RE: Full Wing Flutter
I suspect that your problem lies in the flat plate airfoil. As the wing parts the air, the air has to change direction away from the chord. This causes the pressure to drop across the surface of the wing. Since the top surface is (usually) curved higher than the bottom, the pressure drop is greater. An efficient airfoil will have a curvature that allows for the smoothest possible airflow for a given speed range. What I think is happening is that as the air tries to flow back along what should be a curved surface, it strikes the flat surface, causing it to rebound. The higher the speed, the harder the rebound, until it causes some serious flutter. You might try checking at the Pylon Racing forum for airfoil recommendations, and loose the flat plate. Flat plates work for low speed foamies.
Posted on: 11/20/2009 10:16 PM by Author "dreadnaut" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9268911

RE: Fiberglass cowl build advice needed
Interesting idea. If this is the same stuff I worked with years ago in an industrial application, it "hardens" to the consistency of flower shop foam. I suspect that if you are careful, it may work. Sanding an polishing would be difficult. It may even work as lost foam in reverse. Lay up your cowl, then when it cures, just break the foam off. Tou will still be left with a fuzzy surface in need of a lot of finishing, but it shouldn't be too bad.
Posted on: 11/20/2009 12:16 AM by Author "dreadnaut" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9266754

RE: Build Thread-Scratch built for 8s
Thanks. There are some flaws if you look close, but that was a first try using that method. If you look close, there are pin holes and bubbles. The way I did it was to cut a strip of 2mil painters drop cloth 5" wide x 2" longer than the layup. I taped that to my building board then laid a strip of the carbon fabric. Mixed 15g of West System and squeegeed it on then laid 4 strips of tow, then 1 strip of 2 oz fg. The 2oz fg was used to prevent ripping the cf tow while squeegeing in the next 15 g of epoxy. One more layer of tow, one more of 2oz fg, 15g more epoxy squeegeed in. Then I did another lay up just like it then mated them face to face, put them in the form, bagged it up then vacuumed it. I am pretty sure that the pinholes came from putting breather on only one side. On my next pull, I plan to use breather on both sides, but that will sacrifice the high gloss finish. I use paper towels as breather, but it leaves a texture on the part like they put into the towels; flowers and such. I am going to try to score a roll of "institutional" paper towels, like those used in public restroom dispensers. They are untextured. Tonight the wife has a "girls night out" so I plan to get the wing, stab, and rudder jigs built, and work on the cowl plug.[:D]
Posted on: 11/19/2009 9:10 AM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9264847

RE: What's the
[quote]ORIGINAL: JAS Grab a stick plane and 'practice'. I don't think there is a 'proper' way, there is a way that you will learn it easier, but you will have to figure it out. When I was doing the 3 rolls back in Sportsman (Intermediate now) I only used elevator, no rudder. Rudder was learned for slow and 4pts in Advanced in 89-90. I didn't learn how to use rudder for harder stuff until way late in the game. As a matter of fact, I didn't know how to do a proper rolling circle until I got my first TOC invite in 93 for the 94 TOC. Talk about crash course. Also, try breaking down rolls. 4 points consist of 2 KE flights and an inverted flight. No sense in trying a 4pt if you can't fly inverted or do KE on both sides. Slow rolls are kind of the same as 4pts. 2 regular rolls can be done fine with just bumps of down and up elevator. If you do them slower then you will need to learn rudder. Tip- from upright, you will always use opposite rudder from the aileron direction you are rolling for the first KE. Starting from inverted it's the same rudder for the first KE. [/quote] This reminds me of when I was flying sportsman in the late '90's I was taught to use just elevator in the three rolls. There was one maneuver in that sequence that I [b]do[/b] credit with pushing me to use rudder during rolls, and it was the old outside loop from the bottom. It gave me fits because they always came out more like corkscrews than loops, until I started putting a little blip of opposite rudder when rolling to inverted. I still practice this maneuver as warm up.
Posted on: 11/17/2009 12:45 AM by Author "dreadnaut" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9259437

RE: Turnigy, GT, & I-Charger - Good Chargers
I thought I would give this thread a bump. I just got a G.T.Power A8 Charger from HobbyCity. This is for my first large electric and I had the impression that You needed something like this to charge/balance an 8s (2x4s in series) packs. It has a 9pin xh balance port, but finding a 2x4s to 8s adapter was a major ordeal. Can someone help a beginner when it come to charging large multiple packs? I did finally find an adapter here; http://www.tedani.com/balance-adapter-expansion-board-for-gt-power-a8-charger-p-1260.html . The instructions are kinda clear, but not totally. Does the GT Power 8 charge through the balance port, or do you plug the power leads into the charger through a y-harness, and the balance leads into the balance port?
Posted on: 11/16/2009 11:08 PM by Author "dreadnaut" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=9259261

