Technical FRAME, Chassis guys - give me some feedback!

Did some fooling around with the measurements you gave and my stock A-frame. This is 7.5" back and 7" up with the kick in line with the normal frame taper. I modeled the joint as a 'double Grimlok' cuz it was easier not knowing what the angle would come out to.

I left the stock rail on the pass. side for comparison.

Note that the rear of the frame is now wider by 1.3" or so and the angle of the kick is almost 51°.

If you don't want the frame to get wider, then the cuts on the rails should be perpendicular to the centerline of the frame rather than being perp to the outside of the rails. Everything else would come out close enough for filing and welding, I think.

SolidWorks is a CAD software with it's own native format as well as the 'normal' CAD formats. Just happens to do .jpg and .gif, too.

Hope this is helpful and not too confusing.

Chris

 

That's cool.
I like the colors. think I'll repaint my frame!

 

All good stuff, guys,
Can I make a suggestion?
Make sure the kickup is far enough in front of the axle to allow for radius rod clearance. you can see there is plenty of room in the pic from 345window's site. If the kickup was further back, it might foul the radius rod.
I was lucky on Old Rusty, there was enough clearance, though I didn't plan for it. On the front kickup on the Pop I had to rework it as there wasn't enough clearance.
Mart.

 

[ QUOTE ]
All good stuff, guys,
Can I make a suggestion?
Make sure the kickup is far enough in front of the axle to allow for radius rod clearance. you can see there is plenty of room in the pic from 345window's site. If the kickup was further back, it might foul the radius rod.
I was lucky on Old Rusty, there was enough clearance, though I didn't plan for it. On the front kickup on the Pop I had to rework it as there wasn't enough clearance.
Mart.

[/ QUOTE ]

Damn good point Mart.
It only applies if the radius rods aren't split but definitely IMPORTANT!

Another suggestion.
Something manufacturers find helps design development with their their prototype models, (otherwise, why would they spend LOTS of money doing it?) in various scales...
I think it's a good Idea to mock up all this stuff on a 1/25th scale model first. I chopped the top on a model truck with the exact same cuts I was planning on the steel one before actually cutting the real deal.
No I didn't waste rod building time finishing the model.
I still have it in pieces unpainted, unassembled.
I just used the mods on it to confirm that my planned cuts would work.
just use a caliper and your calculator to check the modification measurements.
AMT is pretty accurate.
Buy a few Model A kits and USE them for research!

 

This has kinda been bugging me, since I saw it....and I may be wrong. I'd like some thoughts.

This joint (or joints- 4 of them). GRIMLOK- I'm concerned about the crossways welds (in RED in the pic). It forms a shoulder at a stress point. A weld, here, is a potential crack waiting to happen.

 

Here's a quick thought on frame "stretch". I just made up th term, but it fits.
Under acceleration, the rearend wants to spin (upwards in front). That pushes forward on the radius rod, and thus, the frame. Add that to the already pre-loaded (weight of the car) frame, and those joints want to "straighten".... the upper rear, especially.

 

[ QUOTE ]
This has kinda been bugging me, since I saw it....and I may be wrong. I'd like some thoughts.

This joint (or joints- 4 of them). GRIMLOK- I'm concerned about the crossways welds (in RED in the pic). It forms a shoulder at a stress point. A weld, here, is a potential crack waiting to happen.

[/ QUOTE ]

Not only is that an area of high stress, but there's a weld there in every common type of joint I can think of - not just Grim's. Best bet in all cases is to reduce the stress overall (by adding a center rib or overlaps, etc...)

As was mentioned above, you also have to leave enough clearance for radius rods, etc..."damned if you do, damned if you don't"

As my welding instructor told me many times, "A good weld is at least as strong as the base material". No cause for concern if your welding technique is good. This is where fishplates and overlaps help - they reduce stress in the joint as a whole.

