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PostPosted: February 7, 2012, 1:21 pm 
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Location: meadview arizona
1/16" = 1.6 mm = .062"
3/32" = 2.4mm = .093"
1/8" = 3.2mm = .125"
1/4" = 6.5mm = .25"

as you can see, its simple, but its not critical, a 1/32 is so small in the big picture, if you are worried about it just redimension the drawing in numbers you will understand then forget the rest,

now work out the specific gravity of the tubes and add the mig wire and you will know the weight of the chassis and the point that your table will buckle under the strain!

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PostPosted: February 7, 2012, 1:22 pm 
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john hennessy wrote:
1/16" = 1.6 mm = .062"
3/32" = 2.4mm = .093"
1/8" = 3.2mm = .125"
1/4" = 6.5mm = .25"

as you can see, its simple, but its not critical, a 1/32 is so small in the big picture, if you are worried about it just redimension the drawing in numbers you will understand then forget the rest,

now work out the specific gravity of the tubes and add the mig wire and you will know the weight of the chassis and the point that your table will buckle under the strain!


ROFLMAO!!!

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PostPosted: February 7, 2012, 1:27 pm 
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i built my car using cubits as the standard measurment,

you could try rods, poles or purches

before they built gallions they would make a standard stick to which all the shipwrights would work.

its not rocket science, if you are off by 1/8" when the chassis is fully welded, you will be one of the lucky ones.

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PostPosted: February 7, 2012, 1:49 pm 
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For those not fluent in conversion of decimal inches to fractions, just Google decimal to fraction. There are many versions of these table, some including metric. Pick your favorite chart and print it out. Put it up near your workbench of wherever.

It is more impportant that the two sides of the chassis end up the same length (within say 1/4") than the absolute length of the chassis is perfect.

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PostPosted: February 7, 2012, 2:10 pm 
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john hennessy wrote:
i built my car using cubits as the standard measurment,


Remember the Bill Cosby version of Noah building the Ark?
"Lord, what's a cubit?"
:rofl:

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PostPosted: February 7, 2012, 2:26 pm 
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its not rocket science, if you are off by 1/8" when the chassis is fully welded, you will be one of the lucky ones.[/quote]
Actually, I think some of us are "OFF" by a lot. Especially Gonzo. :cheers:


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PostPosted: February 7, 2012, 2:32 pm 
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john hennessy wrote:
1/16" = 1.6 mm = .062"
3/32" = 2.4mm = .093"
1/8" = 3.2mm = .125"
1/4" = 6.5mm = .25"

as you can see, its simple, but its not critical, a 1/32 is so small in the big picture, if you are worried about it just redimension the drawing in numbers you will understand then forget the rest,

now work out the specific gravity of the tubes and add the mig wire and you will know the weight of the chassis and the point that your table will buckle under the strain!


Yea, I can convert decimal inches into a fractional inches, that wasn't really my issue.. it was more just wondering what you guys were doing, reading the book dimensions, and them not being typical fractional inches (ie x.9 = x - 14.4/16ths). But, you're right, 1/32 is such a small issue that as long as I'm close, I should be good. So like I said before, just gonna go to the nearest 16th/32nd and be done with it!

john hennessy wrote:
i built my car using cubits as the standard measurment,

you could try rods, poles or purches

before they built gallions they would make a standard stick to which all the shipwrights would work.

its not rocket science, if you are off by 1/8" when the chassis is fully welded, you will be one of the lucky ones.


Hahaha, I'm just gonna use my finger, forearm, and thumb width to measure the rest of this thing, no big deal!

rx7locost wrote:
For those not fluent in conversion of decimal inches to fractions, just Google decimal to fraction. There are many versions of these table, some including metric. Pick your favorite chart and print it out. Put it up near your workbench of wherever.

It is more impportant that the two sides of the chassis end up the same length (within say 1/4") than the absolute length of the chassis is perfect.


Good point. As long as I cut the opposite side tube the exact same, it won't matter all that much. I've got myself a calculator, and know many conversions by heart.. but I might print out one of these charts just to make it even quicker. I'm sure after a day or two of measuring/cutting/drawing i'll know every fractional equivalent there is to know by heart!

------------------

Someone had mentioned this yesterday.. about the sawhorses getting wobbly.. here is a pic of the arms extended. For now, this thing is like a rock.

Image

And one of the newest work space... not a ton of room around the table, but definitely enough to get myself around without too many issues. Gotta push the snowblower out each time, but luckily.. haven't had too much snow (read.. almost none), so haven't had to use it!

Image

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PostPosted: February 7, 2012, 2:35 pm 
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photoman wrote:
Quote:
its not rocket science, if you are off by 1/8" when the chassis is fully welded, you will be one of the lucky ones.

Actually, I think some of us are "OFF" by a lot. Especially Gonzo. :cheers:


"Some of us"? We're attempting to build highway speed worthy cars out of scrap metal, many using 120v mig welders, in our home garages and basements. Lots of us with no prior automotive engineering background what-so-ever.

I'm going to go ahead and say we're ALL off by a lot.

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Build Log: http://www.BrokeAssSeven.com -- http://locostusa.com/forums/viewtopic.php?f=35&t=13293

This build is already locosting a fortune...


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PostPosted: February 7, 2012, 2:41 pm 
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Quote:
Actually, I think some of us are "OFF" by a lot. Especially Gonzo.


I wuz only off by a quarter of a cubit!*
:rofl:



*(On the "good" corner)

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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


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PostPosted: February 7, 2012, 5:03 pm 
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One thing I found with my first frame, some tubes you can cut to the size in the plan, others you need to cut to fit. The cut-to-plan tubes can be off a little bit, the cut-to-fit tubes have to fit.


