Author Topic: Anyone done an electric racing setup? Perky perhaps?? (Read 3554 times)

Wynn Robins · « **on:** April 18, 2011, 02:48:37 PM »

I know its against the rules in Perky Postal - but just for sh*ts and giggles - I want to do a perky on electric power

what I really need to know is - what is the best combo for a model like this and any suggested cooling as i would imagine it would get pretty hot ....

Tim Wescott · « **Reply #1 on:** April 18, 2011, 03:12:34 PM »

Well, you're defining the racing "class", so you can make some choices that'll influence how hot it'll get!

If it's going really fast, you may find that you get decent (or even better) cooling by cowling things in pretty heavily -- there's been some pretty specific features of cooling air theory that's been proven true in full scale flight for years, and which can't work differently in model airplane usage. The guiding three are:

Slow moving, high pressure air cools better than fast moving, low pressure air
You can slow air down, and increase it's pressure, with a "diffuser"
Air that doesn't touch a hot surface doesn't cool for squat!

What this adds up to is to tightly cowl your hot parts, with a small, forward facing hole that lets the incoming air 'grow' gracefully (this is the diffuser, that's turning that fast outside air into slow inside air), make sure that all the air that comes in gets directed through the motor and by the battery (or else it's wasted effort), and to pay attention to the air path on the inside of the cowl as on the outside.

I'd just build the airplane any old way you like, paying attention to the fact that LiPo batteries really don't like to be discharged too fast. Putting in a "fuel tank" that keeps you in the air for three minutes is probably about the maximum you can go before you start really chewing through batteries.

If you want to get serious about electric racing, I'd suggest that you write up a set of rules, keeping them as simple as possible: I'd start with all pertinent safety rules for racing, a wingspan limit, and a weight limit on the power system (battery, motor, esc.) or just on the battery. Then stand back and see if anyone comes and races with you. As folks find ways to trade money for performance, or safety for performance, or complexity for performance, think about refining the rules to keep the event affordable and accessible, while still making it a good contest.

Maybe you want a maximum weight limit on the battery, and a sponsor-provided fuse of published current value (an automotive blade type would be cheap, and easy to replace). Leave it to the contestant to design his electrical system however he wants to, knowing that if he pushes the current too much he'll be out of the race. This will let you choose a battery weight/fuse combination that won't have people running their $60 battery packs hard enough to burn them out in ten flights, while still leaving you with a system that's humanly possible to administer.

Wynn Robins · « **Reply #2 on:** April 18, 2011, 04:07:18 PM »

Perky Racing already has rules - one of them is "no electics" but I want to do it for fun.

I was sorta hoping for advise on motor size and KV - battery pack etc.

existing rules are.....

.14 to .1525 cu. in. glow or diesel engines
52'-6" lines 2 x .012 stranded
no pressure tanks
no tuned pipes
one entry per engine
1 1/2" wheels
1 1/2" or 1 3/4" spinner mandatory
Perky model built as plan outline. Construction modification allowed.
one mile (16 laps) standing start times from model release

ash · « **Reply #3 on:** April 18, 2011, 05:00:45 PM »

I think Tim's advice is spot-on, even though it doesn't explicitly state the specs you are after. The most important rule to take frome the Perky Postal rules is:

Quote

Perky model built as plan outline. Construction modification allowed.

That pretty much defines your battery size and by adding a few more parameters, the motor size.

The other rule for Larry's postal event is a max speed of 90mph. There's your target.

What motor/prop/rpm do you need to get 90mph over one mile? Some Perkies running IC engines are probably ranging around the 0.5kW at 20,000rpm mark at a guess.

Then you work out how to make it fit without catching on fire.

There is an FAI electric speed class called F2G which sets out a bunch of well considered rules and specs. Too much for a Perky, but worth a look. F2G info seems pretty hard to find so far.

I like Tim's auto-fuse idea. Get something going, publish some rules and see who joins in for an electric Postal event.

I'd like to do something to establish a fun open Proto Speed event here in NZ based on the Perky Postal event, but open to other designs and technology.

