LocostUSA.com

Online metals sells cold rolled sheet in 1008 and also 1018. Unlees people think otherwise for some reason, I'm suggesting going with the 1018. It has a little more carbon which makes it stronger and stiffer. The tubing is 1020, so it's a more similar material.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Ok, 1018 it is, and ready for me to pick up at Will Call tomorrow along with some 2.25" aluminum rod for the bushing hats.

In the meantime, I made up an aluminum prototype tab for the upper TA. Easier to take a picture than describe it. Only one tab of the two tab over-under pair is shown.

This tab has the tightest clearances. The pen line near the jam nut shows where trimming will be required. The scallop drawn on the angled side shows an area likely needing relief as well. The tab will be welded to the UCA tube along the edge under the spring clamp.

The tabs for the lower TA will be beefier as a larger rod end is involved. No trimming should be required for clearance on these.

Marcus, as you've eliminated the roll hoop down-tube in your build, the roll hoop clearance issues should not occur.

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Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52

The tab looks pretty good, you're leaving a generous margin around that 1/2" hole. I am wondering whether it makes sense for the bolt hole in the Hennessey Hat to be offset by 1/4" or 3/8"? Maybe that's just another way to run out of tire clearance.

I think it will be OK to include the bung when welding on the tabs. Just a little more painful to make though...

Does anybody know if you should thread something into the bungs when welding them to keep them from distorting or corroding on the threads?

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Certainly not, I have trapped my fair share of bolts inside learning from experience.

Keep a good quality hard tap on hand for the cleanup, I have also trapped soft cheap taps and lost the part before today. The welding can turn the thread into a surprisingly hardened and distorted state. About 50% need the tap run down them. Oh and use a blind hole or bottoming tap if possible, not a tapered one which can get locked in by the taper, whereas the blind hole tap has square edges that just cut their way through. I use a dry lube usually, but in this case use oil.

I wish I knew this much about females ....

100% agree with Cheapracer here. You don't want anything threaded into a bung or nut as you weld it in place (other than tack welding). The internal threads will likely distort and then you have all kinds of fun trying to get the threaded fastener back out. Depending upon what you're welding and how close you are to the opening, if you're MIG welding you might want to cover the end with alum foil or something else to keep spatter out of the internal threads.

And there is an amazing difference between a sharp high quality tap and a cheap POS tap (which are usually duller brand new than a well used "good" tap). Often times the cheap ones are also oversized (effectively a H3 or H4 instead of and H2, for example) and therefore the thread fit isn't as good as it should be.

JustDreamin

Any brand names you can throw us on some good Taps for this general purpose?

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30 years old, not sure what I want to be when I grow up…

Its all getting very busy on and around that top joint , as you have adjustability on the top wishbone inner rod end it may pay to include one of these joints below on the outer and fabricate the bracket for the top of the four link off of it.

http://www.keytebearings.co.uk/

Bob

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Build Log viewtopic.php?f=35&t=16640&p=187700#p187700

Mancave http://s1116.photobucket.com/user/mypic ... ow/mancave

OSG, Cleveland, Greenfield, Hertel - All pretty good stuff.

Depending upon where you're buying, you can get good (not as good as above, typically) but cheap stuff. An example would be ENCO (use-enco.com). They are a machinery / tooling vendor (actually a sister company to MSC) that does discount stuff. Their low quality stuff is almost always better than say Harbor Freight's best junk. The cheap stuff from good vendors will fair pretty well under many circumstances, but not well enough under really demanding environments (100's of holes or tool steel or SS, for example). But if you've got an application (like say 3/4"-16 threaded bungs) that only need to have threads chased, not cut, and you're not likely to use the tool much else,an import tool may serve you well and cost a bunch less (Enco's Interstate = $18, Hertel = $35, Cleveland = $65).


Also, there are different kinds of taps. The standard hand tap typically has 4 flutes. My personal preference is to use spiral point taps for most every application. They're really only recommended for through holes, not blind holes, because they push the chip forward, but they cut much easier and are stronger since they typically only have 2 flutes (less material cut away). But they're more expensive, and have more limited availability. And don't confuse spiral point (also called gun taps) with spiral taps and some of the other specials out there.

Hope that helps a bit,

JustDreamin

Bob, at the moment the plan B for that link would be to use a kit from Whitby Motorsports that puts a spherical bearing inside the bushing hole. When those kits are used you put a U bracket on the end of the radius trod - and your right that makes a nice way to weld on the tabs for trailing arm.

I'm torn between the choices but this approach looks a bit simpler and cheaper. It also allows for a larger rod end than the internal spherical bearing. This bearing does not take loads from the coil over, but does see axial loads from the brakes.

I spent a little time trying to think how to put a bigger bearing in there, it would fit a 3/4" mono ball (spherical) bearing, but I'm not sure how to retain it.

