Bubbles Build Thread
03-28-13, 10:50 PM
#1026
Literally just read this whole thread throughout my boring classes today and dinner and all I can say is WOW!! Benny this build is insane and sheesh I'm glad I have someone that can do crazy fabrication and builds like this in the amount of time you do it in. I definitely plan on taking a visit up North this summer when i get my rex. BTW best of luck with that wing I built a miniature version of one back in high school for some engineering class i was taking at the time.
03-28-13, 10:53 PM
#1028
Any CFD analysis done after you modified the shape? Changing the shape of an engineered profile just a little bit significantly affects the performance of the aerofoil.
Again, Tom is right on here... it is possible to create too much downforce/drag. Have you done load testing on your composites? What process are you using? vacuum infusion? curing in an autoclave? what about a core material?
Honestly I would not want to be driving behind you on the highway if this has not been thoroughly engineered with a large factor of safety built in. What could happen, is that by modifying the aerofoil shape without any legitimate design process then it could create a significant amount of downforce AND drag resulting in a very high load on the mounting points resulting in failure.
For what its worth, I am a mechanical engineer. I have taken an aerodynamics class back in school and MANY fluid dynamics classes...
For what its worth, I am a mechanical engineer. I have taken an aerodynamics class back in school and MANY fluid dynamics classes...
03-28-13, 10:57 PM
#1029
Literally just read this whole thread throughout my boring classes today and dinner and all I can say is WOW!! Benny this build is insane and sheesh I'm glad I have someone that can do crazy fabrication and builds like this in the amount of time you do it in. I definitely plan on taking a visit up North this summer when i get my rex. BTW best of luck with that wing I built a miniature version of one back in high school for some engineering class i was taking at the time.
im done with this wing, spoiler, airfoil discussion on hypothetical and assumptions
03-28-13, 11:35 PM
#1031
Failcopter..it's here..
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lol seriously, if he wants to try his hand at building a spoiler, fenders,hood, shift ****..etc let him do it. i'm pretty positive when he puts it on and drives with it.. he's not going to flip over, roll 6 times crash in to your beautiful fd and explode causing everyone in DGRR to be arrested for being guilty by association. chill out. he mention about 16 times that it hasn't been tested. wait till its finished..and even then.. shut up. there is a difference between constructive criticism and well, being a douche about things. stop being a stick in the mud and be patient. definitely a cool build Benny, looking forward to seeing wind tunnel testing, lots of track testing, proof of appropriate curvature that is approved by someone of high status..somewhere.
PS: I'm pretty sure you ruined the FD aerodynamics, power to weight, and classic look.. geez no respect.
PS: I'm pretty sure you ruined the FD aerodynamics, power to weight, and classic look.. geez no respect.
03-29-13, 12:22 AM
#1032
and that was an APR wing. At least be aware of the consequences of failed aerodynamic parts at high speeds.
Good, i wouldnt want you driving behind me either. you're clearly being a wiseass because you know i didnt test it. I pointed out various times i have no tested it and dont know how it will perform. its based off a legitimate design, TWEAKING that design will not be the end of the world. I'm not an idiot, its either going to perform good or ok. Its not going to be the end of the world. the likely hood of the spoiler breaking is slim to none. brackets? maybe, but neither you or I have seen how that will be made so what are you making assessments on? ohhh a design you have not seen nor tested either.
03-29-13, 01:45 AM
#1033
Come on guys let's be a little more respectable to fellow forum members here. There is a learning curve when designing anything engineering related when you have no background in it. Like Gordon stated, you have to start somewhere. I recall some of you "designing" some LED tail-lamps that couldn't be seen during the day and could also cause serious accidents. So, take a step back and realize you started from knowing nothing too.
JhnRx7, when you came in here asking him to "share some of the calculations" it came off as very rude. Obviously, the guy is working out of his garage. As a mechanical engineer I would assume you're smart enough to know that's not what he meant and you were just trying to be a dick.
JhnRx7, when you came in here asking him to "share some of the calculations" it came off as very rude. Obviously, the guy is working out of his garage. As a mechanical engineer I would assume you're smart enough to know that's not what he meant and you were just trying to be a dick.
03-29-13, 07:16 AM
#1035
Oh god...the amount of ridiculousness that has gone on since my last post.
So now we have FDmuri calling me a "douche", gmonsen coming up with conspiracies, and blackade trying to compare apples & oranges - all because I was giving feedback and trying to figure out his intentions for trying to make a wing...
It's no wonder traffic on this forum has dropped off.
Everyone is free to go back and read my original post on the previous page. I didn't come into this thread to flame him or "talk ****" or say it couldn't be done. I started out by sharing information relative to the design of a 3D airfoil, based on my own limited knowledge.
