DMac's F1000 Build

[DMac]

I know that many of you have been asking about my F1000 design, so I finally decided to start a thread for it. Right now, I have designed the frame on SolidWorks and performed simulated testing on it. Attached are images of the frame and simulation images.

My target date for completion is January 2011, just in time for those early season races. *knocks on wood*

Once I get back to school and SolidWorks, I continue on this project in earnest.

Plans from here:
Insert GSXR cad model and work on motor mounts
Add front suspension mounting points to frame and design front suspension
Insert "stock" parts into assembly - wheels, brakes, steering wheel
Design rear suspension and suspension/differential/wing mount assembly
Design an initial body and wings
CFD CFD CFD CFD...
Check everything over a.k.a. GCR compliance
Build it

Shouldn't be bad at all, eh?

[RussMcB]

Excellent. Welcome. Best of luck. Look forward to watching your progress. I think you'll find plenty of help and support here.

[RobLav]

Looks like a neat project with good design progress.

Recommendations;
- Check the GCR for rollhoops requirements before moving along much further

- Don't forget that the bottom of the chassis can be riveted and bonded shear panels. You might not have the need for as many tubes on the bottom.

- Think ahead about spring/damper mounts integrated into the chassis, as well as bell crank location.

[DMac]

Looks like a neat project with good design progress.

Recommendations;
- Check the GCR for rollhoops requirements before moving along much further

- Don't forget that the bottom of the chassis can be riveted and bonded shear panels. You might not have the need for as many tubes on the bottom.

- Think ahead about spring/damper mounts integrated into the chassis, as well as bell crank location.

I looked at the GCR while I was building it, but I will definitely go back and check it. Much better to fix it now while I am still working in pixels.

This was my first pass at building just a frame. Once I get back to SolidWorks, I'll start adding mount points, etc.

[Mike B]

- Don't forget that the bottom of the chassis can be riveted and bonded shear panels. You might not have the need for as many tubes on the bottom.

For that same reason, you should consider square tube for the bottom rails to give more bonding surface.

[Northwind]

D Mac,

You're off to good start. Keep the updates coming.

Have you looked into your suspension upright design yet? I would be willing to bet there are a few guys watching this thread that have some great parts available for your application. You may want to look into sourcing a variety of parts to tie your geometry together. From a person that has built a couple of cars from scratch, you will need to start cutting metal in the next couple of months to meet your completion date.

Good luck and welcome to the F 1000 ranks.

[na94]

I am fairly new to Simulation and Flow Simulation, so it's not obvious to me what you are using for your fixture points, and where you are applying your forces and their resulting vectors.

Also, what factor of safety are you designing for? I'm guessing the material you are using is 4130?

If anyone wants to post a primer on how to correctly analyze a chassis for crash-worthiness and for rigidity when seeing loads through suspension pickups, I am sure that there would be a few of us quite interested.

Also, what environment are you running in? I am trying to do some external CFD in 3D with WinXP x32, however, I receive errors about not having enough continuous free memory, so I can only solve a 2D domain. I will be upgrading to windows 7 x64 tonight in order to take advantage of my processors and additional memory. Any advice on this front?

[DMac]

I am fairly new to Simulation and Flow Simulation, so it's not obvious to me what you are using for your fixture points, and where you are applying your forces and their resulting vectors.

Also, what factor of safety are you designing for? I'm guessing the material you are using is 4130?

If anyone wants to post a primer on how to correctly analyze a chassis for crash-worthiness and for rigidity when seeing loads through suspension pickups, I am sure that there would be a few of us quite interested.

Also, what environment are you running in? I am trying to do some external CFD in 3D with WinXP x32, however, I receive errors about not having enough continuous free memory, so I can only solve a 2D domain. I will be upgrading to windows 7 x64 tonight in order to take advantage of my processors and additional memory. Any advice on this front?

In the simulation pictures, the purple arrows are the forces, and the green arrows are the fixtures.

I am running Solidworks with XP x64, but the computations are run on a server on my network. Moving to x64 will make a big difference.

