Alberta Canada Build Fiat Spider Based

[mohle]

I'm worried enough about eventually tackling the hood & scuttle. Can't imagine the work to properly form a complex curved piece like the nose.

Trying it is the whole point of it. Figuring it out how it is done is the reward!

From what I can tell, I will need to build it out of at least 4 pieces: top, sides and bottom. My scuttle is essentially built on a buck, one that staid in place. I just stretched the metal around the flat bar that I used as a frame. Alone the flat bar was rather week and flimsy. Once I wrapped the sheet metal around it, it got really solid.

scuttle frame



creating scuttle metal cutting template



metal cut and rough fitted



metal stretched around frame

[cs3tcr]

I'm sure you seen Sean's post, but here's a link to where he started on the nose for his Kurtis build: https://www.locostusa.com/forums/viewtopic.php?f=23&t=18818&start=60

[mohle]

That is one nice build that Sean is doing.

Got a little done on the wire frame buck. Here is the first piece. I will build it into a 3D shape from here.

[Miatav8,MstrASE,A&P,F]

Nice looking rolled edge on the cowl. May want to keep that removable until you fit a wiper linkage/"transmission". A protruding lip out of the cowl is useful to support (through a glued rubber strip or push-on weatherstripping bulb) and maintain alignment the hood edge, but you could make the hood rigid with ribs spot welded or riveted if there is enough rib-engine clearance.

[JAMADOR]

Luckily, I don't plan on running wipers, nor a full windshield. Will keep the 'tab' extension for the hood in mind when I get to that point.
Not a bad idea to rib the hood, for support, as well. My current vision is to do a split/center hinged hood, rather than a lift-off, but we'll see what happens 'down the road'.

[mohle]

Nice looking rolled edge on the cowl. May want to keep that removable until you fit a wiper linkage/"transmission". A protruding lip out of the cowl is useful to support (through a glued rubber strip or push-on weather stripping bulb) and maintain alignment the hood edge, but you could make the hood rigid with ribs spot welded or riveted if there is enough rib-engine clearance.

As I'm using a Fiat engine, it's not a true book build. A bit of freehand design. Different engine height, but pretty close to book. I enclosed the scuttle so I can better use a straight edge for the proper contour, slope and curvature for the nose frame and hood shape. The hood support lip will be 19 gauge 3/4" wide "L" shaped sheet metal spot welded to the firewall and nose cone end. This can then be covered with some edge molding to cut down on any rattling noise and to protect any paint. I was even debating putting a bar down the middle of the hood, between scuttle and nose cone, and mount two hood halves. I could make it removable if I need to get the engine out. As you said, I could run some beads down the side to give the hood some stiffness. Until I get my distributor relocated, I may put a "power" bulge in the hood above it anyway. If I did it to the top on both the left and right side, it would also significantly strengthen the hood. Ironically my Spider had them. It may even look nice. Will have to see where to go with all that.



Hood support cross section, nose cone end would be similar.

[mohle]

Ran out of rod for the buck. So until I get around to picking up some more, I started to try and figure out my front control arms and steering. Anyone know where there is a good reference on ball joint dimensions? The studs taper from 17 to 14 mm. Very close to 11/16" to 9/16". Or is it best to just use Fiat ball joints and modify the con A-arm design to match? I completely forgot that the steering knuckle is removable. In theory I could make it front or rear steer. The kingpin angle I'm getting is 8 degrees. Does that seem about right?

[marafonets]

Ran out of rod for the buck. So until I get around to picking up some more, I started to try and figure out my front control arms and steering. Anyone know where there is a good reference on ball joint dimensions? The studs taper from 17 to 14 mm. Very close to 11/16" to 9/16". Or is it best to just use Fiat ball joints and modify the con A-arm design to match? I completely forgot that the steering knuckle is removable. In theory I could make it front or rear steer. The kingpin angle I'm getting is 8 degrees. Does that seem about right?

I see that you have a steering knuckle from a VAZ))). And you are looking for standard ball sizes. Here I hasten to share))

The kingpin angle 7 degrees.

[davew]

"The kingpin angle I'm getting is 8 degrees. Does that seem about right?"
8 degrees is right in the middle. KPI is typically 6 to 10*.

[Miatav8,MstrASE,A&P,F]

Ditto, though some newer applications can have up to around 15deg. 70’s fiat 124 is 6 deg KPI, 2.5-3 deg caster.

There are refs for commonly used commercial racing joints and oem tierods but not a published list of specs for oem LBJs and UBJs. Precise measuring of the boss or pin is needed with each ID and distance between them to determine the taper. This is compared with measurement of other oem joints and fine tuned with a reamer if needed or adapted to a known taper joint. Reamers can be very expensive.

If the oem joints are available, reasonable, and the spring is applied to the original joint, I’d use them. Reamers to adapt a taper are expensive though now you can buy taper inserts, but it all adds up.

For front or rear steer, swapping sides on the arms or the spindle are also worth consideration.

[mohle]

Nose cone buck taking shape. Never done anything like this before. Kind of fun actually.

[sony1492]

It's looking good!

What materials did you use for the wireframe and the process for copying aide to side?

[mohle]

It's looking good!

What materials did you use for the wireframe and the process for copying aide to side?

It's made out of 1/4" round cold rolled stock. It's relative inexpensive and won't easily deform when you clamp your sheet metal to it to verify it's shape. You don't actually bend bend metal over it, just verify. It is literally bent on a home made tool that I got off of Wray Schelin's Youtube video. I drew out a 1:1 drawing of the shape and bend the wires to match. You can see the side view drawing if you look close at the buck picture. The buck is resting on the drawing. The dimensions are on a previous page in the post, and also available online. It can be a little tedious, but once you get a hang of it, it's not bad.

Here are some videos on the buck making and on the tool fab. [youtube]https://www.youtube.com/watch?v=DLagys65iD0&t=929s[/youtube] and
[youtube]https://www.youtube.com/watch?v=yYn5JIx8aQQ&t=1062s[/youtube]

[mohle]

Didn't have a lot of time last night, but made a little progress on the buck.

[mohle]

Had to take out some frustration and hammer away on something. Started to build the center console. The recessed area will be where the parking brake will be mounted. A lot more shaping to do, but starting to look like something. Might even put in some cup holders.