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Oct 29, 2012, 10:47 AM
Proud of Brushless Sprouts
Commander Clumsy's Avatar
Quote:
Originally Posted by mopar_man
You canard lovers will be disappointed with the plans. The canard isn't on there. Having flown both versions extensively, I think that the standard tail is much more predictable and easier to set up. Of course, it can be done. But, I thought there were just too many variables involved with the canard (on an already unusual plane) to expect success across a wide range of builders. It bumps the required experience level up several notches.

That being said, I'll provide my canard details to RCG folks who ask.

Terry
I understand the difficulty of adding a canard (now), but is there any chance for further development of a canard version based on the plans?
Maybe even call it Parallax 2?
You know we would love it.
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Oct 29, 2012, 08:46 PM
Terry Dunn
mopar_man's Avatar
Thread OP
Quote:
Originally Posted by Commander Clumsy
I understand the difficulty of adding a canard (now), but is there any chance for further development of a canard version based on the plans?
Maybe even call it Parallax 2?
You know we would love it.
I wouldn't say there's much too much development required. It's just a matter of providing the data for those who want to take on the added complexity. Then again, maybe someone out there will want to invest the time to "perfect" the canard version so there are no concessions compared to the plans version.

Honestly speaking, I doubt that guy will be me. My intent was to prove the concept was feasible. With that accomplished, I'll be ready for a new (different) challenge soon.

Terry
Nov 06, 2012, 01:13 PM
Proud of Brushless Sprouts
Commander Clumsy's Avatar
OK, thanks. I think people more capable than me in aircraft design will have to handle this.

Any info about a release date for the plans/article? What magazine again? (I read it somewhere but forgot, sorry)
Nov 06, 2012, 09:25 PM
Ken's CAD Models
dz1sfb's Avatar
Terry,
Is it the intention that the article for Model Aviation will contain the design principles that you used to arrive at this creation? If not, will you share them here prior to release of the plans?

Ken
Nov 06, 2012, 10:18 PM
Terry Dunn
mopar_man's Avatar
Thread OP
Quote:
Originally Posted by dz1sfb
Terry,
Is it the intention that the article for Model Aviation will contain the design principles...
To explain all of it would probably be too in-depth for a print article. I'm still working on it. But with the scope of what I have planned, I think most tinkerers will walk away with the nuggets they need to design their own asymmetric creation. However, I can give you the 3 basic tenets right here.

1. Find the centerline of the airplane by determining the point at which there is equal wing area to the right and left (not counting any area obscured by the fuselage, a pod, or whatever). No matter what, the lateral balance point must be here (with reasonable tolerance).

2. Having the motor offset to the left of the aircraft centerline is okay. In moderation, it acts the same as right thrust. Offset to the right is also okay as long as you use a reverse rotation prop.

3. Dont worry too much about drag from unevenly distributed frontal area. In the case of the Parallax, the drag from the pod on the right is not significant and can be ignored. If your pod gets too far outbound or too draggy, I suspect that you'll begin to see effects.

In other news, I've got a doubled up sheet of MPF drying in the garage. I brushed minwax polyurethane on both parts, stuck the wet sides together and sandwiched it between two mirrors to keep it flat. I wonder how long it will take to dry like that. When it's done, I'll try a Parallax build with it.

Terry
Nov 06, 2012, 10:23 PM
Terry Dunn
mopar_man's Avatar
Thread OP
Quote:
Originally Posted by Commander Clumsy
OK, thanks. I think people more capable than me in aircraft design will have to handle this.
My buddy Fitz claims to have improved his canard Parallax by giving the full flying canard a KFm airfoil. I haven't seen it yet, but maybe I can get him to chime in here. It was previously just a flat plate canard, as is my prototype.

Quote:
Originally Posted by Commander Clumsy
Any info about a release date for the plans/article? What magazine again? (I read it somewhere but forgot, sorry)
As Ken noted, I have a handshake agreement with Model Aviation. But of course that is contingent on them liking the final product. I've done a few gigs with them, so I'm not very concerned. As for timing, you just never know. Right now, the ball is in my court to finish the article. Then it's up to them.

Terry
Nov 07, 2012, 05:22 AM
Ken's CAD Models
dz1sfb's Avatar
Terry,

Thank you for sharing! I would like to try one of these out if for no other reason than the novelty of it. I really like the engineering challenge that it presents.

Ken

Quote:
Originally Posted by mopar_man
To explain all of it would probably be too in-depth for a print article. I'm still working on it. But with the scope of what I have planned, I think most tinkerers will walk away with the nuggets they need to design their own asymmetric creation. However, I can give you the 3 basic tenets right here.