Tom are the bearings in the Whitby kit easily replaceable? I'm trying to remember if they are held in with a snap ring. If they are held by a snap ring I wonder if they move back and forth because it seems you would nee a little clearance to install the snap ring...

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Bob, thanks for stopping by and your thoughts on using spherical bearings, that area does get busy and has been the subject of a lot of offline discussion. Current plan is to use a 1/2" x 5/8" rod end with Hennessey Hats in that upper "bushing" hole as Horizonjob mentioned (also in the lower front hole) and a Whitby spherical bearing kit in the lower rear "bushing" hole which carries the spring load.

Marcus, as I understand it, the spherical bearing is positioned by shouldered finger sleeves on each side which are then held in place by the U bracket. A 14M bolt goes through all of this clamps it all together. Shouldn't be any wiggle and easily replaced. O-rings hold the pieces together until fit into the U bracket. A snap ring helps hold the outer sleeve. I have a pair of the Whitby kits on order and will post photos of them when in hand. In the meantime, here's Whitby's website http://www.whitbymotorsports.com/UInvDe ... oryid=1610 with more info in their instruction manual http://www.whitbymotorsports.com/upload/irskit.pub I believe the kit was originally built for the FFR Cobra IRS set up.

JustDreamin and CheapRacer, thanks for the education on taps and their use. I was just about ready to head out and buy a tap to clean-up some threads that have a little heat distortion. I'll be a lot smarter now.

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Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52

Got to load the all-metal bushings into the T-Bird knuckles today. Two of the bushings holes will be filled with aluminum hats. The third will use a Whitby spherical bearing set. Here's the set of hardware:

The hats were nicely machined from 6061-T6 by Kartracer47. Thanks again, John.

The spherical bearing kit came from these folks http://www.whitbymotorsports.com/UInvDe ... oryid=1610 and was originally developed as an option for the FFR Cobra IRS. Each assembly consists of a steel sleeve with a 5/8" FK spherical bearing mounted inside. The bearing is mounted against an internal shoulder and held there by a snap ring and Loctite. The smaller diameter sleeves fit into the bearing and extend out to fit against a surrounding U-bracket. The O-rings keep the road crud out. Its all held together with a 14M thru bolt.

Here's the hardware assembled in the knuckle:

The bushings are pressed (lightly) into the knuckle. Loctite 640 Sleeve Retainer helps hold the pieces in place. The Whitby assembly is further retained with a snap ring. Thru bolts tie it all together with the suspension.

The aluminum bushings will bolt to UCA and LCA rod ends. The spherical bearing bracket also connects to the LCA. Stay tuned...

_________________
Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52

Im so confused as to why one has the fancy bearing and the other 2 done but I'm sure that will be explained when you get the control arms finished and the uprights installed.

Looking forward to seeing the rear suspension finished and it becoming a roller.

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30 years old, not sure what I want to be when I grow up…

Hey Joshua, I was working on your model tonight. I have this detail wrong in it. What's going on is that when the coil over is mounted to the control arm instead of bolted to the upright, it puts a big bending load on the shank of a rod end. So where you have that case you use a spherical bearing instead. It's just like a rod end bearing, but it doesn't have the threaded part and fits into a sleeve. On your model I need to redraw the control arm and put the spherical bearing on the back of it. You'll see that makes doing the toe adjustment more difficult, but not impossible. If we can mount the shock on the front of the control arm that will be better. I think it was hard to find room for it though.

On the bottom arm it's nice to have one rod end so that you can adjust the toe. The brakes will still try to bend those rod ends so we are using heavy duty ones that have a larger shank.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

Geeze, what beautiful work!!! Reminds me of the Cadillac ads from a few years ago, "Art and Science"...

Nice work on the aluminum bits, Kartracer! Good stuff with the spherical bearing in the one "arm" to counter the load from the coilover. Makes perfect sense... Good work, Tom and Marcus! And a good explanation of the reasons behind it. Either of y'all ever considered becoming teachers?

I'm goin' out to my cave now, and pound on a rock...


JDK

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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

Joshua, its like Marcus said, only he said it much better than I could have.

Today I'm waiting arrival of some AN bolts from Aircraft Spruce so rod ends can be bolted in and work on the trailing arm tabs can move ahead. Some mock-up photos of how that will look can be found a few posts back.

Oh, and the aluminum bushing hats were inspired by John Hennessey's design. For awhile we were calling these "Hennessey Hats."

JD, at least your rock rolls

Part of the reason for the detailed build posts is an open kimono approach to a new 7-ish chassis design. Lookin' for feedback from the community while also providing Marcus feedback on build issues (and questions) as they come along. As the old saying goes, "You can always tell the pioneers by the number of arrows sticking out of them."

_________________
Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."
Ultima Spyder, Northstar 4.0, Porsche G50/52