"Study Haul" 2k7
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Author:  JackMcCornack [ April 12, 2007, 2:16 am ]
Post subject:  "Study Haul" 2k7

A five-guy team at Illinois Valley High School in Cave Junction, Oregon, is building a Locost as an autoshop project. The plan was, Kinetic Vehicles (that's me) was providing a soon-to-be-introduced Kinetic 7 kit and a Miata, but a few things prompted a change of direction:

1) "nick47" offered LocostUSA.com readers a pranged-but-running '91 Miata for $200. It has a couple of thousand miles and it would be more expensive to fix than it would be worth once fixed, and it has a salvage title so this wasn't its first dance with danger...but on the other hand it has some nice eBay parts. I think any mechanically sound Miata is worth $500 FOB CJ (or wherever you are going to do your building) but even with the drive and recovery and the electrical mystery, this one was a bargain.

2) It turned out that the current autoshop class includes several skilled welders, ranging from scholastic award winning (we didn't have multischool welding competitions when I was a kid, but they do now), down to merely much better than me.

3) The Grassroots $2007 Challenge has a Locost exhibition class again this year.

4) Coyote Steel in Eugene had a bunch of surplus 1" x 1" .065" square tubing for $.40 a pound--that's about 32 cents a foot.

5) The guys on the project think building a GRM Challenge Car is a cool idea (even though it'll be more work).

6) We got to chatting and Nick <donated> the car for the project and suggested we could raise a few bucks by selling the parts we don't need...the GRM$2007C rules require we value donations at actual value, but that's been established at $200 (as noted, a bargain indeed, but legitimate and verifyable, and bargains do come up now and then) and we're allowed to recoup the donor's value by hawking leftover parts...heck, we can get that out of the nearly-new convertable top...which means...

Well, crunch the numbers and we can project $0 into the donor, $50 or so in the tubing, and $1957 left for the rest of it. Man, who could pass up an opportunity like that? So today's New Improved Plan is to build a GRM Challenger. See http://grmotorsports.com/challenge/2007rules.html for rules and http://grmotorsports.com/news/category/2007-challenge/ for other details.

Gosh, I can hardly wait to see what tomorrow's plan is going to be.

PS--The name (Study Haul) just popped into my head while I was posting this. Got a better name for it? The IVHS colors are red and white, the school teams are called the Cougars, what else can I tell you?

File comment: My friend Sharon Westcott drove to Willows with me on an olive tasting trip, and we drove back in two cars. Note the duct tape hood retainer. The note on the windshiled tells where we can find the extra battery (the crumpled front hides a pinched wire).
N47GetDonor.jpg [ 22.98 KiB | Viewed 35588 times ]
File comment: A few hundred miles, a handfull of jumpstarts, and here we are. The hood didn't fly up and neither of us had to chat with any policemen or anything. Sharon had always wanted to drive a Miata and had great fun. Wait 'till she drives the Locost.
N47Arrives.jpg [ 33.12 KiB | Viewed 35587 times ]
File comment: The team. I'll introduce them when/if I get premission--they are minors there are privacy issues--it's been barely a week and they're doing a fine job on the teardown. They got the windshield so clean, you can see right through the middle guy's trousers.
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Author:  JackMcCornack [ April 19, 2007, 7:44 pm ]
Post subject: 

The Team takes their car stripping pretty seriously. Everything is coming out and getting labeled, e.g. "Headlight bulb." I'm learning a bunch from the experience, and the guys are learning where every nut and bolt and washer goes in a Miata, but unfortunately it slows things down a bit.

Meanwhile, back at Coyote Steel, I picked up the tubing and a sheet remnant of surplus 18 gauge for the belly pan, and asked their Accounts Receivable manager to take a photo of me spinning The Wheel of Steel. I'm not much of a gambler, but what the heck, you can win a discount on The Wheel of Steel. Anyway, the spectators quickly decided that I should take the photo and April should do the spinning, for purely aesthetic reasons. I don't know if I'd put her in charge of collections, I'd be afraid that people would bounce checks so they could talk with her.