[Rick Ross]

Also, what environment are you running in? I am trying to do some external CFD in 3D with WinXP x32, however, I receive errors about not having enough continuous free memory, so I can only solve a 2D domain. I will be upgrading to windows 7 x64 tonight in order to take advantage of my processors and additional memory. Any advice on this front?

What 3-D CFD application do you plan to use with Windows 7x64? Thanks.

Rick

[na94]

What 3-D CFD application do you plan to use with Windows 7x64? Thanks.

Rick

SolidWorks Flow Simulation.

Ah, I notice the forces now. Explains the stresses =P

I'm assuming the roll-hoop is a multi-part surface?

[DMac]

The hoop itself is not, running from the floor, through the bend and back down to the floor. I specifically designed it to be one piece.

[nulrich]

SolidWorks Flow Simulation.

SolidWorks Flow Simulation is not capable of useful formula car aerodynamics, for several reasons: (1) it doesn't handle viscous effects or real boundary layers; (2) the brick meshes aren't accurate enough at any reasonable mesh size, nor is the mesh control fine enough to produce small elements where you need them and larger elements where appropriate; (3) it can't run the 10M to 25M element meshes you need to accurately analyze a half model of a simple formula car.

There are some other minor issues. I wouldn't waste your time, you'll just get bogus results, models that never converge, and system crashes.

Also, unless you're very experienced at CFD on formula or sports racing cars, you're unlikely to model the problem correctly. There are lots of little techniques and tricks of the trade that it takes years to learn. I have a PhD in mechanical engineering, a strong academic background in fluid dynamics, and a fair bit of practical aerodynamics experience, and I wouldn't attempt CFD on a formula car myself.

I would try to find someone who is a CFD expert, preferably with some experience with automotive CFD, and who has access to proper CFD software and convince them to do your aero design.

On the main roll hoop, if I'm seeing it correctly, you aren't in compliance with the GCR. There is a minimum width of the legs where they attach to the floor.

Nathan

[DMac]

I would try to find someone who is a CFD expert, preferably with some experience with automotive CFD, and who has access to proper CFD software and convince them to do your aero design.

I am a current member of the Team for Advanced Flow Simulation and Modeling at Rice University (http://www.tafsm.org/). Finding an CFD expert should not be an issue.

On the main roll hoop, if I'm seeing it correctly, you aren't in compliance with the GCR. There is a minimum width of the legs where they attach to the floor.

One (1) continuous length of tubing shall be used for the main hoop member with smooth continuous bends and no evidence of crimping or wall failure. The radius of bends in the roll cage hoop (measured at centerline of tubing) shall not be less than three (3) times the diameter of the tubing. Whenever possible, the roll cage hoop should start from the floor of the car, and, in the case of tube frame construction, be attached to the chassis tubes by means of gussets or sheet metal webs with support tubes beneath the joints to distribute the loads. It is recommended that gussets be used.

I assume this his what you are referring to. IIRC, I based the radius of my bends off of this.
R=3*1.375" = 4.125" I'll check my model when I get back to it on Sunday.

[nulrich]

I am a current member of the Team for Advanced Flow Simulation and Modeling at Rice University (http://www.tafsm.org/). Finding an CFD expert should not be an issue.

I apologize, I misread the previous posts and thought you were using SolidWorks Flow Simulation, but it was "na94."

CFD expertise is helpful, but direct experience with formula cars is necessary as well...or at least access to someone who has that experience. Very different from road cars or aircraft.

I assume this his what you are referring to. IIRC, I based the radius of my bends off of this.
R=3*1.375" = 4.125" I'll check my model when I get back to it on Sunday.

Nope, I was referring to part of 9.4.5.A: "...On Formula cars and single seat Sports Racers the vertical members of the main hoop shall not be less than fifteen (15) inches apart (inside dimension) at their attachment to the chassis."

Nathan

[DMac]

I apologize, I misread the previous posts and thought you were using SolidWorks Flow Simulation, but it was "na94."

