It's Time To Make A Body For The Land Speed Car
ฝัง
- เผยแพร่เมื่อ 5 ก.ย. 2024
- Check Out AirShaper at: airshaper.com/
Thanks to Banks for their awesome iDash: bankspower.com...
TSC Race Car Aero Design Video: • Can this Pikes Peak Hi...
Superfast Matt is supported by:
SendCutSend - For 15% off Fast laser cut parts, click here: sendcutsend.co...
Tires by Falken Tires: www.falkentire...
Wheels by KMC: www.kmcwheels....
Oil by Motul: www.motul.com/
Become a Patron: / superfastmatt
Join The Discord: / discord
Subscribe - www.youtube.co...
Instagram - / superfastmatt
Twitter - / superfast
![[กูเพิ่งซื้อมึงปิดหนี] 20 นาที ผมรีวิวเกมที่แย่ที่สุดในโลก CONCORD](http://i.ytimg.com/vi/XhC-3q3Ii7I/mqdefault.jpg)
As someone who LOVES doing fiberglass work, I'm really excited to see this body be built!
Back to fixing the workshop now, Finger
Make the workshop out of fiberglass
As someone who HATES fibreglass. I'm excited to see someone else do it 👍
Kid named Finger what are you doing here
I am a composites technician for wind turbine blades. I was thinking the same thing. I can't wait to see him make these parts.
Im on the Penn State FSAE Aerodynamics team. Can confirm that the pink insulating foam from the hardware store is the way to go. We do all of our airfoils with it. It mills (and hot wires) very nicely.
I’ve done both and tooling block is so much nicer to work with, you can sand it you can put body filler in it (and sand some more) you don’t have to use special primer, epoxy doesn’t melt it, acetone doesn’t melt it. It’s more durable, you can seal to it (once primed) it has better dimensional stability, you can put smaller features in it to add bond gaps and trim lines. Sooo much better.
Seen people make RC planes with a CNC using that foam, so I do believe it will work well.
I’ve done both and tooling block is so much nicer to work with, you can sand it you can put body filler on it (and sand some more) you don’t have to use special primer, epoxy doesn’t melt it, acetone doesn’t melt it. It’s more durable, you can seal to it (once primed) it has better dimensional stability, you can put smaller features in it to add bond gaps and trim lines. Sooo much better.
You should read his book on formula sae if you havent already. He won design comp at oklahoma. Its called racecar: searching for the limit in formula sae
Tooling block is the way to go
"if i need new parts, i'll just re-do the whole process" I felt that in my bones.
I feel it in my fingers,
I feel it in my bones.
"Pink foam" has a big advantage, Acetone dissolves it. (also polyester resins, so only use epoxy) So I've seen a lot of write ups of people making bicycle fairings by shaping a block of pink foam, doing wet layup n bagging with fiberglass/carbon, then dissolving the foam plug out.
I think the YT channel "Hack-a-day" did this to create a petrol tank for one of his bikes.
Learned this the hard way: spray-painting pink foam (after CNC profiling) is dangerous. Get too close and the solvents won't flash off before landing on the foam, and if that happens, your carefully-carved surface finish now looks like the moon.
This is basically how we used to do the bodywork (especially the nose cone) on our university's Formula SAE car. Though instead of dissolving all of it, they'd carve out the bulk of the foam plug manually with power tools and *several* vacuums, then dissolve out any of the tricky or stuck bits. While messy, its a fairly simple way of doing it.
I will cast a vote in favor of Dow blue foam over Cornings pink foam, as it is just a bit smoother to carve and hotwire-but blue/pink foam is far superior to any other method I have tried.
You can build a quick foam core composite layup with pink foam at the center, and good duck tape on the outside as the skins (like 3M or gorilla brand).
It isn't terribly rigid; but it is nearly indestructible. Pink and blue foam are pretty brittle and weak, even when fiberglassed; but if you do a layer of tape on both sides instead of FRP, it's extremely tough and difficult to break.
And you can make very smooth curves if you cover one side in tape, bend the foam so that the taped side is being bent outward/convex, and then tape up the inside and attach it to a frame.
It has the perks of zero curing time, zero resin mixing, and immediate results.
I wanna see Matt do the fiber glass
HAHAHAHAHAH said by a man who has used fibreglass.
NA ! needs use carbon fiber its much nastier and hardwork !!! 10x the cost and about 2 lbs light after all the extra work !
Better than doing glass fiber. I hear it’s tough to smoke.