Monday the class starts welding the chassis. I'll update this when the smoke clears.

File comment: The guys hit this Miata like a plague of locust. Next time I'll give them a list instead of saying &quot;take everything apart.&quot;
StrippedInterior04.jpg [ 34.75 KiB | Viewed 35423 times ]
File comment: April doing her Vanna White impression...or in her case, Vanna Eurasian. She had to hop up on the desk so I could get her and The Wheel in the same photo. It was a lot of trouble, but hey, I won a buck
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Author:  nick47 [ April 20, 2007, 3:24 pm ]
Post subject: 

Thanks for the photos, Jack. I don't quite know what to think when I see pictures of the Miata stripped down like that. My daughter and I put 200,000 miles on that car. Lots of memories. But it's great to see it going into a Locost. Hope the kids are having fun.

Author:  JackMcCornack [ April 20, 2007, 9:54 pm ]
Post subject: 

nick47 wrote:
Hope the kids are having fun.

They seem to be, though some might rather be putting lift kits on pickups--fortunately my five are volunteers, nobody got assigned the Locost under duress. And if one of them really "gets it" re the Locost life, a summer apprenticeship at Kinetic is not out of the question.

My biggest concern right now is curbing their enthusiasm for dismantling. There's a tendency to make assemblies into subassemblies and subassemblies into hardware.

Author:  chetcpo [ April 20, 2007, 10:50 pm ]
Post subject: 

Jack, if you see them overdoing it you may want to spend a day letting them each re-assemble something rather complex that they have "over-disassembled". Perhaps this exercise will illustrate to them that they are only making work for themselves by tearing down things that don't require it.

Just out of curiousity, what happens to this project when summer break/graduation does come? It's not that far off and no offense (and not to question their abilities) but I honestly don't see them finishing a locost working only an hour a day between now and then. Is this project going to be picked up by the next group of students who pass through?

Author:  Mandurath [ April 21, 2007, 9:59 am ]
Post subject: 

I know at our local tech schools each class takes up where the last left off on a project.

Author:  chetcpo [ April 21, 2007, 11:59 am ]
Post subject: 

Mandurath wrote:
I know at our local tech schools each class takes up where the last left off on a project.

I was hoping that was the case, I really look forward to seeing this thing finished. I wonder how Uncle Ron has individual students completing cars on their own. (or at least that's the impression I got from his book) They must really do things differently across the pond. Perhaps they have them start on the frame as soon as they are old enough to weld. (what's that, 6th grade? :P )

Author:  Mandurath [ April 21, 2007, 3:42 pm ]
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Well, school is diff in Europe. When i was in Germany, they went to school year round, pretty different than what we have. Going less per day. I imagine that this would also be done over there as extra curricular too.

Author:  JackMcCornack [ May 4, 2007, 11:37 pm ]
Post subject: 

The guys are on a roll now. The car is a carcass, the cockpit is welded together, the rear subassembly mounts are cut out and ready to present to the chassis...it's getting done!

Here's the first signs of how the 2k7 chassis departs from the book. First, the cockpit is rectangular from above, not tapered. Since the full body will enclose the front corners, it makes sense to enlarge the footwells, and by widening tubes C and Q (Champion book part numbers) by 8", the engine bay triangulation is improved, plus the engine can be moved back without running out of pedal space in the driver's compartment. Also it makes the sides dead easy to fabricate.

Second, tubes K3 and K4 (hey, y'all don't have my plans in front of you, but everybody's got The Book) are 2" square, 16 gauge--only twice the weight of 1" tube with 4 times the strength and stiffness. Important because the loads from the pontoons and rear suspension will be primarily carried by those tubes.

I'll give you my thought processes on various departures from Book as they come up.

File comment: The demolition team is about done; here two of the guys face wiring harness removal. Meanwhile, the bottom of the 2k7 chassis is being laid out and welded up in another room.
AboutGutted2.jpg [ 34.18 KiB | Viewed 35055 times ]
File comment: The cockpit sides are aligned on a simple fixture (the red tubes) which is bolted to a 1/8&quot; hardboard pattern. The blue tape strips are for upright placement. Note there is only one diagonal--the pontoon shear web will carry diagonal loads.
CockpitSideLayout.jpg [ 31.45 KiB | Viewed 35039 times ]
File comment: The finished sides are inverted and clamped to the edges of the build table/pattern with the 2&quot; tubes flush against the end of the table. The finished (including bellypan stitch welded in place) cockpit bottom section is welded to the sides.
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Author:  JackMcCornack [ May 6, 2007, 12:45 am ]
Post subject: 

Some intermediate pics of the side section fab and alignment.

On the last photo above, you can see (barely) that the sides are aligned by pushing them forward until the 2" tubes fit against the stern of the build table...and you can just make out the end of the clamp holding the 2" tubes parallel. The clamp was made from a smaller clamp, cut in half and welded to a yard of 1" square tubing that was too crummy to use on even a $2007 car. A 10" board, cut 36" long...

[Okay, this one is a 42" wide frame, though we can go up to 45" with this style of rear end. The 2" tubes are set in 1" from the perimiter rails of the frame, they're 2" wide, 1 + 2 + x + 2 + 1 = 42 so x =36. A very accurate 36"--this one got sawn an eighth inch shy (I'm as good a carpenter as I am a welder) so 1/8" shims went between the right end of the board and the right (left, actually, since the frame is upside down--not that it matters which end, as long as it adds up to 6" less than the chassis width) 2" tube.]

...10" board, 36" long with precise 90 degree angles is put between the 2" K3 and K4 tubes (that's Ron Champion book nomenclature--they're called SB1 in the Chris Gibbs Book), the lower edge flush with the build table, and clamped down tight. A similar (except it's 40" long--42" chassis minus two 1" uprights) board goes between the front uprights and is similarly clamped. This holds the sides parallel and secure while they are being tacked to the lower frame rails. To finish weld, flip the frame over but keep the boards in place.

One could add other braces between the inner upright pairs, but there's apparently no need. The bellypan keeps the bottom square, the upper frame rails are clamped to the build table...but if you don't want to install the bellypan until the tube structure is complete, you'll probably want to brace all the uprights when you weld them to the upper and lower frame rails.

Regarding the cockpit side fixture, the unpainted tubes are the chassis tubes, the (red) painted tubes are the fixture; we've painted all the steel fixture parts red to remind people not to weld them to the frame.

File comment: The tape is a guide, but precise location is 5th (rear) upright to fixture, diagonal to 5th upright, 4th upright to diagonal. 3&quot; holes in pattern give room to tack weld without burning the pattern.
UprightDiagonalPlace.jpg [ 20.34 KiB | Viewed 34933 times ]
File comment: The diagonal locates one end of the 4th upright, weld upright to frame rail, remove the diagonal and weld 5th upright. Grind the points off the (lower right) end of the diagonal to clear the bead and tack it to uprights and frame rail.
UprightsDiagCU.jpg [ 21.25 KiB | Viewed 34930 times ]
File comment: The board braces keep the ends of the sides in place, and the middles follow the ends. We'll weld on the rear subframe mounts and backrest tube (O3 old book, SB3 new) next.
BoardBraceSides.jpg [ 20.98 KiB | Viewed 34915 times ]

Author:  JackMcCornack [ May 9, 2007, 1:15 am ]
Post subject: 

On to mounting the Miata rear suspension subframe.

This is the very first scratch-built 2k7 chassis, and I must say the instructions for this car are improving tremendously from the experience. If we like the results, Kinetic will offer plans as well as a kit--and while developing the do-it-all-yourself plans, we are simultaneously demonstrating it can be done on a $2007 budget if you get a fabulous score* on a maimed-but-mobile Miata, have all the tools you need, and either lots of time for fabrication or lots of help from a group of enthusiastic high school students.