Tim Wescott · « **Reply #4 on:** April 18, 2011, 05:26:45 PM »

500W pretty much narrows things right down -- choose the number of cells (it's probably a toss up between three and four, although I'd lean in the direction of four). Choosing four cells chooses the current for you -- 36A or so (I'll bet you can get fuses for 35, certainly you could for 40). The current and voltage choose the ESC's that you can buy (look at specs -- the CC ICE 50 is certainly a candidate, although there's plenty more). Now go shopping for a 500W motor. I'm going to _guess_ that you want to aim at high RPM and a small-diameter sharply pitched prop. So you have to pay attention to the motors RPM ranges -- you'll be getting into speeds where motors may want to fly apart. You may even want to use an inrunner motor.

If you go for a 20C discharge rate and a four-cell pack. you're talking a 1800mAh pack. Go up to 30C discharge and you'll get down to a 1200mAh pack -- but the batteries may not last as long, and you'll lose some 'oomph' to cell heating.

For starters I'm look for a motor that turns between 15000 and 30000 RPM at 14V (if you want that 4-cell pack). That implies a Kv between 1050 and 2100. Then experiment with props to get one that doesn't blow a fuse, experiment with batteries to figure out how to keep them alive, experiment with motors to see how much you can crowd the power rating without burning them up, etc.

BillLee · « **Reply #5 on:** April 18, 2011, 07:01:37 PM »

In spite of this thread's title, Perky is NOT a racing event, it is a speed event.

Racing includes multi-plane races, pitstops, etc. Somehow I can't envision a pitstop with an electric model! Particularly since the CL Racing rules specify that at least a token amount of fuel must be added.

Regards,

Bill

Tim Wescott · « **Reply #6 on:** April 18, 2011, 07:43:54 PM »

Quote from: BillLee on April 18, 2011, 07:01:37 PM

In spite of this thread's title, Perky is NOT a racing event, it is a speed event.

Racing includes multi-plane races, pitstops, etc. Somehow I can't envision a pitstop with an electric model! Particularly since the CL Racing rules specify that at least a token amount of fuel must be added.

The plane comes to a stop, the pit man removes the old battery, slaps the new one on, pushes the "go" button, and they're off.

BillLee · « **Reply #7 on:** April 18, 2011, 09:00:19 PM »

Quote from: Tim Wescott on April 18, 2011, 07:43:54 PM

The plane comes to a stop, the pit man removes the old battery, slaps the new one on, pushes the "go" button, and they're off.

Tim, I didn't see a smiley face on your post. Certainly it was intended, was it not?

Bill

Tim Wescott · « **Reply #8 on:** April 18, 2011, 09:04:57 PM »

I was dead serious. How else would you do a pit stop with an electric?

"The pit man catches the plane, attaches it to a charger in 0.5 seconds, then drives to the nearest burger joint for lunch" would demand a smiley face.

Keith Renecle · « **Reply #9 on:** April 19, 2011, 06:17:09 AM »

I say.......give the pit man a hand generator and let him pump up the batteries!

Keith R

ash · « **Reply #10 on:** April 19, 2011, 07:13:42 AM »

You've seen the video clip before, but there are a few details listed in the thread. The original webpage seems to have died, unfortunately.

http://www.rcgroups.com/forums/showthread.php?t=1119221

ash · « **Reply #11 on:** April 19, 2011, 07:20:28 AM »

OK, here's a cached, translated version:
http://translate.google.co.nz/translate?hl=en&sl=de&u=http://www.fesselflug.ch/werkstatt/modellvorstellung/elektro-speed-catfish.php&ei=W4utTZuuGJKosQOQkI2SAw&sa=X&oi=translate&ct=result&resnum=1&ved=0CBwQ7gEwAA&prev=/search%3Fq%3Delektro-speed-catfish%26hl%3Den%26safe%3Doff%26rls%3Dcom.microsoft:en-nz:IE-Address%26prmd%3Divnsb

Keep in mind that this is MUCH faster and more powerful than an electric Perky should ever be.

Tim Wescott · « **Reply #12 on:** April 19, 2011, 09:58:17 AM »

Man flying plane, or plane flying man? I've seen speed videos where the guy was obviously working hard to get back to the pole -- that's the first one where it looked like the plane was going to drag the guy around the circle.

