Eric's Build

Follow progress of your fellow builders. Pictures encouraged!
ChrisS
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Re: Eric's Build

Postby ChrisS » 06 Sep 2018, 04:43

Looking good Eric. Casting your own parts is a bit above & beyond for me though ;)

I worry about those upper rear wishbones though. Specifically, how they are going to handle forces acting on the top of the upright.

Midlana1
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Re: Eric's Build

Postby Midlana1 » 06 Sep 2018, 09:25

I can't see enough of the upper rear suspension to comment, but it appears to be different than the plans. If so, be sure to check rear bump-steer to make sure it's not too crazy.

ChrisS
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Re: Eric's Build

Postby ChrisS » 06 Sep 2018, 09:39

I’ve got into trouble before for making observations that I honestly thought could be helpful, so I absolutely accept I could be talking utter bollocks :)

ShadowCat38
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Re: Eric's Build

Postby ShadowCat38 » 06 Sep 2018, 21:37

ChrisS wrote:Looking good Eric. Casting your own parts is a bit above & beyond for me though ;)

I worry about those upper rear wishbones though. Specifically, how they are going to handle forces acting on the top of the upright.


Midlana1 wrote:I can't see enough of the upper rear suspension to comment, but it appears to be different than the plans. If so, be sure to check rear bump-steer to make sure it's not too crazy.


I've run it through its travel, and I couldn't detect much bump steer, but I don't have all the bushings in place around the rod ends, yet, either, so there might be something that needs to get adjusted for.

The layout for the rear suspension is based on the book, only with the inside pivot points moved aft about 8 inches as a block. That makes things look strange with the upper wishbones, so I'm curious to see how they hold up as well. Technically, they should be fine. But since everything is at a significant rearward angle instead of somewhat centered over the axle, forces might play a bit rougher with this shape of triangle. The way this is designed, the lower wishbone seems to have to take most of the energy out of things, but sometimes paper and reality don't match.

Worst case, I get to cut it all off and start over. :lol:

ChrisS
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Re: Eric's Build

Postby ChrisS » 07 Sep 2018, 04:21

I hope my concerns are groundless - I've not done any calculations, just eyeballed it and jumped to a conclusion :) My old Applied Mathematics teacher would set me something like that as a test question I suspect ;) Hah, Mr Barton - not thought about him for 40 years.

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Re: Eric's Build

Postby ShadowCat38 » 14 Sep 2018, 07:10

My list of things to get done to become self-driving by December 31st:
  • Brakes - run lines and verify function
  • Electrical - adapt stock donor harness to accommodate the custom build, and mount controllers and protection
  • Cooling - Fabricate radiator mounts, power the fans, run the coolant lines
  • Fuel - buy or build the fuel cell, install the fuel pump, connect the fuel lines
  • Air - ...yeah, this is going to take some thought

Since I have so much to do to meet my goal, I've decided to start prepping the wire harnesses for the car while i'm waiting for the rest of my brake parts to arrive. I'm also very aware that this goal might be a bit overzealous. That's a lot of stuff to get done in essentially 3 months.

That said, brakes are very close to complete.

Cooling is going to be less complex (famous last words) in this build since I'm using rear-mounted radiators, mainly because I'm not making a run to the front of the car and back again. I'll still need to figure out how I want defoggers to work, and I have some ideas, but nothing that can't be added in later.

Fuel will be as easy or as hard as I want to make it for myself. I love Kurt's fuel tank design, but I'm a bit apprehensive about taking on something that potentially catastrophic myself. Buying a cell, while likely more expensive and less likely to take full advantage of the available space, could put my mind at ease a bit. Adding to that my TIG and stainless steel welding skills are largely unexplored and that's the primary source of my apprehension. I could do very well; I could also make a very large and expensive non-functional "piece of art." All that just means I'll probably save that for last.

Air... air. Technically, this is pretty easy. Just bolt the donor filter back up to the engine and go, but that seems like too much of a cop-out. Plus, it won't fit well when the panels are made. I don't want to repeat Kurt's collapsing plastic vacuum, but I also am not sure which way I want to go for air intake. Coming in the sides would be neat, as long as I don't aggressively collect road debris, or at least have some way to let that fall off the filter. I don't know how this is all going to wind up, yet, so as much as I don't know about how I'm going to do the fuel, the air intake is even more so. Usually, when I dive into things like this, pieces start lining up as I actually start working towards something, so this will certainly get better when it becomes a focus.

Electrical is where I'm in my element. I've seen lots of groans in other builds about working on this step, but I've been looking forward to this part. I've spent a few years running diagnostics on harnesses in construction equipment and RVs looking for problems in controllers, security systems, engine connectivity, gauge functionality, etc. Over the past several months during bits of spare time over lunch breaks or while travelling, I've been pouring over the donor FSM schematics and redrawing them to focus on physical layout as opposed to service functionality. This helps me find where wires are routed on the actual harness and add or remove connections as needed with confidence. The engine harness remained entirely unchanged. The harness connecting the drivetrain to the ECM and dashboard was mostly unchanged, just a few circuits modified to remove the unnecessary power steering pressure sensor and separate the A/C support for removal later (although, my brother is trying very hard to convince me to keep A/C...we'll see). Dash and Cabin harnesses have a lot more modification to them since a majority of that part of the car has no equivalent in this build. I'm two days into this, and that's what I start working on next, so I'll be able to get a picture up of the pile of wires left over when that's done.

wiring.jpg
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ChrisS
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Re: Eric's Build

Postby ChrisS » 14 Sep 2018, 11:33

If you retained the book space for the fuel tank, a Lotus Elise/Exige tank is a perfect fit.

Funny enough, I’m looking forward to the wiring too (if not finding space for it all). I guess we always go to what we know. Just short of 40 years of messing with wires means I never really appreciate why others are put off by them.

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Re: Eric's Build

Postby Midlana1 » 14 Sep 2018, 14:46

I'm an electrical engineer by training, so wiring isn't a big deal, but the amount of time it takes to do it well is not lost on me. Like mention somewhere in the book, adding big parts to the car does wonders for a positive mental attitude. When doing the electrical, you have to keep reminding yourself over and over that it's just time, and regardless of what you're working on, it's that much closer to getting done. But yeah, seeing the car look exactly the same for months as dozens of wires were cut and shrink-wrapped did kinda get to me.


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