emspilot

What's the fastest ship out there?

Don

cobratraxxas69

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I'd say it's one of the F3D-class pylon racing planes (with one of those raging Nelson motors)....200+ MPH



http://www.resume-connection.com/f3d...H_RCPlane.mpeg


Next up would be QM-40 (Quarter Midget-40) which comes out at 180+ MPH

Then in the Sport plane class would be our Diamond Dusts and Weston Magnums with Jett or West motors (140-150 MPH)

crasharama

I would say the guys running in the top few of the German Speed Cup would be the fastest in a straight line. Slowmo777 can tell you what airframe/ engine combos they use, but from what you see on here there are alot of home grown designs, cards held close to their chest[sm=surprised.gif]

Then a well set up F3d such as a BBR Evolution, & MB Profi engine like in the photo.

Then the QM40's, & some of the DD's & stuff we play with.

If you really want to go fast you don't need an engine at all. The dynamic soaring guys make our stuff look decidedly boring, with speeds much closer to 300mph. Just need the perfect hill & right weather conditions...[sm=spinnyeyes.gif]

slowmo777

Hello,

the 250 mph "barrier" has already been broken using a glow powered prop plane. That took place in the 90s here in Germany within the objective 150 meters speed trap eliminating wind impact. That is inofficial world speed record. During the next German Speed Cup there will be similar straight horizontal line speeds.

You need a:

- well designed purpose built speed plane (full composite highly recommended)

- a super hot RIRE or FIRE speed engine (fully enclosed engine + pipe)

- the right sized carbon fibre speed prop

http://www.rcuniverse.com/forum/m_37...tm.htm#3740991

Regards

slomo



P.S. What do you think, which setup will be faster: the MB 40 driven or the .60 to .90 DF driven speed planes?

[8D]

KD5NOI

My dad had a RCM Magnum 40 that would go 200 MPH plus back in the 80's as clocked by police radar. i might build me one of those one day and probably put my thunder tiger Pro 46 in it.

soarrich

My Feedback: (98)

crasharama

You won't get very fast DSing the way you show, it's the other way around, with the wind up high, coming back in the dead zone low. I've seen videos of 262 mph.[8D][sm=spinnyeyes.gif]

TheTick

301mph is the record for DS. the video is here http://slopeaddiction.com/thekids.html

crasharama

Hi Soarrich,
I thought that is how it was flown, but found a picture on some site last night & used it to explain what I was on about[:@]

The photo would make more sense if the hill was see through, & the wind is coming up the back side of the hill & spilling over the top.

Slomo,
From you club website the largest engine catagory is 6.5cc ? The Michael Jakob aircraft appears to be a modified F3d airframe am I correct?

My guess, & it is only a guess is that the MB 40 with the correct set up prop for staight line speed, would be quicker than the ducted fan engined aircraft. The MB's sound like they are at the top of their rev range with pylon props at around the 320-340kmh mark, but a different set up would probably give them some more top end.

Tony.

slowmo777

Hello crasharama,

well there are three speed classes to compete within the German Speed Cup:

class 1: -3.5 cc
class 2: 3.51 to 6.6 cc
class 3: 6.61 to 15.00 cc including electric powered speed planes

As you already mentioned, speeds of regular F3D pylon planes are well known. They will not play an important role for the first places (because of their too fat airframes and the “wrong” prop setup for pure speed).

I think the “real” winner will be the person achieving the best ratio between available Horse Power and terminal Speed (considering that you need x times the HP to double speed using the same airframe).

For instance, take a small speed plane powered by a hot 2.5 cc engine reaching true 200 mph. That makes about 2 HP for impressive 200 mph. Aerodynamics rules here!

On the other hand a BVM .91 does offer about 6 HP enabling speeds of 250 mph (yes, true 250 mph have already been reached using “only” 9.9 cc using the “Kaiser” speed plane. Mr. Kaiser was the designer and pilot 17 years ago).

That “Kaiser” model is the same airframe M. Jakob and many other participants will use this year. It is definitely time to come up with several new speed plane designs. Everyone uses that more or less identical and almost 20 years old airframe now – boring!






Crasharama, although the Dutch MB 40 represents the technical pinnacle of model speed engine technology (35 K rpm in flight), why do several German speed freaks doubt that the MB driven pilots will be faster than their 15 cc combatants? Hint – let’s not ignore the relationship between available torque versus HP and their distribution by rpm. Think also about the practicable prop size solutions...





BTW, everything above 10.00 cc of engine capacity is not allowed for an official FAI world speed record attempt. Also the FAI stipulates that the wing load must not exceed 75 grams/dm². So the “real” challenge is the wing load IMHO.

Regards

slomo

PS. What I personally would like to see in the future is somebody from abroad using his highly modified Diamond Dust or Wiplash (fully cowled engine + pipe) to compete within the objective 150 m speed trap of the German Speed Cup. I bet there will be some surprise…

crasharama

Hi Slowmo,
My German is fairly broken, can kind of understand what they are on about, but can't talk it at all

I am lucky to be in the same model club as the #1 F3d team in the world, Chris & Kev Callow, & possibly best F3d airframe designer as well in Bruce de Chastel. So watching fast & low is becoming common place every weekend.

I ask alot of questions & am learning all the time. Kev helped set my racer up & called for me in my 1st day of racing which was a real buzz. All I could think was holy cr*p, not everyone has a world champ help them in their 1st day of racing

Anyway,

I can understand that swept volume, available torque, & ability of swinging a bigger prop will give a quicker top end. So an airframe like the Evo T, minus the pregnant guppy bulge under the wing, & no canopy bulge, with a 90 size DF engine shoe horned in, should be quicker than the standard 40 size F3d style airframe. It all has to do with gearing. ..

My guess is this is what Mr "King"has designed 20 yrs ago....