I'm looking forward to see what he does to the Jag next after the fiberglass pisses him off haha
So much pain!!🤣🤣
Hey Matt, I worked for many years at an Industrial Design company in Montreal, Canada. We designed & built quite a few vehicle prototypes over the years. The bodies were always fiberglass. One method that worked really well for "one off's" was to literally carve the body shape from urethane foam blocks. The blocks can be cut up & attached to the structure of the car. The blocks can be bonded together with urethane insulation spray foam cans from the big box store. This boding method allows you to carve & sand the body "buck" without having variations due to typical adhesives. Once the shape is completed, we would apply fiberglass directly on top of the foam. As the foam is urethane, it doesn't dissolve due to the styrene in the FRP resin. The shape will be exactly the same as the foam, but offset by the thickness of the fiberglass layup. Once the thickness desired was achieved, we let it cure completely, then carved all of the foam out from the inside, which oddly enough leaves you with a pretty smooth interior finish. The body is then cut up to suit the various component segments, ie nose, roof, tail etc. This method would also help you with maintaining the windshield shape relative to the remainder of the body. The exterior surface is then smoothed out using bondo etc using the typical body shop methods, then painted. As we were doing it this way many years ago, without access to CAD & 5 axis milling machines, the result was very "artistic", however I would imagine these days you could find someone to mill these blocks individually using your body shape cad files, then stick them together to create the overall shape. Both sides would be mirror images of each other. Fine tuning of the buck can still happen after the assembly of the blocks with sanding blocks. I believe this will be the fastest & most accurate method you could create your body. Good luck with your project! PS I am also a car guy & a race car guy, however the racing I was involved in 30+ years ago was production road racing in the summer & ice racing cars on the frozen lakes of Quebec & Ontario in the winter.................big crazy thrills : )
I come from the RC airplane world and immediately thought that fin would be an excellent place to put a control surface attached to a basic gyro. This could let you get away with a smaller fin since it could actively work against side slip. Of course it also gives you the exciting possibility of nearly dying due to a malfunctioning servo or gyro, but you might gain a little bit of speed.
Double redundant motors and gyros and now you're more reliable than a 737 Max.
Better yet have it cable controlled by the steering as that's cheaper and easier.
@@redwaller1 The RC stuff is comparably cheap, but I'm not sure if there are RC servos strong enough.
I was just wondering about how useful some kind of active aero might be before I read this
@@906MediaProductionsthat hurt, and I'm an Airbus fan boy...
Being a long time fan of this channel, I'm surprised this didn't lead to a large scale 3D printer project lol
3D prints aren't smooth?
It has, he just didn't want to tell future Matt yet
This is true, but it's not difficult to treat the surface and get it just as good as fiberglass
@@martinshoostermancouple of quick coats of epoxy coating resin and a polish and you've got a lovely surface for low tech composite moulds
Is there a printer large enough which doesn't cost a fortune to use?
The sequence at 15:10 is my peak favorite kind of comedy. Thank you for always executing your jokes so well. I'm so excited for every update of this project. I will get a car to Bonneville one day.
the little shot with the hand pistol at the end. :glory:
@@namenmalkav he got me good with that one
Matt In my 18 years of racing and modifying my VariEze aircraft, I have had a ton of experience on making plugs designed to lay up over. I used easily shaped 2 inch thick urethane foam. sandwiched between bulkheads. Depending on the curvature I would have bulkheads about evert 4 to 12 inches. Next sandwich the foam between the bulkheads using a hot glue gun. At this point the foam is sticking out past the bulkheads. Keep the glue inside of the bulkheads or it will be a pain when you start cutting and shaping the unwanted foam away. Next take a knife and carve away the foam till you about .150 inches away from the bulkheads. Use 40 grit sandpaper remove the last of the foam to the bulkheads. To do this use adhesive backed sandpaper stuck to flexible sanding boards. The tighter the radius the more flexible your sanding board needs to be. If you go a bit too far it is no problem because the next step is to cover it with drywall compound! then use 80 down to 400 grit sandpaper to do the final shape. Then go back and sand in any low areas where you intend to overlap the body to join it to another section. Also, for addental ply's where it is fastened to the body. you want to leave room, so you don't have to add ply's after the part is built. Once you are happy with the shape spray the thing with MANY thin of coats of PVA, allowing ample drying time between coats. Then wax it a bunch of times. Do not use vacuum infusion it will crush the plug. Use epoxy with slow cure hardener and around 4 to 6 plys Bid Fiberglass RA5277 bidirectional glass. You want to finish your layup with Peel Ply. It will cause the plys to laydown much better. one cured it peels off leaving no sharp fibers and the filler is ready to apply with no sanding.
A 19 minute Superfastmatt video is such a gift
Regarding rivets and fasteners being exposed: When the US analyzed the MIG 25 that was used to defect to the US (by landing in Japan) they were shocked at how primitive it seemed to be put together: It used steel and a lot of the fasteners and bolts were exposed. They figured out where it made sense to smooth them out when not. See the Wikipedia article for more...
Wasnt the grumman wildcat like that aswell? I feel like ive heard someone say before that it only had flush riveting where it mattered the most, and regular rivets where it didnt matter so much
The front half of the F6F was flush riveted while the rear was standard. Drastically reduced cost and maintenance. @@Colt45hatchback
The Brits did the same with the spitfire, the story goes they built one fully flush riveted and then glued halves of peas on top of the rivets to simulate normal rivets for testing.
