Projects Introducing the Roofus Special

very cool build!

 

very interesting home built speedster. good work!

 

Any updates on the boattail? Prime driving seasons here and that thing aint gonna finsih itself. I wanna see it on the ground!

 

I'm anxious to get back to it. I'm not real sure when I will get a chance. I just swapped jobs and it looks pretty crazy for the short term. Hopefully I will have things under control when the weather cools off.

 

I'm going back to my old job (in two weeks). Hopefully I will get a chance to play with this thing again.

 

Some belated inspiration for you, Flipper: http://www.jalopyjournal.com/forum/showthread.php?t=720448

I hope this doesn't get you rethinking too much ...

 

Bags are packed. After work, I'm headed to dad's place to play! Temps are supposed to be bearable this weekend.

 

The front spring rate had to be tested. The only way to be sure that it would work with a-arms was to mount the a-arms....
I made tabs from a piece of 2x3

Bushings in the arms




And a video of dad making stuff move. Springs are just sliding on greased a-arms.

 

It needs shackles and hangers.
the same axle that gave up the spring pack


The plan is to cut and turn the end.

 

TADA!!

I decided I need to see what the rear spring rate was like before I got too carried away with the front.....

It HAD to be on all four corners at once.

 

The springs are soft on both ends. The rear sagged more than I was expecting. It needs to be adjusted up an inch or so.

I sent this pic to my wife and asked if the noticed anything different. ...her response was "new duck tape?"





red panels back on





Dad making racecar noises

 

It's been a while since I've seen this.

 

There is, of course, the theoretical alternative: http://www.speed-wiz.com/calculations/suspension/leaf-spring-calculation.htm

or: K = (WN/12) x (1000t/L)³

K = Spring rate
W = Width of leaves
N = Number of leaves
t = Thickness of one leaf in inches
L = Length of springs in inches

 

Sweet!
Great to see it off the work bench finally! I've been watching this for a while and always look forward to an update. Nice work Flipper.

 

Yeah, there is that "math thing" too. ....but I don't know what spring rate I really need. This has been a seat-of-the-pants type build from the start.

 

It is nice to see it at close to ride height. Overall I am pleased with the body shape that is evolving. Its hard to get a good pic shows how cool of a shape that random sheetmetal pieces can make. The cowl area is gonna be neat when it is all welded together and and painted a solid color. This is the best picture. The small red piece is the piece that came from the door opening. This was the first time I tried it at the top of the dash. I like it.


This sucker is low.

 

Looks like a real car and not just parts now! Reminds me a lot of an early Indy roadster. Will be a bit tough looking over that long and tall hood!

 

Looks kinda like a car on the driver's side....

The final seating position will be a couple inches higher with a cushion on the seat. I feels pretty good as is though.

 

Yeah, but just a couple inches higher on that car will make a world of difference!

 

Another big reason that its on the ground....I've been needing to roll it over and weld all of the bottom joints. I have to make myself do that before I get too much farther.

I also plan to box in the front frame rails at the same time.

 

That's always the way. The math isn't that hard, it's all the other information; stuff like material yield strengths and moduli of elasticity and the like, that engineers use every day but I have to scrounge somewhere and then not be quite sure that I haven't got the wrong end of the stick.

I've gleaned some useful fragments, though, like the way static deflection is a good indicator of ride quality. That is quite easy to calculate from the weight of each end of the car and the spring rates. If the weight of the car (with fuel and yourself and everything you need in it) compresses the springs 10" to reach ride height, you've got a very soft ride (0.99Hz). If the springs are compressed only 2½" on the same weight, the ride will be decidedly firm (1.98Hz). Most passenger cars will have a static deflection around 7", and a frequency around 1.2Hz.

See http://www.rqriley.com/suspensn.htm

At the risk of appearing officious, I'm a bit uneasy about the bracing to the bay just behind the root of the frame rail. It feels like the compression in the top part of the rail would want to bend the first post in. I'd be inclined to triangulate back to the space-frame from the top corner of the rail, thus:

 

Loving every post.

 

Maybe just add the lower of the two diagonals that Ned drew in. That would "fix" the triangulation good enough.

 

Ned, that weakness has already been brought to my attention. My idea for a fix is to add a lower diagonal and then extend the "front frame boxing plate" down the side of the chassis.

 

That should fix it!!

 

man Flipper! this is an awesome thread! makes me wanna go chop something up! great job on the fab work! keep it up!

subscribed!

 

That'll be one totally bitchin' ride !!!!!! Keep us posted re; progress..... Can't wait to see more of it !!!

4TTRUK

 

That C clamp looks like a pretty cozzey arm rest too!

 

It was pretty comfy. I sat there for like two hours, just checking things out

 

For those on the board that can draw...

Anybody want to take a stab at what this thing will look like when done?

Feel free to take any artistic liberty you want...tweak what you think needs tweaking.