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Warren’s Isuzu-based COLD +401 with SR20DE
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Author:  GonzoRacer [ August 9, 2011, 10:26 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Warren said:
Quote:
Unfortunately, you may also see that I had a Team Slotus moment and bent one tube on the short side of the die mark (the green tape) and the other on the long side.


HEY!!! I resemble that remark! :evil:

Not really... I laughed out loud when I read that, and then read it to TWWTFM, bragging. She said that Team Slotus has become the "world's standard for measuring screw-ups". I think she was bein' proud of me... I think... Maybe...

Oh, and I note that the inspector agreed that the windshield frame should be tied in to the chassis rail and not just the floor.
HA! Chalk that one up to Slotus Engineering! So there!!! :rofl:

Good to see you making progress, Warren, keep up the good work. (And do try to limit those "Team Slotus" :roll: moments, OK?)
:cheers:
Take Care-
JD

Author:  Warren Nethercote [ August 10, 2011, 6:39 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Chuck,

Here is your bracket in all it's glory! Thanks for the idea.

Author:  GonzoRacer [ August 10, 2011, 9:44 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Brackets look GOOD, Warren!
Well done, Sir!
:cheers:

Author:  rx7locost [ August 10, 2011, 9:53 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Looks good. :cheers:

I can now see that any force on the roll bar could bend the upper or lower rail due to no diagonal bracing at the junctions. If it were my car, I'd fillet weld the vertical roll bar tubing to the round diagonal tubing between the "Chuck brackets" 8) . This would form 2 triangles and might help the situation.

Author:  Warren Nethercote [ August 11, 2011, 6:55 am ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Chuck,

I share your concern around bending loads on the frame rails, and I can't imagine that the alloy side skin will help all that much, and I don't really want to learn from experience ....

Welding the two tubes together where they cross might challenge my skills, or more important, require too much stick-out, resulting in an ugly weld. My inclination is to add some sort of bracket in there. I will be doing the same where the rear roll bar braces touch the rear horizontal upper tube, in that case to avoid buckling of the braces where they bend.

Thanks for the observation.

Author:  GonzoRacer [ August 11, 2011, 7:49 am ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Quote:
Welding the two tubes together where they cross might challenge my skills, or more important, require too much stick-out, resulting in an ugly weld. My inclination is to add some sort of bracket in there.


Hey Warren-
A piece of flat stock, same width as the frame rail, could be bent to fit flat on the frame rail for an inch or so, curve outward over the round tube and back to flat on the frame rail on the other side. You could then weld it in nice smooth seams along the frame and similarly on the round bar.

*Edit* Looking at the angle of the intersection of those two, you'd need flat bar wider than the frame, bend it around the round tube and trim it down to match the width of the frame.

:cheers:

Author:  Warren Nethercote [ August 11, 2011, 8:11 am ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

JD,

Unfortunately the diagonal tube is flush with the frame rails (tube is 1 inch OD) so a strap over the tube would cause a 'bump' in the skin. I will work up a planar bracket, probably on an oblique plane to give fillet welds reasonably close to square. I will play around with paper cut-outs before deciding on an approach.

I'm probably going silent for a while soon, to begin that inexorable slide towards page 2: I've got a septic tank to uncover this afternoon, after which a bunch of honey-do's before being occupied by regatta stuff through to the end of August. For the sailors out there: local clubs are running the J24 North Americans, the Optimist Nationals, and the Canadian Youth Nationals consecutively beginning next Wednesday, and I'm organizing the judging at all three.

Author:  rx7locost [ August 11, 2011, 8:17 am ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Quote:
Welding the two tubes together where they cross might challenge my skills, or more important, require too much stick-out, resulting in an ugly weld


Come on. No pain - No gain! Besides, even if it looks bad, more than 1/2 of it will be behind the roll tube, the other half will be under the dash and out of sight. Just hope for good penetration over good looks. A rat tail file could clean up any unsightly blobs. If you are after good looks, after the weld cools (naturally 8) ) and inspecting for good welds, any low areas can be prettied up using regular household paintable caulk. Put it on and smooth out with your fingers. I saw a similar process on some Chip Foose TV show, but they used body filler instead of caulk.

