Traditional hobbyist methods of finding where to draw the X

[idrivejunk]

I wish to learn how each of you who is comfortable doing so would accomplish these basic 3D tasks, and ask that you outline your procedure fully.

No electricity may be used and no level parking surface or wheels / tires are available. Gravel driveway scenario but its a nice day.

Chassis origin is unknown but can be assumed undamaged and is made for the vehicle.

Are you ready? Thanks in advance.

I will use current "high-end" customer projects as examples but will not reveal my slipshod personal methods unless called for if-ter responses are given.

Just tell me how you would do it in your hobby shop, to your heart's satisfaction, but with no lasers allowed.

Like a math problem but the answers are how you determine final position of components. I want to know how it's done, educate me please..


1930 Ford coupe:

Install frenched 4" round, OE type "duolamp" tail lights in rear fenders.

About a 60/40 split describes how much lamp sticks up out of the fender and factory cut back edge of lamp bezel butts to fender hole edge.

Where the bezel overlaps the lamp housing. So the top half or more of the bezel is fully visible but the housing is completely hidden.

Please include both sides in your procedure.


1951 Ford pickup:

Same driveway and chassis scenario but not one bolt hole exists yet. Get everything in position to bolt together.

Each fender has a horizontal character line. Rears curve down behind the axle slightly. Where front fenders meet their extensions, the line is a gap but no matter. All points along that line, ahead of rear axle, must match perfectly front to rear as well as the rest of the body and lie parallel to frame.

Cab rear height on this OE design was originally controlled by a nonadjustable shackle and bushing arrangement which allows cab to sway.

Position all body parts correctly and assure fender lines follow each other and that all horizontals are parallel to chassis.



Hoping you will see fit to provide your take on such things, and that multiple individuals participate with different approaches, and that I have not made the parameters overly complex. Pick one or both "problems" and go to the chalkboard if you will. In quest of no bad angles. Writing "Eyeball!" would not be much help, for example. I see that as a fine tuning or checking method, mostly.

Much obliged. (tips hat)

[chimp koose]

coupe fender : find a position you like on one fender and cut it in . Then make a pattern of the cut out by placing tape all over the fender and over the hole .cut out the tape that is over the hole. cut the tape along the fender to body side as a reference edge . Take the pattern off (carefully ) and lay it upside down on the other fender using reference measurements to bottom of fender and the reference edge . Mark the position of the hole . I would also level the car side to side so you could use a reference guide of a stick or something taped to the trunk at an equal distance from the back of the trunk lid (parallel to trunk edge)to string a plumb bob down to each fender off the sides an equal distance from trunk center line for checking equal distances apart . If you already have one done you could also just remove both fenders and bolt them together at the mounting flanges to make sure you could mark the second one in the same spot . If all else fails just paint it metalflake as it would draw the eye hypnotically away from any minor discrepancy .

[chimp koose]

By the way , I am in no way a professional . I have spent the last 4 years staring at and avoiding any further attempts to make the passenger door on my coupe line up properly.

[416Ford]

For me the first part of installing the taillight would be to look at the car from a distance and find the right spot to put. then mock it up and go to the back side and look at it from a distance.  For me the flow is first, next would be to cut it in and make sure it flows as to not have a spot where water could sit when it rains on the car or when its washed.
Similar to chimp on the opposite side but I don't trust the numbers on old cars. Put the template where it should be and step back and make sure it is level. One fender could be rolled differently at the bottom then the other so measuring only gets you in the ball park.

I installed frenched taillights in my 46 multiple times till I found what I thought was a good flow. I have mine in the car about 3" further then most so they run parallel to the trunk line.

$.02

[WZ JUNK]

I have thought about this problem some over the years.  I have always wondered how they were able to add Quad headlights to cars in the early days of customs and make them the same side to side.

My thoughts would be to build a jig/fixture to hold both of the add ons in place based on the distance and angle I wanted them on the car.  Then attach this fixture to the car temporarily by careful measurement.  I suppose the fixture could also be on stands on a level surface and the vehicle is level with the floor.(everything in the same plane)  Once you have the part you are adding to the car in the position you want it, you build out to the part being added.  The fixture holding the add on could be made of wood or metal.  Our friend Sumner used a building technique like this for his land speed lakester.  He built a lot of the car out of wood and then removed the wood parts and replaced them with metal as the build progressed.  It allowed him to position the major components where they needed to be as he worked.  This gave him a good visual reference also.  I have not built anything this way but I have used some variations of this method.

Just my thoughts  

[idrivejunk]

Great replies! Keep them coming. I have responses but not time, at the moment. Hearing others' approaches is mighty interesting. I feared the thread would go unanswered but the response is encouraging.  

[phat46]

If I understand the 51 fender problem correctly, lining up the lines on the two fenders, I would level the frame, then put one fender where I want/like it, make the line level (parallel with frame) mount the other fender, or mock it up on blocks clamps etc. and simply stretch a string along the feature line on the already mounted fender to line up  the  feature line on the other fender.

[enjenjo]

I tend to go with what looks right rather than what measures right. For instance with a shorter tire, the front wheel looks better move ahead 3/4 to 1" ahead of the original position because most wheel openings are not symmetrical front to rear and if located in the original position when radically lowered it makes it look too far back in the opening. Moving it forward gives it a more aggressive look, like it is straining to move. By the same token the rear axle often looks better moved back because the taller tire in the rear tends to overwhelm the wheel opening. For instance when I do a 41 to 48 Chevy car the wheelbase ends up closer to 118" than the stock 116".

So when doing body modifications I measure, but if it doesn't look right mocked up, I will move it to where it does look right. So many cars are not symmetrical left to right it isn't funny. If the fenders are slightly different in width what looks centered on one side may not look right on the other.

When mounting a body on a prebuilt frame if the front fenders are attached to the body, that has to be taken into account when mounting the body. Get the front fenders right and go from there. I do have a Laser, and I have used it to mount bodies. It impresses the hell out of customers.

[moose]

What Frank typed is spot on for body /fender placement. For items like tail lights exhaust etc I use movable templates. I will take a piece of pattern board (cereal box, shirt board card stock etc) and make a pattern the size and shape of the light then use magnets or tape till the placement is pleasing to the eye. Then I will break out the measuring tools to set the other side. Exhaust placement is similar. A short length of tubing held in place and moved till it looks right.
As Frank stated sometimes the eye is a better tool than measuring do to the "tolerances" found on ancient sheetmetal!

[idrivejunk]

My measuring fetish has dulled in a decade of almost no hooks and chains and with old Fords anyway, it is mainly just a way to reduce the number of eyeball-and-reattempts.

Its still Friday so still busy busy but again, more excellent replies. Just what I was looking for.

A couple guys not heard from yet will probably (if time and will allow) rush to hand in their quizzes right as the bell rings. Their answers will likely be well thought out and I bet they even know who they are. ~:)

Its a really nice day so I'll take my time getting back here. I need a rip snort off the 455 real bad.

One thing though, in this hypothetical scenario I specifically wanted to exclude lasers. So I put no electricity but meant that. I thought about saying the year is 19-something but figured someone would out-know me on when lasers came into play. It doesn't have to be gravel, call it an uneven slab or asphalt. Don't be a'feared of the '51 question but do include cab / hood and core support plus bed in your panel placement approach if you tackle that one please.

Gosh, I haven't really documented my own processes on these tasks and would be hard pressed to report them accurately but I am impressed with the stack of wisdom building up on this thread!

Continue. Theres no wrong answers, this is the gathering of info from a trusted collective in order to help form my own decisions. Great tips here for beginners, thats a neat plus side effect. I will digest slowly and belch thoughts back in due time.


More. More!


Thanks, gents.

[jaybee]

Go out in the country and find a stop sign. Wait, that's to build floors.

Here's where I'd probably start with the 1951 Ford pickup:

Level the frame front to rear and side to side. Get two pieces of ABS pipe big enough to not sag across the width of the truck. Cut slots partway through each one at right angles to the lengths. Use a steel rule, saw, or just a scrap of steel to line those slots perfectly. Go to the other end of the pipes, just far enough away to be a little wider than the truck, and cut a similar slot in both pipes at the same time.

Now you have two pipes partially cut through with slots an identical distance apart.

