Glow Starter Battery Replacement
Hello, I have a Hot Shot2 glow starter where the battery is nearly dead it will give me about three starts before quiting. I bought a sub-c nicad to put in it, but am having trouble getting the thing open. Any suggestions? Carl
Posted on: 6/29/2009 7:38 PM by Author "Siefring" in the forum "Batteries & Chargers"
http://www.rcuniverse.com/forum/fb.asp?m=8892227

RE: First Scratch Build
The first flights went relatively well. The elevator trim was way off on the first takeoff and I did several loops before getting it adjusted. The control throws were also very sensitive, but I managed a nice landing. After 7 flights I have 3 ground-loop landings (just like scale [;)]). Only did some minor damage on one of the ground-loops. Maybe I was landing with too much speed on the first couple of flights? The CG seems to be about right at my first guess of 28% of MAC, I may still play with moving it back a little to see if I can get better spins. This is the first time I've tried to post videos, let's hope it goes well. They seem to load relatively quickly with a dsl connection. My neighbor deserves thanks for bringing a video camera! First Takeoff [link]http://www.youtube.com/watch?v=75Jij-v46Sw[/link] First Landing [link]http://www.youtube.com/watch?v=Pi4HacCTIrg[/link] Bench Check [link]http://www.youtube.com/watch?v=V96Y48Ia4i0[/link] Enjoy, Carl
Posted on: 5/31/2006 10:17 PM by Author "Siefring" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=4338518

RE: How do you Pre-Dtermine an Airplanes Center of Gravity?
[quote]just put it to a hair in front of the 1/3 point[/quote] Unless it is a biplane (triplane) then you should start with the CG further forward at about 28% of MAC instead of 33.3%. Carl
Posted on: 5/25/2006 4:35 PM by Author "Siefring" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=4315869

RE: First Scratch Build
As requested, some more pics. You may notice, I add the seriel number using white monocote and trim solvent. I'm not sure how long they will stay on. Does anyone have a good way to make small white markings? I wasn't happy with my ability to brush paint the "BLACK DEATH" and we all know the difficulty of printing white decals. Carl
Posted on: 5/11/2006 9:41 PM by Author "Siefring" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=4268116

RE: Suggestions needed for new plane
[quote]I ordered as Airsail Chipmunk kit from them a few months ago. [/quote] Airsail also makes a Piper Tomahawk -- right size, scale, should be a good slow flier, do some aerobatic and is a little different (although not as different as the Airtruk[:)]).
Posted on: 5/11/2006 4:19 PM by Author "Siefring" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=4267063

RE: Glues
CA is great for balsa and fast. One drawback is it is very hard to sand. Being careful when applying pays off. I'd suggest buying some of the very fine applicator tips, these are cheap enough to be thrown out when they get clogged. I find that yellow wood glue is better when gluing hardwood or ply. The CA cures so fast it does not seem to penetrate the surface of the hardwood. However, if you have a large bonding surface it doesn't matter. Carl
Posted on: 5/11/2006 4:00 PM by Author "Siefring" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=4266997

RE: Green Coverite?
Take a look at Nelson Fabric, also. I don't think there any light or bright greens, but if you're thinking of a dark green or olive drab those are available. [link]https://www.nelsonhobby.com/covers.html[/link] Carl
Posted on: 5/9/2006 5:19 PM by Author "Siefring" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=4259101

RE: First Scratch Build
I wanted two aileron servos because with three working ailerons on each side I was worried about adverse yaw from the drag. It is simple to adjust the aileron differential electronically. I put the servos near the CG in the middle wing keeping all of the mechanical linkages short. I'm sure I could have made the plane a little lighter using one servo and bellcranks or running a loop of kevlar string, but I felt more comfortable with the simple michanical setup and the easy adjustment advantage. Maybe comming from an electrical engineering background biases my opinion. Carl
Posted on: 5/8/2006 12:36 PM by Author "Siefring" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=4254024

