rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 351 ONLINE 20 EVENTS SEARCH REGISTER  START HERE
 
2 pages [ <<    <     1     ( 2 )    >    >> ]1981 viewsPOST REPLY
Model Rectifier Corp . Heli Wholesaler . 3D Heli Depot

.
.
HIROBO Freya - Sceadu - Shuttle > just bought evo 50 swm
 
 
DS 8717
rrProfessor
Location: Here wishing i was somewhere else

We have Evo's both the SWM and HPM and it's the census that the SWM flys much better. They both have 9252 servo's,and after back to back flying everyone agrees the SWM is much better. It's faster on both cyclic and collective. We didnt think there was that much difference untill we did the back to back test. DOUG
05-11-2006 Over year old.
 
 
Andi G
Veteran
Location: Switzerland

Which MHW issue is that? I'm thinking about another Evo but the MHW is hard to get around here
05-12-2006 Over year old.
 
 
davehour
Key Veteran
Location: Guayama, Puerto Rico

Hi:

I've converted my Evo 50 and Evo 90 to SWM. The conversions have made both helis faster on collective and cyclics. The difference found in the Evo 50 was greater than in the Evo 90, but the Evo 90 does 3D much better with the SWM mechanism. In order to had a fair comparison between both mechanisms, I tested and used both using the same amount of cyclics and collective travel.

David
05-12-2006 Over year old.
 
 
davehour
Key Veteran
Location: Guayama, Puerto Rico

Quote 
If anyone out there wants to learn about the benefits and short comeings of CCPM than I would suggest going out and buying the Model Helicopter World issue in which James Wang compares a Conventional Mix EVO and a CCPM evo. I think its important to realize that either system is a series of compromises... you just need to decide which compromises suit your flying style and even your mindset.. because the differances in flight performance are so minute that if anyone of us had a double blind test with CCPM and mechanical mix EVO back to back I think almost noone could tell the differance in flight if both were set up well with fast high torque servos. The


I would like to give my point of view about other's experiences, even mine. I've learned that having others say "no difference found" is relative to the person, the flying, and what he likes. There have been many instances where I didn't do or used something because someone else said it wasn't worth it, just to find later it really is. I don't mean we shouldn't take in consideration other's opinion, but it's important we raise our own way of being and give credit to ourselves as testers.

And as far as I know, Mr. James Wang, a very knowledgable and repectful pilot and designer, isn't the kind of hard 3D pilot who can put both mechanism to a real flying test.

David
05-12-2006 Over year old.
 
 
hootowl
Elite Veteran
Location: Garnet Valley, Pa.

Does the swash move the same speed up and down the main shaft in both configuations? Is servo torque high and enough to overcome loads. If so there will be NO flight differences. If your servos are of the high torque variety it is unlikely the three servo -vs- single servo collective, effects acceleration of the swash. Acceleration and speed of collective being the same, there should be NO flight differences.

Aileron and elevator.... heck you don't really have an advantage servo wise either way as I see it. Again based on the latest digital high torque servos I would bet speed and acceleration would be comparible.

Probably comes down to geometry of the control systems and interaction.

One interesting phenomena sp? is if you turned this around and started with eCCPM.... then came out with conventional mCCPM... people would convert to it, test it... and because of natural human tendancies... truly feel and believe mCCPM flew better even if technically the swash speed and accellerations on both ships were the same.

All of what I am saying is based on assumptions that speed and acceleration of the swash in all directions is the same.

Linkage slop is probably the biggest difference between the two.

Member Bog Troll Club #1
05-12-2006 Over year old.
HOMEPAGE  
 
 
DS 8717
rrProfessor
Location: Here wishing i was somewhere else

Quote 
Does the swash move the same speed up and down the main shaft in both configuations? Is servo torque high and enough to overcome loads. If so there will be NO flight differences.

Well evidently they dont,because our testing shows a difference.
05-12-2006 Over year old.
 
 
hootowl
Elite Veteran
Location: Garnet Valley, Pa.

Did you measure swash speed and accelleration?

Member Bog Troll Club #1
05-12-2006 Over year old.
HOMEPAGE  
 
 
DS 8717
rrProfessor
Location: Here wishing i was somewhere else

Can,t do that without a load on the blades,but actual flight testing shows a difference. everybody at our field has converted to SWM.
05-12-2006 Over year old.
 
 
davehour
Key Veteran
Location: Guayama, Puerto Rico

Quote 
Does the swash move the same speed up and down the main shaft in both configuations? Is servo torque high and enough to overcome loads. If so there will be NO flight differences. If your servos are of the high torque variety it is unlikely the three servo -vs- single servo collective, effects acceleration of the swash. Acceleration and speed of collective being the same, there should be NO flight differences


Of course there is a flight difference.

Servos? What about the Airtronics 758's with the Arizona Regulator and Peerless Lion pack? Yeah, talk about poor electrical gear . And as I said, I'm not taking both system differently because I did use the same gear and travel on both to make a direct comparison. The result: There was a difference.

I wasn't trying to go and get the best gear, trying to make one mechanism work the same as the other. Just the facts. They fly different, being SWM better for hard 3D.

David
05-12-2006 Over year old.
 
 
Dr Lodge
Elite Veteran
Location: Guildford, Surrey - UK

davehour has a good points, performance is all relative to the person, they're flying and preferences. I'm not a stick banger and don't need the fastest cyclic movements. A 9350/9351 on 6 volts is fast enough for me and what I do.

