LocostUSA.com

Nice to see this picking up steam.. you did in fact make the requisite "Vroom-Vroom" sounds when sitting for that picture, right?

Cool build- please keep the details coming

--ccrunner

_________________
Dean

1972 Honda N600 Restomod "ccrunner's N600 VFR800 repower"

1963 Volvo P1800 Restomod
http://locostusa.com/forums/viewtopic.php?f=36&t=16309

1959 Berkeley SE492 Restomod...
viewtopic.php?f=36&t=19397

"ccrunner's 1960 MGA coupe Restomod" found on MGExp.com

I don't think it is humanly possible to be in the position I was in without making a vroom, vroom, sound -- which indeed I did.

That is a novel method, very good solution. Could you please post those files (I think its the same as posting a photo) , they would be very handy.

Keep up the good work!

FYI, You can upload it in a a zip file. I doubt if an stl or other 3D file type is an allowed file type to be uploaded.

_________________
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

Yes, I am uploading a zip file I have been playing with them some more and I find that the one that just extends a General brand digital T bevel with the laser beam is more useful and accurate. My little ball socket device is not very accurate. So now I just use the T bevel extender device. In tight places I clamp plates to the chassis and find other ways to use the T bevel. It is important that you line up the little laser with the targets, dots, you make on the chassis. I modified the extender by taping a wire to it to make it easier to line it up. I could make this part of the design but it would be too fragile (or I'm too lazy to go back and do it).

The resulting cuts are not perfect but I cut the bars a few mm too long so that I can grind them down to a near perfect fit for welding.

Of course you may have a different brand or kind of angle measuring device or different small laser pointer. But if you have a 3D printer you probably also have some kind of CAD system and should be able to design your own. I included drawings, STL, and Step files in the zip.

First: congratulations on this great project. It is gratifying to see someone learn so much in such a short time. I will be following your work with interest as it aligns with a lot of mine. I've driven an MX-5 daily for about 15 years so am in love with their dynamics. I also have followed engine swaps for them - especially the Mazda KL V6 a (see CRAP Engineering's kit) and the Alfa V6. I've been teaching myself Fusion 360 too - it is a powerful free tool. I'm keen to make a car using MX-5 (Miata) running gear - suspension, steering, brakes, diff with a chassis similar to yours. As far as body goes I'm not sure - I do have a fibreglass mould for a Fiat Dino Spider, which is an almost perfect fit.
Did you get to the point of sharing your CAD files of the skate etc?
Cheers
Ross (in NZ)

Thanks for the kind and undeserved words. I checked out your web site and you are far ahead of me. I, being a bit of a goofy car guy, am approaching the project backwards from most people. I am ignoring the engine and just trying to succeed at taking the car apart, adding a custom chassis and body, and putting it back together to see if it still runs. I should be planning to upgrade the engine (with 200k miles on it). But instead. I will just hope I leave enough room to do something later if I decide I want more power. If so, I will be very interested in your upgrade to a bigger Mazda engine.

That said I have uploaded the step file for my latest chassis design (the one I used for the stress test) but here are some caveats.

• This design is really an approximation of the actual chassis. It is more of a guide rather than an exact plan. That is because my CAD model of the roller skate is way off (thus I am not posting the roller skate model). You are better off just modeling mounting points and clearances yourself in Fusion based a real roller skate. Thus, I am making adjustments as I build. I built the two sides (see photo) and am now building the tunnel. I found I had to completely redesign the tunnel based on better measurements using a recently acquired Bosch GPL3 laser tool. I mapped the trans and drive shaft to the floor like real hot rodders do, using this laser, and got some good measurements. I will post the final chassis design when I complete it by connecting these three parts on the car itself (to be sure I hit the mounting points). I may either update the Fusion design or just post photos with measurements. Also note I use 1.5x1 inch tubing on some parts which is not in the model (sorry for the Imperial measurements). The STEP file is metric, luckily.
• This is my first chassis design and it is only designed for the street, not racing. I did to a stress test as shown in my log, but It is still my first design, and I am a computer engineer, not an automotive engineer. Consequently the design might kill me and anyone who copies it. Since you live in an advanced country, I think the government will stress test your chassis. But I live in Tucson, Arizona (USA), the wild west, and here any dang fool can build and drive whatever they want. If you get kilt it your own dang fault. So keep this in mind and do your own safety validation — whatever it is.

