'72 K5 - Greg's @MightAsWellK5 Build

[Greg72]

.....and welcome to Page 41.

Not much new to tell from this weekend. I welded up the remaining pressed steel centers so that I am now ready to CNC four more and press them into the remaining hoops.

I also started trying to cut 3.5" long slugs out of that 2" steel round bar. So far I've got 5 done...with 5 to go. Even with my "special" Sawzall blade the work is slow going.




-G

 

[bp71k5]

'72 K5 - Greg's "Might As Well™" Build - !!! HEAVY METAL MADNESS...!!!

Greg,

Maybe the guy cnc'ing the centers also has a lathe to cut the round bar? Would be super simple on a lathe.

 

[Greg72]

Greg,

Maybe the guy cnc'ing the centers also has a lathe to cut the round bar? Would be super simple on a lathe.

Brian,


Oh, I'm sure it could be done there..... they've got multi-million dollar machines there, and LOTS of them.

The problem is that I don't want to use up all the good will on things that aren't 100% critical. I can cut the solid rod myself.... it's slow and lame, but I can do it.

Ultimately, once they are in smaller and more manageable pieces they end up going into a lathe for the taper and threading processes. From what everyone is saying, I don't need a very sophisticated machine to do it... so I can get help with that project from several local sources.


-G

 

[Greg72]

2014.12.03 - UPDATE! - PUNCH LIST PROGRESS...!!!

Unlike those cool car building shows on TV, real-life builds are often filled with slow and frustratingly dull process steps that have to be completed before the "fun stuff" can begin again.

Such is the status of this build currently.

The last few sessions have been nothing more than just logging hours on rather boring, repetitive stuff as you will soon see.....

For example:

Cutting 2" solid slugs into 3.5" lengths (5 down....5 to go!)

Welding up the small 1/8" shim plates on 4 more wheel centers (at 4 plates per wheel) and 36 rosette welds per wheel.... Fortunately, they are 100% finish-welded now and waiting patiently for scheduling of the CNC processes to mate them to the outer hoops.

With those items out of the way, I needed something a bit more "creative" to get the juices flowing again. I have been staring at the rear strut mounts for several days now and decided to add the next obvious support braces to the assembly....

The process ended up being somewhat straightforward. The C-pillar notch came in at 25* which was easy to cut with my notcher. Unfortunately, the longer opposite side notch was about 65* and slightly beyond the adjustment range of the notcher. It took a bit of hand-fitting and shaping but eventually it dropped into place with nice tight joints. As always.... the first tube took a couple of hours, and the second tube (For the drivers side) took about 20 minutes.

Those bars were an obvious decision, and once I install a beefy C-pillar cross sill underneath like I already did in the B-pillar area there will be some good strength and distribution of loads into the cage structure.

Where I'm still coming up short is in the support of the inboard (double shear) tube. The more I look at it, the more it becomes clear that it can't just hang out there without SOME kind of down-bar to lock everything together...

At this point, I'm just trying to decide if I should run another diagonal bar from that inside tube to the B-Pillar or C-Pillar... I need to keep the rear seat area as wide-open as possible.... so even though the easiest and most direct way would be to go straight down to the top of the framerail, that isn't really an option.

For those of you in more moderate climates, this won't make any sense... but for those of you in the northern states, I have added a new "tool" to the workshop and now need to find space for it every night when I do my clean up... It helps to give context to this build and everyone will know that I have now transitioned to "winter build" mode.

I also did a bit of shopping for titanium sheet, just to see what sort of pricing I could get. I'm not sure if 1/4" thick is going to get the job done as a skidplate or not, but as you can see.... the prices are pretty breathtaking even at that relatively modest thickness....

Guess I'll wait a bit longer before I make a final decision on THAT purchase.


-G

 

[bp71k5]

If the strut has room in the wheel well without rubbing the tire, couldn't you drop a tube parallel to the strut straight down to the frame, or really close? The frame looks like it needs some reinforcement from that giant notch anyway. Maybe design a bracket that beefs up the frame notch and has a spot for a tube to land?