The smoke was impressive.

dynasoar1948 · « **Reply #13 on:** April 19, 2011, 04:32:14 PM »

AMA has two official CL speed events. Class A record about 116 MPH My Class B record is 142.46 MPH.

Check Control Line Speed section.

Will Stewart AMA 1947

ash · « **Reply #14 on:** April 19, 2011, 04:36:05 PM »

The Catfish model weighs 1.3kg, so at that pace the pull must have been ridiculous. I think I saw someone calculate 36kg line tension.

Keep that in mind, Wynn. You don't want to get the Perky weighing more than a Goodyear model.

Wynn Robins · « **Reply #15 on:** April 19, 2011, 05:10:44 PM »

Quote from: ash on April 19, 2011, 04:36:05 PM

The Catfish model weighs 1.3kg, so at that pace the pull must have been ridiculous. I think I saw someone calculate 36kg line tension.

Keep that in mind, Wynn. You don't want to get the Perky weighing more than a Goodyear model.

thats why I go to the gym........I am sure I can hang onto a toy plane.... HA. 36kg is a bit of a pull......must be about the same as your Zone 2

dynasoar1948 · « **Reply #16 on:** April 19, 2011, 09:32:50 PM »

The really beautiful Catfish, on 59 foot lines, weighing 45.75 Oz and moving 159.36 MPH pulled at 80 pounds.
My AMA Class B ship, on 60 foot lines, at 142+ and weighing in at 60 Oz, pulled 84 pounds. The backup flight, at about the same speed, for a total of about 30 laps was enough for one day. I'm working to get the AMA rules rationalized to a more realistic line length of 70 feet.

The proposed FAI electric rules are totally unrealistic- weight is too light for any reasonable battery complement unless aerospace methods (read astronomic cost) are used. Battery must be commercially available and ship officially sealed to prevent smoking a system each flight. Only prop and spinner replacement and recharging between flights. Speed average of three flights.

Rules being prepared for submission via USA F2A team.

Will Stewart

ash · « **Reply #17 on:** April 19, 2011, 11:35:08 PM »

Look up some small RC electric pylon racing set ups, Wynn. Any system running around a 6x6 to 7x6 prop that weighs 300-500g is going to be in the ballpark.

I bet there are pages of plug and play systems listed for electric pylon.

BillLee · « **Reply #18 on:** April 20, 2011, 04:24:43 AM »

Quote from: dynasoar1948 on April 19, 2011, 09:32:50 PM

... Rules being prepared for submission via USA F2A team. ...

Will;

What does this have to do with F2A? Is this an FAI rule change or something for AMA rules?

Regards,

Bill Lee

dynasoar1948 · « **Reply #19 on:** April 20, 2011, 11:15:32 AM »

Hi Bill,

Check message 4 (ASH) for mention of FAI F2G Electric CL Speed. When Billy Hughes was out here for the December contest we discussed the FAI approach (published in Speed Times) and agreed that many parts were unrealistic. I said I'd put together an alternate rule set based on actual experience with CL Electric for his submission to FAI.

Incidentally he witnessed some of my B Speed flights on proposed 70 foot lines. A video of one of my flights is available on Joey Matheson's Speed section of this forum. Look at the end of the 2010 Toys for Tots Section.

Best, Will Stewart

dynasoar1948 · « **Reply #20 on:** April 20, 2011, 11:31:43 AM »

Bill- cont.

Check Speed Talk, Toys for Tots, 2010, Page 4, next to last video. Turn up the sound for a transonic prop and silent motor.

Will

BillLee · « **Reply #21 on:** April 20, 2011, 12:04:56 PM »

Quote from: dynasoar1948 on April 20, 2011, 11:15:32 AM

Hi Bill,

Check message 4 (ASH) for mention of FAI F2G Electric CL Speed. When Billy Hughes was out here for the December contest we discussed the FAI approach (published in Speed Times) and agreed that many parts were unrealistic. I said I'd put together an alternate rule set based on actual experience with CL Electric for his submission to FAI.