RE: First Scratch Build
I'll take some pictures from other angles to show the receiver, servos, fuel tank etc. The snapshot I uploaded intentionally hides most of it [;)]. Mostly stuff is hanging out in the breeze, except the battery which is in a compartment in the nose. Actually, some might consider the Nieuport in my aviatar to be scratch built but that was from a plan and I purchase a set of laser cut wing ribs. This one I drew my own plans etc. and it is much clser to scale than the Nieuport It did not take long to build the frames for three wings, but it sure takes a while to cover them! Now I sort of wished I'd gone all the way and made a scale fuselage and under-carriage, but I wanted my first project to be somewhat limited so it would not die on the work bench. Here's some info on the model and hardware: 1/8th scale, wingspan 40 inches, mass is about 3.25 lbs, wing loading about 12 oz/ft^2 Engine: Thunder Tiger GP-25 Receiver: Hitec Electron 6 Servos: Hitec HS-81 (4) – Ailerons (2), Elevator, Rudder Hitec HS-55 (Throttle) Battery: NIMH 700 mAH Covering and Decorations: Nelson Fabric (Top-PC-10 Green, Bottom – Linen) Major Decal Roundels LusterKote (Black, White, Red and Blue) Carl
Posted on: 5/8/2006 12:00 PM by Author "Siefring" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=4253904

First Scratch Build
I just wanted to share a picture of my first scratch build -- a profile-fuse Sopwith Triplane. It was a lot of work, but I'm sure I'll do another. The biggest challange was getting the three wings aligned, I have pictures of the proccess if anyone is interested. Carl
Posted on: 5/7/2006 10:05 PM by Author "Siefring" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=4252000

RE: Electron6 battery/ch6 connection?
Great. I thought so, but receivers are not cheap and did not want to run a smoke test. Thanks, Carl
Posted on: 5/1/2006 7:48 PM by Author "Siefring" in the forum "Hitec/MultiPlex Radios- Ask Hitec Customer Service"
http://www.rcuniverse.com/forum/fb.asp?m=4229257

Electron6 battery/ch6 connection?
A quick question. Can I connect the 4.8 v battery to any of the channels on the Electron6 receiver? I am building a small Sopwith Triplane and don't intend to use channel 5, but I am using two aileron servos. I'd like to connect the battery to channel 5 instead of using a y-connector in channel 6. Thanks, Carl
Posted on: 5/1/2006 7:41 PM by Author "Siefring" in the forum "Hitec/MultiPlex Radios- Ask Hitec Customer Service"
http://www.rcuniverse.com/forum/fb.asp?m=4229204

RE: Whats the closest you have ever gotten to crashing?
I recently went out to fly my little electric 3d Flatana. I went to change the model number in my computer radio. I selected the correct Model #6 but apparently did not press the button sequence correctly and in stayed as Model #1. Of course, I did not notice. Throttle, ailerons and rudder were the right direction but elevator was reversed. Aileron throws were BIG and there was little exponetial. I hand lauched the thing and fortunately it was well trimmed and climbed before I put in the first aileron or elevator inputs. After 5-6 seconds of wild gyrations and much looping, I realized I was upside down with wings level about 3 ft off the ground. I manage to kill the throttle and it glided to a very pretty inverted landing. Sometimes its better to be luck than good. Carl
Posted on: 11/10/2005 4:49 PM by Author "Siefring" in the forum "Crash & Rebuild"
http://www.rcuniverse.com/forum/fb.asp?m=3540078

RE: fabric covering
I'll second the recomendation on NELSON ColorFab. I've used SolarTEX and the Coverite painted fabrics. The Nelson's is lighter, seems to stick better and is easier to work around complicated shapes. Carl
Posted on: 11/1/2005 2:04 PM by Author "Siefring" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=3511161

RE: CG range for Tiger 2?
The Goldberg web site has this information. [link]http://www.carlgoldbergproducts.com/tiger2.htm[/link] I think you can download a manual for the kit, too. Not sureif there is any charge for the manual. Carl
Posted on: 11/1/2005 1:44 PM by Author "Siefring" in the forum "Questions and Answers"
http://www.rcuniverse.com/forum/fb.asp?m=3511107