Vibe 90, Vibe 50, Vigor CS x2,
Dyna-x, Knight 503D, Logo 10,
Trex 500, Mini Titan, Gaui EP200
05-12-2006 Over year old.
 
 
hootowl
Elite Veteran
Location: Garnet Valley, Pa.

I'm just stabbing at this from a pure technical point of view. It's all about linkage slop, differences in swash speed an accelleration under load and kinematics (dynamic design).

To make what I'm sayng a little more simple I try to look at it at the swash. Do both swashes react the same.

There are concrete technical answers to these questions that can be answered with real engineering testing using load meters, potentiometers and other guaging.

Seat of the pants I do not argue that eCCPM most likely wins out because of the one link connection mostly.

Mike

Member Bog Troll Club #1
05-12-2006 Over year old.
HOMEPAGE  
 
 
DS 8717
rrProfessor
Location: Here wishing i was somewhere else

Quote 
davehour has a good points, performance is all relative to the person, they're flying and preferences. I'm not a stick banger and don't need the fastest cyclic movements. A 9350/9351 on 6 volts is fast enough for me and what I do.

Same person,same prefernce and same conclusuion,the SWM is faster by actual flight testing. You would need a 270 oz servo in HPM to equal 3 90oz servo's in SWM. However you get that torque be it battery power or just a killer servo.DOUG
05-12-2006 Over year old.
 
 
IYKIST
Veteran
Location: London united kingdom

Quote 
Which MHW issue is that? I'm thinking about another Evo but the MHW is hard to get around here
April 2006
05-12-2006 Over year old.
HOMEPAGE  
 
 
Donkey
Senior Heliman
Location: Punta Gorda, FL

I am going to make this short and sweet.
No the swash does not move at the same speed.
The servos use a lower portion of thier throw to develope the smae movement of the swash. Does this reduce torque? Yes but you are now sharing the load betweeen three servos so it works out about the same.

Donkey you have the right to remain silent what you lack is the capability
05-12-2006 Over year old.
 
 
raptorheli2
Elite Veteran
Location: rip off britain and no changing it

wow!

i didn't want to start a war. lol

anyway, the reason i wanted to get away from the raptor is i wanted ccpm, so, i was never going to buy the normal evo 50.

to answer a question in response to mine about top brands being ccpm. show me the last major comp that was won with a mechanical machine.

cheers


www.waterfoothelis.com
05-12-2006 Over year old.
HOMEPAGE  
 
 
davehour
Key Veteran
Location: Guayama, Puerto Rico

This is not a war but a discussion. Aren't we in a discussion forum?

Theory vs. real life testing, oh well....lot of things and lot of points of view. When I see our debate, I do remember the case of the 50 size helis ratio being used for the engine. According to the numbers, current ratio and headspeeds used by pilots aren't supposed to work, but in fact, what the pilots are using work, and if you use the theoretical numbers, they won't work as well.

David
05-13-2006 Over year old.
 
 
hootowl
Elite Veteran
Location: Garnet Valley, Pa.

They are all CCPM

Collective Cyclic Pitch Mixing

All full collective machines do the above.

It's how well the two differnt CCPM designs do it is what we are discussing.

eCCPM is three or four servos directly connected to the swash and controlled by computer radio. e = electrical

mCCPM is Raptor and HPM EVO m = mechanical

I'm confident the people who slap these helis around hard know the difference in flight characteristics and I'm sure eCCPM is snappier, mainly do to direct connection to the swash with less mechanical slop.

Member Bog Troll Club #1
05-13-2006 Over year old.
HOMEPAGE  
 
 
raptorheli2
Elite Veteran
Location: rip off britain and no changing it

once i have my heli built i can maybe answer the questions myself as to what i think will be quicker. (but i'd bet the swm will be)

however, the mechanical evo is much snappier on collective than my raptor, i'm not sure why as the servos are about the same and i have all the bling bits so the slop is as little as it's going to be on a raptor. i guess it's just down to slop.

cheers


www.waterfoothelis.com
05-13-2006 Over year old.
HOMEPAGE  
 
 
Dr Lodge
Elite Veteran
Location: Guildford, Surrey - UK

I've seen a raptor 60 with slop in the collective linkage, nothing to do with the servo, but the design of the arms - they bend. Crappie design I'd say, another reason why I fly a Sceadu EVO (HPM of course )

Vibe 90, Vibe 50, Vigor CS x2,
Dyna-x, Knight 503D, Logo 10,
Trex 500, Mini Titan, Gaui EP200
05-13-2006 Over year old.
 
 
Donkey
Senior Heliman
Location: Punta Gorda, FL

Just so everbody is clear the SWM EVO is not a TREX. The servos do not hook directly to the swash. They still have a bell crank. There is one less bell crank on the fore/aft & L/R cyclic and basically the same on the collective.

Donkey you have the right to remain silent what you lack is the capability
05-13-2006 Over year old.
 
 
2 pages [ <<    <     1     ( 2 )    >    >> ]1981 viewsPOST REPLY
JR-Spektrum . Gyro Hobbies . E-flite

.
.
HIROBO Freya - Sceadu - Shuttle > just bought evo 50 swm
 PRINT TOPIC Advertisers 

Subscribe to This Topic

Sunday, November 23 - 12:08 pm - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie