Here is a list of all the postings Ed Anderson has made in our forums. Click on a thread name to jump to the thread.
|Thread: Motors ...for beginners - please keep it simple|
That is a good approach.
Wattmeters are an essential piece of kit for electric flyers who are moving away from Ready to fly or bind and fly packages. As you change props or battery voltage you change the power curve of the motor. As a result you can overload something leading to component failure. So you check with the wattmeter to insure that you are not overloading the motor, the ESC or the battery.
They are not expensive. I have two.
Here is an example of a wattmeter from HobbyKing.
Edited By Ed Anderson on 21/08/2016 14:51:19
Whether the friend has a Wattmeter or not, if he is going to play around with props he should be checking the power with a wattmeter. Don't have one?
If he doesn't want to get one he should stay with the MFG recommended, which, in this case is a 9X4.5 as reported in the post.
Edited By Ed Anderson on 21/08/2016 02:46:04
If he is going to start changing propellers he should check it with a wattmeter. The advice you just received is to go from a 9X4.5 to an 11X6. That is a big prop jump.
That might be OK or it might overload the motor, the battery or the ESC. Once you stray from the MFG recommendations you must check with a wattmeter.
I have seen too many crashes and too many buned up components due to people bumping up the voltage or changing the prop and burning something out as a result. They cry foul and blame the components until I put my wattmeter on and find they are pulling 40 amps against a 25 am ESC and a motor rated for 30 amp.
Poof and all the magic smoke comes out, assuming it doesn't start a fire.
Edited By Ed Anderson on 20/08/2016 21:24:38
That is the joy of the hobby. We can all approach it a little differently yet share in the same experience as we find lift and take it high into the sky.
Clear skies and good lift to you!
Good luck with the new glider. I have never flown a glider that was launched with a glow engine. I have only flown pure gliders and e-launched gliders.
Why would you use a glow engine rather than electric? Electric can be restarted and controlled. A glow can't.
Do you put a folding prop on a glow engine? I would assume not as it would make it tricky to start.
Edited By Ed Anderson on 20/08/2016 19:00:58
I know the Spectra quite well. Here are some thoughts.
* If you just swap the NiCd pack with a 2S lithium that is sized for 20 amps it will fly better because it will be lighter. Still not a fantastic climb but it takes nothing to do this. A 2200 mah 20 C pack would be great.
That speed 600 on 7 cell nicad was taking in about out about 160 watts but only delivering about 100 watts to the prop which as I recall was an 8X4.
Now, which spitfire?
If I search on HH for Spitfire this is the only 950 kV motor that comes up. There are no specs given on the motor and I can't find a spitfire using this motor on their site so I am guessing this is a model they no longer sell. The current Spitfires use different motors.
I am assuming the prop is a 9X4.5 as props are not marked in degrees they are marked in pitch according to how many inches the prop would move forward through the air on each turn if there were no slippage.
This motor seems to be close to the motor your friend has so we will use the specs from this motor:
You did not say what voltage, how many cells, the battery pack would be and that would be critical to know in order to estimate the wattage the motor will draw. And you did not say what amperage rating the ESC had so I have to guess.
Here is a WAG. 3S pack, 9X4.5 prop prop, probably draw 20 amps for about 220 watts input and about 180 to the prop. That would nearly double what the Speed 600 was doing. So that would be fine. Glider would probably climb at a 45 degree angle or steeper as compared to about a 25 degree climb on the speed 600 and a 7 cell NiCd pack.
Should work fine.
Edited By Ed Anderson on 20/08/2016 16:59:58
Edited By Ed Anderson on 20/08/2016 17:00:37
|Thread: HKM Solitaire Plus - looking for information|
Curious, what glider were you flying for that competition? What was the all up weight?
Edited By Ed Anderson on 23/03/2015 18:26:41
Great insights. Thanks!
I am curious about the thermal soaring part of the task. I would think these would be bricks in normal trim. Do they really thermal or is it just a matter of crazy fast climb and then glide? I can't imagine these things having much of a glide ratio at that weight and that wing loading. Would you run some thermal camber during the glide portion?
Also, why no rudder?
Edited By Ed Anderson on 23/03/2015 13:23:40
Edited By Ed Anderson on 23/03/2015 13:25:05
Just picked up an HKM Solitaire Plus at an estate sale. Brand new, never been assembled.
Anyone have this glider or care to share anything about it?