RE: New to pattern flying
[quote]ORIGINAL: spencer321 . . . i have a ys 110 nib that i can use . . . [/quote] Wow is right. That alone gives you a lot of options. There are a lot of entry level planes that that is the perfect engine for.
Posted on: 11/16/2009 9:44 PM by Author "dreadnaut" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9259056

RE: fibreglass for .40 aerobatic plane?
To be truly competitive against 2m pattern planes, it would have to be a 2m pattern plane. At the lower competitive levels (sportsman and intermediate) .40 sized planes are sometimes seen, but .60 sized is really the lower limit of what is competitive at the sportsman level. I would suggest making it from wood first. Fly it, maybe go to a few contests to talk to some experienced pattern guys, then make any changes then build another. If it is good, then use it to make your plug. Lost foam will not give you good results. You will either have to sacrifice finish to get low weight, or sacrifice weight to get a good finish. If you pull a mold from a well finished plug, you can get both low weight and good finish.
Posted on: 11/16/2009 12:37 PM by Author "dreadnaut" in the forum "Composites Fabrication And Repair"
http://www.rcuniverse.com/forum/fb.asp?m=9257744

RE: Build Thread-Scratch built for 8s
I decided to make my own CF gear from a mold I made several years ago. The layup was 1 later of 5k woven fabric, 16 runs of 20k tow and 1 layer of 5k fabric, because I think it looks cool. I’m not really happy with the results, but I will use them for now, and make a better mold later. Why make my own? I have had the material sitting around, so I may as well use it.
Posted on: 11/16/2009 1:05 AM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9256891

RE: Build Thread-Scratch built for 8s
Finally able to get back to the build. I had to get the motor mount cut, I had left it off the original cut file [8|]. I decided to make the canopy and turtle deck from fiberglass, so I started to build a plug. I cut two pieces of white foam insulation with a hot wire. I did it by hand, as you can see from the rough finish at the tail. No big deal. I soaked some balsa sheets then formed them over the foam forms and let them dry to the rough shape, the glued them on with contact cement. The shape was a little distorted near the tail, so I will have a little bit of a job filling and shaping. The built-up area will be blocked out with flower shop foam and shaped. I hope to get all the plugs done by next weekend so I can start on the wings, stab and rudder.
Posted on: 11/16/2009 1:04 AM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9256888

RE: Regulator Voltage
Dave, it's just one 9411 for the elevator. I mounted it in the back of the fuselage to keep the pushrod short, and went to a low profile servo to get it as far back as possible. I thought long and hard on this choice, but I see them used a lot for ailerons on 2m IC planes. I am doing a build thread on it here http://www.rcuniverse.com/forum/m_9245009/tm.htm . Post #1, and post #8 show how it is mounted.
Posted on: 11/15/2009 10:18 AM by Author "dreadnaut" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9255026

RE: Regulator Voltage
[quote]ORIGINAL: NJRCFLYER2 Not an advertisement, but for the record I use JR servos almost exclusively, which are known to be able to handle higher voltages well. Other brands/models can handle it too, but I would not push those which carry explicite warnings not to. Check with their service departments to see what they recommend. [/quote] One of the specs I looked at when selecting the servos was 6v rating. That said, in engineering they often deal with "design factors". There is always a fudge factor to the high side when a manufacturer specs a product; sometimes as much as 25%. Price was another, but I understand the difference between frugal and cheap. I got mid-range Hitec digital servo's for rudder an aileron, and found a good internet deal on JR 9411sa's for the elevator, so I got three at 65 bucks each. This is my first time using digitals. So I am back to 6v (Thats my final answer, Regis).
Posted on: 11/15/2009 9:53 AM by Author "dreadnaut" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9254975

RE: Tupperware bowl for mold
I hadn't thought of that, but it makes sense. I had one that would have made a great GeeBee R2.
Posted on: 11/15/2009 12:21 AM by Author "dreadnaut" in the forum "Composites Fabrication And Repair"
http://www.rcuniverse.com/forum/fb.asp?m=9254522

RE: Regulator Voltage
That was a flurry of very good responses. Ed Alts rather lengthy response pretty much confirmed what I was thinking. As far as centering, speed, and power; for an 8s setup flying intermediate I am leaning towards 5.1 being enough. I so not have a large budget, so if I can get an extra 100 flights off the servos I'll go for that. I'll take a look at the Tech Aero.
Posted on: 11/15/2009 12:06 AM by Author "dreadnaut" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9254505

RE: Subscription count.
Might it be easier to just get a numerical count? Listing specific subscribers may scare some off of subscribing.
Posted on: 11/14/2009 11:38 PM by Author "dreadnaut" in the forum "Forum questions or problems"
http://www.rcuniverse.com/forum/fb.asp?m=9254460