But I'll admit I don't have the patience to do it this way myself. The plans will have cardstock templates for the fab-it-yourself bits, but for this car, the guys are tracing $10 laser cut parts onto 40-cents-a-pound steelyard scrap and cutting them out with plasma cutter, chop saw, and angle grinder with cutoff wheel...then cleaning them up with grinders and files. But hey, it keeps the budget down. These two rear suspension mount plates would have cost $20 for the pair if they'd bought them (and no, the GRM$2007 rules prohibit me donating stuff...or I can, actually, but it goes against the budget at retail) so doing it this way probably saved $19 of the $2007 budget, but I don't think they made minimum wage. If the school had a band saw, there would have been less grinding involved. The parts look good, though, and it'll be a car to be proud of.

There are a few items (e.g. suspension brackets) where I think I'd rather dip into the budget and "buy" them (in quotation marks because I'm buying them from myself) than have them handcrafted. We'll see as we go along.

*Not so difficult if you're willing to remove every useable part you don't need and sell it on eBay.

File comment: A 1/8&quot; plate marked for subframe mounts, with a straightedge clamped on to guide the first plasma cut. You'll appreciate its robustness if you stop at a light and the Suburban behind you doesn't.
SubframeMountPlate.jpg [ 20.45 KiB | Viewed 34808 times ]
File comment: After the plasma, there's considerable touch-up involved in making these fit right and look nice. After grinding, the holes were marked and drilled, avoiding the measure-with-micrometer, mark-with-chalk, cut-with-axe problem inherent with hand held plasma
GrindingPlate.jpg [ 27.33 KiB | Viewed 34797 times ]
File comment: The plates are drilled, notched, and welded to the 2&quot; x 1&quot; back brace tube. It's upside down so you can see the 1/2&quot; holes in the mount plates, which match the 1/2&quot; holes in the tube, which have 3/4&quot; holes on the other side.
UpperSubframeSupport.jpg [ 15.8 KiB | Viewed 34792 times ]

Author:  JackMcCornack [ May 9, 2007, 2:35 am ]
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By '94, Mazda had added bottom braces to its rear suspension. This one is a '91, when the four corners of the lower control arms could each do their own things. Unfortunately, that's where we attach the bottom of the rear suspension subframe to the chassis, so we have to add plates to the old ones.

Further unfortunately, the Mazda brace plates are a stamping that I'm sure is very cheap by the million (and at four per Miata since '94, they're at close to a million) but nothing you can whittle out in your garage. So these plates aren't replicas, and they fit about 1/2" lower than the ones on the later Miatas. Thus the attachment standoffs on the chassis are different for pre-94 subframes.

I guess that'll only make a difference if we produce kits--either the rear subframe attachment standoffs will have to be welded on by the builder, or we'll have to stock two chassis.

File comment: The stamped subframe pickup points require a lick of the hand grinder to get them flat, so the plate can be welded flush. The notch in the plate is for control arm droop.
OldMX5BottomPlate.jpg [ 22.38 KiB | Viewed 34784 times ]
File comment: This plate was welded to the subframe without removing the control arm--and its rubber bushings. The student welded a little at a time and let it cool. It worked, but removing the control arm is safer.
WeldedBottomPlate.jpg [ 20.03 KiB | Viewed 34791 times ]
File comment: Two more plates will be added, to the rear pickup points, and sub-subframe braces a la later Miatas, but these two brackets on the front are enough to fit the subframe to the chassis.
BothBottomPlates.jpg [ 30.82 KiB | Viewed 34785 times ]

Author:  JackMcCornack [ May 11, 2007, 11:21 am ]
Post subject: 

Installing the rear suspension.

