Fabricating Lower Suspension Clevis Spacers & Washers

Posted by jjludemann on May 10, 2012

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:

: Starting the lower suspension clevis spacers by facing, turning to size, and drilling aluminum rod.

: Lathe cutting the angled face on spacer

: Using a cutoff tool to cut the part off.

: Long rod to be used for washers is center-drilled for tailstock support

: Aluminum rod is lathe-turned to correct outside diameter.

: Rod is milled flat to half diameter

: Drilling holes for bolts that attach clevises to frame

: Washers are cut to approximate size with angle grinder, then faced at 30 degrees with this setup.

: Eight lower suspension attachment clevis assemblies finished.

: Each assembly consists of these eight parts.

Making Chips… Finally!

Posted by jjludemann on May 10, 2012

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.

: Start with a solid chunk of 7075 aircraft aluminum, here scribed for cutting slightly oversize

: Blanks are cut to size with thinnest abrasive cutting blade in high-speed angle grinder. I tried using a 12″ cutoff saw, but it couldn’t cut this high-strength aluminum.

: Finished raw blank

: Facing both sides of the blank with carbide-insert face cutter end mill

: Milling holes for bolts to attach to chassis. PDF drawing printed on sticky paper at 1:1 eases the layout and provides a useful double-check against errors.

: Milling the first outside radius on the rotary table.

: Milling the second outside radius

: 45-degree faces are rough cut with the angle grinder, then clevises are supported on V-blocks clamped to the milling machine.

: 45-degree faces milled smooth with face cutter

: Repeat eight times. Ready for slot milling.

: Milling the slots for the rod ends using a ball-end mill.

: Milling holes for the rod-end retaining bolts

: Milling an additional relief for the rod ends. Test assembly showed interference, so I went back to the computer model and, sure enough, there it was. Now I know to use the interference and clearance detection tools.

: Finished lower A-arm clevises. Outside radius on front was also cut on the rotary table / milling machine.

: Lower suspension attachment clevis assembly drawing

Modifying the Lathe Quick-Change Toolpost

Posted by jjludemann on May 10, 2012

So I imported this quick-change tool post for my lathe, which appears to be some kind of standard, but a standard that my lathe just doesn’t happen to abide by. I needed a large (~1 1/2″) hole in the bottom of this solid tool-steel block. I tried drilling it with a carbide-insert drill, but after several minutes had made a cut so shallow it could only be felt by dragging a fingernail across it. After watching a few Youtube videos, though, I decided it must be possible and came up with the setup below, a solid carbide end mill slowly enlarging the hole on a rotary table. The mill left an amazingly high-quality finish.

: New Aloris quick-change lathe tool post mounted upside-down on the rotary table on the milling machine, being cut with a solid carbide end mill.

: Finished hole as cut. Note mirror-like quality from solid-carbide endmill

: Aloris quick-change toolpost in place on lathe after modification, a selection of quick-change toolholders in boxes in background.

Contents: 1 Race Car Kit, some assy. req’d

Posted by jjludemann on May 2, 2012

I’ve been accumulating parts for almost the past two years in a warehouse in Los Angeles as it’s easier to buy things in the US and ship them all the way to Thailand than it is to just buy them in Thailand. Also, I only wanted to navigate Thai customs one time. Finally gave them the go-ahead to ship, and a few weeks later everything arrived at my door. Includes just about everything that I can’t make myself or buy in Thailand: wheels, brake calipers, brake discs, brake pads, master cylinders, Aeroquip tubing and fittings, torsen differential, rear axles, spherical bearings, bearings, rod ends, 2007 Suzuki GSX-R1000 engine, crash padding, radiator, oil cooler, kevlar, vacuum-bagging materials, vacuum pump, Halon fire system, and more. Also, everything I need to fully fit out my machine shop, like a rotary table, angle table, and cutting tools. Better than Christmas!

Some assembly required. May require common household items such as tape, scissors, stapler, lathe, milling machine, and TIG welder.

: Race car kit, somewhat the worse for wear after storage of up to two years and trans-Pacific shipping.

: Some of the parts: centerlock OZ Racing wheels, 13×8″ and 13×10″

: Truck carrying goodies

LudemannEngineering

Formula 1000 Race Car Blog

Monthly Archives: May 2012

Fabricating Lower Suspension Clevis Spacers & Washers

Making Chips… Finally!

Modifying the Lathe Quick-Change Toolpost

Contents: 1 Race Car Kit, some assy. req’d