RE: Build Thread-Scratch built for 8s
It is the -20. I appreciate your views on the CF gear, but I already have a mold I made when I was working on a 2m glow back in '04 when I dropped out. I had (still have in fact) a Webra 1.45 that swung an 18" prop, so I will try to use those. If it doesn't work I have a lot of experience working with 6061. I will probably wind up with several 17"-18" props to try out to see what works for me. Thanks for the input.
Posted on: 11/14/2009 11:30 PM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9254445

RE: Subscription count.
Totally cool. Thx.
Posted on: 11/14/2009 7:27 PM by Author "dreadnaut" in the forum "Forum questions or problems"
http://www.rcuniverse.com/forum/fb.asp?m=9253913

RE: Build Thread-Scratch built for 8s
After a short interruption tot he schedule, I have started working on the plugs for the canopy/cowl/turtle deck as I had to get the fuselage framed to this point to match things up. I am also going to attempt laying up my own CF landing gear. To do this I first need to decide on the prop. Searching the web, it looks like something in the 16"-17" range. I can worry about pitch later, just want to size the legs right now. Ed, do you have any experience with this?
Posted on: 11/14/2009 3:03 PM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9253414

RE: Regulator Voltage
Thanks, Jason. I pretty much thought [i]you[/i] were an expert.
Posted on: 11/14/2009 12:26 PM by Author "dreadnaut" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9253185

Regulator Voltage
I'm about to order a voltage regulator for a .110/8s sized pattern plane I am building. I'll be running a Rhino 750 receiver pack, and am about to order the regulator, and am wondering if I should get 6.0v, 5.7v, or even the 5.1v. I'll be running 3x HS6965, and 1x DS9411, and a CC ICE 75 ESC. Since I am not using them in a full 2m plane, I don't think I will need the power of the full 6.0 volts, but am not sure what the advantage of running a lower voltage is. Would it extend battery time? Would it extend servo life? Input appreciated. Dave. edit; I'll be flying intermediate, or possible stepping back down to sportsman depending on how thick the rust on my thumbs is.
Posted on: 11/14/2009 11:14 AM by Author "dreadnaut" in the forum "Pattern Flying"
http://www.rcuniverse.com/forum/fb.asp?m=9253074

RE: what kind of foam is this?
I use it for padding. It's kinda stiff, but now I fly electric (non-foamy)which has a lot less vibration.
Posted on: 11/14/2009 1:10 AM by Author "dreadnaut" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9252549

RE: plans to kit
[quote]ORIGINAL: Scar If you have plans from Ziroli, Palmer or one of the other plans services, check out the Laser Cutting Services. They have the [b]laser cutting programs[/b] already for many of those plans. Look in the Scratchbuilding or Kit building forums, or search online for Laser Cutting Services. [/quote] This sounds scarier than it is. A laser cutter is noting more than a printer/plotter with a laser instead of a pen. The "program" is just a vector graphic file of the patterns. A laser cutter can even work from a raster file, like a .jpg, or.bmp, but the results will not be precise enough for good quality parts. If you are working from a paper plan, it will have to be scanned, then traced in CAD to produce an accurate laser ready file. Done properly, this involves a skilled drafter who would charge ~$35-$40/hr. Depending on the quality and accuracy of the original plan, this could take as little as an hour for a profile foamy, to 10 or 20 hours for a fine scale model like the ones from Platt and Hostetler (Which are already in CAD files) You could ask for those files, but I bet I would hear them laughing at you from here. Drawing in CAD is a lot like programming, and the files them selves can be pretty valuable "source code". I would do it for you, and either sell you the code for more than the kit would be worth, or I would get you a kit cut, and sell it to you at a reasonable price, and keep the code for myself. If the plane was your design, we could work a deal where you could sell them as your product, and I would be the supplier. If they were someone else's design, I would try to work a deal with whoever owned the rights to the plan. [quote]ORIGINAL: Scar If you drew your own plans, then you're probably on your own, unless you want a production run of kits made. [/quote] . . . unless you drew the plan in CAD, then you're more than half way there. I am getting a scratch built plane laser cut, but I drew the plans in CAD, so they were pretty much laser ready from the get go.
Posted on: 11/13/2009 10:17 PM by Author "dreadnaut" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9252240

Subscription count.
I recently posted a build thread and would like to know if there is some way I could find out how many people have subscribed to it. Is this possible?
Posted on: 11/13/2009 2:02 PM by Author "dreadnaut" in the forum "Forum questions or problems"
http://www.rcuniverse.com/forum/fb.asp?m=9251209