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PostPosted: February 7, 2012, 5:32 pm 
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GonzoRacer wrote:
Quote:
Actually, I think some of us are "OFF" by a lot. Especially Gonzo.


I wuz only off by a quarter of a cubit!*
:rofl:



*(On the "good" corner)

Not bad, that's less than 2 palms. A cubit is about 20.7in and is divided into 7 palms of 4 digits each. I'm not making this up. That's what Noah told me.


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PostPosted: February 7, 2012, 5:43 pm 
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nick47 wrote:
One thing I found with my first frame, some tubes you can cut to the size in the plan, others you need to cut to fit. The cut-to-plan tubes can be off a little bit, the cut-to-fit tubes have to fit.


Interesting. I'm going to assume (and hope) that most of them are cut-to-plan. I always expect to make small adjustments with the cut-off wheel, grinder or files to make it all fit in the end anyway. Boy, it would be nice to have one of those stand-up belt sanders.... *looks at the Harbor Freight website... 4x36" belt w/ 6" disk = 99$... with 20% off coupon.. 80$. This might need to be picked up!

Just for the record... I went ahead and calced out this table to the nearest 1/32" real quick so I can reference it when measuring/cutting.. we'll see how it works out! Feel free to steal it, or add to it. If anyone sees something to adjust.. let me know!

.1 = 2/16- (1.6/16)
.2 = 3/16 (3.2/16)
.3 = 5/16 (4.8/16)
.4 = 6/16+ (6.4/16)
.5 = 1/2 (8/16)
.6 = 10/16- (9.6/16)
.7 = 11/16 (11.2/16)
.8 = 13/16 (12.8/16)
.9 = 14/16+ (14.4/16)

+ = +1/32
- = -1/32

ie. = 91.9" = 91 14/16+" (91 29/32")
= 15.1" = 15 2/16-" (15 3/32")
= 39.2" = 39 3/16" (39 6/32")

-Updated the site to include this.

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Build Log: http://www.BrokeAssSeven.com -- http://locostusa.com/forums/viewtopic.php?f=35&t=13293

This build is already locosting a fortune...


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PostPosted: February 7, 2012, 7:59 pm 
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I don't know about McSorley's plans, but the decimal fractions in Champion's book look like they were converted by an editor. For instance 6.3" was probably originally 6-1/4", not 6-5/16". A good example of this is the dimensions for the differential brackets.

Fortunately, most of the cut-to-plan tube lengths are integers, like 11" for the H tubes and 25" for the RU tubes. The cut-to-fit tubes have the odd fractions, and you don't want to end up with a tube that's .05" too short because of rounding. That's not a huge gap, but it's bigger than it needs to be.

Everyone must have had their own method for dealing with this, but mine was to cut a little long and trim to fit. The belt sander is a great idea.


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PostPosted: February 8, 2012, 9:28 am 
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nick47 wrote:
I don't know about McSorley's plans, but the decimal fractions in Champion's book look like they were converted by an editor. For instance 6.3" was probably originally 6-1/4", not 6-5/16". A good example of this is the dimensions for the differential brackets.

Fortunately, most of the cut-to-plan tube lengths are integers, like 11" for the H tubes and 25" for the RU tubes. The cut-to-fit tubes have the odd fractions, and you don't want to end up with a tube that's .05" too short because of rounding. That's not a huge gap, but it's bigger than it needs to be.

Everyone must have had their own method for dealing with this, but mine was to cut a little long and trim to fit. The belt sander is a great idea.


I went ahead and converted some of the mm to inches, and all of them came out as what the plans say. No more, no less. I didn't do them ALL, but I did a few, and they were all correct. Plus, by my small schedule above, the most i'll be off is +/- .024, and that gap is acceptable, especially for welding.

But, as you say, I'll most likely cut a hair long (1/32 - 1/64), and grind/sand to fit. It's going to be damn close no matter what.

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Build Log: http://www.BrokeAssSeven.com -- http://locostusa.com/forums/viewtopic.php?f=35&t=13293

This build is already locosting a fortune...


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PostPosted: February 8, 2012, 5:32 pm 
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Idea: Good/Bad/I'm out of my goddamn mind.....

I've got a Subaru SVX that i'm trying to trade for a donor car... I was thinking about POSSIBLY using it for the locost... It's got a 3.3L H6... super low profile will allow for low hood line, but I'm worried about the width. I've already posted on my SVX forums to get physical dimensions... so obviously if it's way too big I won't bother. It's essentially just an EJ22 out of an impreza with 2 cylinders smacked onto the end. Same internals (+2) and all that.

My biggest concern with using this motor isn't really even the width... it's the steering. With a straight 4 cyl, the steering column is a pretty straight-ish shot to the rack. With the flat-6.. I'm worried I might have to go OVER the drivers side head, and then down into the rack. It's not a problem on the SVX because the steering rack is located behind the engine (it's AWD, so the engine is ahead of the front axles)... but on the locost, the rack will be in front of the engine.

What kind of angles are just 'way too much' as far as column angles go? Obviously using U-joints and the like it can WORK, but is the effort going to be too much? Will it bind up like a mother? Will be using the SVX rack, after depowering it and shortening it (its got a blown seal right now... reason i haven't been driving it and driving the civic instead). Once I get dimensions, I'll ghetto draw it into the plan, and see what kind of angles i'd be looking at on the column....

What do you guys think? Anyone have any experience dropping a flat subaru motor into their locost? I think if I went with a +442E i'd probably be fine as far as width goes.. but I'm still doing the book frame, so we'll see. I think having the valve covers sticking out the side of the hood could look really cool though!

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Build Log: http://www.BrokeAssSeven.com -- http://locostusa.com/forums/viewtopic.php?f=35&t=13293

This build is already locosting a fortune...


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