pretty well figured out there, Taxus. For future reference, you might want to have slightly longer floats (typical length is 75-80% of overall fuselage length) so that you can have about 2 inches of float in front of your prop, and put the step behind the CG. You have two things to think about with the fore-and-aft location of the float. One (which has been mentioned) is that when the plane is "on step" you want it supported by the step, which means that the step must be no further forward than the CG. The other point is that on the water, you want the floats to sit level or slightly bow-up. This means that the CG of the plane + floats should be at or slightly aft of the center of buoyancy of the floats. Given the design of most floats, the center of buoyancy will be somewhat forward of the step, but it isn't always easy to determine its exact location unless you are good with trigonometry (or CAD software). This is why most people recommend putting the step slightly aft of the CG - you will likely be in about the right place for both parameters that way.
Posted on: 5/22/2012 2:02 PM by Author "fledermaus" in the forum "Seaplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11090780

RE: Not a good week.
About 5 years ago I witnessed an air-to-air collision at our club field. A small hot-dog type plane was being zoomed around, while a large scale bird (I forget exactly what it was - something like a Citabria anyhow) was in the pattern. The hot-dog climbed right up the scale bird's rear end - whack whack whack smash! The big bird staggered in the air but kept on flying. The little hot-dog disintegrated - heavy engine dropped like a stone while the remains of the wing fluttered back. The scale pilot made a very nice safe landing and we could see there were three slashes through the right side of his aft fuselage where the hot-dog's prop cut the lower longerons and stringers, and then a crushed segment where it smashed in - but the integrity of the fuselage was not compromised. Scale pilot was pretty pissed off, but at least he knew he could repair the damage. Your poor Tomcat wasn't soo lucky.
Posted on: 5/22/2012 1:38 PM by Author "fledermaus" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11090750

RE: Polish for canopy
[:D]lol! I read the title of the thread and immediately thought Google Translate. Polish for "canopy" is apparently "baldachim". Silly me.
Posted on: 5/9/2012 8:34 AM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11074297

RE: WW1 aircraft display Wanaka 2012 Vid
Wait! Those weren't models! These guys are serious...
Posted on: 4/29/2012 2:04 PM by Author "fledermaus" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11061479

RE: WW1 aircraft display Wanaka 2012 Vid
[quote]ORIGINAL: Kiwi-al The Camel has a Gnome Rotary and the D VIII has a Oberursel Rotary made be Vintage Aviator in Masterton New Zealand.They are building a lot of cool WWI aircraft .http://thevintageaviator.co.nz/ [/quote] That's great, didn't know there were commercially-made rotaries out there. Only working model rotary I've seen is this home-build in a 1/3 scale Avro 504 [link=http://modelrotaryflyer.tripod.com/avro.htm]http://modelrotaryflyer.tripod.com/avro.htm[/link]. The engine itself is more work than I can imagine putting into an RC model[8|]
Posted on: 4/29/2012 2:01 PM by Author "fledermaus" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11061475

RE: WW1 aircraft display Wanaka 2012 Vid
Those were gorgeous! I notice the pilots were blipping their throttles to simulate the "no-throttle" ignition kill-switch behaviour of the rotaries - unless they actually had rotaries in the Camel and the D-VIII?
Posted on: 4/27/2012 9:31 AM by Author "fledermaus" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11059070

RE: Is this aircraft stand still being made?
Don't think that stand is intended for starting/running. As Villa said, it will tip if the plane produces enough thrust.
Posted on: 4/27/2012 9:22 AM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11059061

RE: Allied Planes vs Others
Build what you love. They all have their fans and their foes, but if you like a plane, that's what matters.
Posted on: 4/26/2012 6:42 PM by Author "fledermaus" in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11058385

RE: Sig Kadet LT-40 Build
Definitely go for visibility. Back during WW II here in Canada we had the "Commonwealth Air Training Programme" which trained thousands of RAF and RCAF pilots. They painted all their planes a bright yellow, a bit redder than "Cub Yellow", to avoid midair problems. That makes a great colour scheme for an LT-40 although you probably want to distinguish the upper/lower surfaces as the other guys suggested. [image]http://www.rafmuseum.org.uk/milestones-of-flight/images/p032043.jpg[/image]
Posted on: 4/26/2012 6:39 PM by Author "fledermaus" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=11058380

RE: Custom landing gear engineering question
Just from the look of that plane, I think you should go with a fixed undercarriage. The plane sort of looks like the Polish PZL 11 fighter, or other 1930s designs. It would be easy to make a music wire undercarriage anchored into the wing support structures, and fair the wires with balsa.
Posted on: 4/24/2012 1:59 PM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11055170

