First CNC Parts, Class Photos

Uprights

Suspension uprights, two left, two right

Getting caught up on my blogging…

Shiny Happy CNC Parts

I’m getting some interest in the car from here in Thailand, but they want it SOON. So I’ve had to step up the rate of progress, even though it hasn’t showed here on the blog. Instead, I’ve been designing and designing and designing… It’s a big step from an assembly design that seems pretty much correct, to a set of drawings and IGES or DXF files that you’re willing to pay real money to fabricate. Everything has to be checked, from the load cases used in the finite element analysis to the hole clearances for every bolt.

For example, did you know that a 1/4″ bolt doesn’t go into a 1/4″ hole? The proper size of the hole is 0.257″ for a close fit or 0.266″ for a free fit. Of course, then you have to take into account the width, or kerf, of the laser beam used to cut the metal, which can be 0.01″ or 0.25mm but varies with the type of material and thickness being cut, and the laser beam is actually a cone that can be focused on the top, middle, or bottom surface of the piece. Many parts had to be redesigned for the materials and processes I’ve been able to locate in Thailand. Here it’s not a simple matter of looking up all the local suppliers on Google and giving one a call. Thailand has a great number of very small companies that rarely have websites, and even if they exist they’re mostly in Thai, which as a special favor to web search engines uses no spaces between words. Yes, you read that right. Using no spaces would be OK if there were only one way to parse a stream of Thai characters, but haha, you make joke, eh? And then if I can actually get someone on the phone, I have to communicate in Thai. Like that’ll work.

Last year I was looking for a foundry to cast aluminum uprights, and I found one (using Startpage, not Google) less than an hour from here. Their website had a Google map and everything! So I drive there, and I’m within 100 feet or so, asking motorcycle taxi drivers where the company is. No idea; there’s never been a foundry around there. I show them the address and they say oh, that’s way over on the other side of town. The person answering the phone number has no idea what I’m talking about. I give up.

On the other hand, recently one of those Google ads that look like the first links on your search actually showed me something that I needed and couldn’t find with a search: a small local company that fabricates custom radiators. So I managed to find their shop this week and got a quote for the radiator. Quote comes by email entirely in Thai. Google translate does a pitiful job of translating Thai, but I caught on the email wasn’t spam. Fantastic price, by the way. Cheaper than what I paid for a used race car radiator on EBay. I decided I didn’t really like how that one would fit, so I designed one that’s ideal for my application and figured I’d worry about fabrication later. Problem solved, yay!

The Thai racers who are interested in the project have emphasized that the price is crucial, which means more redesign. Surprisingly for me, this is the same thing I’ve heard from the people in Singapore who’ve contacted me. Sometimes it’s easy to dash off a quick machined aluminum design, but it takes a lot more thinking to do it with laser-cut steel pieces. The equivalent in steel typically ends up being a little heavier, but that’s an example of why Formula 1000 has a minimum weight rule. Laser-cut steel hand-welded into a complex component is just about free in Thailand.

Where before I was planning on making just about everything in my machine shop, now I’m looking at fabricating as much as possible at subcontractors. Luckily a friend found a large CNC machine shop not too far from here, and the guy running it speaks English and understands drawings and computer files and tolerances and clearances and everything. I’ve now received my first batch of CNC machined parts from them and they look great. Combined with the first batch of laser-cut parts and a few parts I’ll fabricate and modify myself, I now have everything to make the car a roller.

Anyway, on to today’s gallery:

Fabricating the Lower A-arms

No, I haven’t just been sitting around the house eating chocolate, but a major malfunction in my main computer leaves me time to update the blog and get caught up on other things I should have done, like taxes. Unlike EVERY OTHER COUNTRY IN THE WORLD (except the Phillipines), even though I haven’t set foot in the USA in over four years, I still have to pay US taxes. The bright side is that California no longer considers me a resident so I don’t have to pay California taxes anymore, which is quite reasonable given that I moved out 11 years ago.

I made the mistake of turning the computer off overnight to help save the planet and all, and the next day it kept dying like someone pulled the plug. Computer shop says I need a new motherboard and graphics card, and oh, by the way, there are no new LGA 1366 motherboards for Intel i7 CPUs in Thailand and the old one will take about a month to fix under warranty. Which is understandable, given that Intel stopped making LGA 1366 i7 CPUs ages ago! Oh wait, they still make them? Or maybe not, from Intel’s website I can’t tell. At least Gigabyte’s warranty will cover their product, or maybe I just haven’t heard what their fine-print objection will be, yet. Azus, on the other hand, says my graphics card is corroded, and corrosion isn’t covered under warranty. Great plan! Make a product that corrodes, then say corrosion isn’t covered. It might be more honest to say “No Warranty”, though. The Azus graphics card was inside a warm computer (which was _almost_ never power-cycled) in an office environment for it’s entire life.  Azus is now on my Deferred Vendor List.

Anyway, on to fabricating the lower A-arms, or control arms:

Class Photo

Repeat everything four times. Final result: four lower A-arms

Fabricating Lower Suspension Clevis Spacers & Washers

Need some spacers to keep the clevises from interfering with some of the frame tubes. Also, custom load-spreading washers that my FEA says are important:

Making Chips… Finally!

Assembly Drawing

Lower suspension attachment clevis assembly drawing

It seems that other people who’ve built cars from scratch attempt to get their cars rolling on the ground as soon as possible, so I figure I’ll do it that way too. With that in mind, it’s time to start fabricating the suspension. First up: lower suspension attachment clevises. I ordered 7075 aircraft aluminum from the United States as part of my big shipment. It’s amazing stuff– stronger than steel but light as aluminum. These assemblies have to be extremely strong, as I calculate that under braking the front one takes a load of over 4400 pounds.