1. Find the centerline of the airplane by determining the point at which there is equal wing area to the right and left (not counting any area obscured by the fuselage, a pod, or whatever). No matter what, the lateral balance point must be here (with reasonable tolerance).

2. Having the motor offset to the left of the aircraft centerline is okay. In moderation, it acts the same as right thrust. Offset to the right is also okay as long as you use a reverse rotation prop.

3. Dont worry too much about drag from unevenly distributed frontal area. In the case of the Parallax, the drag from the pod on the right is not significant and can be ignored. If your pod gets too far outbound or too draggy, I suspect that you'll begin to see effects.

In other news, I've got a doubled up sheet of MPF drying in the garage. I brushed minwax polyurethane on both parts, stuck the wet sides together and sandwiched it between two mirrors to keep it flat. I wonder how long it will take to dry like that. When it's done, I'll try a Parallax build with it.

Terry
Nov 08, 2012, 11:56 AM
redwhskers
redwhskers's Avatar
Terry

I hope that I'm not steping on your foot, I have draw plans for a PLF Parallax. I will post it now let me know if it should stay. I can post a PDF file tonight with your OK.


RW
Last edited by redwhskers; Nov 08, 2012 at 01:58 PM.
Nov 08, 2012, 01:11 PM
Terry Dunn
mopar_man's Avatar
Thread OP
Quote:
Originally Posted by redwhskers
Terry
I hope that I'm not steping on your foot.
I don't think so. In fact it's flattering to think that my work has inspired similar efforts.

But I do a a couple of questions/observations:
1. Have you figured out where the lateral centerline is? With the profile fuselage and pod, there is quite a bit more effective wing area...relatively speaking. This must be accounted for to get the lateral balance correct and also the positioning of the motor.

2. Same question as above, but regarding CG.

Have you built one of these yet? With a more conventional design, I think you could sketch up some general dimensions and be confident of a successful model. In the case of the Parallax, the lateral balance, CG, and motor location are closely interdependent and crucial to airworthiness. Personally, I would hesitate to post plans for this design unless I had vetted the proportions with a flying example.

I don't intend to sound discouraging...my attitude is quite the opposite. I want to share the aspects of this design that are not intuitive...and thus help others be successful with asymmetric projects.

Terry
Nov 08, 2012, 01:58 PM
redwhskers
redwhskers's Avatar
Terry

Sorry I will pull the plan, because I Draw for the aesthetics and do my CG and balance as I build the Plane. I have found that this all depends on what equipment you are putting in aircraft and building PLF you have a lot of freedom to place the gear. So my plan are more of a guide and then let the individual do there own thing.

Sorry
RW
Last edited by redwhskers; Nov 09, 2012 at 12:50 PM.
Nov 08, 2012, 02:09 PM
Terry Dunn
mopar_man's Avatar
Thread OP
Quote:
Originally Posted by redwhskers
Sorry I will pull the plan
RW
No need to apologize...really. There's just some more details to be ironed out. Your design approach sounds similar to mine in most cases. It just may not be applicable here because of the nuances of asymmetry. If I get a spare minute I'll try to find the centerline of your version (the 1st step).

Terry
Nov 08, 2012, 02:34 PM
redwhskers
redwhskers's Avatar
Quote:
Originally Posted by mopar_man
No need to apologize...really. There's just some more details to be ironed out. Your design approach sounds similar to mine in most cases. It just may not be applicable here because of the nuances of asymmetry. If I get a spare minute I'll try to find the centerline of your version (the 1st step).

Terry
I removed it, do you wont me to repost. Will do gladly. I like to see how different builders interpret my drawings.
Thanks Terry

RW
Nov 08, 2012, 04:08 PM
Terry Dunn
mopar_man's Avatar
Thread OP
It doesn't really matter to me whether it's posted or not. It's your drawing, so do whatever you feel is appropriate, knowing that it may or may not represent an airworthy design. In the mean time, I'm happy to lend the benefit of my experience to help determine if tweaks are needed. I just don't know when I'll be able to find the time to look in more detail...hopefully soon.

Terry
Nov 08, 2012, 05:45 PM
Ken's CAD Models
dz1sfb's Avatar
RW,
I believe your KFm2 panel would benefit if you set it up at 50% of chord for the entire wing.

Ken
Nov 08, 2012, 06:17 PM
Terry Dunn
mopar_man's Avatar
Thread OP
After all my warnings of not vetting the dimensions, it looks like you nailed it. According to my rough calculations, the centerline is somewhere close to the inboard edge of the fuselage...which should work just fine.

I'm still uncertain what effect the horizontal profile of the fuselage behind the wing will play. But I'm confident enough that I would press forward with a build based on this drawing.

Well done.
Terry


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