The Brits did the same with the spitfire, the story goes they built one fully flush riveted and then glued halves of peas on top of the rivets to simulate normal rivets for testing.
The Brits did the same with the spitfire, the story goes they built one fully flush riveted and then glued halves of peas on top of the rivets to simulate normal rivets for testing.
You could Vacuum Form the body. This would allow you to use Polycarbonate/Lexan on the nose, for better visibility through the front axle.
Vacuum forming tables are very simple to DIY. Its basically a table with lots of holes, like an air hockey table, and a shop vac pulling the vacuum. You have a heating element above the table, you slide the sheet of plastic up near the heating element, and when it begins to droop, you slide it downwards onto the table. You just need a foam plug on the table to create the inside dimensions of the plastic panel you wish to create.
I was thinking the same, probably because I also hate fibreglass. A big vac former with cnc'd foam bucks would be very repeatable to make a few spare sets of bodywork. It'd probably take a while to dial the process in with heavy duty materials, but surely easier than fibreglass.
This is what I thought as well. Might have some rigidity issues, but he can use aluminum send-cut-send ribs to strenghten it.
Matt, this guy has the answer to your prayers against fiberglass.
Looking at your design It seems your calculations are based on the fact that the skin is totally rigid. If any part of the skin starts to oscillate in and out (like the top of a jar of jam after it has been opened once) you might find a different aerodynamic reaction. It might help to have some sort of a honeycomb material glued to the inside. Just a thought.
I’ll add reinforcement thickness in some areas where it doesn’t cause the body to stick out more. Probably with a 5mm foam core
Also good to have extra fixation points. I haven't watched the full video yet, but you can import many Quick-Latches from China for cheap and they work wonders holding fiberglass body down
It would also probably be insanely noisy considering you're basically inside of a drum that yells at you
@@SuperfastMatt some internal ribbing perhaps? For her pleasure?
In rocket-land we call this flutter and you can squelch it with thickness or dimensionality (as you mentioned). You don't have to get fancy with foam core. You can use "rods/lengths" of semi-circle foam adhered to the interior of your lay-up which will allow you to crush them against your frame for proper fitment and then finalize with an interior layer of fiberglass to complete the matrix. E.g. - th-cam.com/video/2PsWqc6nBr4/w-d-xo.html @@SuperfastMatt
I have to say this seems like an enormous amount of work to go through to result in your fiery, fragmented, untimely demise. Your level of sarcasm and risk-adversity seems wildly appropriate for the task at hand.
Excellent video! Don't assume a body will fix all of your salt ingress problem. In my experience racing solar cars (at lower speeds in reasonable roads), road debris still gets all over everything.
I'm thinking you should collaborate with Xyla Foxlin on the body build. She's already laid up fiberglas and carbon fiber for several projects. She's definitely destroyed a mold or two in the pursuit of fiber parts. At least you'll have someone with a sunny disposition and a lot of useful knowledge to help you ensconce the burnt hulk of the land speed car in resin as a reminder to never work with fiberglas again. Well.. until the next time.
I was also thinking about Xyla's tribulations with fiberglass and carbon fiber layup. She did stuff with 3d printed sacrificial molds and also had release problems.
Fiberglass is so terrible.
That's a collaboration I'd love to see!
I thought the same thing!
I mean, the Landspeed car will end up bullet proof, but it would be great!
Yeah was just gonna say - she knows how to deal with that stuff well!
Came to the comments to say this too. Plus, she might be relatively close as I think you're both in SoCal?
Instead of making a negative mold just make what you need. Make it 1/4 inch smaller than you need then need. Make your buck out of the pink foam you were talking about and fill in the curved areas where it gets tricky with expanding foam. Sculpt it out with a d/a sander and done!you can drape your fiberglass over it and bag it down tight. If you squeegee over the bag surface you can get more of the resin out and the bag will lock down tighter giving you a smoother surface finish. After that you can get coat or whatever it. Popping it off of the buck should be easy enough. Just dig the foam out or melt it down with a heat gun or acetone.
I really love the Easy Composites channel. That would be a hell of a collab to make this bodyshell.
Something we do on latemodels to cover up our messes on the fiberglass bodies is to cover everything in vinyl. It covers up all the rivets and smooths the overlaps. It may be worth a shot for you and it’s pretty easy to apply especially if you have one or two people to help. You cut the paper backing in the middle and do one half of a sheet at a time
Fun fact about fiber glass: It's more aerodynamic in it's raw form, than glass/gel coat finish. The raw form works like a golf ball, creating a vortex layer on top of the fiberglass, so there's no separation between the surface and laminar flow. Another fun fact: if you add humps and bumps on the edges, these humps create hot spots for the air to separate, giving the separation drag less surface, thus making it less effective. So in a nutshell, the uglier your aero tub is, the faster it is. So, for a fast fiberglass aero tub, you need mounting points on the frame, bucks for the overall shape(foam and fresh foil) and a slight "high", then you lay the fiberglass and let it dry. remove the tub, carve out the buck(s), and voilá, the fastest aero tub is done. You can even glue the windows directly to the drying tub.
