'72 K5 - Greg's @MightAsWellK5 Build

[Greg72]

No speed holes (yet) but here is the progress from last night:


The interior side of the front heim brackets has an odd little notch in it so that it can fit snugly against the lower plate as well as the first vertical brace in the crossmember. I want to make sure that I build things with the fewest numbers of individual parts as possible for strength and uniformity.

I transferred a mirror-image of that pattern to the opposite side and was able to pretty quickly render the second inner plate. Here they are in position sandwiching the transmission mount plate. The front links are converged at a 34* angle... so each of these plates is angled outward at 17*. It makes buiding the crossmember a bit more complicated, but there is no angularity on the heims at ride height so I've got plenty of design margin when things are flexing.... no bind anywhere.

As a comparison, here is a shot of the inner and outer heim mount plates just before assembly into the monolith... you can see the slight differences in the overall size as well as the fact that the outer plates do not need any notches to install them.

(These remind me a bit of the stone statues on Easter Island for some reason)

Finally, I installed the heims onto the new brackets along with my .010" brass spacers and slid the whole assembly into place without any welding (yet). I still want to get a few more parts done before I start tacking things down.... and the underside of these brackets still needs to be tapered from 2" (heim side) down to 1" to match the available clearance underneath.

It is definitely going to be a challenge to figure out the proper weld-sequence for all of these items. Without careful planning it will be VERY easy to accidentally block access to areas that need welding, so I will need to come up with a plan to pre-weld some of the sub-assemblies, and to work from the inside-out....


-G

 

[82355]

So what's to become of your giant bolt?

Martin

 

[Greg72]

It's around here somewhere....

McMaster Carr is pretty cool about returns so ill probably send it back for beer money.


-G

 

[rdn2blazer]

Sick. Nice job Greg.

 

[tRustyK5]

Just a tip, I don't ever like to tack an inside corner...for two reasons. First I want to be able to burn into the corners nice and hot. Second, and sometimes a lot more important, is if you do need to break a piece out to re-fit, massage, change it's impossible to grind out a tack in an inside corner.

I like to tack mid weld area and edges of plates...

As for sequence, I see a few things looking at the pic's so far. Your biggest issue I think is going to be overall shrinkage. There are areas that will want to pull in, which I think you know enough to predict now. However the whole part may shrink 1/16"-1/8" overall. That probably won't be enough to create any problems.

Definitely want to weld that thing center out.

What bracing do you have planned so far?

 

[chulisohombre]

Wow that's a pretty piece of metal there. Tucks in perfectly. Would have been cool to see the adjustable bars but seems to be a ton of work. You can always do something with it later. I'm sure you'll have this rig for life so there's time. Lol. It's cool how you put it together so quickly from thought to metal. Sweet dude and many prouds of course.

 

[Greg72]

Rene,

I heard a voice in my head as I burned-in those corners..... Guess it was you!

The fitment was perfect before I did any of those welds and I checked and triple-checked everything because I knew it would be permanent. I just couldn't risk having any of the plates swinging out of position when I took the clamps off and putting a heavy tack on both sides of each corner pretty much guaranteed they would stay put.

I am not sure about bracing during the big weld processes. I was thinking of doing something similar to when I did the rear axle truss.... That backstepping style of welding, and alternating my welds on either side of the vertical braces so the cooling and shrinking is somewhat neutralized. I think it will help to have a lot of heavy tack welds at small intervals also so that the part is locked-down and won't be able to shift much across long welded sections....

-G

 

[Greg72]

......and now since this thread is a lot like Playboy magazine and none of you guys are here for the WORDS, I'll show you the PICS!


When we last left our fearless hero, the front brackets were coming together nicely and the complex plate shapes had been mostly completed. The only remaining item was to put the correct taper on the underside of those mounts...

KellyJohn watches from a safe distance.

A bit of measuring, and Dykem to insure that the plates would land perfectly, and as a sanity-check that the plates were not slightly warped (which they were)...

For my evening snack.....

