Aerodynamic Tailgate Storage Prototype

I've had a design in my head for years to leverage the tailgate for storage with an aerodynamic shape to improve mpg's. Our tailgates have been neglected far too long, it's time to customize them. I started with a simple cardboard model, then a 3D CAD model. Working on a couple options to get a physical prototype in hand for testing

 

IMHO, you skipped a step, if the cardboard aided design was too flimsy to take on the road. If you opt out of printing for your proof of concept, you’d slash your development costs exponentially and would be effective enough to see if you have any tangible drag reduction before asking for development funds. With some of that data on hand, you’ll have an easier time GoFunding a couple of printed copies, vs. “I think this simple shape might work, but I need $15,000 to find out if I am on to something here.”

 

How many MPGs did the cardboard prototype gain you during your testing?

 

I know the shape reduces the drag via the Computational Fluid Dynamics (CFD) model. The 3D printed part is for fit/finish/does it hold the stuff without falling off...etc. and it's not $15K
Thanks for the input though

 

i can't find any information outside of this one youtube video, but someone's already supposedly making a similar product, claimed at "$60"--unclear if that's per unit, or as a set.

it's called truck tail, at 10:50 in this video:

https://www.youtube.com/watch?v=ISzm9h5S8to

the sticker on the products appears to be 'trucktail.com', if i'm reading the blurriness correctly, which now goes to a random aerial drone photographer on facebook.

regardless of if that other product exists at all, or if it even ever existed:

while 3d printing is all the rage, i would really suggest instead to make a set out of ABS sheeting, using MEK as a bonding agent between the sheets. especially with a product as large as this, it would significantly reduce material usage and upfront costs, and would allow you to develop a much better suited model, even a completed sellable unit.

https://www.youtube.com/watch?v=oIoxWJ8lyyA


fair warning, i personally don't believe the market for such a product is all that large to begin with, regardless of the cost of the final product.

the flat tailgate, and the triangular shapes aerodynamic benefit is pretty well known to even a person like me that has only accidently stumbled into vehicle aerodynamics internet discussions. in this case, given the market for pickup trucks, and the number of accessory companies that not only have large R&D budgets, but also the rotational and/or blow molding equipment easily available, i have to believe that if such a product were so desired, there'd already be some significant major players with an active product. given the lack of such players, it indicates to me that while there might be an interest, that interest is likely in the range of less than 1,000 product sales annually. more than enough for a DIY-er to come along and make a buck, but also far too low to justify burning that big corporate R&D money on new molds as well.

in this case, custom-making ABS-sheet units to sell yourself might even be a better official product option for at least a little while until you either satisfy the current market demands, or if i'm wildly wrong, such a version would allow you at least establish yourself within the market, quickly create a sellable product, and with those two major hurdles out of the way, it would then offer profit and a viable customer base to create a better iteration of your now-existing product.

 

Ha - I don’t know why I doubled your GFM goal in my head. It looks like you’d have a left and a right side so maybe that was it. Regardless, that’s still a big jump from a static cardboard mockup. I had written out basically a giant echo of the post above and forgot to hit ‘post’ but basically..going all in on the first prototype of your first tangible iteration is not really a good approach if you don’t have that kind of funding to throw around freely. There will be changes, and potentially some big ones.

Also, don’t forget you can mix your medias; maybe reel in your printing a bit and fasten in cheap materials where you’re flat, like coroplast or something. Hell, you can do some impressive stuff with high quality corrugated cardboard (so long as it stays dry!). Additionally, leverage services like Send Cut Send or something as well, for short run production and prototyping - I simply can’t believe their prices and I’ve always been pretty happy with their results (I have used them personally and professionally, fwiw).

 

fair warning, i love manufacturing, reverse engineering, and tools...

so while the product doesn't apply to me, the idea of developing anything always interests me.

2 methods that i left out that i feel should be mentioned would be 'segmented' 3d printing, and fiberglass moulding.

3d printing, if you have one, it's absolutely possible to create something larger than your printer bed dimensions, like this guy that built a full-scale car by breaking down the parts into panels that he can print on his significantly-smaller 3d printer, and then gluing the panels together.

https://www.youtube.com/watch?v=HsDyYyoDREU

and the second method which is so old, i don't even know where it started, is fiberglass around a form. this method existed long before 3d printing ever existed conceptually, and can be done cheaply. the biggest advantage here is that the mould setup is inherently great for low-volume parts repeatability.

if you re-watch the video of the truck tail iteration i posted earlier, it appears this is the method he used to create his version. the tell-tale signs are that the exterior is smooth, and when he opens the lid, runs and waviness is apparent on the interior surface finish. this indicates that he cast the parts 'reversed'-- the same as boat hulls, kit car body panels, or airplane body components.

i'm not going to go into much detail on fiberglass forming as there's loads of resources everywhere for building with fiberglass/composite components, from youtube videos, dvd's, and tons of books. i've got this one on my bookshelf.

$35 How to Fabricate Automotive Fiberglass & Carbon Fiber Parts

https://www.amazon.com/Fabricate-Automotive-Fiberglass-Carbon-Fiber/dp/1613253664

this site is also extremely addictive to spend time on as well.
https://compositeenvisions.com/

 

Thanks for the tips. I had already broken up my design with smaller ones, however all the small ones add up to the 1 large print. I'm going to try some iterations with abs sheets. Creating a "plug" for a mold will be my last resort

 

Just a heads up, TW does not allow go fund me links without permission from the staff. You might want to delete that before a moderator spots it.

https://www.tacomaworld.com/threads/code-of-conduct.709541/

 

Interesting idea -- a fun one to think about. Do you have any CFD results you can share?

ISTR once upon a time reading the ratios needed for blending streamlines at the tail of a vehicle. It's something in the range of multiple meters, I think, not inches, and keeping the flow from spilling off the edges is important to stability and controlling lift. Aero is tricky, and a Kamm back isn't really a bad idea.

Recall the development pathways leading to the Porsche 917 langheck and kurz at LeMans.



I just finished a 6000 mile trip from Saint Louis to San Diego and back in my 2015 Tacoma with iKamper RTT mounted on my tonneau. 18.2 miles/gallon overall. It's not clean science, but that's slightly better than I've gotten making that same trip a number of times without rooftop tent -- certainly no worse.

 

cybertaco