Incidentally he witnessed some of my B Speed flights on proposed 70 foot lines. A video of one of my flights is available on Joey Matheson's Speed section of this forum. Look at the end of the 2010 Toys for Tots Section.

Best, Will Stewart

Right on, Will. Just didn't see the "F2A Team" connection.

There is a procedure for making rules changes of the FAI rules. Distinctly separate from what AMA has for the AMA rules. Involving Billy is a good place to start, and he knows where to go from there (me).

Keep in mind that F2 rules proposals need to make their way through the AMA and be submitted to the FAI by November 15. It's awful easy to let that date get away since getting them through AMA isn't a necessarily quick operation. I.e., don't wait until November 15 to try: it would be difficult at best!

Bill

PerttiMe · « **Reply #22 on:** April 20, 2011, 12:18:07 PM »

FAI electric classes (mainly R/C now) are getting pretty complex with attempts to keep the playing field level using limits on total amounts of energy. It is hard to make battery size a reasonable thing to limit too, with the fast developments in power storage (batteries and other).

A while ago, I was watching an electric free flight discussion. One guy had just got some new gear and got 990 W out of it with a 90 g LiPo. Looks like his gear survives that for the 4.5 seconds of his motor run. On the American side of the Atlantic, people thought he must be joking...

dynasoar1948 · « **Reply #23 on:** April 20, 2011, 01:07:22 PM »

Electric Speed for FAI

My Thoughts: A reasonable total airplane weight.
Commercially available batteries (Some minimum number produced, and on FAI list)
Airplane sealed after initial inspection; No replacement of internals such as motor, controller
battery etc.
Speed average of three flights.

This would eliminate kamikaze (read expensive) one flight-one battery efforts.

First thoughts lead to metric equivalents of 40 Oz maximum weight and 70-foot lines. Maximum Voltage 4S or 16.8V. This would allow maybe 2.75 HP at the prop and speeds comparable to present day F2A without impossible line pull.

Will Stewart AMA 1947

Tim Wescott · « **Reply #24 on:** April 20, 2011, 02:01:07 PM »

Quote from: dynasoar1948 on April 20, 2011, 01:07:22 PM

Electric Speed for FAI

My Thoughts: A reasonable total airplane weight.
Commercially available batteries (Some minimum number produced, and on FAI list)
Airplane sealed after initial inspection; No replacement of internals such as motor, controller
battery etc.
Speed average of three flights.

This would eliminate kamikaze (read expensive) one flight-one battery efforts.

First thoughts lead to metric equivalents of 40 Oz maximum weight and 70-foot lines. Maximum Voltage 4S or 16.8V. This would allow maybe 2.75 HP at the prop and speeds comparable to present day F2A without impossible line pull.

Will Stewart AMA 1947

Speaking not as a speed flier (which I'm not), but as an electrical engineer (which I am), I wouldn't put in the limitation on batteries. The mass limit is going to limit the amount of energy that can be stored in the battery, and there's probably not a great advantage to going to a higher cell count. Putting the cell count is going to limit the use of new battery technology, and I see things like speed and racing as the breeding grounds for high-performance techniques that the rest of us can use. So I think you have taken care of any potential "too much battery" problem with the mass limit, you've taken care of the "astronomical cost" issue with the battery minimum production rule. To then add a cell limitation means that you're either leaving the rules subject to endless need for revision as other battery chemistries come onto the market, or you're building obsolescence into the rules. Neither of those are good things.

It also raises a thought, which is almost certainly too impractical, to have an "unlimited" speed class. Just hold things to the mass and line length limits with no limit on the battery at all (plus all applicable safety rules, of course). This would provide a venue for wild experimental cells to be tested, keep a venue for 'normal' speed competition, and hopefully both promote innovation and allow battery chemists to come have fun flying control line.

PerttiMe · « **Reply #25 on:** April 20, 2011, 02:11:13 PM »

IMO:

Lists of allowed equipment is not a great solution. Of course, electric rules are being revised all the time, so one more thing to revise every year might not be all that bad.

Go lighter, even if it means being slower, for now, than current top F2A.