Chicken. Chicken. Chicken chicken... Chicken. Chicken. Chicken, chicken.
Chicken. Chicken... Chicken. Chicken. Chicken... Chicken!! Chicken. Chicken... (with Siracha sauce)

There was one additional brace that needed to be fit up, and that was a 2.75" wide backing plate that sits behind the heim joints. This is the first component that I would install which would completely block access to seams that needed welding.... so I fully welded the areas underneath before tacking them into place.

A few more tacks were laid down arcross various spots on the monolith and then it was time to pour some heat into the front link mounts themselves... It's amazing how quickly welding skills are lost when you don't do it every day... The welds are strong and have good penetration (22.0V @ 435 ipm), but my technique was just a bit sloppy. I was weaving a bit too much across the fillet to draw my "C"s and in some places I was moving too slowly and the weld profile got a bit taller than I like. Fortunately, these welds are all hidden when the mini-skidplate ramp gets welded across these two brackets anyway.... so this will just be our little secret!

Here's a shot of those brackets from a low-angle viewpoint to show how little they will hang down below the framerail. Basically the center of the bolt head is where the skidplate is, so only 1" of bracket is exposed below that point...

The next step will be to start plating in across the top of the bracket to lock them down from above also. The original foam core template part is placed to show the general idea.....

More shop time tonight!!!


-G

 

[BARRAZA]

Question that I may have missed the answer to previously. How are you cutting all that steel? plasma then grind?, bandsaw?, cutoff wheel? other?

 

[tRustyK5]

You're on the right track there Greg. From the pic's your overall part looks fairly neutral as far as welds pulling and where it's braced and rigid. Really, as far as plates pulling and distorting my main concern are the cheek plates on each side that sit against the frame. The outer parts that are unbraced are going to pull in for sure, unless you do some serious bracing. It'd be nice to have a pair of decent screw jacks and some bar stock to put in between them. Push the edges out 1/4" past the target width dimension, weld it and it should come back and be close.

Make sure when you do your final tacking that your tacks are actually little 1/2"-3/4" long fillet welds in the range of 1/8" to 3/16". If you get them a little big you can dress em down a bit with the grinder. You can tack in even increments and back step it, and I think you'll have very good results.

The fit-up work looks excellent!

 

[y5mgisi]

Damn that's sexy.

 

[Greg72]

Question that I may have missed the answer to previously. How are you cutting all that steel? plasma then grind?, bandsaw?, cutoff wheel? other?

Plasma for the initial cuts... But surprisingly, I get a faster result on the subsequent cuts with a cutoff wheel. I can hold to a scribed line within maybe 1/32" with a cutoff wheel.... then a quick dressing of the edges against my 20" grinding disc finishes it off.

Got a few more "welded inches" finished up tonight, but I'll upload those photos in the AM.....


-G

 

[Greg72]

Here are a few more photos from last night's effort....

As mentioned previously, the challenge with a complex part like this is figuring out a way to gain access to weld all the seams and to avoid getting trapped along the way by welding the wrong parts first....

The transmission mount plate is a good example. It's a raised platform sitting roughly 1-3/4" above the bottom plate. The pocket it creates is very deep and it would be next to impossible to get a MIG gun in there to do any welding. The only choice then is to weld as much of that interior space as possible FIRST, then drop in the top plate and burn it in.... so that's what I did:

Welding gloves and Anti-Spatter spray do a good job of protecting the heims (and other parts) from the hot blobs that stick and ruin the look of the finished product.

I decided to put a small divider to add some extra support, but also to allow me something else to weld to from the top of the assembly. Since I still wouldn't be able to get the MIG in that pocket, it made sense to do a series of rosette welds from above into the top edge of that support.

....then the plate was dropped into position for the final time, tacked at the corners and then burned-in nice and hot. Finally, my weld technique was starting to improve again..... a gentler "weave" across the fillet and better attention paid to the puddle and gun angles.

As Rene mentioned.... it can be amazing to see how the heat of welding will pull and bend parts. Even 1/4" plate steel is no match for the heat/cool process and it's resulting shrinkage. Here is a shot showing a slight "wiggle" across the center of my lateral support plate. Fortunately this is not a critical dimension for anything else so there's no need to fuss over it.