RE: Older Engines for Twinstar
I'd put my abilities in the intermediate range and have been flying for about 2 1/2 years. I feel comfortable flying pattern type planes, the "old-fast style" like a kaos . I can't do all the basic maneuvers yet but when doing single maneuvers at high speed the plane isn't getting ahead of me. I fly a small Neuport28, an Uproar, a Killer Kaos, a Tiger 60, and two recycled pattern style ARFs (+ a trainer and 3d electric). I'm fairly patient and conservative with new planes so starting the Twinstar with 25 size engines seems like the thing to do. I've built everything but the Trainer (and the planes that were given to me) so if I decide to mod the Twinstar later it is no big deal. My big plans are to do scale warbirds, so learning to fly a twin and/or planes with high wing loadings are on my to do list. I guess I was mostly wondering if going with a BB engine versus the GP25 would make much of a difference in the performance of the Twinstar. The Magnum 25 comes to mind as a good possibility for a reliable 25 BB engine. Carl
Posted on: 10/21/2005 3:56 PM by Author "Siefring" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=3476997

RE: Thunder Tiger Engines from the 1980s
No one said anything bad about recent Thunder Tiger engines. They're great and not expensive. Every pylon racer I know runs TT40Pros in their Quickie 500 planes. I have GP25s on two small aircraft and they are great. I did have to use a hot plug and lean them out at the low end to get them to idle reliably but that is just normal tuning. The question was about TT engines that were on the market 20-25 years ago. The TT 25FSR ABC weighs about 11g more than the GP25 and I was hoping they might provide a little more power in a twin than the GP25. Carl
Posted on: 10/21/2005 3:19 PM by Author "Siefring" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=3476905

RE: Older Engines for Twinstar
That sounds like good advice. I think I'll start with TT 25GPs. I know they are reliable and not expensive. After flying it for a season, I can always soup it up with OS 40FPs [;)]. I'll save the BB 25 for another use. Thanks, Carl
Posted on: 10/20/2005 10:34 PM by Author "Siefring" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=3474922

Thunder Tiger Engines from the 1980s
I recently bought an unused Thunder Tiger 25FSR ABC engine at an auction. I was wondering if the older TT engines were as reliable as the more recent era engines. I also wanted to know how this older BB engine compared (powerwise) with the newer TT 25GP bushing engines. I'm thinking of getting a second NIB 25FSR ABC for a twin, so relibility is important. Thanks, Carl
Posted on: 10/20/2005 9:22 AM by Author "Siefring" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=3472615

Older Engines for Twinstar
I was looking for opinions on what to use in the Twinstar, which would be my first multi-engine planes. I happen to have a a couple of older engines that would be appropriate. I have a lightly used 40FP (maybe 25 flights on it) and a New in Box TT 25 FSR ABC. It's not too hard to find nearly new versions of either of these engines. I have seen a local flier with this plane running on TT25GPs and it flies well at both low and high power. The TT25 FSR ABC is less than an ounce heavier, is a BB engine but I don't know if it is more powerful than the GP. The OS 40FP is heavier but would swing a bigger prop etc. Carl
Posted on: 10/19/2005 9:48 AM by Author "Siefring" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=3469600

RE: Z p-38 Crash
Howard, Here are a couple of photos I took at the fly-in. We all felt sad at the loss of such a beautiful a model. Most of us only dream of building such things! Carl
Posted on: 10/5/2005 6:12 PM by Author "Siefring" in the forum "Crash & Rebuild"
http://www.rcuniverse.com/forum/fb.asp?m=3425778

RE: Forward thrust reduced by too much right thrust?
Cary/Bax, I am in the same boat with Cary, in that I have a good physics/engineering background but the aerodynamics stuff is new to me. I tend to agree with Bax that when you are accelerating (the take off run or pulling a vertical) the swirling air from the prop is the main effect. And this is what is being corrected for in the right thrust. The trimming charts I have seen adjust the right thrust to pull a straight vertical. [quote]ORIGINAL: jcmccorm I don't quite understand the torque effect with respect to rolling the airplane left and causing it to turn left. It seems like the axial torque would definitely change with throttle setting and want to roll the plane but it would take a lift vector component in the "left" direction for the plane to want to turn left (ie banked left) and I imagine we always subconscously correct for this. Cary [/quote] The torque effect (I think -- Bax, please correct me if I'm going astray) is seen more as changes in trim at cruise speed. At cruise the prop should not be swirling the air behind it so much as it corkscrews through the air near pitch-speed (pitch*rpm). If you trim the plane to do a straight level hands-off pass at half throttle, then make a hands-off pass at full throttle the plane will veer left. I've been told this is due to the torque effect. My guess is the roll rate from the change in torque is only a few degrees per second, so in a 3-6 second pass it looks like a gently banked turn to the left. After 600 yards or so the pilot has to turn the plane around. Computer radios let you mix some rudder into the throttle. Is this usually used for correcting cruise trim or for making take-offs easier? Seems that if you used it for take-off (acceleration effects) it would mess-up the cruise trim when changing throttle settings. Carl
Posted on: 6/1/2005 11:14 AM by Author "Siefring" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=3028937