Are you talking about hand lay-up over a male mold? But he explained that he will do infusion on a female mold. So the surface finish will be the same, regardless of whether or not he applies a surface coat.
@@fredygump5578 Yup, just slap it on a buck, paint, decals and done in one weekend. trying to make any textured finish on a female mold is astronomically more complicated.
One way to get parts out of fibreglass moulds is toinclude an air valve on the inside, and use compressed air to push the part out. (The reverse of air-bagging.
That's a good idea i think
You can also cover the bike with "pink foam" and shape it using hot wire (or with the help of a surf shaper). You can put your carbon/epoxy mats over it, and remove the foam after . Surfs and windsurfs are made like that (but they keep the foam inside)
Tips
Don’t forget about lift at high speed . A number of people have had serious accidents because they didn’t design to prevent and or contend with the vehicle lifting off the ground.
There’s a thing called vacuforming where plastic is heated and sucked onto a form , or blown over it or both depending on the thickness of the material.
Put wheel covers on to reduce drag.
You should absolutely put dimples in it like a golf ball! ⛳
Or just go and play glolf. Or golf.
Its been done in NASCAR in the 60s and by mythbustes and been proven to work
@@channelofchannels7845I dont know about that... As far as I know, its been proven to work under specific circumstances, within specific parameters. I am not too sure this project fits those parameters.
@@channelofchannels7845 It doesn't work, otherwise planes would be golf balls.
@@Splarkszter Agreed. It was originally done on round bombs in WWII to skip across the water to hit land targets, I'm pretty sure that's before golf balls, but I'm not going to fact check.
Some race boats have used it w/ moderate success, only on the planing pad though.
We need a “CFD” analysis of how much liking and subscribing actually helps. You say it helps “a lot”, but that is vague, we wanna see numbers.
Mostly kidding, freakin love your channel.
the conversion is 50 likes = 1 speed parts sticker. And I assume we all know how many mph a sticker adds.
You skipped the biggest difficulty of aero bodies.
Not only do you need to fit in the body, you need to be able to get out of it without destroying it!
Ejection seat!
@@briancavanagh7048 those start with jettisoning the canopy, so I doubt the canopy survives an ejection event.
Though, the idea of a fighter jet plane-like canopy could work, maybe. They don't always eject. The sun would be hot, but the canopy wouldn't need to be entirely a window.
But, all panels gaps have cost. So make the whole thing in one piece, with a giant 3D printer, around the chassis, powertrain, and driver. The whole thing will be the new home of the driver, until after the event. I guess you would need port holes, to feed the driver (&stuff), but those could be flush.
Man, I never regret clicking on your videos. If I'm being totally honest the off road viper has always been my primary interest here, but whatever it is that you're working on you make it super interesting and entertaining. Legend.
maybe you should colab with Xyla Foxlin? She does a lot with fiberglass and epoxy
Beat me to it
You can build a quick foam core composite layup with pink foam at the center, and good duck tape on the outside as the skins (like 3M or gorilla brand).
It isn't terribly rigid; but it is nearly indestructible. Pink and blue foam are pretty brittle and weak, even when fiberglassed; but if you do a layer of tape on both sides instead of FRP, it's extremely tough and difficult to break.
And you can make very smooth curves if you cover one side in tape, bend the foam so that the taped side is being bent outward/convex, and then tape up the inside and attach it to a frame.
It has the perks of zero curing time, zero resin mixing, immediate results. It simplifies a TON of the process and gives you a rapid prototype.
Also notice if you go over 100m/s you have to take the compressability of air into account.
That's mostly solved by letting the air have a way to move sideways as well as up/down, that's why you have planes with tapered wings.
In the case of this car, the frontal areas being really small will do the trick
I think you would have to convert into mph to get it to him
@@adityatadoori8989 that's over 220 mph
@@Wannes_ r/woosh?
Just a suggestion - Easy Composites in the UK do some excellent training videos. Worth a watch. Have you looked at a 'splitter' under the nose of the car? Enjoying all your efforts, please keep up the good work. Covid sucks.
If you do go with fiberglass, try to integrate the fastners in the fiberglass so you get a nice and flush panel. You could try do do the same with the HDPE by 'welding' them on.
Over here in Australia there is mob called 4WDetail that sell a product called chassis shield. It's used for protecting the underbody of your 4wd on the beach etc. Basically the salty sand doesn't stick to it. I'd imagine that would be great for the salt flats too.
This project has been awesome to watch, easily my favorite on the channel since the EV Jag
Interestingly enough, the method you're talking about is exactly how Mike Patey makes his airplane carbon fiber parts. I would suggest carbon fiber except for it's large cost, and also the fact that more weight in land speed racing is generally a good thing, to a point.