Do 70 foot lines fit in existing cages at the few places in the world that have proper speed circles?

dynasoar1948 · « **Reply #26 on:** April 20, 2011, 02:46:52 PM »

I could easily lay out a LiPo battery configured as a wing panel or fuselage element. Battery technologists could, I'm sure, incorporate aerospace exotics as far beyond LiPo as they are beyond NiCad. This is a perfect approach to giving victory to the deepest pockets. If this is what we want, fine. Just not for me.

A list of FAI homologated batteries, with a maximum mass if desired, low enough so that the airframe does not become a similar exercise in exotic light weight materials. I expect that the list might change annually to accommodate emerging technology.

Will Stewart

PerttiMe · « **Reply #27 on:** April 20, 2011, 02:59:03 PM »

You could easily go for minimum battery weight and energy limiters like in F5B and F5D

http://www.f5b.co.uk/?q=node/64

Of course the battery weight might have to be changed annually, but that is a smaller headache than making a list of permissible batteries.

dynasoar1948 · « **Reply #28 on:** April 20, 2011, 05:32:00 PM »

Pettime,

Eight laps per kilometer would require just over 65 foot lines. Certanly not a problem in North America. I visited the current limit site. Strange world. Maybe International control line speed is not such a good idea afterall.

Will

PerttiMe · « **Reply #29 on:** April 21, 2011, 01:08:05 AM »

In F2A the "flight radius" is 17.69 m, (58.04 ft.) making 9 laps equal to 1 kilometer.
That seems to work OK internationally.

There's no particular reason why you cannot make an electric fly with the same line length. ... Unless you want to exclude those who have built their sites to fit F2A.

dynasoar1948 · « **Reply #30 on:** April 21, 2011, 06:47:04 PM »

If F2G maximum weight remains the same as F2A, even shorter lines should work just fine, since speeds would be well below present levels (until we get supercapacitors)

If weight is increased to accommodate a reasonable battery complement, permitting speeds approaching present F2A levels, then increased line pull, like AMA B electric, would require longer lines because of pilot strength and other safety issues.

If European speed sites are limited to the approx. 60 foot lines as you seem to believe, then perhaps a displacement reduction should be considered for the future of F2A.

Will Stewart

PerttiMe · « **Reply #31 on:** April 22, 2011, 03:11:17 AM »

I don't see how F2A could suddenly become so much faster with current displacements that displacement would need to be reduced or lines lengthened.

There's no particular reason why electric speed would have to START from being as fast as F2A is after many decades of development.

dynasoar1948 · « **Reply #32 on:** April 22, 2011, 09:57:40 AM »

Remember the same dire predictions about the loss of F2A sites when the suggestion was made to go up in line lengthh from 10 laps /k to the present 9 laps/k (52 to 60 ft approx. lines)? Didn't seem to happen.

Are you implying that progress in F2A is over? A couple of geared prop setups (like free flight) would end stagnation and the ante is raised to over 200MPH.

Will

PerttiMe · « **Reply #33 on:** April 22, 2011, 12:01:37 PM »

Quote from: dynasoar1948 on April 22, 2011, 09:57:40 AM

Are you implying that progress in F2A is over? A couple of geared prop setups (like free flight) would end stagnation and the ante is raised to over 200MPH.

Let's see it happen, and see if it causes problems to the pilots, before talking about longer lines there.

If you want a longer race course, there's always R/C Pylon racing.

edit:
It seems to be quite possible to fly an F2A plane over 200 mph on 17.69 m lines. I believe it just takes bypassing a couple of rules that are applied in normal contests.

dynasoar1948 · « **Reply #34 on:** April 22, 2011, 04:04:18 PM »

Please clarify, why was the line length increased in F2A the last time? Was it that traumatic?

Will Stewart (Flown an AMA B Electric at 140+ on 60 foot lines. You?)

PerttiMe · « **Reply #35 on:** April 23, 2011, 01:37:41 AM »

Quote from: dynasoar1948 on April 22, 2011, 04:04:18 PM

Please clarify, why was the line length increased in F2A the last time? Was it that traumatic?

I haven't got a clue why it was increased last time. Could be to slow it down with more line drag.

From what I see, your feared 200 mph F2A on the current line length is not a problem for that Hungarian guy. You?