For the different metal gauges, I try to set the MIG welder for the heavier gauge metal. I angle the gun more directly on the heavy metal and then go to town. I spend ~2/3 of the weld time on the heavy metal and then just flick, sorta, over to the thinner steel. I use a "J" pattern. Take a count 1,2,3; 1,2,3; 1,2,3 etc. Spend 1 & 2, on the heavy steel and 3 on the lighter steel. Long part of the "J" on the heavy steel and a light curve on the lighter steel.

Author:  GonzoRacer [ August 11, 2011, 8:19 am ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Quote:
so a strap over the tube would cause a 'bump' in the skin. I will work up a planar bracket, probably on an oblique plane to give fillet welds reasonably close to square.


I think we're talking about the same thing, a piece of "form fitting" flat steel, on the inside of the frame. Sounds like you've got it all planned out, though, so good on ya, Mate!

Good luck with all your sailing adventures! Send us some pictures!
Regards-
JD

Author:  Warren Nethercote [ August 11, 2011, 11:31 am ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Chuck and JD,

Thanks.

I'm already doing 'cursive e's' on my fillets; going to an unbalanced J is a neat way of dealing with the different thicknesses. I admit to poor choice of words when I spoke of ugly welds - I should have said 'poor.' I'm more concerned with strength than beauty at the joints, as should be the case, but there is probably some correlation between weld appearance and strength, as long as it's not a wonderfully executed bead with not enough penetration.

I will think about a fillet weld at the intersections of the two round tubes, but a well-executed bracket should provide a stronger joint, and perversely, I do enjoy designing and fitting brackets. :)

Author:  GonzoRacer [ August 11, 2011, 1:05 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Quote:
I do enjoy designing and fitting brackets. :)


Whatever you do, if a guy named "Bubba" shows up and wants to help with building brackets, DO NOT let him make any. His stuff comes out all crooked and mis-aligned. Had to fire the bast*rd from Team Slotus...

Author:  Warren Nethercote [ September 17, 2011, 9:23 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

It's been five weeks or so since my last post. After a lot of regatta stuff I got back to working on my windshield frame and things. Below are two photos after fitting the windshield-to-roll bar tubes, courtesy of my new tubing notcher. There are still welds to be completed, but that awaits putting the chassis on a rotisserie so that I can do downhand welding.

A quick eye will pick out some engine mounts which I will describe in another post.

Author:  GonzoRacer [ September 17, 2011, 10:08 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Hi Warren-
Glad you're back at it! How was "sailing season"? Surely you've got something to brag about, if it's just a fantastic "sinking" story! :wink:

Roll cage looks good! I like the "bent" overhead bars, they're unique to look at and add lots of strength to the forward hoop. Nice!

Keep us posted!
:cheers:
JD Kemp

Author:  Warren Nethercote [ September 18, 2011, 8:09 am ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

JD,

I regret no bragging about sailing. Courtesy of my officiating I spend more time in motorboats than sailing, by about a 5 to 1 ratio. Winter is my dedicated sailing season, when I sail my ice-boat. I am getting to sail my club's autumn Sunday series in my Soling, courtesy of no conflicting judging plans. The first race was mildly disappointing, coming second by 2 seconds after two hours, but cold 're-play' found more than enough mistakes to cover that 2 second loss. All else being equal, it is he who make the fewest errors who wins .... but back to car building.

After windshield work I began to tackle drive-train. I first located the engine/gearbox longitudinally, to put the shifter in the steering wheel plane - 'playing driver' was required, but absent vroom-vroom noises. I also located the drive-train axis 19mm (that's what evolved; I didn't choose that number - but I work metric or British units depending on which one lands on a gradiation on the scale. :? ) to the right to reduce driveshaft angle with the offset Isuzu pinion. I ended up with an estimated universal angle a little less than the recommended 3 degrees for Hooke joints.

Fortunately, the 6 speed gearbox is long, requiring the engine to move forward, which eliminated any interference issues with the exhaust flange on the stock Nissan header. Unfortunately, the front of the engine now nearly touches a forward frame diagonal, blocking a water inlet: structural mods required!

I blocked the engine in the right location (actually higher, to allow for motor mount compression) and mocked up some Jack-style origami motor mounts, before welding them up as sub-assemblies.

More to follow ...

Author:  bremms [ September 18, 2011, 2:08 pm ]
Post subject:  Re: Warren’s Isuzu-based COLD +401 with SR20DE

Great engineering on those engine mounts. Make a good brace and a motor mount +1

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