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I think what you're really saying is you wanna be like Team Slotus, and start breakin' stuff!!!
And who can blame ya for that?

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

I hope I can be like you and break the small things. Sometimes I come back from the track with just a big pile of stuff on the trailer.

Decided I needed to do more welding on the frame, so turning it about and tacked some places I couldn't get to and also I don't really see being able to weld alternate joints on different sides of the frame so just filling in some of the welds as I go.

That is an issue with deciding to make tubes meet at the nodes. You have to weld the parts that are covered up by the other tubes. Next time I will work harder on making it easier to build as I go along. I make little decisions as I go along that land up making things difficult in the future.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

That's experience for ya - if only we could get it before cutting metal. As they say hind sight is 20/20!

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-Andrew
Build Log
Youtube

Marcus, a little pre-planning works for welding up those to-be-hidden joints. The fun comes when you need to fit a diagonal tube between two nodes and you have to cut off one of the fish-mouth lips to slide it in. Just don't drop the lip-piece into a downward sloping tube when closing the gap. The only way to get it out is to turn the chassis upside down and shake it. Don't ask how I know

Great progress. Keep up the good work

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Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52

Making progress on the welding. DId one side and then the other side, now doing the other other side (bottom).

I was doing a little checking using the Grape FEA program for things like coilover mount and suspension mounting points. Here's a screenshot of the very simple model I used to look at this. This model has the two frame rails of 1 3/8" x .083" tubing at the top and bottom with a vertical member of 1"x2"x .065" for the front bulkhead.

These pictures show a 10" piece of 1" square tubing attached 4" behind the bulkhead. This represents the coilover mount and it has a 100 lb. load on it. I could represent this a lot more exactly, but I find this type of general and simple model more useful to me because for one thing I can remember the results and apply them in other situations, it gives me a feel for the problem. So this should be the same situation as a 1000 lb. load on a 1" stub on the frame tube.

The numbers were crunched and the first picture shows the bending load on the stub attached to the coilover, it is about 14,000 psi. According to the mil test reports received this material it should be good for over 50,000 psi. Some quick mental double checking, we applied a 100 pound load on a 1" tall piece of material thru a 10" arm - that is a 10:1 lever giving us a 1000 lb load at the edge and the material is 1/16 of an inch giving 16000 psi. Hmm, the program measures these tubes from the centerline so I guess the lever is a bit short.

Second picture is the amount of torsion on the upper frame rail. It is only showing a few hundred psi so it is of no concern basically.

The actual plan will not involve a single stub to mount the coilover, but two to allow for double shear on the bolt. Or perhaps a piece of rectangle tube scalloped to hold the coilover. The numbers basically look good, but we would like to mount the top of the coilover outboard a little bit. So caution and a little attention to detail and making the mount strong all seem advisable.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Geeze, really??? None of the rest of us everrrrrrr do that kind of thing...

As for welding those hard-to-reach spots, it helps if you have a -ahem- "diminutive" partner that you can fold up and insert where needed...That's James, doing his impression of a taco, inside the frame welding up the fuel cell mounts. And he fits neatly in the overhead compartment. Saves tons of money on airfares!

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

Hmm, a fold up welder, you might have something there.

A bunch of the frame is done now so I dragged it out into the sun for a picture or two. THe sun doesn't get all that far above the horizon these days, but still it was fun to do.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Looks great, Marcus!...Although I think it needs at least one or two more wheels.

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-Justin

"Orville Wright did not have a pilots license." - Gordon MacKenzie

I stressed and strained to make the centroids of all my chassis tubes meet at a common point where ever possible. That sounds like your "node" notion from a different perspective. It created some overly complex joints from a cutting and welding perspective. In practice, it turns out that the joints done by Justin and Cheapracer are almost as strong, theoretically. In practice, they're probably stronger because the welds are easier to do and they're likely to be better on that account. Plus the amount of heat in the joints is less, so likely less distortion too. I'd do it more simply next time. Being practical, not perfect, has benefits. Next time!

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

Creative as always--using sunshine to add lightness!

Looking good, Marcus.

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Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52

I see what you did there...

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30 years old, not sure what I want to be when I grow up…

Yeah, I was gonna comment on that too, but you beat me to it Briggs... Probably because I was too busy groaning!

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

Just to be clear, I'm not actually 12 years old, that's my son in the pictures. Also it appears that I took JD's advice and shrank him down to 18" in the second picture for better welding help. But at the last minute I said no, don't be rash, that might upset the wife.

No picture yet, but today I made the tubes to finish the inner dash hoop. Look forward to welding them in tomorrow.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Here's what my diff support legs are looking like right now. I'm showing the drawing because I may have worked myself into a corner. When I went to the salvage yard I bought an Explorer diff because I thought they would be more available and they come with the rear cover I wanted to use. I suspect they have a lot more aluminum in the casing though. tHings like large reinforcement ribs for the pinion bearing. So I think it sits higher above my cross tube at the back of the floor, which I raised a few inches.

Long story short I am trying to decide now wether to cut out the cross tube currently in te car, which I already notched down 1" in the center or simply cut out the middle few inches and thing of a way to reinforce it.

At the moment my diff sits nearly 2" above where Tom has installed his in his car. His car has 2" or 2.5" more ground clearance but he is likely using taller tires.

So that's my problem and here is the rest of something like an explanation. Tom's car has a main roll oop that goes all the way to the bottom rail. On mine It only goes to the top rail. I don't see either way as preferable yet, what I did probably gives an inch or two more cockpit room, but I'm 6" shorter than Tom, go figure...

On this car the cross tube for the grasshopper legs is moved forward to the bottom of the roll hoop. Instead of a sleeve to capture the bolt mounting the rear diff cover, I am using a length of flat bar. I built the sleeves, but when I was holding them in place i was concerned about what would happen to the fuel tank if the car suddenly got 6" shorter in the rear. The bar stock will have another hole below the diff mount to bolt strap for supporting the fuel tank. It will also allow adjusting the height of the diff - so this car is more of a working prototype than Tom's is. The diff height will be adjustable to help with playing with aero under the car.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Marcus, your cricket legs look like an efficient alternative. Have you thought about triangulating the diff mount points out towards the roll hoop - top rail nodes?

To make things fit, it may be possible to cut away some of the Explorer diff case webs instead of the chassis.

My solution to the fuel tank “foreshortening” problem will be a race spec bladder. Not fond of the flambé notion. My tank will hang, in part, from the 1” square tube between the shock mount points.

Lots of room for creative alternatives aft of the roll hoop.

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Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52