Have you thought about 3d Printing the fiberglass molds? I've seen quite a few people do that recently
it's way too big to be time efficient
Surface finish
@@alessiocarlevaro6934 depends on the printer. If you already have a printer, printing the mold allows you to step away and do something else.
Making the mold the traditional way requires that you go to a hardware store, plan out what you need, buy it, take it home, make the plug, then make the mold from the plug.
The 3D printer may take longer, but you don't need to watch it doing what it's doing, nor actively work on it.
@@jackdeniston59 a roatary sander and filler will deal with that fine
@@jackdeniston59 That isn't really too much of a problem, there are plenty of Videos out there with people building bodykits and similar with excellent surface finish
Hey Matt, simply glue three pieces of MDF together and take care of the corner radius with a router. Plug for lower bodywork: done.
And cnc routers love MDF, so there's a lot of potential to over-engineer things in an entertaining way^^
I’ve been waiting for this video so long I might just watch it twice.
One idea here. You have a cnc machine and are going to have to make molds regardless. You could make the molds out if layered mdf each time making another stair step and using the inside material that you cur out for another layer a few up.
Then a heat gun heat resistant gloves and heat and lay polycarbonate over It. Some added benifits is your windshield is every part of the car and you get rid of alot of seams this way.
Also since your mold is hollow and mdf is very slightly porous you might be able to run a couple shop vacs into it to have it aid you in layup.
I like the less scripted "extra chat" at the end. Felt super genuine.
Yes! Got so excited for More Unnecessary Rambling 16:08
Having machined a fair bit of styrofoam, you are going to want a substantial dust collector for your CNC. A project this size is going to generate several yards of waste and because you are smart / lazy you won't want to be standing there watching the machine run for days. I would also recommend using a 2# EPS bead foam over the blue or pink XPS, mainly for finish quality but also because the (clean) EPS can be recycled. Use Great Stuff Pro for adhesive, it has a very similar density to 2# EPS and this helps tremendously with eliminating the layer lines during finish sanding. Lastly, V-Carve Pro / Aspire (while looking very windows 1995) are very affordable and have a resting tool paths for STL / OBJ files. They make setting up 3D tool paths pretty easy compared to 'real' CAM programs.
10:48 Shape it like a container ship, including railing and tailpipe and a use a bubble visor for the operator.
A steep rising tail with notched step to release drag ( like a pby Catalina tail) and flue pasage external on both sides in line with middle of wheels.
In rolled aluminium
Ed “Big Daddy” Roth sometimes used plaster of Paris which he hand carved, covered it with fiberglass, then pounded with a hammer to break up the plaster. Sometimes the piece was a closed shape and the plaster got trapped forever.
Matt, you can increase the radius of your brake without modifying it or needing to build a jig! Use another strip of Lexan and leave it on the top leaf while you brake your panel! My brake has multiple “radius modifiers” in the form of strips of sheet at different thicknesses 👍
Love the content by the way!
Have you seen the videos on The Arnold Company’s channel? They’re about building a super low drag airplane but there’s probably some useful insight for a land speed car body in there.
Who lives in a garage and works with cars?
Matt Superfast!
Technical and humorist and porous is he.
Matt Superfast!
If automotive nonsense be something you crave.
Matt Superfast!
Then step on the gas and drive like your brave!
Matt Superfast!
Matt Superfast!
Matt Superfast!
If you do go the hardware store foam route, I suggest finding a place that will sell you high-strength hardware store foam. This is sold as Dow Hi-load 100 or Owens Corning Foamular 1000. It has similar cost and properties to the regular stuff, but it has a higher compressive strength, meaning you can manhandle it more before you start putting dents in it.
Just a crazy suggestion.... wire frame (especially along your defined edges) shrink wrap and do a wet lay-up onto this, Street Bandito style... then sand smooth with the aid of drywall filler, way easier to sand than Bondo
5:01 : I’ve always wanted to go to the Bonneville marshmallow flats!!
I used to work at an auto body shop and the trick with fiber glass is to take small bites and have all of your supplies and tools ready and if you find yourself getting frustrated with the process stop close your eyes and take a deep breath to calm yourself down it only takes a second to help yourself from making a mistake it's not all that hard you've got it
If you do end up bending plastic, a (1000w) Drum Heater will give you a 4-5 inch wide heat zone. Works great with expanded PVC. Very lite and rigid. Your results may vary.
You may want to get a product called 'Salt-Away' which is what boaters use to remove salt from boats and trailers. Works great, salt melts away.
Food for thought. Spray on liquid ACF-50 for anti-corrosion over everything except brakes., wipe off excess, used on aircraft. Fibreglass moulds. Spray in a whisp of PVA release agent into the Mould. In the Mould, fix two compressed air line fittings, one at each end of the mould, cover with Plasticine and PVA mould release. 40psi compressed air should pop the part out of the mould. Remember to duck.