Crist Rigotti · « **Reply #36 on:** April 23, 2011, 08:50:24 AM »

I thought this section of the forum was for electric stunt. See header that says "Electric Stunt". There are speed and racing sections. Or better yet have an electric section for speed and racing.

dynasoar1948 · « **Reply #37 on:** April 24, 2011, 07:32:05 PM »

Prettime,

Right or wrong it does not pay to rile an Admiral...Meet me at the Speed Talk section tomorrow and I'll respond to your rhetorical question, even though you didn't answer my serious one.

Dynasoar

Dennis Adamisin · « **Reply #38 on:** April 30, 2011, 08:48:12 PM »

Circling back to the original post:

THe RC Pylon folks have created the new EF-1 racing class. They are using 2820 class motors of around 1250 KV and 4S. They will also all use a standard APC 8x8 prop and turn around 14k. They have "promised" to keep the rules stable for at least the first 2 years while they figure out what they really have.

From our standpoint, a racing or speed event that used the SAME hardware as EF-1 should have a nice selection available to work with. It is probably a little heavy for a Combat wing, but I'm thinking if you put this power system should result in a 90 mph+ Flite Streak - and that would be a blast!

Oh yeah, I agree with Crist - I would like to see us expand the forums beyond the Electric Stunt: Sounds like there are some good things happening in electric Carrier, a few folks dabbling in Scale apps. and of course, a racing/speed section makes sense.

BillLee · « **Reply #39 on:** May 01, 2011, 04:12:05 AM »

Denny, the problem for CL Racing with the scenario you described is: racing is FAR MORE than just flying the model. It involves (among other things) pitstops. Other than the obvious tongue-in-cheek answers I have seen, how would you race an electric model? How would you add "at least a token amount of fuel" as the rules require?

RC Pylon racing is a neat event, but it will become a LOT neater when they add pitstops to it.

Regards,

Bill Lee

PerttiMe · « **Reply #40 on:** May 01, 2011, 04:51:54 AM »

Quote from: BillLee on May 01, 2011, 04:12:05 AM

how would you race an electric model? How would you add "at least a token amount of fuel" as the rules require?

Switch battery. Simple as that.

Dennis Adamisin · « **Reply #41 on:** May 01, 2011, 05:25:07 AM »

Quote from: BillLee on May 01, 2011, 04:12:05 AM

Denny, the problem for CL Racing with the scenario you described is: racing is FAR MORE than just flying the model. It involves (among other things) pitstops. Other than the obvious tongue-in-cheek answers I have seen, how would you race an electric model? How would you add "at least a token amount of fuel" as the rules require?

RC Pylon racing is a neat event, but it will become a LOT neater when they add pitstops to it.

Regards,

Bill Lee

Yup!

History has also shown that any event has a better chance of success when well defined equipment is available:
* Use available hardware (like the EF-1 stuff)
* Put borders on the power usage (like same prop & battery like the EF-1'ers)
* Pit & refuel. (instead of liquid fuel, change out the pack)

This is speculation - but I THINK an E-rat racer could goe roughly be 100mph, being something like a 1960's rat with a Fox Combat Special or K&B Series 61 (? the original front intake 35).

I would opt for something like a rat racer, but possibly a B-Team race (i.e., full fuslage) based even might be fun too...

BillLee · « **Reply #42 on:** May 01, 2011, 09:14:40 AM »

Quote from: PerttiMe on May 01, 2011, 04:51:54 AM

Switch battery. Simple as that.

I thought I was asking for a SERIOUS answer!

Edit to add: There is no real skill involved in this suggestion. There is in pitting an IC engine.

Electric CL Racing would likely become akin to RC Pylon: see who can fly a given number of laps from a standing start in the shortest amount of time. Eliminating pitstops removes a VERY significant component of racing, just as adding a hard/fast speed limit (that's another rant!).

Edit again to add: And what skill is there in flipping a switch when they say "Go!"? (Again, another element of CL racing that is absent from RC Pylon.)

No, electric racing is just too plain silly to contemplate.