RE: CG Tiger 60 -- Thanks guys for all the help
In the 1940's [:)] the HellCat and BearCat. MinnFlyer, your suggestion to use Elmers wood filler was a good one. Carl
Posted on: 6/1/2005 11:05 AM by Author "Siefring" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=3031979

CG Tiger 60 -- Thanks guys for all the help
I finished my CG Tiger 60 and have had a couple of nervous but successful flights. I need to dial down the elevator and aileron throws as it is too sensitive for me. Sunday was very gusty and it was a real adventure with an unfamiliar plane.... I wanted to thank everyone on RCuniverse for helpful tips and discussion. What a great resource this is!! Attached are some photos and a brief description: Equipment: Super Tiger 75, Futaba R127DF Channel 43, (4) S3004 BB, S148 (recycled) for Throttle, NiMH 4.8V 1450mHh Covering: Dark Blue Coverite 21st Century Fabric Leading Edges: Aluminum LustreKote Paint Wing Tips+Tail Feather Tips+Large Markings: Yellow Latex over AL LustreKote Large Lettering: Yellow Cut from MonoKote Small Markings: InkJet Decals Custom made on PC Fuel Proof Clear LustreKote Modified from tricycle to tail dragger configuration. A Great Planes Dural Main Landing Gear was placed just in front of wing and Sullivan Tail Wheel assembly was used. Mounting locations were beefed up for both. The total weight difference seemed to be "a wash" because of all of the steel used in the stock landing gear. A Dubro Vibration mount was added to bring engine forward. The firewall was reinforced. The decoration scheme is based on the one used by the Blue Angels on the Grumman F11F Tiger from the late fifties to the late sixties.
Posted on: 6/1/2005 9:52 AM by Author "Siefring" in the forum "Kit Building"
http://www.rcuniverse.com/forum/fb.asp?m=3029816

RE: Forward thrust reduced by too much right thrust?
Here are the basics, I think. Two reasons. #1 Looking from behind: The prop spins clockwise so conservation of momentum would suggest the plane wants to spin counter-clockwise. Thus, the left wing tips down and the plane wants to turn left. #2 The air coming off the propeller is swirling. At the rudder the air flow comes from the left. This give a lift vector at the rudder that pushes the rudder right and also make the plane turn left. Both of these effects change with throttle setting. So the rudder needs to be adjusted with throttle to make the plane fly straight. If you trim the surfaces to fly straight at low throttle and then trim the right thrust to fly straight at full throttle, you will have a plane that doesn't change heading much with throttle setting. If you do search on trimming or trimming charts you can look-up the best ways to check the right and down trust. Carl
Posted on: 5/26/2005 4:00 PM by Author "Siefring" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=3014124

RE: Curved covering scheme?
Here is another thread with some ideas for you [link]http://www.rcuniverse.com/forum/m_2003852/anchors_2003852/mpage_1/key_covering%252Cseam%252Copen/anchor/tm.htm#2003852[/link]
Posted on: 4/8/2005 11:01 AM by Author "Siefring" in the forum "Tips & Techniques"
http://www.rcuniverse.com/forum/fb.asp?m=2856403