That said I’m glad you are interested in the project. I will monitor your site because if I boost the power I’d rather swap the engine than add a turbo or supercharger.

Paul

Looks like its going well. In regards to how the body should go, Id suggest trying to bring the hood and fender lines as low as possible for a more sleek look. Also remember that after the main structure is built you can build additional structure for the overhang. Above I drew over your guide design trying to get everything low, perhaps you can use an indent in the side of the body as part of an entry step.

Sorry for being so long to rely. Sometimes I get an email notifying me of a post and sometimes not. I'll have to add a note to check this forum at least once a week.

Yes the design is nice and fits the constraints of my frame nicely. I wish I could draw that well. I have given up trying and just go straight to Fusion 360. I found another design which also looks like it might fit my type of chassis.
https://carbuzz.com/news/restyled-mx-5-looks-even-better-than-the-last-one

I finally returned to the forum because I see that the rear stabilizer bars interfere with my chassis (red circle). I think I will cut it down so it bolts to the chassis at the point of the red circle. Anybody see an issue with this?


Generally making progress -- slowly. Chassis probably 90% done.

If you also add the tubing to the floor area shown in your fusion FEA drawing, then I think it would be fine. I would reinforce the subframe tab then fit a short tube with a washer to attach to the sub, then weld a tube 90 degrees to that to go to the chassis, but just shortening and pinching flat like the other end is probably adequate.

If you don't want to run the long tube under the floor from the FEA, a 30 degree diagonal in the floor over to the tunnel corner would be a good idea. I'm curious why you did not just weld in the sub and save weight. The sub is a well designed piece and light for what it does, just not that attractive.

_________________
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

Thanks for the advice. I have not gotten to the point of adding the final floor tubes but I do intend to add a diagonal as you suggest. I don't have a press strong enough to pinch the cut Miata tube flat ( I assume these are stabilizer or anti roll bars). I don't even have a good anvil to hammer it flat. So I will probably weld some sort of bracket to the end of the cut tube that seals the end and provides a horizontal flat plate so it can be bolted to the chassis (which will have a matching bracket welded to it).

Not sure what you mean by "sub" and welding to it to save weight. Can you explain?

Thanks

"Sub" was for short for subframe. I meant eliminating the weight of the plates, hardware, and nodes at the rear subframe attachment points, building off the subframe as a stressed integral chassis member.

_________________
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

That's a good idea. My only reason for doing it the way I did was that I was imitating kits that used the Miata roller skate. Also, this is a street car and I was not worrying about weight too much. This is my first car project so I'm being conservative. In the past I just fixed up an old TR4 and did not make any modifications.

Well, I don't post very often but that is because I am so slow, despite putting in a few hours each day on the project. But today I have confirmation that my strategy is working. As I have said, my approach to welding the chassis is to fully weld the two side pieces and the middle tunnel. Then connect them while the side pieces are bolted to the skateboard. First, I tack welded the cross pieces then fully welded the top and sides of each bar while bolted to the chassis. The idea was that this would minimize distortion.

It looks like it worked. So far I can't measure any distortion. Of course, I could not reach some welds as the skateboard and motor were in the way. So next I have to raise the chassis, finish the top and side welds, turn the chassis over, and do the bottom welds. I assume, since most of the top and side welds have been done, that I won't cause any distortion doing the bottom welds at this point.

After that, I will paint the chassis and attach the floors and firewalls.

Looks like my scheme for avoiding warping while welding worked. See earlier posts, but basically I built the sides and tunnel first on a build table, clamping them and adding extra bracing to avoid warping. Then I assembled them on the roller skate, tack welding all the cross pieces in place to stabilize it. I then fully welded the top and side welds, jumping around to avoid heating any one part too much. I hoped the skate board subframes would keep the chassis from warping. I then flipped it over and did the bottom welds, painted the bottom and sides of the tubes and added the floors. I then flipped it back upright and painted the tops of the tubes.

Finally, yesterday, I bolted the frame on the skate board to see if it worked. There seemed to be no warpage. All holes lined up, the car is level, and road clearance is what it should be.
[img]frame%20on.JPG[/img]