PerttiMe · « **Reply #43 on:** May 01, 2011, 09:52:11 AM »

Quote from: BillLee on May 01, 2011, 09:14:40 AM

I thought I was asking for a SERIOUS answer!
...
Edit again to add: And what skill is there in flipping a switch when they say "Go!"? (Again, another element of CL racing that is absent from RC Pylon.)

Sadly, electrics don't require flipping the prop to get them started. The rest of it is mainly dexterity.

1) Catch it
2) Get the fueler where it needs to go, or get the battery off and another one on without fumbling too much
3) Get it running
4) Launch it

Control Line, or Model Aircraft in general, is a silly pastime. Why not allow people to try another variety of the silliness?

BillLee · « **Reply #44 on:** May 01, 2011, 11:35:51 AM »

Quote from: PerttiMe on May 01, 2011, 09:52:11 AM

Sadly, electrics don't require flipping the prop to get them started. The rest of it is mainly dexterity.

1) Catch it . turn off the switch
2) Get the fueler where it needs to go, or get the battery off and another one on without fumbling too much
3) Get it running i.e., turn on the switch
4) Launch it

Wow! Sounds exciting!

Control Line, or Model Aircraft in general, is a silly pastime. Why not allow people to try another variety of the silliness?

Have at it, nobody is stopping you. Just that calling it racing is nonsensical.

Ron Belcourt · « **Reply #45 on:** May 01, 2011, 01:14:45 PM »

Quote from: BillLee on May 01, 2011, 11:35:51 AM

Have at it, nobody is stopping you. Just that calling it racing is nonsensical.

Can't seem to double quote here. Anyways by my way of thinking the average pitstop (which seems to be the arguing point) for a IC job is about 5 sec if everything goes well and you're not using a pressure fueler, or equipment designed for serious racing. Changing out a battery takes at least that long so everything becomes a moot point. Also there will probably be things that an electric pitman has to worry about that an IC pitman doesn't-
1./ making sure the connectors are attached to the proper polarity (assuming that bullets are used as Deans can't handle as much current( or so I've been told))
2./ Getting the battery out of and into the plane without wrecking the structure; a holding system- be it Velcro or a positive holding system should be mandatory- personally I wouldn't trust a pocket in the wing to hold the battery in place when you're cathing the bird. 1 lb of battery at 20mph could hurt if it hit you wrong. With at least Velcro on the battery and a strap going fore to aft, the thing would stay where it belongs (assuming a profile racing class or external pack ) An internal fuse mount would be safer, But the swap out time would be excessive and not practical.
It doesn't seem like much, but for a quick stop It will slow you down- maybe not as much as a flooded engine but then again there are no rules that say everyone must stop until the balky engine starts running. That's just racing.
I do fly electric ( prefer diesel ), and I do pit when we have a race event here ( not too often anymore), so I can sort of see it from both sides. Electric isn't ness. plug and play- nor will it wipe out IC quickly as long as pitsops are mandated. You can carry a battery aloft that will go the distance however the plane will be too heavy to be competitive, +50 amp draw for an average race time would be a BIG and Heavy pack. If you mandated a positive restraining system then a swap out is no faster than a good pitstop.
Just my 2 cents.
Ron

BillLee · « **Reply #46 on:** May 01, 2011, 01:45:35 PM »

Hi, Ron;

No problem with what you described other than the fact that it would take little-to-zero skill to do it. And remember that a BIG part of a pitstop is restarting the engine. A lot more iffy than flipping a switch. And a big part of racing is getting a good setting and a reliable engine run. No skill to do that with electric, just flip the switch. Ho, hum.

You must also consider the initial start. Getting a good start is a skill that has to be learned. It takes reliable equipment that works right every time. And even the BEST pitman will blow one now and then. Not so with electric. Flip the switch. Go. Ho, hum!

The big problem as I see it is that electric power had definitely dumbed-down the events where it is being used. (That's not being totally fair: "Allow the competitor to concentrate on other aspects of the event." would be a better way of describing it.) I watched CL Scale at the NATs last summer, and all of the skill that it takes to make an IC set-up work reliably for their flight regime was simply thrown away. Flip the switch. Once or twice or ... for all the motors. Ho, hum. Let the electronics control the speed of the motors. Ho, hum. Flip a switch and kill all of the motors simultaneously. Ho, hum.

