LocostUSA.com

You're probably right on the "OK in practice" designation. With clever placement of the packing, and big, fat weld beads, they'd probably work fine. It just seems like a poor compromise to me. One that you'd make on a seat frame, but not the critical front suspension brackets. I'll see if I can do better.

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

Have you thought about making the suspension bracket a 2-piece assembly. Jack sells them now but I think in your case you would have to make custom ones to get the angles you need and to align the holes.

https://kineticvehicles.com/ControlArms ... lebrackets



BTW, shimming isn't such a bad idea. I did that on my build. After tacking in the front piece, I later added triangle pieces top and bottom.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

@rx7locost

Thanks for those suggestions, Chuck.

I did consider using Heim joints at front, but decided on bushings for some practical reasons. Jack's brackets assume Heim joints, so they're a good fit for my choice.

I appreciate the input on shimming. I was primarily worried about distortion (big MIG beads = big heat = big distortion) and having a weak area in the critical front suspension, especially under braking. I had an interesting and relevant conversation with Perry (horchoa) last night on the telephone, and he too was reassuring about "packing" gaps and welding. I think Perry's built more Locosts than CMC now, so that was good to hear.

I haven't reached my final placement yet, so I'll wait and see how much of a gap I end up with, and then decide how to proceed.

Thanks again,

_________________
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 would sharpie a line around the lca brkt, notch the frame tube as needed (or up to the wall thickness of the brkt) to put the axis where it is supposed to be, weld, then add 1/8" strip at the front and rear the width of the brkt flange (2.5" guess from pic?), that reaches the inboard corners of the frame tubes. The brkt is much stronger and thicker walled than the frame tube. I recall seeing them ripped out of the frame before.

Have to come up with a nice design to support the lca rear brkt.

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

It's been almost a month, but all my real world chores are done now, and I can get back to my Locost.

I had been changing things fast and furiously in terms of the front suspension brackets and suspension geometry when I left off last. My first task was to make sure I was working with the latest data, and all the data from various sources like the suspension analyzer software, my notes and the brackets themselves all matched up, apples to apples.

Once that was done, I restablished the lower, chassis-side, A-arm brackets to a close approximation to my 3D model. I can make that work. Then I tried some general configurations of the upper brackets using what I had made already, just to see if I could make those work. They're not a good match, but I at least verified I could place the upper brackets at the desired height to get my roll center down to near 1" off the roadway.


I'll need to come up with a modification of what I have on hand now. I think I have an idea. The rear, upper bracket is going to be an odd one, but my idea might simplify placement, yet be simple to put in correct alignment.

The front upper is sensitive to fore and aft location due to the nose cone. I think we're good. I'm going to make the upper brackets smaller than the ones shown here, which will look cleaner and place easier.


Fortunately, the front lower bracket looks pretty good. I can move it forward a little bit, which I may do to make it possible for the steering rack to move forward a little as well. My steering rack has arrived, but I haven't even taken it out of the box yet. I can't really fit it out until the suspension brackets are finalized.


I did discover one little issue. My build table top has gone out of level. Thay may muck up my jig making, but I'll see if I can fix it. If not, I'll align the suspension brackets to level, which might give me 1°-2° anti-dive. Meh! It won't kill me.

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

OH NO! You've ruined it!
(Just kidding)
Hooray for lowered expectations!

Think about the tools and production build quality of the 60s and 70s.
Remember the bias ply tires? Remember the welding tools for most were stick or gas only?
You can't screw this up by comparison. Everything is in your favor.

Remember the story about the princess and the pea, who had 50 mattresses but could tell if they was a pea in the bottom one?
There are many princesses out there right now, but none on this forum.

Line up your shot and pull the (mig) trigger.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

@MV8

Yes, I'm trying to overcome my perfectionist tendencies, and not "let the perfect be the enemy of the good." I want to drive this bloody thing before I croak.


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 had a chance to tour the back rooms of a classic car restoration facility. There was a complete body-off restoration of a Ferrari underway, and the bare tube frame was sitting on a stand. The welds were beyond comprehension, looking like a 5-yr old had made them. Big blobs of filler piled up around the joints. Just amazing, but put the body on it and it's a $$$$$$$ Ferrari again...

_________________
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/

I've likely/hopefully got another 40 years left, and I've had that same thought many times about mine!

_________________
Trochu Motor League

@KB58
No kidding? Were they original welds from the factory?

@Trochu
I know that feeling. The "cure" is spending a whole week working on the build. I always feel hopeful after that. If I've got 6 years left, I'll be surprised. Gotta get that puppy built.

Cheers all,

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

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

They were most likely factory welds. The Italians were (in)famous for crap welding on their chassis!

_________________
Mike - Read my story at http://twinlakesseven.blogspot.com/

I'll third this one, I worked on a number of vintage Ferraris back in my restoration days, including a '70 312B F1 car... ugly, ugly welds, and equally ugly castings. They did get the job done though, usually.

_________________
Bill J
442 Locost - in progress
Mid-engine Beetle - In Progess
'12 GTI - Daily
'01 Chevy Cargo Van - Workhorse parts hauler

OK, I think I've found a solution that works, and satisfies all basic structural and geometry requirements. Although, I feel like a little old bracket maker, I've made so many of these bloody things.

The upper brackets are smaller in size, and the bolt holes are different front to back to get the virtual axle to line up with the brackets attached to appropriate chassis members. The rear, upper set with be cantilevered out a little bit, but I'll use a piece of angle iron welded to their backside and the structure to give them support.

So, I set the whole thing up in 3D, did some drawings, and set out to cut the raw brackets from my 2" x 3" stock.



Fortunately, I have enough stock on hand to do more brackets.


Deburred them all and out them in their overnight marinade of white vinegar to get rid of the mill scale. I have 2 spares in case one goes wrong, or I find I need to adjust distances in my real world example.

So, I put them in white vinigar to get rid of the mill scale while I sleep tonight.


I will have to run the suspension analyzer again with the changed dimensions. That may require a slight raising of the top bracket pairs to keep the roll center about 1" off the pavement.

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

Lonnie you're getting closer to rolling that 7 out on the driveway and have all the neighbors come within 6' for a coffee and show 'n tell session
Wish we could be standing on your driveway went that happens

_________________
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

Perry, unless lightning strikes me, I think this thing is going to roll pretty soon.

They're (the Governor & other politicos) talking about having California "back to normal" by Fall. Given I still have to do the steering, fuel and electrical systems (the engine & trans are fitted, but the drive shaft has to be made), it could be you two will be down here by the time it is actually ready to run. That would be great.

They say the Mustang engine will run in a "real stupid" mode if the ECU isn't fully functional, but it is in a real low power, retarded timing state. Not good for driving, but it will do a vroom-vroom kinda thing.

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