9:48 with boats and quite a few modern cars the taper is truncated (and separation edges for cars ) are added to basically make the air or water make the shape for you in a way.
Super interesting - in the mid 90's we modeled and tested in a real wind tunnel some 6 top cars in the Shell Eco-Marathon for analysis and found one like yours that had a dip between the front 2 wheels to channel air that then hit the screen and caused a high-pressure zone and drag - it was effectively cutting the air twice - once at the front and again at the screen - we concluded that was far less drag to do this cleanly in one action even though this would perhaps place the screen well forward of the driver. One of our team produced some highly aerodynamic shapes by Drape and Blow moulding - it was fascinating to see how using either pressure or vacuum complex compound 3D shapes evolved almost naturally
Dont forget that roughing or adding sandpaper at the front will help the airflow.
Quick point on CFD for vehicles with low ground clearance is to make sure that the mesh has enough elements in the ground clearance gap to properly resolve the airflow between the ground or the results are kind of useless. I would also then check your pitch sensitivity well beyond max speed to make sure the car isn't making enough lift to get off the ground and flip. Having a refined mesh under the car is critical for checking things like this.
@SuperfastMatt the high pressure area in front of the cockpit, install a NACA duct, let the air flow around you to feed the intake.
For the sides, model test with 2 inch wide flat splitter running boards from front to back wheels.
After working with composites for far too many years a few tips..
Buy yourself some PVA mould release, it should be blue. start off with a fine mist, followed by two heavier layers. The colour allows you to see anywhere you have missed.
If you do go for a standard mould release, you can test with sellotape, if it's properly released the tape won't stick.
Order some epoxy with a pot life about twice as long as you need.. (watch the temperature you are working in, every 10 degrees doubles or halves the pot life.
Apply a layer of gelcoat to your mould,
While this is curing Precut your glass fibre, don't leave it too long before applying the reinforcement. I wet the fibreglass out on the mould with a penny roller.
If you can keep your hands clean and not sticky everything is more fun.
If you do go for foam mould double check the resin doesn't dissolve it..
Do not skimp on mold release, thick layer of wax (5 to 8 coats) or use the good stuff like Frekote 700-NC. Also for large parts we use the little pump up air wedge inflasion bag things works great once you get a seperation started. Good luck compsite work is always "fun"
That plastic bender you showed us for like 0.67 seconds led me down a rabbit hole of 4 hours of youtube, googling, materials sourcing/research, and a probable redesign of my project vehicle.
Good job.
Smooth is sticky to aerodynamic I have heard said. golf ball dimples a microscopic shark tooth surfaces reduced aerodynamic stickiness by a huge margin in a couple of experiments I saw. A slight turbulence everywhere reduced stiction in windtunnel testing. Also smaller turbulence was better due to a rolling layer of air flow creating a slippery barrier. good luck with crafty innovations! Sand dunes form a ripple pattern in the wind which helps sand to remain on the ground more.
You need to cnc sections of the body out of 1/2 in plywood and using a hotwire, cut blocks of foam. From there you could fiberglass on top of the foam to get the shape. Or use the blocks to vacuum form the plastic.
I have seen foam molds covered in the aluminum HVAC tape then coated with mold release that seem to be easier to demold. I'm not saying it will be easy but easier. I agree that working with fiberglass sucks but I have found that carbon fiber is far worse to cut and sand and writing this is making me itch just thinking about it. This is going to be fun to watch and looking forward to the continued build.
With “zero” budget ive made race car body panels with a laser cut ikea hardboard skeleton mounted together with wooden dowels from home depot, cardboard, paper mache to smooth the surface, wrapped in polyethylene pallet wrap sprayed with canola oil cooking spray for mold release. Then open wet laid up 2x2 boat fiberglass and epoxy resin. This obviously isnt great for high speed applications but for a lower speed car it works great for the price and manufacturing time. I also experimented with expanding spray foam which is a terrible idea because it- well expands too much and destroys the skeleton. Composites are expensive
oh the arm rashes from working with pre preg
Matt, I am with Team McLeish it is much better to go with an aluminum bottom possibly as thick as 1/4 inch firmly attached to the frame. The plastic you are proposing will not last at Bonneville. If you have any rough salt contact, which you will, it will get destroyed. Wrapping it around the bottom and up the side will cause you issues with access to the sides of the vehicle during service. Check out pictures of the Silverrod. Wish you the best.
Great video!
You may want to run 1 more simulation to show what happens if you end up on your side. I don't think you want to skid along the salt spinning like a top or sliding sideways. I think you want to keep the nose pointed forward, so it doesn't barrel roll. Just flip your design over 90 degrees to see what happens. For example, the vertical tail fin will not be effective if the car is on its side.
Here's an idea for lazy fibreglassing. Make a foam version of your part, slightly smaller than you need it to be. Cover it in fibreglass. Smooth the crap surface finish with filler. Excavate foam buck.