Here is what Benny has said: he is trying to make a 3D airfoil, but he's not doing any kind of initial R&D legwork besides looking at photos and trying to copy another design. Meanwhile, he doesn't care if it is non-functioning or hurts performance because he's really only planning to use it as a stand for a luggage rack.
Myself, and others, have simply been pointing out how dangerous this is...e.g. the video posted above. There is certainly a high level of danger in putting an untested, rushed, and cheaply-made giant wing on the back of your car and then driving over 70mph on public highway. The question isn't, "will it fail and fly off" but instead, "when will it fail and fly off".
Seriously, I can't use this emoji enough:
I'll leave you "form over function" kids & conspiracy theorists to play with yourselves now...
So now we have FDmuri calling me a "douche", gmonsen coming up with conspiracies, and blackade trying to compare apples & oranges - all because I was giving feedback and trying to figure out his intentions for trying to make a wing...
It's no wonder traffic on this forum has dropped off.
Everyone is free to go back and read my original post on the previous page. I didn't come into this thread to flame him or "talk ****" or say it couldn't be done. I started out by sharing information relative to the design of a 3D airfoil, based on my own limited knowledge.
Here is what Benny has said: he is trying to make a 3D airfoil, but he's not doing any kind of initial R&D legwork besides looking at photos and trying to copy another design. Meanwhile, he doesn't care if it is non-functioning or hurts performance because he's really only planning to use it as a stand for a luggage rack.
Myself, and others, have simply been pointing out how dangerous this is...e.g. the video posted above. There is certainly a high level of danger in putting an untested, rushed, and cheaply-made giant wing on the back of your car and then driving over 70mph on public highway. The question isn't, "will it fail and fly off" but instead, "when will it fail and fly off".
Seriously, I can't use this emoji enough:
I'll leave you "form over function" kids & conspiracy theorists to play with yourselves now...
03-29-13, 08:31 AM
#1036
For the record I have no plans to ever even attempt to make an airfoil, since I'm well aware that design & fabrication of such a part would be well beyond my own abilities & budget. I made a post a few weeks ago about how I'm working with JhnRx7 to make wing risers (not an airfoil). This has nothing to do with my comments & feedback on Benny's attempts to make an airfoil, since they're not even the same part.
I won't bother posting in this thread again. Good luck with the project Benny - I only posted here in the first place in attempt to find out more about your intentions for the wing, and maybe help out with some suggestions. Isn't that what the forum is for?
03-29-13, 11:07 AM
#1038
Wastegate John
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Come on guys let's be a little more respectable to fellow forum members here. There is a learning curve when designing anything engineering related when you have no background in it. Like Gordon stated, you have to start somewhere. I recall some of you "designing" some LED tail-lamps that couldn't be seen during the day and could also cause serious accidents. So, take a step back and realize you started from knowing nothing too.
JhnRx7, when you came in here asking him to "share some of the calculations" it came off as very rude. Obviously, the guy is working out of his garage. As a mechanical engineer I would assume you're smart enough to know that's not what he meant and you were just trying to be a dick.
JhnRx7, when you came in here asking him to "share some of the calculations" it came off as very rude. Obviously, the guy is working out of his garage. As a mechanical engineer I would assume you're smart enough to know that's not what he meant and you were just trying to be a dick.
Ben, I really want to know if you ever even bought a book on airfoil design and aerodynamics. There are some real good books that use real life scenarios using applied examples to show you what is really going on. This one for example is really good.I learned a lot from it.
This one is a bit more mathematical but it still provides good info. I would suggest reading the first one then get this one to reinforce the info.
To be honest, as some have said, designing and manufacturing an airfoil is no simple task, get one thing wrong and it can spell danger for yourself and people surrounding you. Since you make claims to have learned a lot and know what you are doing can you tell us how you are mounting the wing to the risers and what you are doing to prevent fatigue cracks from forming?
I believe you mentioned somewhere in this thread that there is no core structure in this wing, how it is being manufactured then? I can not picture a way to make a 3D object out of fiberglass (with limited access to specialized equipment) without some sort of core structure. Especially one that will be subject to lateral, compressive, torsional, and large static loads.
I am asking these questions, not to be a douche, but because I want to make sure you have considered some possible scenarios that may not be apparent.
03-29-13, 12:19 PM
#1039
all of you technical data guys, have you ever made anything with fiberglass? I doubt it. guys all talk the talk, fiberglass is NOT a weak material. Do you guys even know who much load vs wind speed vs velocity blah blah blah it takes to break fiberglass? NO, cuz NONE of you even know ANYTHING about this spoiler. everyones making assessments on THIS picture?
seriously, I've built the wing, and I CANT EVEN TELL the exact shape from this picture. and how everyones telling me its going to break already. unbelievable. and ps, APRS spoiler is HOLLOW. pick one up, tap it, there may be inner rib cage but there is DEFINITELY no core material.