CFD expertise is helpful, but direct experience with formula cars is necessary as well...or at least access to someone who has that experience. Very different from road cars or aircraft.

Nope, I was referring to part of 9.4.5.A: "...On Formula cars and single seat Sports Racers the vertical members of the main hoop shall not be less than fifteen (15) inches apart (inside dimension) at their attachment to the chassis."

Nathan

Accepted. I will be using Fluent for my CFD analysis.

I see what you are referring to. I think that I will decrease the angle of the hoop from 180 degrees to a smaller angle that meet this requirement. Nothing a few geometric calculations can't solve.

I just want to say thanks to everybody for the constructive feedback on my design.

[MartinRacing98]

I assume this his what you are referring to. IIRC, I based the radius of my bends off of this.
R=3*1.375" = 4.125" I'll check my model when I get back to it on Sunday.

Also notice 2009 GCR 9.4.5.A

"....On Formula cars and single seat Sports Racers the
vertical members of the main hoop shall not be less than fifteen (15)
inches apart (inside dimension) at their attachment to the chassis...."

[MartinRacing98]

Also don't forget this when getting the 15" of separation.

"Main hoop: 4 bends max., totaling 180º ± 10º"

[na94]

Good to know, I wasn't expecting a lot from something that could run on mydesktop

My interests are purely educational, although I'll see if I can locate a copy of Fluent somewhere for fun.

SolidWorks Flow Simulation is not capable of useful formula car aerodynamics, for several reasons: (1) it doesn't handle viscous effects or real boundary layers; (2) the brick meshes aren't accurate enough at any reasonable mesh size, nor is the mesh control fine enough to produce small elements where you need them and larger elements where appropriate; (3) it can't run the 10M to 25M element meshes you need to accurately analyze a half model of a simple formula car.

There are some other minor issues. I wouldn't waste your time, you'll just get bogus results, models that never converge, and system crashes.

Also, unless you're very experienced at CFD on formula or sports racing cars, you're unlikely to model the problem correctly. There are lots of little techniques and tricks of the trade that it takes years to learn. I have a PhD in mechanical engineering, a strong academic background in fluid dynamics, and a fair bit of practical aerodynamics experience, and I wouldn't attempt CFD on a formula car myself.

I would try to find someone who is a CFD expert, preferably with some experience with automotive CFD, and who has access to proper CFD software and convince them to do your aero design.

On the main roll hoop, if I'm seeing it correctly, you aren't in compliance with the GCR. There is a minimum width of the legs where they attach to the floor.

Nathan

[MartinRacing98]

I keep remember things. GCR requires bracing forward from the main hoop.

[DMac]

Thanks for remembering. It's easier than digging through the GCR myself.

[Rick Ross]

Good to know, I wasn't expecting a lot from something that could run on mydesktop

My interests are purely educational, although I'll see if I can locate a copy of Fluent somewhere for fun.

"OpenFOAM" is a public domain CFD application, but I think that it may require a Linux/Unix platform.

[stephen wilson]

GCR also states if you go over the 180 deg bend you must use the next higher tubing classification. ( but you can exceed 180 )

[na94]

"OpenFOAM" is a public domain CFD application, but I think that it may require a Linux/Unix platform.

I have played around with OpenFOAM, and it does a lot more than CFD, however Flow is a far sight easier to use.

[problemchild]

I would suggest that anyone designing a race car would have the appropriate rulebook(s) in one hand and a creative tool (mouse, pencil, ?) in the other.

That's probably considered "old school" though.

[Billy Wight]

Just a coupe quick suggestions:

1) Finite element analysis can be tricky. Without a good amount of experience and understanding of the underlying theory, it is easy to get a incorrect results. One big pitfall of the analysis is that even though the results are incorrect, you will still get a fancy looking colorful picture to incorrectly base design decisions on... In the case of your chassis analysis, your model is over-constrained. By using fixed constraints throughout the model you are adding artificial stiffness to the chassis. It is especially visible in the second picture. If you were to cut off the chassis behind the front suspension points and re-run the analysis, you would get the exact same result.