No moulds to pry your part from, only a disposable buck to destroy.
I helped my dad with fiberglass once, soo take this with some buckets of salt. We built the entire shape we wanted with 2 part foam and some plastic sheets right on the vehicle, we sanded and shaped it to where we wanted it. Then covered it with fiberglass to make a negative mold, struggled our asses off to get it to release and then once it was off we built the actual mold to go on the car in the negative, then again struggled a lot to get it out.
I don't envy you with those massive body parts. So how you'll do it?
- cnc mill a foam plug?
- wrap the foam plug in ceran wrap?
- spray-glue some peel ply onto that?
- wet-lay-up the glass fibre onto that?
- give the whole mess to a body shop to sand and finish the surface?
- try to get the body panels off the foam plug and damage them, starting again?
😄
Years ago I helped a mate run a ZX10 at Bonneville, was an experience! We got it tuned in NZ, shipped over and had a laptop to tweak the tune. I remember hearing a saying 'run it as lean as you dare, then go further'.. If we had started the bike as we got it, back home, it'd have killed itself! Oh, and we used a brand new U-Haul Ford van, barely any miles on it. I don't think it lasted much longer, from all that salt!!
It's funny you plucked the salt off the tire, and immediately tasted it, because as I watched, I had the very same intrusive thought. Love your content, Matt. Can't wait to see this all slippery to air.
Always fascinating, but I really enjoyed the mix of the main content with your regular delivery, followed by the slightly more informal "musings" at the end.
Fab :)
I like doing vacuum layups SO much. It's so gratifying.
One thing that could be done is the lost foam method of fiberglass, I did fiberglass work for 20 years and always used that method to make parts like this for varying sailboat racing mounts, etc.
Reach out or check it out maybe it will work for you better potentially!
Can't wait to see this come together!
One cheap way to reduce surface friction might be to use aluminum tape inside the body. Toyota added this to the 2024 GR Corolla, apparently it reduces the static discharge of the oncoming air, helping the boundary layer slide past the body more easily. They even went as far as to patent it
Another creative idea : one, plane were just made of a wooden chassis covered with oiled cloth to create a surface... you could actually, for a good part of the project use such a technology (sides, mainly, since I guess the frontal area will need to be quite tough, and I also assume there are some rules about engine bay)
It would be nice to see things like texture drag, paint drag, how the body vibration changes aero, fiber glass thickness studies, etc...
Makes me wish I went to school for ME instead of CS, very cool stuff! Also, the rambling at the end was cool, I liked the casual nature of it (somehow more casual than the rest of the video).
Affordable XPS foam is great for plugs and molds. Any solvent and vinyl/polyester will dissolve it before your eyes. Careful with epoxy, some contain solvents, otherwise its good (but unhealthy). I built a dinghy from a mold made with a CNC cut XPS foam plug in layers. Some tips: use a ball nose bit, you can leave the XPS surface 'grooved' and easily/cheaply fill it with fine mortar (offset in CAD), use cheap latex based paint to shield the XPS if you like the cheaper/safer ester family, drill some holes onto your mold and glue reinforcement pipes in them before you laminate and plug them with play dough or something similar then pop with compressed air once ready, you might have to go primal on the XPS mold anyway once everything is cured :D Apply wax to the mold, it's the only substance I trust, release agent is fine but apply very little and evenly (or you might get unwanted surface effects), a thin layer of hairspray might work on the wax. A gelcoat layer is always nice to paint on and easier to fix in the short/long run (you can let it harden completely overnight then sand, clean and laminate or add more). A few years ago I took a study leave in small boat building and I'm about to graduate, I really like composites, maybe you can tell :D Greetings from Finland!
So many other makers have demonstrated excellent results using insulation foam board for CNC positives, negatives, or even lost foam blanks that you can be pretty confident that will work well.
ALL HAIL THE ALGORITHM zug zug
I work for a plastic molding company and have had a small hand in mold design, I recommend using one or more compressed air ports in the back of your molds to get the part to release.
Pink foam... well I've done a ton of it and the thing that tough to tackle is the rough surface you get when spreading resin on the foam. Epoxy will lift all the dust particles (no matter how good you clean it) and bring them to the surface. Hope you like sanding. The quick way is to cover it with sheet rock mud, sand flat, epoxy coat and you get a pretty good surface for a one off. Hope you like sanding. If you have 1/2 dozen 3D printers, print your molds. Done!
I watched. Yes I did love it. Anyway. From someone who’s worked years and years with fibreglass. If you want fibreglass and epoxy to not stick use lightwrap. Or whatever y’all call it. It will not stick. You will not cry. Maybe.
It's possible to 3d print a lof of things for this car. Using foam filaments you can print strong lightweight parts. The finn in the back its a perfect piece to do this.
I really hated fibreglass work until I started doing vacuum infusion. You still have to lay up your mold by hand but there's almost no sanding and cutting. My success rate has been pretty good.
