80 series 3rd row seat bolt hole CAD or positions?

[Potholesandwich]

Hey folks-
Do any of you have CAD for the locations of outside seat mounts? Or accurate measurements including relative position and angles? I want to design some stuff to replace the seat mounts but measuring bolt positions and angles accurately is super tricky.

I'm guessing you'd need a good scanner or FARO arm or something to measure well, but also curious if you've figured out a good way to measure those without. Sorry if this has already been posted somewhere. I couldn't find a thread. Thanks and I'll post whatever I make!

 

[PIP]

It's fairly straightforward to reverse engineer almost anything with basic measuring tools.

To measure threaded holes I like to use gage pins that are a tap fit in the minor and measure across the outside of the pins. Then subtract the diameter of one pin.

If you have any specific questions about obtaining the measurements you need I will try to help.

3D scanners are neat, but a lot more work than just measuring stuff in many cases.

 

[Potholesandwich]

Hi Pip. You are probably better at this than me! For me it's a heck of a brain teaser.

The forward two fasteners holes are not planar to the car's "flat" plane. How do I get the plane and position accurately relative to the bed, side wall etc? They are parallel to each other, so their relative position isn't hard for me...but figuring out where they are relative to everything else gives me a headache.

The three rear fasteners are even harder for me. Two are parallel to each other but not to anything else in the car. The third isn't parallel to anything. I'll (seriously!) buy you a beer and forever owe you props if you can accurately figure out their positions with basic measuring tools!

 

[PIP]

I'd think it would be no problem with a tape measure, 6" dial calipers and a Klein digital angle finder or manual protractor.

To figure out all the weird hole angles measure hole centers diagonally and across and draw circles with radii matching those measurements. Where the circles intersect is your huckleberry.

Use the angle tools to measure the angled section. Or just measure it with calipers and do some trig.

Your hole locations are all in 3d space. The ones in a different plane just need to be described in relation to the other holes.

If xx bolt hole is X0,Y0,Z0 all you need to do is describe every other holes relative position. The angled ones can be measured center to center than measured how far below the floorpan they are and at what angle. That gives you everything you need to draw it in cad.

 

[mudgudgeon]

I'd think it would be no problem with a tape measure, 6" dial calipers and a Klein digital angle finder or manual protractor.

To figure out all the weird hole angles measure hole centers diagonally and across and draw circles with radii matching those measurements. Where the circles intersect is your huckleberry.

Use the angle tools to measure the angled section. Or just measure it with calipers and do some trig.

Your hole locations are all in 3d space. The ones in a different plane just need to be described in relation to the other holes.

If xx bolt hole is X0,Y0,Z0 all you need to do is describe every other holes relative position. The angled ones can be measured center to center than measured how far below the floorpan they are and at what angle. That gives you everything you need to draw it in cad.

Kudos for the succinct step by step.

You do know that's a 120word word salad for most of the population?

Pretty sure he's talking about the seat mounting points on the wheel arches.

I've looked at those seat bracket holes and thought about building a storage system attached to them, but even as a skilled carpenter measurung and drawing this accurately enough to build something from is daunting enough that I haven't taken it on yet

 

[Potholesandwich]

Pip, Can you post a sketch or picture or explain in different terms what you mean by “measure…diagonally and across”? I'm trying hard to understand. Also, for example how do I use this technique to measure between bolt clusters with the equipment mentioned? The two groups of bolts are more than 6" apart. Larger calipers? Arbitrary datum location between groups of bolts? You mention a tape measure... but generally I don't think of that tool as precise enough for work like this, and the bulges of the wheel wells (wheel arches?) get in the way of straight line measurements. A sketch showing your technique applied in a non-planar situation would be super appreciated. I'm trying hard to make sense of the word salad

 

[PIP]

Pip, Can you post a sketch or picture or explain in different terms what you mean by “measure…diagonally and across”? I'm trying hard to understand. Also, for example how do I use this technique to measure between bolt clusters with the equipment mentioned? The two groups of bolts are more than 6" apart. Larger calipers? Arbitrary datum location between groups of bolts? You mention a tape measure... but generally I don't think of that tool as precise enough for work like this, and the bulges of the wheel wells (wheel arches?) get in the way of straight line measurements. A sketch showing your technique applied in a non-planar situation would be super appreciated. I'm trying hard to make sense of the word salad

A tape measure is generally accurate to the width of a line. The lines are about .01" wide. so +/- .005". Like many tools, it's how you use it.