2) Chassis design should be secondary to nearly every other system. The chassis is simply there to connect the dots. By starting with the suspension design, aero, and packaging, you will be able to connect the dots and hold everything together in its "optimum" place in space. Starting the car design with the chassis and adapting everything to fit inside it isn't ideal.

Keep us updated on the progress. Good luck, and have fun!

[DMac]

The chassis is simply there to connect the dots.

I had not thought about the design like this. I just had an "eureka" moment. Can't wait to build all of the "dots" first.

[DMac]

I have reconsidered my design process. I am starting from square one more or less. Tonight, I laid out a "jig" to design my car on. Its dimensions are based on the min and max dimensions in the 2010 GCR. It represents the maximum width, maximum overhangs, and minimum wheelbase. In the picture, the tires are constrained against the outside of the plate. Their position will change accordingly as my suspension design progresses.

The wheels that I am using for the model (so far) are 13 inch BBS. The front tires are modeled after Hoosier 43289 slicks, and the rear tires after Hoosier 43293 slicks.

[DMac]

I would suggest that anyone designing a race car would have the appropriate rulebook(s) in one hand and a creative tool (mouse, pencil, ?) in the other.

That's probably considered "old school" though.

The new GCR is open on the computer whenever I am in SolidWorks.

[S Lathrop]

Why minimum wheel base?

[DMac]

Why minimum wheel base?

That distance is just a placeholder for now. I needed a distance to separate the axle centerlines, and I have not decided on an actual wheelbase.

[DMac]

This afternoon, I was quite productive. I designed and modeled some motor mounts for the GSX-R1000 and the spindle for the center-lock rims. I began designing the upright.

[Wren]

If you get to design the upright from the ground up, do a radial mount caliper. Radial mount should be better all the way around.

Wilwood has some cheap 4 piston calipers that are ok.

PFC has a new set of radial mount calipers that are very, very nice. They are expensive though.

[DMac]

If you get to design the upright from the ground up, do a radial mount caliper. Radial mount should be better all the way around.

Wilwood has some cheap 4 piston calipers that are ok.

PFC has a new set of radial mount calipers that are very, very nice. They are expensive though.

How is the radial mount an improvement over standard post mount or floating mount calipers? I tried to find a coherent answer through Google, but I did not have any success.

Anybody?

Plans for this afternoon are working more on the upright and the rear hub. Next part will be suspension.

[S Lathrop]

Mountings can influence caliper strenght and torque loadings during brake application.

[DMac]

I see. A normal post mounted brake is mounted in single-shear usually.

[S Lathrop]

Look at the geometry of the force developed at the brake pads and the mounting of the caliper.

[R. Pare]

Radial mount calipers allow the upright to be 'wider' at the mounts, as well as allows the mounts to be closer to the rotor centerline.

[lancer360]

I am using a Wilwood Powerlite 4 piston for the rear brakes on my F600. It is a nice light weight radial mount. From what I understand some DSR's use them also.

[Billy Wight]

This afternoon, I was quite productive. I designed and modeled some motor mounts for the GSX-R1000 and the spindle for the center-lock rims. I began designing the upright.

DMac,

Like the chassis, the upright is just a fancy bracket that connects the dots. I suggest designing the suspension kinematics first, that will determine where your outboard pickup points as well as your brake packaging, then design the upright around that. And as others have said, radial calipers are the way to go.

[DMac]

I have worked out some of the geometry on the front suspension. For now, rod ends are just floating inside the wheel, waiting to be connected by the upright. I am designing around an unequal length, non-parallel a-arm setup. I am going to add in some anti-dive to keep the front wing from dragging under braking. Currently, the a-arms are parallel and in a position that gives zero camber and castor. The next step is positioning the a-arms to give the proper amounts of camber, castor, and anti-dive.

Front track: 1600mm 63in
Rear track: 1550mm 61in
Wheelbase: 2590mm 102in
Wheelbase/F Track: 1.619
Millimeter values are exact