Jeez - make sure your mold has draft! Parallel sides = lock the part into the mold. Small taper angle (1-2 deg) = Not a problem releasing then. And use chemical spray mold releases AND mold wax. Several coats.
I haven't done a whole lot of fiberglass work, but I learned a lot from watching easy composites on TH-cam.
Matt, just wanted to say I thoroughly enjoy your content. Your dry humor is refreshing in the automotive/engineering corner of TH-cam.
Cover all 4 wheels and put in a cockpit with windscreen and then attach a parachute type fabric to the nose- as you go the fabric will blend itself around the car in the most efficient shape.
I managed to postpone my ultralight project for DECADES ,and thus have never had to do large scale fiberglass.I highly recommend this approach
I'm gonna caution you against routing pink foam. When I was still a student working in my university prototyping shop I attempted to make a 14 ft wingspan glider out of pink foam on the router. The stuff makes a huge mess and statically clings everywhere. More importantly there's uneven stresses from the extrusion process that make it warp as you're cutting it. I was using 2 inch pink foam that was 250 density iirc.
Laminated MDF with a resin shell works way better IMO
Why not straighten out the area behind the front wheels to above your head. Obviously would have to be clear but once that air is obstructed from the front end it has a low pressure area behind the "tire bubble" and has to be obstructed again by the windshield. Just a thought
One of my favorite DIY TH-cam race car builders swears by using kevlar and fiberglass to make strong, lightweight and most importantly rigid composite body panels. Bill's Build & Race.
I used holgen lamps on rheostats/digital dimmers for heating and bending plastic sheets. I do fiberglass work on vintage corvettes and have a lotus for fiberglass work in now.
If you're not concerned about preserving your molds, you can easily dissolve most foams with a hydrocarbon, such as petrol or kerosene. As long as whatever it is doesn't affect your resins it should just wipe off.
It seems like the perfect time to get a bigger Z axis on your CNC router (and jack up those side rails) ... you know, BEFORE you start making lots of complex foam forms with it. :)
Something ive learnt with CFD is never run the airflow perfectly parallel with the car, always add something like a 2 deg yaw as airflow in reality will never be perfect. for composite lay up from experience, mylar sheets and lots of releasing agent help allot. Last thing, maybe i missed it but what was the Cl of the car.
Lol liking the build dude
Now some advice to you and everyone…… and bear with me ….
1
don’t even attempt to build your pattern / plug by heat bending the polycarbonate , it will expand, distort, warp and cool in ways you couldn’t imagine. Trust me !!!!!
2 stay clear of any thermoplastic like PP ABS HDPE if you don’t have any experience especially on a large pattern .
My advice is use 3mm polycarbonate and make 2 identical sides with reference marks say every foot , scratch it on the reverse side . These can be used as reference marks when cutting and modifying for accurate symmetry.
By using 3mm polycarbonate it will be stiff and stable enough for a pattern and also give you 3mm for your fiberglass thickness for a snug fit .
The only way you will bend polycarbonate for what you need is by routing half way through maybe more then heating gently with a localised heat source from a hot air gun etc .
Any gaps or notches, screw ups can be filled with filler etc etc , wood can be screwed to the back if needed and screw holes filled easily .
Temporary fixtures or permanent fixtures ideally need to be filled during the pattern making process for accuracy and ease of fitment .
Mold flanges can also be temporary fitted to make mold making easier .
If your careful and clever only filler will need a quick seal with paint , after that 3-4 layers of PVA release agent is fine and one layer of wax .
PVA is cold and moisture sensitive so don’t do it in damp conditions IT WILL NOT DRY and go all dusty .
Double Gell your mould , preferably in a dark colour or something opposite to your body colour ( this is just way better and you can see thin patches of gell ).
PP ABS HDPE is fine but only if you know what it can be used for .
Anything requiring a long length radius use a length of PVC waste / drainage pipe , this can be bonded/ screwed to the polycarbonate. ( polyurethane adhesive is best as it can be easily cut once cured for alterations/ removal.
If you temporarily bond some of your pattern to the car tape over the steel tube with lots of masking tape in the area then simply bond to it as using tape makes a barrier and adhesive is not actually bonded to the car .
I’d honestly do the body for you but I’m in the UK , I’d expect at least 4-6 weeks for everything, make a tidy job of your pattern and you will spend far less time arsing around with your final product and may even get away with a quick flat block and buff without painting 😀👍🇬🇧.
Msg me if you need any advice
Nice offer and great info. Bob
@@manitobaman5588 your welcome, I’ve made plenty of patterns and molds in my life especially one offs that need to be cost effective and full body shells in Grp and bits in carbon. Any questions just ask
Why not add a rudder coupled with an acceleration sensor, so it automatically cancels out any side movement of the back axle.
Another option would be to add two air pressure sensors which measures the relative wind pressure. If there's a side wind the rudder will turn and cancel out the differential pressure