 

[Greg72]

If the strut has room in the wheel well without rubbing the tire, couldn't you drop a tube parallel to the strut straight down to the frame, or really close? The frame looks like it needs some reinforcement from that giant notch anyway. Maybe design a bracket that beefs up the frame notch and has a spot for a tube to land?

This is an interesting idea!

The only hiccup will be how to still allow the cage to be removable, and how to adjust it (for height) as I shim the other cage mounting points for door gaps, etc.

Perhaps some kind of traditional "plate mount" at the top of the wheeltub so that the upper part of that tube stay connected to the rollcage, and the lower part stays fixed to the frame?


-G

 

[folkenheath]

Have you considered 7075 aluminum for the skid plate? It has a tiny bit of Titanium in the alloy and about 73 ksi yield instead of 40 ksi like 6061. Yes, the titanium can be stronger at 120 ksi, but it's also about 60% heavier than the aluminum, so the AL could be a little thicker and not weigh more than the titanium. It also should be a lot cheaper than pure titanium. 7075 is not very good for welding but I am assuming you are just bolting a flat piece to the bottom.

As for those slugs, if you are having them cut the taper on a lathe, I wouldn't be cutting them to length, it's easy enough on the lathe to cut the taper, then cut it off at the correct length and slide the material out of the chuck and start the next one. The slugs might actually create more setup time if they have to flip it over to finish the taper, and then there isn't much material to grab onto so they might need a front support, etc. I would just take a bar long enough to make 1 extra slug, and that will work good.

 

[blazinzuk]

Your at full bump right now correct?

Soo while I assume you are gonna do this gonna ask anyway. The suspension needs to be cycled here pretty quick with a temporary strut mount to determine it's a actual location. Pretty sure your on that though.

So to keep everything below eye level ( out of the window) I would add two down tube going from your armrest bar to the 2 new tubes you put in last night. This will add to the armrest bars rigidity.

That idea breaks all sorts of rules I go by when doing a cage but to me this is just attached to the cage. This is about the strut mount more than anything.

Have fun coping those bad boys

 

[Greg72]

Have you considered 7075 aluminum for the skid plate? It has a tiny bit of Titanium in the alloy and about 73 ksi yield instead of 40 ksi like 6061. Yes, the titanium can be stronger at 120 ksi, but it's also about 60% heavier than the aluminum, so the AL could be a little thicker and not weigh more than the titanium. It also should be a lot cheaper than pure titanium. 7075 is not very good for welding but I am assuming you are just bolting a flat piece to the bottom.

As for those slugs, if you are having them cut the taper on a lathe, I wouldn't be cutting them to length, it's easy enough on the lathe to cut the taper, then cut it off at the correct length and slide the material out of the chuck and start the next one. The slugs might actually create more setup time if they have to flip it over to finish the taper, and then there isn't much material to grab onto so they might need a front support, etc. I would just take a bar long enough to make 1 extra slug, and that will work good.

Heath,

I haven't really spent much time thinking (seriously) about skidplate materials yet.... that titanium sheet comments were just to shut up the haters who call my build fat!!!

Honestly, there are probably all sorts of fun ways to design a skidplate for strength while keeping the weight reasonable. I could use traditional steel, with speed holes all over it (to cut weight), or some kind of cutting board (UHMWPE) material backed with a thin, strong metal sheet to give it a bit more durability...or perhaps just a few strategically placed structural rails so that I could use a flimsier material (like UHMWPE) and not worry about large unsupported spans of material which would be likely to crack.

Your at full bump right now correct?

Soo while I assume you are gonna do this gonna ask anyway. The suspension needs to be cycled here pretty quick with a temporary strut mount to determine it's a actual location. Pretty sure your on that though.

So to keep everything below eye level ( out of the window) I would add two down tube going from your armrest bar to the 2 new tubes you put in last night. This will add to the armrest bars rigidity.

That idea breaks all sorts of rules I go by when doing a cage but to me this is just attached to the cage. This is about the strut mount more than anything.

Have fun coping those bad boys

Eric,

Yes the truck is at full-bump (front and rear) in all of these recent photos. The rear is longer strut, so I've got the rear tires on more blocking to take up the extra inch of bump travel.