Mount your first front fender. Now, set up your ABS pipes on stands, one just ahead of the truck, one behind, measured off the truck so they're parallel to their respective frame ends. Hang a plumb line on each side of the truck with the line strung through the two slots. Measure off the door frames of the cab, the bed sides, whatever you know is already centered on the frame to make sure the strings are parallel to the frame. Put a Level on the tubes and line levels to make sure your string is perfectly level and at the same height as your character line.

Now you have a sight line the same height all the way around the truck equally distance from the centerline on both sides.

When you're done don't lose that stuff, you can use it for your home wheel alignment.

[idrivejunk]

That center line is important stuff, I guarantee. My experience has been that during the measured phase, adherence to CL ought to be strict, maybe above all else. When the eyeballing starts it becomes less critical and if you've done your work there will be little fault to discover by eye. Just opinion, a dab of feedback and more to come as I digest the inputs.

Bodyman mind food feast.    I do best with visuals, how ever crude.

Heres about what I did. The steps on the 51 threw me and by the end I had like six inch slots for height under the radiator area. What a circus. But come on, the back of the cab came with shackles.  

Whether I ever put up proof of slaying that beast is another story. For eventually. Let me know if I flubbed this X splanashun up, (whether it makes sense, if you care to try to follow it) it was a mind trip and a couple weeks distant in memory. I laid out the A tail light today.

[enjenjo]

someone would out-know me on when lasers came into play.

My laser was a Christmas present about 1990. It's actually powered with a 9 volt battery. To use it to set up a frame, I set it at the rear, leveling the laser, and tack weld targets under the frame. Then I measure to the targets front and rear, setting the frame on stands, shimming them so the frame targets match the laser. Now I have something to work to.

Before I had the laser I did the same thing with strings and tubing and levels to do the same thing. This one was done that way for a frame clip  http://enjenjo.com/frameclip.html  You might find it interesting.

[kb426]

My garage floor was built to be a carport. It slopes 1.5" over 14'. If I had any idea how much grief it would cause me over the years, I would have paid extra to have it replaced before the contractor added the garage to the house when we purchased it. More hindsight from youth. I own multiple levels, machinest rules, several squares , numerous tape measures, a string line and a home made plumb bob. That is what I have used since my 1st build decades ago. Parallel, plumb and perpendicular are important to me. I center mark frame builds to use as a basis. I measure for equality to the best of my abilities and go forward from there. Perfection is never achieved. On the 72 and 78, both were rolled outside for a visual from a distance to see if the bed and cab were parallel. Truck frames around here have a tendency to be bent from use. They both have some shims to level the bed some. The 72 has a twist that I couldn't rectify. Once again, perfection is never achieved. I'm an amatuer and lack the space and desire to build a good frame table to make the projects way better. I used to trust my eyes with how proportions looked but not so much with age. Optical illusions occur with brain functions decreasing. We all agree that sometimes things just don't look right. It doesn't matter what methods are used as long as the end result is good. I do think I will purchase a laser level. I really don't know why I didn't do that 20 years ago. Duh would be my answer.

[idrivejunk]

My string has a nut tied to the end. Theres not 4 of anything same height to set stuff on and that has plagued me too. As has varying suspension heights at each corner.  But my last body build is done, to the best of my knowledge. I have never spliced a frame, never wanted a spliced one, and hope to never be asked to do that. Did trim horns off the front of the 51 frame. I don't have the skill to splice frames nor do I condone it. No use buying a laser level now, the era of need has passed and I tried to rule that out. I did see mention in Frank's link, of wheel position within fender lips.

The shop stall I work in is actually remarkably flat and level and for the most part, fine for the necessary degree of accuracy required when as you say... perfection will not be achieved. With a Shark system I could locate everything with unibody accuracy. Or once could. The hanging target approach was used by one measuring system long ago. I have been known to level a stick of tubing across a ladder on one end and lift safety screw jack on the other, as something to measure things from above with.

A new aftermarket chassis merely serves as a straight foundation in the context of this thread and on these examples. Building straight frames just isn't relevant to my part of the discussion. But the same principles apply to body parts. Eyeball is most important to me on exterior panels but measuring alone would be sufficient for me when checking a new or repairing a damaged frame.