Suspension height is determined by where the backrest tube is positioned. In this case, the backrest tube is even with the frame rails, which puts the rear suspension at roughly 1/2" higher than Mark Rivera's (or the chassis 1/2" lower, depending on how you look at it). This tube carries the vertical loads, the lower mounting studs keep the bottom of the subframe from moving fore/aft (and stiffen it slightly side-to-side as well). The measurement between the top and botom surfaces of the subframe determine (in association with the backrest height placement) what material you'll use for the lower subframe attachment stubbs.

In this case, we use 1-1/2" x 1-1/2" square tubing. Our prototype, which had a subframe from a '94 (and thus the lower braces installed by Mazda) used 1" x2" rectangular tubing.

Incidentally, the spring perch assembly you'll see here (and will be seeing for a while) is temporary, it's a tool I made to make it easier to move subframes around. It is a removable/replaceable part on these cars so one can change rear ride height using stock Miata coilovers. The actual spring mounts are CAD/CAM cut, not freehand plasma cut. We may have to sell ourselves a set and take them from the budget 'cause they're pretty hard to get right (plus they're not terribly expensive). But that's down the road.

File comment: Place a loose tube under the lower mount plates and the backrest on top of the subframe--with a 3/16&quot; spacer--and measure between them.
MeasureVSpread.jpg [ 27.9 KiB | Viewed 34660 times ]
File comment: Slide the rear subframe onto the chassis, with the center mount bolt in the notch of the mount plate (under the spring perch). Bolt the front of the subframe to the backrest/mountplate.
UpperMountTop.jpg [ 23.33 KiB | Viewed 34656 times ]
File comment: Use a tiedown strap to pull the bottom of the subframe forward until the subframe is level with the chassis.
UpperMountRear.jpg [ 32.82 KiB | Viewed 34654 times ]

Author:  JackMcCornack [ May 11, 2007, 11:44 am ]
Post subject: 

Please advise me if you'd like less detail. Where this car departs from The Book (or The Books, as I guess we'll be calling them) I'm drifting from build log to how-to and back...but this string still keeps getting looks so it must be interesting. :-)

Normally one would build from the cockpit forward at this point, but the demolition crew hadn't cleaned the engine/trans assembly yet, and though we have the measurements for Miata placement, I want them to treat it like it's a custom installation--and I don't want to get myself (or the chassis) all greasy and gross.

File comment: Measure, cut, drill...the lower mount stubs were fabricated, then tacked in place. Note the strap between a lower control arm and the front of the cockpit.
TackingStubs.jpg [ 24.85 KiB | Viewed 34645 times ]
File comment: Once trimmed and positioned, weld the lower mount stubs to the chassis.
LowerMountStubs.jpg [ 18.22 KiB | Viewed 34639 times ]
File comment: Ta-dah! Now you're done mounting the subframe, so take it off. On this one, the four bolts came out with finger pressure and the subframe stayed in place--nice fit, eh? My compliments to the welder.
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Author:  JackMcCornack [ May 11, 2007, 12:09 pm ]
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We interrupt this build log by request, to show what's different about later Miata subframes.

The Mazda lower brace plates are higher than the ones we made for the '91, and the attachment hole is farther forward. These photos are from the k7 prototype chassis, which was made for a '94. The subframe was mounted 1" higher than Mark did his, which puts the bottom of the subframe 1" above the tube at the back of the bottom of the cockpit. For adjustability, and for the option of fitting earlier subframes (hey, it's a prototype) I made the attachment stub a bolt-in. It doesn't carry vertical loads anyway so it's no prob structurally.

Ignore the Grade 2 bolt--it's there strictly for fitment. Ignore the crappy welds, too--I did them myself.

PS--the non-crappy stitch welds on the floorboard were done by a pro.

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94BracePlateTop.jpg [ 19.43 KiB | Viewed 34614 times ]
94BracePlateQtr.jpg [ 22.17 KiB | Viewed 34611 times ]

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