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Continuing on, the engine bay/transmission cutouts are complete.


It's all coming together nicely, if I do say so myself.


The Hougen cutter is always exciting to use. I got out my 1/2" drill and center punched/center drilled before creating the two holes used to radius the rear of the transmission cutout. You do not want this bit to get away from your while you're drilling. They make beautiful holes, though.


The gentle radius and angle translation are meant to tie the transmission mounts to the major crossmember behind it as well as the RHS of the tunnel structure itself.


In theory, I just have 5 straight cuts left to do, plus drill the plug weld holes, deburr it everywhere and I'm done with the piece and it's ready to weld in.

Cheers,

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

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

And I'd be chompin' at the bit to glue some steel together with the squirt gun

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

@horchoha
Sorry, Perry, but the motto around here is, "We will stack no dimes before it's time."

Cheers,

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

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

I'm almost done. The major cuts are done. Two minor pieces need to be created, plug weld holes need to be drilled and the floor need to be turned over and deburred before welding.

The setback margins for welding are turning out very well after a little hand work with the angle grinder and hand files after the saber saw and/or power shears are use for the initial cuts.


Cheers,

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

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

I think some hot weather is in order tomorrow, just to keep progress under control :p

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

@KB58
I know, Kurt, I know. I have been frustrated by the weather this summer so many times. My garage turns into a "sweat box" in the afternoons. I doubt I'll finish tomorrow as I need to do some test coupons to get my MIG welder settings right for both the floor-to-chassis-rail and plug welds.

Cooler weather is due on Monday. I expect to get it done by Monday evening, anyway.

Take care,

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

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

Hey Lonnie, trade you weather anytime.

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

Lonnie
You may want to consider adding a few drain holes in the center tunnel area of your new floor pan. It does not take long to collect stones and $hit in that area. The holes make it a lot easier to hose out the stones.
While putting in holes, you might as well add a 5/8" Dia. drain hole on both the LH and RH sides of the engine bay, right in front of the fire wall.
DaveW

@horchoha
Man, you guys are getting jacked around with your temperatures: up; down; up; down.

Locally, we refer to ourselves "weather wimps", Perry. We get very spoiled with the consistent, easy weather. However, this summer has been a lot of the weather variation you're showing in Holden, except the temperatures are going high and the humidity is going up right along with the temperature.

We're not used to it and it makes us very fussy.


@davew
Thank you for the suggestion, Dave.

I recently bought some rubber plugs off Amazon with the idea I could use them in the tunnel/floor pan. They're made for sheet metal, so they have an indentation where the sheet metal fits and it looks like they will make a nice seal. This sounds like a good time to make a plan for using them.

Cheers,

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

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

I'm looking for input from my welder friends. Looking around on the Internet/YouTube for good videos on plug welding, I can across the video below. It really appeals to me. It has 3 much simplified techniques, each of which applies to welding in my floor, at least on the bottom side facing the road.

Here's the YouTube video ==> https://www.youtube.com/watch?v=aoTFcYw_qwc

For me as an amateur welder, I don't get enough time in welding to produce the nice, crisp, consistent weld beads I'd like to see. These techniques simplify the process greatly, and I think will reduce hand fatigue over a large welding project like my 44" x 60" floor.

The questions in my mind are: 1) is penetration going to be good enough; and 2) is there a danger of creating "cold spots" in the welds.

Also, I made up my own idea of how I'll fasten the two, small, free-standing floor segments (photos below) at the front end of the engine bay. The green shows the 3 spots where I plan to effectively produce slots between the pieces to be joined. The idea is that I will use these slots to weld the pieces to each other and to the chassis rail RHS at the same time. I would fill the rest of the butt weld with essentially tack welds to close up the rest of the butt joint.

The red circles are where I'll need to drill holes to get a socket and nut/washer up to the motor mount bolts from under the car. The motor mount plates are welded to the chassis rails above the segments on each side.