And how many times have I heard my PA friends expound on how much better it is since there is no longer the worry about engine runs and flight times and .... all of the skill has been taken out. "Just think! Now we can concentrate on FLYING!" Ho, hum.

If all we want to do is FLY the models: great! Electric is the way to go. But there are so many OTHER aspects that are lost.

O.k., guys, bring 'em on!

PerttiMe · « **Reply #47 on:** May 01, 2011, 02:32:12 PM »

Quote from: BillLee on May 01, 2011, 11:35:51 AM

1) Catch it . turn off the switch
2) Get the fueler where it needs to go, or get the battery off and another one on without fumbling too much
3) Get it running i.e., turn on the switch
4) Launch it

Wow! Sounds exciting!

Glad you like it.

Just less cleaning up to do afterwards. If you get it wrong, you might even manage to burn the aircraft, just like I've seen IC racers burned.

I believe a timer would handle the switching off. As far as I know, the pit man does not stop the engine of an IC racer either.

Ron Belcourt · « **Reply #48 on:** May 01, 2011, 05:00:09 PM »

Quote from: BillLee on May 01, 2011, 01:45:35 PM

Hi, Ron;

No problem with what you described other than the fact that it would take little-to-zero skill to do it. And remember that a BIG part of a pitstop is restarting the engine. A lot more iffy than flipping a switch. And a big part of racing is getting a good setting and a reliable engine run. No skill to do that with electric, just flip the switch. Ho, hum.

You must also consider the initial start. Getting a good start is a skill that has to be learned. It takes reliable equipment that works right every time. And even the BEST pitman will blow one now and then. Not so with electric. Flip the switch. Go. Ho, hum!

The big problem as I see it is that electric power had definitely dumbed-down the events where it is being used. (That's not being totally fair: "Allow the competitor to concentrate on other aspects of the event." would be a better way of describing it.) I watched CL Scale at the NATs last summer, and all of the skill that it takes to make an IC set-up work reliably for their flight regime was simply thrown away. Flip the switch. Once or twice or ... for all the motors. Ho, hum. Let the electronics control the speed of the motors. Ho, hum. Flip a switch and kill all of the motors simultaneously. Ho, hum.

And how many times have I heard my PA friends expound on how much better it is since there is no longer the worry about engine runs and flight times and .... all of the skill has been taken out. "Just think! Now we can concentrate on FLYING!" Ho, hum.

If all we want to do is FLY the models: great! Electric is the way to go. But there are so many OTHER aspects that are lost.

O.k., guys, bring 'em on!

Howdy, I almost agree with everything you said. However because this is out of the norm, there is a large learning curve involved. I can't take any airframe and stuff an electric powersource straight into it and be competitive. Too heavy for acceleration and then , once again the batteries get too big. As for flip the switch and away you go.... well some of the best racing I've witnessed it was exactly like that. I was amazed at what the Ryans could do. But then again that is alot of practice and being familiar with the equipment.
No matter how familiar you are though things do go wrong. Motor eats a plug, hole in the fuel line, etc. Same as Electric- put in the wrong battery, speed control dies (gone through two now, so it does happen even with good equipment) and so forth. I understand people "griping" about Elec. will make IC obsolete for much less money invested, but I can't see it. Run cheaply made stuff and poof. Even the good stuff might be run closer to it's max limit, if you want a competitive plane. Magnet out the case- there goes a big part of the system and it would be hard to change mid-race. Personally I think the advantages and disadvantages would be equal between the two.
I haven't seen an electric yet that would up to max throttle instantaneously when you flick the switch, so they have to wait a half second ( or more ) before launch. Races have been lost by less than that amount. Pilots then become a larger part of the picture- if they can't fly smooth and are reactive as opposed to active, you lose. By that I mean you might use more amps and end up coming down early needing an extra pit.
I still think that IC is the way to go for serious racing ( read that as experienced ), but for a relative beginner or sport flyer Elec. is a way in. Like anything if the activity is enjoyed and they get a "buzz" out of it, they will look for a more competitive equipment.
Later,
Ron