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 Post subject: Re: A build in Bulgaria
PostPosted: March 28, 2021, 7:27 am 
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If the 25x50 that replaced by RS7 and RS4 or 5 measured 361mm overall with a 17 deg back cut at the front then it should be right. It should now be 306mm, SB3 to RS6, measured 25mm below the top. This is the overall length of RS4/RS5 minus 25mm for RS6. I see what you mean about the warpage in img4610.

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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


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 Post subject: Re: A build in Bulgaria
PostPosted: March 31, 2021, 12:26 pm 
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Joined: August 12, 2011, 1:46 pm
Posts: 85
Good day to be a Locost builder today .
Motivation in a box .
Attachment:
IMG_4626.JPG

Attachment:
IMG_4625.JPG

Front and rear . All four and all ready .
There's even some newspaper inside to read :D . Tho not the page I would have liked :D
Just looking at these makes me want to drive this thing .


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 Post subject: Re: A build in Bulgaria
PostPosted: June 6, 2021, 3:56 pm 
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So things are coming along nicely .
Slowly but surely I'm gluing more and more metal to the frame .
Front A arm brackets are in place .
Attachment:
IMG_4788.JPG

Attachment:
IMG_4789.JPG

Some reinforcement added too .
Attachment:
IMG_4787.JPG

I intentionally added the bend in the rear tube to make it easier to assemble .
Also put the engine mounts in place .
TIG welded those on the bench and put them crooked in the frame (my signature piece) .
Attachment:
IMG_4784.JPG

Attachment:
IMG_4786.JPG

The camera adds a few degrees . It's not that bad, but I know it's there and it'll bug me . Moving on to triangles .
I intentionally placed the end of the tube in front of the engine mount to get better leverage, and filled in the space with some plate .
Seems pretty strong to me . Additionally I'd like to incorporate the tunnel in the structure as well .
And that's where this little tube comes in . Hope it'll let me send some load there and increase the overall stiffness .
Attachment:
IMG_4790.JPG

Still not completely sure about it though .
So this is where we stand now .
Attachment:
IMG_4794.JPG

I even placed the rubber bushes in .
Next weekend I'd like to make the engine mounts themselves with about 25mm offset to the right to give me a couple of degrees in the drive shaft and sort of offset my weight a bit .


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 Post subject: Re: A build in Bulgaria
PostPosted: June 10, 2021, 12:27 am 
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Joined: July 20, 2009, 1:16 am
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Location: Sydney, Australia
I like the look of the engine mounts!

What size pipe, and what bushes did you use?

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http://locostusa.com/forums/viewtopic.php?f=18&t=19549


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 Post subject: Re: A build in Bulgaria
PostPosted: June 11, 2021, 3:58 am 
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The rectangular tube is 50x30x3 mm . The bush tube was just something lying around . Had to fill it up with the MIG and turn it to size . Ended up with 4 - 5 mm wall thickness .
The bushes are ID 16mm OD 34.5 mm length 47 . Think they hold a scania or volvo truck cabin . I pressed in a sleeve to reduce the ID to 12mm .
I got lazy on the sleeves as well . Found a supplier that stocks 18x3 seamless pipe in 1045 material . Every bush for an M12 bolt is cut from that (on the bandsaw ).


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 Post subject: Re: A build in Bulgaria
PostPosted: June 12, 2021, 5:58 am 
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Since the engine and trans angle is now fixed (unless you build it into the block brkts or preload the engine mounts) I guess you will be mounting the diff pinion at close enough to the same height as the trans output shaft to keep the side view angles to 2 degrees or less?

You could change the output angle by preloading the engine mounts, but it makes mount replacement more difficult since the holes won't line up unloaded.

_________________
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


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 Post subject: Re: A build in Bulgaria
PostPosted: June 12, 2021, 4:01 pm 
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Joined: August 12, 2011, 1:46 pm
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That's right . I'll be aiming to put everything in one plane so the 1-2 degrees are visible from top . The height of the centers is 130mm from the lowest point on the chassis . That was defined by the diff . Today I started on the engine mounts, themselves . They'll have different lengths .
Initially I aimed at 2 degrees, but that is 25mm off center, which interferes with the tunnel . Sow I'll settle on 10mm instead .
Not sure how those rubber donut things react to a degree of misalignment .


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 Post subject: Re: A build in Bulgaria
PostPosted: June 13, 2021, 8:58 am 
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Probably soft enough without too much effort. Just another consideration.