Now for all you genius, who "think my wing will break" am I using a fiberglass mat or cloth or wooven fabric? e-glass? s-glass? or how bout how many layers im using? or what oz the weight of the fabric is? how bout what resin im using? epoxy? polyester? vinylester? LOVE how you're determining it will break even before how the construction is determined. classic troll move guys
why even bother posting in my thread. clearly none of us get along yet you guys all want to follow and throw your 2 cents in to be a douche bag. seriously just avoid my path and ill avoid yours.
03-29-13, 12:29 PM
#1040
John, no need. I'm well aware that engineering involves more than software program analysis. I should have my little piece of paper that says I'm a mechanical engineer in about 30 days. 
Thank you though, seriously. I don't mind asking questions about things I don't know, and you personally know that.
All I'm saying is that pointing out that this is a bad idea could have been done with a little more respect rather then acting all high and mighty.
Thank you though, seriously. I don't mind asking questions about things I don't know, and you personally know that. All I'm saying is that pointing out that this is a bad idea could have been done with a little more respect rather then acting all high and mighty.
03-29-13, 12:50 PM
#1042
From my first post:
Your wing appears to have the center "flat U-shape" (roughly) but the outer tips of the wing are nearly flat relative to the center. Also I'm wondering if your airfoil is truly an airfoil (similar to the shapes discussed on that first link I posted) or if it just looks like one. Compared to the APR GTC-300 wing, you wing looks like it won't generate much downforce unless you have it angled at a very aggressive angle (which will create a ton of drag, slow your car, and put a ton of strain on the mounts at higher speeds).
Just my thoughts. Not saying you can't do it, just saying it's a lot more complicated than just making something that resembles a 3D airfoil...
Just my thoughts. Not saying you can't do it, just saying it's a lot more complicated than just making something that resembles a 3D airfoil...
"Cardboard Engineering" was not mean't as an insult. I use cardboard to mock up things all the time - brackets, panels, etc. The problem is, "cardboard engineering" just doesn't work for certain things, like complex-shaped airfoils.
[...]
I'm not an engineer.
[...]
No worries man, I wasn't trying to come of as a dick either. Just sharing my opinions based on what I know about this...
[...]
I'm not an engineer.
[...]
No worries man, I wasn't trying to come of as a dick either. Just sharing my opinions based on what I know about this...
Like I said before, I didn't come into this thread to "talk ****"...I was just asking questions and sharing what I knew based on my own limited knowledge of the subject...and again, like I said...Isn't that what the forum is for?
If you guys can't handle someone asking you questions about what your doing, why you're doing, or how you're doing it, without getting so 'effing worked up and defensive, maybe it might be best if you don't post on a a public internet chat forum.
and ps, APRS spoiler is HOLLOW. pick one up, tap it, there may be inner rib cage but there is DEFINITELY no core material.
Now for all you genius, who "think my wing will break" am I using a fiberglass mat or cloth or wooven fabric? e-glass? s-glass? or how bout how many layers im using? or what oz the weight of the fabric is? how bout what resin im using? epoxy? polyester? vinylester? LOVE how you're determining it will break even before how the construction is determined. classic troll move guys
why even bother posting in my thread. clearly none of us get along yet you guys all want to follow and throw your 2 cents in to be a douche bag. seriously just avoid my path and ill avoid yours.
Now for all you genius, who "think my wing will break" am I using a fiberglass mat or cloth or wooven fabric? e-glass? s-glass? or how bout how many layers im using? or what oz the weight of the fabric is? how bout what resin im using? epoxy? polyester? vinylester? LOVE how you're determining it will break even before how the construction is determined. classic troll move guys
why even bother posting in my thread. clearly none of us get along yet you guys all want to follow and throw your 2 cents in to be a douche bag. seriously just avoid my path and ill avoid yours.
The APR wings are built out of 100% carbon fiber and they are NOT hollow. Inside the wing is a 100% carbon fiber skeletal structure that is filled with foam material to create a solid shape and maximize rigidity.
He said hollow wings (including ones with non-engineered skeletons), and especially fiberglass wings, are extremely prone to bending, cracking, and breaking at speeds (even 55-75mph highway speeds). APR used to produce an FRP wing, but discontinued manufacturing them because the manufacturing cost was only slightly less but there was major difference in strength and performance compared to the superior carbon fiber versions.
A good (properly designed) airfoil of this size should generate about 150-800lbs of downforce at "track speeds". Are you confident that you can place 800lbs of weight on your fiberglass spoiler without it bending, cracking, or breaking?