RE: Prop effective speed
[quote]ORIGINAL: agcatsbest Now. I had heard in several places statements like "you need a gear setup with a larger prop because if you just keep speeding the prop you reach a point where it's just beating the air and adding nothing. [/quote] Some of the these statements were part of the problem with the thread. People seemed to jump on a misunderstanding of how props work -- maybe a danger of asking a question in this forum[;)]. If you hold a plane on the ground and run your 8x6 prop at 15,000 rpm then the prop blades are stalled and in that case you might say that you are "just beating the air". If you release the plane and let it speed up the portion of the blade that is stalled gets smaller as the velocity picks up. At about 25 mph your prop is not stalled. So whether it is "just beating the air" depends on the velocity also. I still think you would be better off with an 8x4 or 8x5 prop, which will not be stalled on the ground. You will get a lot better pull in the 0 to 25 mph range and I doubt if you care about the extra top speed that the 8x6 prop gives you. Try the freeware program prop selector. [link]http://www.gylesaero.com/freeware/propcalc.shtml[/link] it gives an indication of when a prop is stalled and how badly it is stalled. This site has good diagrams showing props and velocity vectors and a little on why they stall [link]http://www.auf.asn.au/groundschool/propeller.html[/link] I do note that you had 3 estimates for motor power, 200 W min, 320 W max and a fairly careful calculation stating [quote]The big story is that the 8x8 prop would require something around 620 Watts of input power and the 8x4 would only require 220 Watts.[/quote] You went with 277.5 Watts, an 8x6, and seem to be happy. So I guess you did get a some help[:)]. I'm glad it worked out well and I'm sure most people appreciate the update and happy outcome on the project . As for some of the other comments, come on guys, it's a glider. Under the right conditions it doesn't need the prop at all. Carl
Posted on: 4/8/2005 10:10 AM by Author "Siefring" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=2856216

RE: Fool on the field
If you are operating right at the noise level of the receiver almost anything will interfere. However, another transmitter shouldn't interfere with your receiver unless you are at the limits of your range and the other transmitter is close to the receiver. On a crowded field, it's pretty common, if you turn your TX OFF and leave the plane RX ON to see the control surfaces react weakly to other sources. The minute you turn the TX ON even with the antenna collapsed it all goes away. Unless the plane was 500-1000 meters away and he was just under, I wouldn't expect another TX to jam you. If you had a marginal receiver, RX or TX battery, your TX antenna partially collapsed, or your RX antenna run near metal linkages for much of its length, the combination of the two things might do it.
Posted on: 4/5/2005 3:40 PM by Author "Siefring" in the forum "Crash & Rebuild"
http://www.rcuniverse.com/forum/fb.asp?m=2845939

RE: What part turns a plane
[quote]ORIGINAL: LouW The pylon racer will often enter the turn a little high, roll into a vertical bank, pull as much additional lift as possible without stalling the wing and accept the inevitable loss of altitude during the tightest part of the turn.[/quote] I know the pylon racers at our field spend a lot of time trimming to get very little drop or rise at turn 1. [quote]As BMatthews said they "coast" in this vertical bank condition momentarily before rolling out of the turn. They would not intentionally fly actual knife-edge, as the resulting sideslip would add drag that would eliminate the advantage of a tighter turn. [/quote] Sorry, my question on the Pylon racers was phrased poorly. I realize that a racer is not in an actual knife-edge and was really trying to describe the relatively "vertical bank" that seems to start early in the turn. I've called "cuts" at turn 1 at a couple of events and (from the side of the field) it sure looks like the planes are flying with banked wings but straight as an arrow. Thinking on this, if the pylon racer is going 150 mph it would take several seconds and several football fields to turn in a 1 or 2 g bank. So Bruce must be correct the entry and exit from the turn look really stretched out because of the velocity of the planes. Clearly the appearance of straight flight is enhanced by a side view, also. I'm still wondering if the final quick and violent change in direction, in this case, is done by elevator input (to maximize AOA and force a very high-g turn) or is it just banked to nearly vertical? At the speeds they are going you would not expect much of a vertical drop in the fraction of a second that it takes to do the sharpest part of the turn, even if you lost all vertical lift. Carl
Posted on: 4/5/2005 9:09 AM by Author "Siefring" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=2844707

RE: What part turns a plane
So a related question. What goes on when I see a pylon racer make a turn. It almost looks like they approach the turn in a knife edge and make the turn with the elevator (w/conventional tail). I'm not sure what goes on with a v-tail. Is that really what is going on? Why would this be a good way to make a quick turn? Carl
Posted on: 4/4/2005 8:05 PM by Author "Siefring" in the forum "Aerodynamics"
http://www.rcuniverse.com/forum/fb.asp?m=2842979