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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


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 Post subject: Re: A build in Bulgaria
PostPosted: June 21, 2021, 5:35 am 
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Joined: August 12, 2011, 1:46 pm
Posts: 85
Since the Ford uprights are really heavy (16 kilos each) I decided to design a pair of aluminum ones . To make things easier I'm sticking to the original dimensions .
Attachment:
sierraupright.jpg

For reference
Attachment:
Front_upright4.png

Attachment:
Front_upright5.png

Attachment:
Front_upright6.png

This shows the bottom plate which is removable to make ackermann easier to change .
I made good use of the lower spherical bearing bolt . Its an m14 bolt threaded in about 20 25 mm of thread in the upright .
Additionally two m12 bolts hold the plate in place .
The top joint uses the caliper bolt (another m14 bolt) and an additional m12 bolt . Lower bolt on the caliper will thread in the upright itself .
Thickness there is 20mm . The same as the thickness of the caliper mounts .
Attachment:
Front_upright7.png

Possibly overkill, but that's what's on the caliper .
The ones I have here are from the rear of a porsche cayenne 4 piston and fairly light . Almost 800 grams less than the original ford ones .
This design uses the original 260 mm discs and aluminum hats .
It's a bit of a tight fit, which is the reason for the windows in the hat itself .
That I plan to hold with 10 M6 bolts .
Attachment:
Front_upright8.png

Attachment:
Front_upright9.png


And thta's the overall look .
Attachment:
Front_upright1.png

Attachment:
Front_upright2.png


I should point out that I plan to use 7075 . I'm a bit concerned with the threads on this .
Haven't worked much on aluminum . (not even a mechanical engineer to be honest )

TL:DR Critique my design .

P.S. The first drive will be with the original uprights . This bit is just an improvement and not a necessity and I want to go for a drive this summer .


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 Post subject: Re: A build in Bulgaria
PostPosted: June 21, 2021, 10:56 am 
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I'd use steel inserts or helicoil if you must have threads and steel inserts or steel bolt-on bits.
Bolt the steering arm to the front of the carrier with four, fairly wide spaced fasteners so the height of the tierod is adjustable. Machine the steering arm offset on the mounting base so you can switch them from side to side without making new arms to adjust tierod ball height.

Typically the higher the rack, the wider it can be ball to ball plus the intermediate shaft can better clear headers and have a nice wheel angle with potentially no joints/less weight/more header clearance. It is better to use a wider rack so the pinion (and rack travel stops) can be further away from the center and easier to clear the engine.

_________________
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


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 Post subject: Re: A build in Bulgaria
PostPosted: June 22, 2021, 3:31 am 
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Joined: August 12, 2011, 1:46 pm
Posts: 85
I actually thought about mounting it to the front but the bolts would work in tension possible thread engagement issues .
What I didn't realize is that the tie rod bolt is in bending . I'll have to look deeper at that .
The steering rack has an angle to it and I haven't thought much about the whole steering arrangement .

P.S. Just dawned on me that a thinner bottom plate can be combined with a top support, as you proposed .


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 Post subject: Re: A build in Bulgaria
PostPosted: July 11, 2021, 2:19 pm 
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Joined: August 12, 2011, 1:46 pm
Posts: 85
Slowly but surely I've been working on the car .
The engine got it's new front cover . That's from a later version with injection .
Attachment:
IMG_4796.JPG

I made the gearbox mounts for both engines last week .
Attachment:
IMG_4798.JPG

Attachment:
IMG_4802.JPG

Ended up filing a bit more to make the gap wider .
To be honest I don't expect a lot of mevemnet here .
Attachment:
IMG_4804.JPG

A quick coat of primer and tack welded in place
Attachment:
IMG_4805.JPG

Attachment:
IMG_4806.JPG

I put a ratchet strap in for good measure .
I made the mistake of buying a digital angle meter .
Now I know where my frame took a bend while welding.
Some strategic cutting and welding will take place soon .
##### Sage advice for readers #####
Do not leave an engine and gearbox in an incomplete frame without any triangulation for 8 years .


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 Post subject: Re: A build in Bulgaria
PostPosted: July 12, 2021, 7:52 am 
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Location: 4AGE in S.E. Michigan
As a general rule of thumb, you should allow 2/3's of the rubber thickness in the bushing, to compress. You might want to add a little more clearance for deflection in the trans mount. Easier to do it now Vs after the build is finished, and you end up with NVH issues.
Davew


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 Post subject: Re: A build in Bulgaria
PostPosted: July 12, 2021, 10:38 am 
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You could completely remove the forward piece of angle iron and box the bottom or corner gusset the outside of one flange to locate, the other without a gusset to flex to take up the slack needed for inserting the bush inner sleeve.

_________________
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


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 Post subject: Re: A build in Bulgaria
PostPosted: July 12, 2021, 11:12 am 
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Joined: August 12, 2011, 1:46 pm
Posts: 85
Now you mention that the bit in the middle doesn't do that much . When the tunnel is covered up that'll be accessible underneath, so a plate on the bottom will only make me curse the designer .
To be hones the whole thing isn't ideal . The bolts are covered up, I want to add triangulation later on and I don't like how the welds will be loaded . But the engine mounts are quite sturdy and really don't move much so the whole rear support won't be doing that much work .


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