Just because you don't have the answers, doesn't mean you can start making them up and making assumptions. You also should realize that when people ask you questions, they're not attacking you...they're just asking questions. Getting all worked up and calling everyone "douches" just makes you look like an angry child throwing a tantrum. No one is "trolling" you - we're all raising legitimate questions.
03-29-13, 02:45 PM
#1043
Actually, you're wrong. I have "tapped" on my own APR wing, and I know it does not "sound hollow" as you so imply. Either way, I just called APR and spoke with one of their engineers. Here's what he told me:
The APR wings are built out of 100% carbon fiber and they are NOT hollow. Inside the wing is a 100% carbon fiber skeletal structure that is filled with foam material to create a solid shape and maximize rigidity.
He said hollow wings (including ones with non-engineered skeletons), and especially fiberglass wings, are extremely prone to bending, cracking, and breaking at speeds (even 55-75mph highway speeds). APR used to produce an FRP wing, but discontinued manufacturing them because the manufacturing cost was only slightly less but there was major difference in strength and performance compared to the superior carbon fiber versions.
The APR wings are built out of 100% carbon fiber and they are NOT hollow. Inside the wing is a 100% carbon fiber skeletal structure that is filled with foam material to create a solid shape and maximize rigidity.
He said hollow wings (including ones with non-engineered skeletons), and especially fiberglass wings, are extremely prone to bending, cracking, and breaking at speeds (even 55-75mph highway speeds). APR used to produce an FRP wing, but discontinued manufacturing them because the manufacturing cost was only slightly less but there was major difference in strength and performance compared to the superior carbon fiber versions.
A good (properly designed) airfoil of this size should generate about 150-800lbs of downforce at "track speeds". Are you confident that you can place 800lbs of weight on your fiberglass spoiler without it bending, cracking, or breaking?
Just because you don't have the answers, doesn't mean you can start making them up and making assumptions. You also should realize that when people ask you questions, they're not attacking you...they're just asking questions. Getting all worked up and calling everyone "douches" just makes you look like an angry child throwing a tantrum. No one is "trolling" you - we're all raising legitimate questions.
Its one thing to ask a question in curiousity, and another thing when you ask questions in the tone of attack, sarcasm, and talking down on someone, which Your original post was fine, and i made it clear i was cool with it. your second post you became a wise ***. Your whole "sakebomb clique" always make comments to me like that, grow up guys, just leave me alone if you dont like what im doing.
03-29-13, 03:03 PM
#1044
Wastegate John
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Ben, because this is your thread I want to know.. do you want any of this deleted or would you like it to stay up for people to read?
Re: the wing, I still would like to know how it will be mounted and attached to the uprights. Will you be molding in attachment points or fastening directly to thefiberglass?
Re: the wing, I still would like to know how it will be mounted and attached to the uprights. Will you be molding in attachment points or fastening directly to thefiberglass?
03-29-13, 03:08 PM
#1045
http://i426.photobucket.com/albums/p...DSC_0887-1.jpg
http://i426.photobucket.com/albums/p...n/DSC_0931.jpg
http://i426.photobucket.com/albums/p...327_232908.jpg
There's certainly enough there for anyone to start asking questions...
03-30-13, 07:41 AM
#1049
Benny and Collin, I love reading both of your threads and hope you choose to continue posting up progress. It saddens me greatly what has gone on in this thread for the past few days but please note the vast majority of us appreciate what you do.
You've both got mad skills and I really like the ideas and concepts you are developing. Keep it up and keep posting please
You've both got mad skills and I really like the ideas and concepts you are developing. Keep it up and keep posting please
03-30-13, 12:04 PM
#1050
No one directed anything at me and I don't have anything personal against anyone on here.
The reason for my post is that I come on here to do 3 things:
1: see cool pictures of cars
2: get new ideas/share my ideas
3: buy and sell parts to help with my projects
Now every time I come on here to do number 1 and 2, I have to sift through retarded arguments and it has become a waste of time. There are other forums where guys actually focus on building cars, and even when one guy does something stupid or people don't like it, they just say "that sucks" or "thats a dumb way to do something" and move on. Here it gets drawn out and goes on and on and on and on and on.
So for number 1 and number 2 ill stick to speedhunters and a few other forums.
The reason for my post is that I come on here to do 3 things:
1: see cool pictures of cars
2: get new ideas/share my ideas
3: buy and sell parts to help with my projects
Now every time I come on here to do number 1 and 2, I have to sift through retarded arguments and it has become a waste of time. There are other forums where guys actually focus on building cars, and even when one guy does something stupid or people don't like it, they just say "that sucks" or "thats a dumb way to do something" and move on. Here it gets drawn out and goes on and on and on and on and on.
So for number 1 and number 2 ill stick to speedhunters and a few other forums.