It's been tough to plan out the welding to do a "from-the-center-out" strategy so far... there have been so many small contingent parts that needed to be attached before I could put the large x-braces into the assembly... but now those can finally go into place. Here is a parting shot for the evening showing the frontmost sections of that x-brace that begin to tie the front axle link mounts diagonally into the rear mount areas.

Sunday will probably be my next garage day, so at that point I will continue on the x-brace parts and try to get them all tacked into position in the center of the monolith. Then I can begin cutting out parts for the rear link mount hangers and tack those in as well.... I'm hoping the rear will be a bit less "fussy" to build since the rear heims are only 6" apart (heim-center-to-heim-center).


-G

 

[BARRAZA]

Plasma for the initial cuts... But surprisingly, I get a faster result on the subsequent cuts with a cutoff wheel. I can hold to a scribed line within maybe 1/32" with a cutoff wheel.... then a quick dressing of the edges against my 20" grinding disc finishes it off.

Got a few more "welded inches" finished up tonight, but I'll upload those photos in the AM.....


-G

I sometimes build some miscellaneous brackets for a homebuilder friend of mine that need pretty tight tolerances, and I have found the same thing. Cutoff wheels can be very accurate, and a torch needs too much cleanup. You must go through boatloads of cutoff wheels though. I was hoping you would tell me you were using an industrial grade bandsaw, it might give me an excuse to buy one.

BTW, this project is getting better and better. If you look back at the beginning, it was well thought out, but you have definitely progressed over the years. The trans/front suspension/rear suspension/skid plate multipurpose thing is what good designers strive for, everything serving more than one job. Another Proud.

 

[Greg72]

Thanks!

I'd love a DAKE sponsorship! Sometimes I watch the shows on SpikeTV and they cut out some small little tab on a DAKE bandsaw.... looked cool. So I climbed online to price one out a couple of years ago and it's something like $6000 - $8000!!!

On the flip side, I thought about buying a Milwaukee Portaband saw and the miniature bandsaw attachment from SWAG Offroad.... that would get me into a bandsaw for around $500 but I'm just not sure how precise or useful it would end up being. Ultimately, I don't have floor space for a full-size bandsaw so that's not really an option anyway regardless of price.

I do go through a lot of cutoff wheels, but since switching over to the WALTER brand that Rene recommended (instead of the cheap Norton ones from HomeDepot) I get better life out of each one. It depends a lot of how you use them... if you lean into the disc too hard, you don't cut any faster but you really burn through the disc. Also, I've found that when cutting plate it's better to come in from the end and keep the disc relatively low, so that the cut you make is mostly vertical. This seems to allow the debris to clear-out better and you make better cutting progress with less wear. If you try to cut along the line (from above) the cut is very horizontal and is slow going... it also seems to allow the disc to "walk around" more and it's harder to stay close to the scribe mark.

There is definitely a "finesse" aspect to using almost any tool in the shop. If you pay attention to the techniques that give good results it can be amazing how nice parts can look.....even when they're being made with a simple 4-1/2" cutoff wheel.


-G

 

[NorCal69]

Are you still using the 4.5" disks. I switched up to the 5" sometime ago and a least you don't need to change them out as often.

 

[Greg72]

Are you still using the 4.5" disks. I switched up to the 5" sometime ago and a least you don't need to change them out as often.

I still run my safety guard on the grinder, so the 5" wouldn't fit.....



.... unless I notched them on one side.



-G

 

[Chevy305]

I run 5" with my guard. They fit, barely, but they fit. I hate using cut off wheels without a guard. If you've ever had one explode on you then you know that guard is very important.

 

[tRustyK5]

I have had one explode on me...my Zippo lighter took the brunt of the hit. Looks like it took a bullet. My face shield had a chunk embedded in it too.

 

[Greg72]

2013.10.20 - UPDATE! - THE $10,000 CROSSMEMBER....