Chris

 

[ QUOTE ]
Here's a quick thought on frame "stretch". I just made up th term, but it fits.
Under acceleration, the rearend wants to spin (upwards in front). That pushes forward on the radius rod, and thus, the frame. Add that to the already pre-loaded (weight of the car) frame, and those joints want to "straighten".... the upper rear, especially.

[/ QUOTE ]

I think we went through this before with Harlan-book-smart... but when you anchor the rear wishbone in more than one spot... and then the rearend (or front end) with the spring in another spot... that radius rod/hair pin no longer just forces in the forward direction...

Anyway, I think most of these are sound designs... not neccasarily pretty, but sound enough to hold up under most driving conditions... so, weld away.
Sam.

 

I agree... There's alot of cars with Z'd frames, and you don't see them broken in half all over the roads. I'm sure every one has a different layout. The body/body mounts act to strengthen the whole thing, too. It's just, as a repair welder, I know what breaks. After all, it IS only steel...
I can see GRIMLOK put alot of thought and effort into the job, and I don't wanna piss on his pillow. That might be the strongest joint in the history of hotrodding... That's why I asked.

I guess I'd still like to see a plate, at least on the inside corners... (don't weld the ends...)


JOE

 

More work, but it’s stronger. The length of the welds are longer/stronger!

 

^^^^ this is exactly how I do all my angle cuts ^^^

It gives full width of tube while more weld area and no straight weld seams making it harder for the weld seams to fracture from twisting.

Like I said do all mine this way, here's a picture of my rear crossmember. You can easily see the added strength thru added weld seams and no straight seam to flex and fracture.

..

 

Dude, you just replied to a thread that has had no posts in 20 years!
This may be a record

 

Could win tech week competition, which reminds me, what happened to it.

 

why do people freak out about old threads? information is timeless and its good to keep the information in one place instead of scattered all over the site

 

Hell I learned something new……

 

Good information is good information, no matter when you get it…

 

Yep. As someone who reads almost every thread that pops up regardless of whether applies to my current project if I remember reading a zombie thread I may skip ahead when it pops up. Otherwise it's a "new" thread to me. Good info here. I sometimes wonder if it might be cool to have a random zombie thread of the day/week to bring back some of the old discussions for us new guys.

 

At the bottom of each page on here, you can select any page listed, including the 5 digit page number on the far right.
If it’s actually a record, did I win anything?

 

See post 49…click on the 5 digit # and work your way forward… (15570)!

 

You guys do realize this thread is more than 20 years old. HRP

 

Post a question regarding tech advise everyone says use the search function been discussed before, search and find a old thread and ask follow up questions every one posts how old the thread is....

 

I posted because of the very thing @trad27 brought up.

I spend a lot of time building and researching every aspect of my tudor build.

I have used the search function countless times to find things or at least try too, I hate it when I will find an old post on the very thing I'm wanting to know and finding either the thread is incomplete with follow up and/or answers.

I don't care the age of the thread, only the content, answers and completeness of that thread when searching for answers.

So that's why I'll answer any thread brought back up, regardless of its age. Who knows, 10 yrs from now my grandson may be googling the exact same question and find the answer right here in this thread. Same reason I keep my old car books around, answers to questions....

..

 

...Yupp...totally agree...

 

Have to actually read the new portion of this thread, to fully understand what is actually being discussed!

 

The search function on this website seems virtually useless to me. When I need to search for something on here, I do a google search, type in what’s wanted, and then add H.A.M.B. at the end…works like a champ!

 

Well, at least @Ryan is still here. A lot of these old posts that get brought up are the OP asking a question 10, 15, 20 years ago...and is never heard from again...or hasn't posted in years

 

This^^^^^

 

Ryan, when posting pictures hit the full image option.

 

Unfortunately not, I came across one once that had been awakened after 21 years……and on the same day another that was asleep for 14 years !

yes, sometimes they have sadly gone permanently yet get missed for the member emeritus list.
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