RE: 8s Charge Setup
[quote]ORIGINAL: gaRCfield [quote]ORIGINAL: gaRCfield FOUND IT!!![link=http://www.tedani.com/balance-adapter-expansion-board-for-gt-power-a8-charger-p-1260.html]expansion board[/link] EDIT: fixed wrong link [/quote] Just to clarify, this link is to a balancing board made specifically for the OP's charger. It will plug into his current charger and allow a combination of any two lipo batteries, with sum less than or equal to 8S, to be charged together. If you go to the site and click on the 'chargers' button on the left, you can get a balance board for a few other chargers as well. [/quote] There is a lot of info out there, and this leads to some confusion on my part. This is what I get so far. Charging two 4s or 5s in series (8s or 10 s) is not recommended, but if it must be done, the two packs should be the same cell count, c rating, and capacity (mAh). One of the guys I talked to at the F5 event was Steve Neu, who I hear is a pretty knowledgeable guy. He was using two 6s chargers to parallel charge his flight packs. If I had seen that before ordering my stuff, I would have ordered a different setup. I have just ordered the balance adapter from Tedani. I will probably go to a paralel charge setup at a later date, but for now will use this setup. Woodie mentions a parallel charge setup that sounds like he is talking about a single charger. Maybe I misunderstood. The parallel setup I saw those F5 guys using seemed to involve two chargers and a single balance board. Thanks all for the input.
Posted on: 11/3/2009 4:27 PM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9225680

RE: 8s Charge Setup
I think I'll just have to visit the SD Silent fliers field again and see how those guys set up. I'm a little peeved, and somewhat confused that someone would make 8s and 10s, chargers, then recommend against using them, and not provide the connectors to do so. [8|] Jim S, could you maybe put up a schematic of how the Blinky would work in this case?
Posted on: 11/3/2009 12:37 PM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9225170

RE: 8s Charge Setup
Thanks I'll try it. A new LHS opened across the street from where I work. I had the guy order me a JR ds9411sa and he told me "it will be here tomorrow". This went on for a week and a half. I got one off the internet. I went in there Friday for some CA, and the guy did not seem to recognize me. I hope he is getting a lot of business on the web, He hasn't got me to go out of my way.
Posted on: 11/2/2009 5:48 PM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9223260

RE: Crashing is NOT an option, M A article!
[quote]ORIGINAL: dreadnaut Years ago when I used to fly at Sepulveda basin, there were a number of ''experts'' who would grab an unsuspecting newby and volunteer as instructor. The problem is that while a lot of these guys had some stick skill, they were horrible teachers. Lesson 1; ''I am totaly awsome, and you should strive to be just like me'' Lesson 2
Posted on: 11/2/2009 11:04 AM by Author "dreadnaut" in the forum "AMA Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=9222344

RE: 8s Charge Setup
[quote]ORIGINAL: Jim Schwagle Purchase an inexpensive Blinky balancer or equivalent, plug one pack's balance lead into the charger, the other's into the Blinky then go ahead and charge them in series. [/quote] Is this it? http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXMRZ9
Posted on: 11/1/2009 5:03 PM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9220668

RE: 8s Charge Setup
[quote]ORIGINAL: ntsmith Should it not be possible to obtain 1 X 8S XH connector and 2 X 4 XH connectors (Assuming they are XH and not EH or even some more exotic balance connector) and take the first four wires from your 8S plug to your Nr 1 XH Lipo connector and the next four wires to your Nr2 XH Lipo connector? The batteries can remain connected in series and the batteris charged and balanced with no problems. [/quote] I'm afraid thats what I will have to do. Still can't find an 8s xh. From what I know now, a dual charger set up would be preferred, but for now I have to go with what I have. I had to spend money on the wife for useless crap, so she will let me buy my "useless crap". I have a budget, and it does not allow me to change charge setups right now.
Posted on: 11/1/2009 7:36 AM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9219567

RE: 8s Charge Setup
Thanks, I went to a F5B event a few weeks ago and saw that they were all using dual 6s chargers on their 10s packs. I'd hate to have to change because it will put me over budget.
Posted on: 11/1/2009 12:09 AM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9219043

8s Charge Setup
I finally did it. I am getting back into Pattern with a scratch built 8s electric setup. The plane is a scaled down version of the Gator Giles that I got plans for back when Gator was still around. I modified the wing to have double taper, moved the canopy forward, and made other changes. I'll be getting the laser cut parts next week, and will be getting the work shop prepared tomorrow. Question; I just received 4x Zippy 4s4000mAh lipos, some 750mAh 2s reciever packs, and a GT Power A8 charger from HobbyKing. This charger has a port for an 8s balance connector, but HK (or anyone else for that matter) does not sell a 2x4s>8s adapter cable.[:@]. Do you guys running 8s setups make your own? How do you do this? Did I get the wrong charge setup?[:(] Other info AXI 4130-20 CC Ice 75 ESC Jaccio 4.7v Reg (on order)
Posted on: 10/31/2009 10:24 AM by Author "dreadnaut" in the forum "Electric Pattern Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=9217339