The end of the tape measure is the inaccurate part. Don't use the end for precise work. It's called "shaving an inch". The actual scale part of a name brand tape measure is accurate.

You're going to draw this in 2D views or model this right? In order to do that you have to establish a datum, an origin point, yes? So you start at X0,Y0,Z0 and measure everything, make your drawing or your model.

I think geometrically, like old school drafting/CAD. I usually make multiple 2D views of a part/project then I will model it if I have to. I hate iterative design, it feels slow and dumb to me. Like starting a design without acknowledging the fundamental constraints.

I guess the answer to your question is you must supply the geometry whatever design method you are using requires. If you don't know what geometry you need to draw or model the part then we have an impasse?

If you have a SPECIFIC "how would you get this measurement from this location to this location" problem you can post a picture or diagram and I'm happy to help. "How do I measure something past a bulge?" Is not specific enough for me, sorry.

 

[Potholesandwich]

Hi Pip,

The thing I’m trying to measure is relative fastener locations, including angles, for 3rd row outer seat mounts for my ‘97 80 series Landcruiser (the title of this thread).

I’d like locations to maybe +/- 0.020” and angles to +/- 1.0 degrees. Nothing crazy high tolerance, but not sloppy.

I’m assuming you have access to an 80 series Landcruiser based on the fact that you’re on this forum, but if that’s not the case I can provide more information…. except not accurate location data for what I’m tryin’ to measure lol.

I’ve attached a picture of the mount on Driver Side. Passenger side is different, but a similar challenge.

For the sake of your question choosing a datum: Let’s say 0,0,0 is the center of the fastener hole that the bolt is in in the upper left corner of the picture. We need an angle too, so let’s also say that fastener’s axis is normal (orthogonal) to the reference plane. Can you take me step by stem from measuring that point and angle to the center and angle of the fastener hole in the lower right corner of the picture?

The distances apart are more than 6”, there is solid stuff between the mount areas. And...if any of this is word salad lemme know and I'll try to clarify.

 

[PIP]

I would start by measuring chassis zero- The angle of the rockers and cargo floor. I'd zero out a digital angle finder on that angle. Then I'd measure the fore-aft angles of the top and 45 degree bolt hole surfaces. If the angles are compound angles, measure them fore-aft and side-side.

The I'd hold a 123 block with one hand on the upper two bolt holes with one edge on the centerline and square to both holes. With my other hand I'd use a tape measure and measure from the lower corner of the 123 block to the center of the 45 hole at the top surface. Using a short straight edge with a digital protractor I'd hold it level off the datum bolt hole and measure straight down to the top center of the 45 bolt hole. Then I'd measure off something side-side in the vehicle. Either establish a centerline or just measure off the interior plastic, whatever matters for what you are doing.

There also a tool called a trammel which is basically two points that can slide and lock on a rod. These are handy for measuring around features pt to pt.

That gives you more than enough information to draw or model it in CAD.

Then I would draw those holes. Either 2 or 3 2D views or a solid model.

Then I'd measure the relationship of the horizontal bolt hole using similar methods.

I would look for symmetry in the geometry.

More work to type that than to do it I suspect.

Once you have things in CAD you can verify all your dimensions are correct in 3d space. Check with your eyeball and a tape measure.

I've reverse engineered entire vehicle chassis this way. I have an accurate model of my entire 100 year old 3400 sq ft house done exactly the same way.

 

[Potholesandwich]

understood thanks!