I don't usually think in those terms when it comes to my build projects, but as the crossmember project wore on for another week and the hours piled-up, for a brief moment the idea did cross my mind....."What would it cost to have a REAL fabrication shop design and build me something like this?"...

Sure, a fab shop will probably work faster and have cooler tools than I do... but if they had to design a crossmember from scratch and integrate all of the necessary features, cut it out, assemble and finish-weld it at a shop rate of $85 - $95/hr. the bill would be astronomical. At last count, I've got well over 100 hours worth of design and build time and probably at least another 20 hours before it's 100% completed and installed. Ultimately, I guess this is the reason why you simply DON'T see this kind of stuff happen very often through your local 4X4 shop.....

It's stands to reason also that even a great fabrication shop isn't ever going to love your truck the way that you do.... so there is very little motivation to get all the little details perfect. Those "extra" hours can't be billed anyway.... so if you want a truly unique truck that's EXACTLY the way you've imagined it you need to build it yourself. BUILT NOT BOUGHT!


To that point, this weekend I logged another 8 hours on the monolith. Most of that time was spent behind a welding mask laying down what seemed like miles of welds on all of the interior fillets. It was actually fun to get so much "trigger time" since it really did help me to re-learn the subtle techniques in welding that produce the best results....

Here's a re-cap of my weekend efforts:


First off was fitting up the major "X-Brace" component to the monolith. This is a critically important part since it is the focal point for all of the simultaneous loading from both the front links and the rear links.

Conceptually, it is simple: Two plates notched to cross in the middle with the necessary clearances made for the Atlas to nestle in between...

Assembled:

.....and dropped into position inside the monolith:

There have been some slight variations in dimensions as I converted my foamcore model to steel, and I thought it would be wise to do a quick sanity check to insure that the x-brace cleared properly before I burned it in permanently. At this point, the monolith is now too heavy to hold in place and slide the bolts in from the sides (like I used to do). The process is definitely more tedious and difficult now with a floor jack and spacer blocks...

A couple of areas needed some tweaking. The cutout for the Atlas was a little tight on the rearmost edge and needed to be opened up about 1/2" more. And inexplicably, the holes for the transmission mounts were off by almost 1"!!! No idea how this happened, as they match the foam model perfectly... but I suspect that when I made the side plates longer, it changed the "index" for where these holes needed to land. I marked up the new locations and clearances, moved the monolith back to the workbench and made the necessary corrections.

Then, it was time to do some welding.

Actually, a LOT of welding.

The plan was to follow Rene's advice and use a backstepping method for the welding and also work from the inside of the part toward the outside edges. I made some marks in specific intervals so that I could keep my welding process organized.

Here's is an example of how the welding was done. The first weld is the one in the center..... then I moved away to the mark roughly 3" off the weld bead, and weld back toward the first welded section until it overlaps. Then I move to the opposite side mark and back-step that weld toward the center as well. This allows the heat to stay a bit more even and not saturate the part from long, continuous welds.

After completing the interior welds on the x-brace, I took this shot of the backside of the monolith. It shows the HAZ marks (and the individual start/stops) really well... The uniformity of the HAZ in each section looks good to my eye, so I think the backstepping method is doing it's job.

Even after all of those lower plate welds were complete, there were still a number of vertical welds that needed to be completed. The very center of the "X" needed 4 vertical welds and each end of the "X" also needed to be burned in to the tall horizontal plates too... I decided on most of these to flip the part so that I could weld flat instead of trying to do a true "vertical weld". Mine always end up looking messy and it wasn't that much more effort to flip the part a few times....

At the end of the day, all of the interior joints were welded and were looking good.

Overall, the monolith is looking good, I don't see any obvious twisting of the part, and although there is sure to be some shrinking of the part overall this can easily be overcome when it's bolted tightly to the framerails.... drawing the framerails in by 1/8" per side won't matter, there is plenty of freeplay in the nearest bodymounts to compensate.

The final process will be the contruction of the rear link bracketry and getting it all welded up and joined to what's already been built. I'm guessing at least a few late nights this week, and maybe a full weekend day should be enough.....



-G