As far as a DD with enclosed engine & pipe, would it be as fast as a standard airframe, given that the relative slow speeds that we fly at ?. The delta really isn't in it 's speed zone, unless we start to push past Mach 1.2 !!!!

When we do, I will make sure I am there every year[:-]

Tony.

p.s This picture is Chris Graham's Evo T

slowmo777

So you want to try exactly that in future?

Well, Mr. "King" and most other speed freaks did another approach. They took their 10 cc engine + pipe and designed a fuselage around them - skin-tight. Also the moments (lever) between wing and stab as well as the fuse length to wing span ratio is considerable different from F3D pylon planes - no hot turning abilities required here. In fact they're completely different layouts. And the wing airfoils of purpose built speed planes are characterised by a neutral momentum - optimised for straight line speed.

… everything you ever wanted to know about prop driven deltas [sm=spinnyeyes.gif]

http://www.rcuniverse.com/forum/m_38...2CDELTA/tm.htm

Regards

slomo

cobratraxxas69

My Feedback: (31)

slowmo,

Is there a web-site for the MB Profi (is it also called the MB Profi 40). I was googling it and couldn't find anything. Where are they sold?

Can one buy a "Kaiser" airframe, if so where?

slowmo777

Hello cobratraxxas69,

so far the MB 40 site was located here:

http://home.kabelfoon.nl/~fiorimet/Index.htm

Currently their homepage seems to be down. Rob Metkemeijer himself does sell his engines.

Well that Kaiser model is not available commercially as well as good CF speed props (not talking about CF pylon props here). But you can noticeably improve that old design, believe me. From todays standpoint it does not provide the most efficient airfoil for instance. The fuse shape also can be improved. And last not least it is the wing layout being highly improvable.



So I’d say: Design your own fuselage! That will be a fantastic next winters project.




Why? During the past few month I recognised almost no advance in terms of home made speed designs here in this forum - after all it is called Extreme Speed Prop Planes. [sm=confused.gif]



I may be wrong, but I believe maybe 50% of the US nitro speed freaks want to break the 200 mph barrier. Why do they still keep up buying the commercially available kits such like Whiplash, DD, Magum R etc which will never enable true 200 mph (true = without wind impact). Or in other words: Why does nobody compete during the German Speed Cup using these kits?

So for at least 220 mph all you need is either a new

.60 to .90 ducted fan engine and a non-muffled tuned pipe (about EUROS 200 to 500)
or the MB 40 Profi w/ stock pipe (about EUROS 500)

http://www.rcuniverse.com/forum/m_38...tm.htm#3811478

Then take the silhouette/outline of that engine/pipe compartment and draw the cowl, plus leave some space for a custom tank for 250 ml of fuel being enough for 2 minutes of flight time. No throttle recommended, but you need a fuel shut off device for safety reasons.

And of course you need a home made speed prop made from carbon fiber (that’s one major problem for the average Joe, most serious speed freaks do not give away their “record props” to a third party). Prop design is very tricky.

For more details, just take a look at Combatpiggs ambitious project. That’s a sophisticated way to go faster than any other glow powered speed plane design here on RCU. All he now needs is a MB .40 engine to come close to 240 mph (with the right designed prop).

http://www.rcuniverse.com/forum/m_23...key_Hey/tm.htm

So you already can find all the “ingredients“ and tips here on RCU - to go super fast. [sm=thumbup.gif]

Regards

slomo

HaveBlue

you should see what I've got on my building table at the moment ...you might get your wish..both DD and Whiplash!!!!..will post pic of my modified diamond dust in a week or two should be finished by then...

slowmo777

Fuse length is 125 cm.

You don’t need more info, don’t you?

As for the design, don’t make a simple knock-off cause there’s definitely room for aerodynamic improvement. [sm=cool.gif] Be creative!

Cyclic Hardover

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MINE!

Cyclic Hardover

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That looks like the same OPS 60 I have NIB that I may put in a Diamond Dust. Carb barrel opens sideways.

emspilot

Slowmo-

Incredible wealth of information you provide! I'm new to this forum, and newly returned to the hobby after a 20 year absence. Since 1986, the glue has changed, the type of planes have changed (all ARF's now, very few kits), the internet/exchange of information has just exploded, the radios have computers, the freqs are different, 3D, foamies, electric, CA, composites, park flyers, ready-to-fly, made in China, and CNN Headline News!!!

So I built a Top Flite Contender, powered with a Super Tigre G90. It's good to be back!

Don

emspilot

Cyclic Hardover-

I'm also a retired Army Pilot. Don't tell my Mom, she thought I was in the circus for 20 years (which is kinda the truth!).

Flew the UH60. Flew in the Gulf for a while (Air Logistics), now with an airline flying CRJ's, and part time EMS in a BK117.

got a Contender, a cub, a Dual Ace, and a trainer for the kids.

Cyclic Hardover

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I was in from 75-95. Huey's (Medevac) and Cobras. R/C is the only flying I do now. Funny thing is 10 years with R/C and I don't do R/C Helicopters. I have a couple but still mess with them on a simulator. If you think control reversal was fun on a plane, try it on a helicopter. The good thing with you and I is we don't need to understand the concept of it, just practice.

Glorfindel

Where can i get this Evo-T airplane? Is it comercialy available???


This winter i will trying to do my own design. I will need input from you guys. I have CNC mill to make the plug. I have CatiaV5 to do the 3d model and i have Fluent/FlowWizard to do the CFD. I want to built it around the 'new' JeTT 60 Fire engine. Maybe i can sell some kit with very little to non-profit. We can do a 'lets built a fast plane ' Part 2 with more sofisticated software and hardware

I never made any mold, that will be fisrt time for me.

RANIERY

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go to bigbruceracing.com and look for FAI planes