RE: Is it just me?
Looks like whatever the problem was, it's fixed now. I can rest easy[;)]
Posted on: 4/23/2012 7:30 PM by Author "fledermaus" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11054334

Gas Engine for Bellanca Aircruiser
I've been playing around with a design for a Bellanca Aircruiser in about 1/8 scale - that will be a 97.5 inch span. If I can keep the weight down to around 12-13 lbs the wing loading would be in the 24-28 oz/sq. ft. range. Although one of the radial engines would be way cool, they are pretty pricey for me. I have been thinking about the Evolution 26, the DLE 20 or DLE 30, all of which are reasonably priced and readily available. I guess since I haven't used gassers before, I just am not sure about the engine size/airplane size ratio. Obviously for an Aircruiser I don't want aerobatic performance but I also don't want it underpowered so I can fly it on floats as well as wheels. Any thoughts?
Posted on: 4/22/2012 12:32 PM by Author "fledermaus" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=11052389

RE: Kit for twin Saito 62's?
@korvette - fair enough as long as the 0.62s fit in the cowl. I had the 2-strokes sitting in the shop when I did my Twotter, so I stayed with them. No argument about the sound.[:D]
Posted on: 4/21/2012 6:02 PM by Author "fledermaus" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11051521

RE: Kit for twin Saito 62's?
The Twotter from H9 is a great plane, but I don't think it would benefit from the bigger engines. It flies in a beautiful scale fashion with the EVO 36 2-strokes that are recommended. If you have to mess up the cowlings just to stuff in bigger engines it seems a waste. People have put in smaller 4-strokes but I don't see the point in over-powering this bird.
Posted on: 4/19/2012 1:46 PM by Author "fledermaus" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11048882

RE: CWHM Lancaster Bomber damaged in flight.
Hope the patient is healing well. That Lancaster is a vital link to the past, and I'd hate to see anything serious happen to it.
Posted on: 4/17/2012 2:01 PM by Author "fledermaus" in the forum "RC Warbirds and Warplanes"
http://www.rcuniverse.com/forum/fb.asp?m=11046095

RE: New ARTF Mosquito - Is there a Market?
A decent ARF Mosquito in the 90-100 inch range would suit me just fine, but I agree it MUST have scale outlines, retracts and the correct spinners. I also would appreciate a "ready to paint" option, but basically any authentic RAF colour/marking scheme would be acceptable. Don't mind either the bomber or the fighter version.
Posted on: 4/17/2012 2:00 PM by Author "fledermaus" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11046091

Is it just me?
Not about aerodynamics, but about this aerodynamics forum. I can't "mark forum as read" for this forum only. Am I the only one? When I click the "mark forum as read" link, nothing whatsoever happens.
Posted on: 4/16/2012 5:58 PM by Author "fledermaus" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=11044868

RE: Silver Soldering for Dummies (HELP)
I had never done much soldering before I decided to build proper "Sopwith" undercarriage for my scratch Camel. Thanks to the tips from abufletcher and others I decided to give it a go. It is really easy if you take it slowly and prepare your parts carefully. I actually used "brazing" rather than soldering, with a gas torch from the local hardware/automotive emporium. Got the silver brazing wire and the proper flux from a local welders' supply store. No need to wrap the joints if you have them properly fitted and cleaned, and if you are brazing. I have used steel wire wrapping for the struts on a set of floats that I built for my LT-40, and there I just used plumber's solder since the wrapping was going to provide a lot of the strength. Just go for it![8D]
Posted on: 4/14/2012 8:06 PM by Author "fledermaus" in the forum "RC Scale Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=11042187

RE: What the heck is Ad Fly?
[quote]ORIGINAL: huck1199 The offending posters should use 'tiny url' [/quote] I agree. tiny url is a completely innocuous way to shorten URLs, but greed is a powerful thing unfortunately.
Posted on: 3/24/2012 6:27 PM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11013613

RE: What the heck is Ad Fly?
AdF.ly is a URL-shortener website that some people use to avoid those huge involved web addresses. The people who use it get paid a certain amount every time someone clicks on one of their links, because as you found they get to view a bunch of ads before they can then proceed to download or stream the content they wanted. Personally, I would favour a large-scale airstrike against whoever runs this website, but that's just me.[:-] I don't think RCU is doing this (I may be wrong). It is probably that all the content you chose to see had been linked using an AdF.ly-shortened URL.
Posted on: 3/24/2012 6:19 PM by Author "fledermaus" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=11013602