I understand this was a competition F5B glider from the late 90s, early 2000s.
I have a sheet that looks like the one at the second link. It appears to be in German.
I have no intention of entering F3B competition. But It looked like it might be fun to set it up at as a warmliner, maybe 150 watts/pound.
Appreciate any advice or insights from current or former owners.
|Thread: What did I buy? Shredair ????|
Yes, Dieter says it is the Stork 2 Pro. It is still available from Soaring USA but this one has a Shredair label on it so it has probably been sitting around for years. But now that I have it together it looks like it has never been flown.
Soaring USA also has an electric fuse for it. If I like the glider I may get the e-fuse too. I have my supra pro set up for winch or electric launch. Maybe I will do the same with this one.
Now to check out the servos and such to see if anything needs to be replaced. And 6-10" of snow on the way so not flying this weekend.
Glad I got a snow blower for Christmas rather than another glider. :D
I went to an estate sale today. At the sale was this Shredair glider. Looked pretty nice so I bought it. 127" wing span. V tail, Molded construction. 3 piece wing.
Sort of a lime yellow with red on the bottom of the wings and V-tail.
Trying to figure out how to insert photos.
Edited By Ed Anderson on 31/01/2015 21:49:21
Edited By Ed Anderson on 31/01/2015 21:53:57
|Thread: Propellers...for beginners - please keep it simple|
We are all in the same boat. When you know something it seems easy, even obvious. When you don't it seems difficult and complicated. Remember learning to ride a bicycle?
If I had to buy a glow or gas motor for a plane I would be lost. sizes, sleves, tuned pipes, 5%, 10% 15%, oil? and all that glow plug stuff, sticks, starters, changing CG as the fuel goes down, a clink on the fuel line ..... black magic. And fuel proofing, vibration considerations ... really?
Tune before a flight? Tune what? I tuned it last time. Rich? Lean? Choke?
Give me a nice simple electric set-up.
Watts per pound target
Target battery or target prop.
Use one of the calculators and it becomes trivial.
Once it is installed it works every time.
Don't know how you fuel guys ever got them into the air.
Edited By Ed Anderson on 01/10/2014 14:17:07
One note on kV. There is no direct correlation between kV and the watt capacity of a motor. You can have a 75 watt 1000 kV motor and you can have a 500 watt 1000 kV motor.
What would be the difference? The size of the wire that is used to wind the motor. Larger wire can carry more current and produce stronger fields and more powerful motors. But it also weighs more.
So, in the end a motor's power is measured in Watts, always watts.
kV is what you use to adjust for prop size and battery voltage.
While kV applies to inrunners in the same way as outrunners, inrunners typically reside in the higher kV ranges.
Inrunners, can drive a prop directly but are often teamed up with a gearbox which effectively lowers the net kV rating at the prop. This is common in helicopters, gliders but can apply to airplanes too. While you can team an outrunner with a gearbox typically gearboxes are teamed with inrunners.
|Thread: 'C' rating . . . how much do we need?|
Lots of good information here so I will not rehash. BTW I am also an e-glider pilot. I fly a Radian and an E-Supra for ALES contests in the USA.
In reference to C rating, the closer you run to the packs maximum rated amperage the harder you are working the pack and the faster it is likely to degrade. Also, the closer you run to the max rated amperage the more the voltage drop which will translate into a slower climb.
You can't have too high of a C rating. But you can have too low, as has been stated above.
I usually try to keep my top amp draw at or below 80% of the maximum sustained C rating in my gliders. I typically ignore burst numbers.
My e-Supra weighs about 68 ounces all up with 1300 mah TP 65C 3S pack. It pulls about 45 amps for 24 seconds to reach the specified 200 meters for the typical ALES launch. I use the 65C rated Thunder Power 1300 mah 3S pack most of the time. That battery is rated for 84 amps but I am only pulling 45 so I am not even working the pack hard.
BTW, each launch, followed by a 10 to 20 minute flight uses about 30% of the pack's capacity, about 400 mah. For contests I swap packs after each flight. For sport flying I will take 1 full climb and two 15-20 second reclimbs for about an hour's flight on a pack. This consumes about 70% of the capacity. I don't want to take it any lower than that but there is enough reserve to get me a short burst if I need it to save the glider.