If I follow you.... you're saying to put 1 tube on each side, starting where the upper strut mount will be, and then landing the other side as a "dead node" about 1/2 way across that new rear diagonal tube???


-G

 

[blazinzuk]

Yep you will end up with a dead node on either side of the tube. It didn't look to me like going to the frame was doable and your still gonna end with a dead node.

I think the best way to do it would be build the tower for the strut than run a tube vertically between the upper horizontal and the 2 lower bars. But then I would also run a roof bar between the two tower bars. I know you don't wanna do that. So just kind of throwing stuff out there

 

[blazinzuk]

In all reality though if the strut mount is built correctly. You should be fine with no extra tubes there.

The inside bar is just a bracing bar, not the one that carries the main load. Building the strut tower with that in mind no more tubes.

I still favor the vertical bar going from the top of the strut tower to the horizontal bar above it. Then one going across the roof area.

I should think some before I type

 

[tRustyK5]

Greg, on skidplate material, look into "Hard-Ox" in 11 or 12 gauge. Incredibly strong, very abrasive resistant, and shouldn't horribly expensive.

 

[AJs72K5]

Those strut braces are the first thing you've done that really cut into your interior and passenger space. The rear seat should still sit between them, but shoulders and/or elbows will be smashing into them.

 

[NorCal69]

Those strut braces are the first thing you've done that really cut into your interior and passenger space. The rear seat should still sit between them, but shoulders and/or elbows will be smashing into them.

Shhhh, he was going to make the thing into a three passenger rig for the longest.

Let him keep going.


Real question... How many 1.75 sticks do you have in this thing so far?

 

[bp71k5]

The only hiccup will be how to still allow the cage to be removable, and how to adjust it (for height) as I shim the other cage mounting points for door gaps, etc.

Perhaps some kind of traditional "plate mount" at the top of the wheeltub so that the upper part of that tube stay connected to the rollcage, and the lower part stays fixed to the frame?
-G

Since all your other body panels are removable, maybe the wheel wells could be removable too? Then you could fab a cage plate somewhere in the notched area (and clear the link mount at full bump too) and drop a straight tube down onto a plate. Could shim the plate as needed.

Or use those tube disconnects? Strength might be a concern there and no shimming possible.

 

[kgblazerfive]

Are you going to make the bars that run in front of the wheels to the rock slider mounts bolt in able ?

Or are they going to stop at the floor and be bolt in.


I wasn't saying it was fat, it is phat, well "mound of round, of rebound" kind of phat.

 

[Greg72]

Yes.


-G

 

[lectric80]

Hmm, ATI is a few miles from me, I wonder if they could get me a discount on titanium sheet by buying from the source? Might save a few bucks.

 

[Greg72]

Quick partial update......

Wednesday night progress.


Figured out my mount height and then built a plate to lay across the parallel tubes to support it.

If one plate is good, then building TWO (one for each side) is even better.... (except if the idea doesn't work out. Then it's 2X worse!)

Needs more triangulation!!!

This is the hat I built for NorCal69's "Pity Party"....

It obviously gets a nice radius at the top to get rid of the pointiness, and will get plated-in on the leading edge for strength. This is basically a copy of the design I used for the front strut mounts, the only difference is that the overall height is larger..... meaning that there is plenty of room to sneak some "speed holes" into these plates! (I will probably NOT put holes on the inside plate since that would be too tempting for little fingers sitting in the back seat).

The other nice thing about this layout is that the spacing of the vertical plates allows me to completely avoid having to build around that bend in the double-shear support bar. These plates are inboard just enough that I can just let them run straight across.

The nice thing about building these hangers first is that it's starting to reveal some interesting ways that I might be able to tie them into the diagonal down-bars in a simple way. Small plates with speed holes could be dropped in to connect everything together tightly and simply.

That's your update until Sunday.


-G

 

[jekquistk5]

This is the hat I built for NorCal69's "Pity Party"....

Making it look easy. Triangles and squares are so much easier to do then slugging tubes. Then spending hours making a not so good body lift.


Speed holes are a must if you want to keep your easy adjustability for ride height. I guess you could always remote mount a schrader valve somewhere.