Cheers,

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

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

You'll be fine Lonnie. Just make sure you find the right heat/wire feed balance. If your weld bead is piling up higher than the weld material it's 1) too cold a setting, 2) too fast wire feed, 3) you're moving the molten pool too fast. If you're burning through you are 1) too hot a setting, 2) too slow wire feed, 3) moving the molten pool too slow. I would sooner repair burn through than grind down non penetrating cold welds.
I watched the video and I do it a bit different when plug welding. For .065" steel floor I used 3/8" holes when plug welding the floor to the frame.
I start the weld at the center of the plug hole. This is the thinest part of the plug weld and is the frame material, so it heats up and gets penetration the fastest. I weld counterclockwise, so I move the arc counterclockwise within the plug hole without touching the floor material til it gets a bright red pool. Then going (wait for it....counterclockwise) to the floor material I move the arc in small circles around the plug hole drawing the floor material into the hole, you regulate your speed doing this as the added material takes more heat to penetrate. There is no burn through because I'm transferring from the frame to the floor/frame. Do this for 360 degrees around the hole and finish with the arc near the center of the hole. The end result is a plug weld no more than 1/16" higher than the floor material. This is easily ground flush if need be. If you could see the back side of the plug weld, you'd see a nice 'bump' at the center of the hole from good penetration.
As I write this it sounds like a lot of time but it only takes 3-4 seconds per plug hole.

By the way I use the same principle welding the edge of the floor to the frame. I start the arc on the frame, build the pool, then small counterclockwise circles to the floor drawing the floor material into the pool. You regulate the weld heat by how fast you move your molten pool. If it's getting too hot, spend a little more time drawing the floor into the pool. For this welding I go with CCCCCC's instead of small circles.
Practice with scrap material til you're satisfied with the results. Remember just about burn through is better than cold welds that look like chicken sh1t.
I am NOT a welder, this is just what I find works best for me.
Below is some chicken scratch drawing if it makes any sense.
I've typed so mush I r confused now.

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

Uhhh... When you put the word "welder" in there it kinda leaves me out. I'd do what Perry says, even if he did draw a purple daisy at the bottom of his message.


JDK

_________________
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

@horchoha
Thanks for taking the time to do that detailed write up, Perry. Your welds always look really good and they're very consistent, so I'm taking all you've written seriously.

The plug welds are the thing that has worried me most as (like you) welding tutorials recommend what you start in the center of the hole. Most say also to have the wire as closed to vertical at the start as possible to create a molten pool quickly. That's the finger nail biting part for me, as early on in learning to weld light RHS (I consider 16 gauge light), I did have blow through on my practice pieces. That's not something I want now as the chassis is coming to the completed state.

Most of the tunnel structure where the plug welds are located is 3/4" square, 16 gauge material. Like you say, I need to practice and experiment to see what works on some practice coupons. My first thought was trying 5/16" holes. Hole size seems to be an area where opinions differ. Some say 3/16" holes closer together works fine on 18-20 gauge material and 1/4" works well for 16 gauge. Intuitively, I thought 1/4" was too small and planned 5/16" holes all along. I'll give 3/8" a try too and see what happens.

I've spaced the plug welds at 1-1/2" apart, mostly because that's what looked good to my eye given the small and light nature of the tunnel RHS I'm plug welding to.

My thoughts so far about the other welds is 1" of weld bead spaced every 2" on the outside. Then, I'd weld 1" on the inside of the chassis rails in between any two outside welds where ever practical. Do you thinks that's overkill?


Cheers,

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

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

I believe I did 2" of weld with 1" spacing.
Attached 3 pics of the 3 car builds floor welding.

If you choose to weld on the inside you can aways do that once you've welding the perimeter on the outside. You can then decide if you want to weld the inside perimeter.

I stagger stitch welded all cross members (on each side of the sq tube) where ever I could.

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

@horchoha
That's more welding than I planned to do, obviously. Welding on the roll of the tubing put the weld where there's the most metal, but did you get any distortion of the chassis from welding the floor in, Perry?

With the alternating outside/inside weld scheme of mine, I'd have about 1/2" separation on the weld beads along the lower chassis rail, but they would be non-linear, as the chassis rails are 1" wide. So it's really about 1.4" absolute distance between them. I was more worried about distorting the chassis than oil canning when I came up with the idea.

Thanks for the photos, Perry.

Cheers,

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

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