I have also used Thunder power 850 mah 70C 3S packs to try and shed some weight. That pack is rated for 59 amps so I am running at about 76% of the sustained max C rating. I get about the same launch time but only do one full launch on these packs as that climb plus the flight is pulling about 400 mah. That leaves me enough reserve to do a restart if I need it to save the glider but I typically don't do reclimbs on these. They are mostly for contest work where a restart would get me a zero for the flight.
Hope that practical experience is helpful.
Edited By Ed Anderson on 30/09/2014 14:21:30
Edited By Ed Anderson on 30/09/2014 14:23:14
Edited By Ed Anderson on 30/09/2014 14:24:11
|Thread: Airplane Locators|
Plane Finders - We all try to fly carefully but sometimes stuff happens and the airplane or glider ends up in the woods or somewhere else where it will be hard to find. Unfortunate but it happens.
If you start to fly contests, especially glider contests, sometimes, during contests, we push ourselves and our gliders too far and can end up in the deep woods. A little preparation now can make it much faster and easier to find the plane.
Put your name and phone number in your planes. If someone finds it but doesn’t know how to contact you, they my pick it up and take it home and you will never find it.
Article on lost model locators – $5 to $500
For most airplane pilots something as simple as the beeper type finders are more than adequate. For glider pilots or FPV pilots the longer range finders may be justified.
|Thread: Propellers...for beginners - please keep it simple|
I will add a few thoughts.
We need to look at the motor specs (volts/amps/kV) the prop and the battery as a system.
As a general rule smaller props with deeper pitch will give you more speed than wider props with less pitch even though they might consume the same watts.
Think high gear vs. low gear. You go into high gear for steady speed cruising on the highway. You would go into low gear to get up to speed quickly. If you came away from the light in high gear the car would accelerate very slowly assuming you did not stall the car's engine, but would eventually get to that high speed for the highway.
So, are we gearing up for speed or low end power?
We need to look at goals. As I discuss this, think about cars or bicycles and gears. We can't change gears on planes so we set-up for the goal we are working toward.
A pylon racer is looking for top end speed on the flat more than low end acceleration for steep climb. We would probably go for a higher kV motor that spins a smaller deeper prop faster for high pitch speed.
A sailplane is looking for low end power to climb at a steep angle to get to height. We would normally select a lower kV motor that can spin a wider prop slower for climbing power even though the top speed may not be very high.
Both motors might be rated for the same wattage but they deliver the power in very different ways.
Lower kV motors usually receive manufacture recommendations for wide props and are optimized for low end power.
Higher kV motors usually receiver manufacturer recommendations for narrow props that are optimized for high end speed.
I mentioned the battery as part of the system but left that out of the discussion.
If a given motor is rated for 300 watts we can achieve that power level in several ways based on battery voltage and prop size.
Often the motor specs will express a voltage range by listing 2-3S lipo and a prop range, for example 9X6 to 11X8 prop.
People miss read this as that they can put an 11X8 prop on this motor with a 3S lipo and that is good. More likely what the specs tell us is that you should use an 11X8 prop on a 2S lipo and a 9X6 on a 3S lipo. Both will result in a power draw within the motor specs but they achieve it differently and produce different results.
The 2S is spinning a larger prop more slowly.
The 3S is spinning a smaller prop faster.
Going back to the descriptions I provided above thin of 3S for the pylon racer and the 2S for the sailplane.
Edited By Ed Anderson on 29/09/2014 14:36:04
Edited By Ed Anderson on 29/09/2014 14:38:00
|Thread: What's the main radio brand you fly?|
I have only been flying 11 years so I don't have the history some of you have.
Started on a 27 MHz RTF Aerobird. Went through a series of 27 MHz RTF radios as I bought RTFs. Still have some of them and they still work.
Purchased a used Hitec Prism 7X as my first computer radio for glider flying.
From that I went to a new Futaba 9CH. Then added a used 9CH as a back-up radio for contest flying.
Later replaced both with 9C Supers which is what I fly today.
Not looking for a new radio, but if I was I would probably look at the Futaba 14 SG or the Taranis.
I fly competition sailplanes and am seeing Taranis showing up at the contest field and those flying it LOVE it! And these are mostly former JR, Airtronics and Futaba pilots.
What is just as important is how it is driving down the cost of main brand systems. Futaba now has a $49 7 channel receiver (USA) and Spektrum now has a DX6 that seems to be loaded with features.
It is the nature of the computer business that competition drives price down and capability up and these radios are following that path rapidly.
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