I need to be able to lift the engine into the chassis, but due to the lowered floor of the work area a standard engine lift won’t work. While I’m at it, it would be nice to be able to lift the entire assembled car off the build table, turn it ninety degrees, move it to the door, and roll it out of the shop. Below is the solution. Sorry there aren’t any plans. The build process was “go to your local metal recycling center, buy some scrap beams, clean them up, cut them as necessary, and weld them together”. I’m getting more comfortable with winging it in the machine shop.
Also shown below is a mount I built to mount an angle grinder on the lathe. Parting-off has always been a problem. I’m just about to make the engine mounts, requiring at least 36 cutoff operations, and I figured I’d better solve the problem. I have a cutoff tool but only purchased a small number of carbide inserts; the inserts wear out really fast and I either have to order more from the US or drive at least an hour to a store that MIGHT have them. This baby works great, giving a clean straight cut. Just have to be careful not to let the abrasive get into the lathe.
Here’s what the overhead beam looked like when I started.
Drilling holes to mount the wheels. Milling machine makes this easy.
Welding the uprights to the wheel supports
Thick steel is so much easier to weld.
Welding the uprights to the overhead beam, upside down. C-channel is temporary, so it doesn’t fall over.
Finished. Trolley and chain hoist bought at Hardware House, Rayong.
So easy, even our spokesmodel can do it.
Test lifting the chassis. Easy!
Building adapter to lift the engine.
First lift of the engine.
While we’re building tools, here’s a holder to mount the angle grinder on the lathe.
Parting off has always been a problem. Not anymore. Plastic is to keep abrasive off lathe.
Next up: mount the steering column in the chassis. Nothing magical here, just lots of little steps. The steel bearing cup insert did work well at preventing distortion during welding. To get a proper press fit for the rear support bearing I decided to use my new internal bore gauge. At first it didn’t work at all (made in China, of course), so I had to disassemble it completely, figure out how it was supposed to work, unstick the rusted shaft, replace the dead battery, and reassemble it. All in a day’s work out here on the frontier. So now I can measure both holes and shafts to a few microns and press fits are much easier to make.
Front bushing; sheet metal cut on bandsaw and with die grinder
Front bushing support bent to shape
Front bushing support cap, ready to weld
Finished front bushing support
Turning steering column rear bearing cup
Finished rear bearing cup
Finished rear column support parts
Steel insert bushing to prevent distortion of the bearing cup during welding
Rear support, ready for welding. Note steel insert to prevent distortion.
I originally sent all these parts out to the CNC shop, but they never got back to me with a quote so I ended up making everything myself. The spline onto the steering rack was a tight press fit, so for now the entire column including the rack is a single assembly. I don’t know it’s possible to remove the rack later, and I’m not going to try as it might destroy the rack. The U-joints are special units from Sweet Manufacturing in the US, but don’t seem to be anything special. In the future I might try to adapt standard Honda steering column U-joints and column splines. These use a perpendicular pinch bolt so the column can be disassembled at each joint.
Parts turned on lathe, purchased, and laser cut
Front bushing and adapter
Finite Element Analysis (FEA) mesh of collapsible steering column joint in frontal impact
Finite Element Analysis (FEA) of collapsible steering column joint under maximum torque
Finite Element Analysis (FEA) of collapsible steering column joint in frontal impact
Collapsible column takes shape. 1mm steel is strong in torsion, weak out of plane.
Collapsible section finished
Finite Element Analysis (FEA) mesh of steering column quick-release adapter to column.
Finite Element Analysis (FEA) of steering column quick-release adapter to column.
Turning the adapter from column to quick-release
Finished adapter from column to steering wheel quick-release
Parts finished, still need welding
Welded double U-joint. Note clocking of joints. Important!
Welding the U-joints. Kept cool with wet cloths.
Machining the steering wheel to fit the quick-release.
Just a quick update here as the next one will be big and I want to keep it together as one post. I want to get all the tabs and brackets attached to the frame as soon as possible so I can paint it, so I started with an easy one: the seat bottom. I had the pieces laser cut, but the shop forgot that there are two identical side pieces and I had to cut that one by hand. I turned out to be easy after making a paper template. Each of the four pieces is a section of a cylinder and some of the edges intersect off-axis with frame tubes, so those lines that look straight really aren’t. The seat bottom is curved like this to get the driver as low as possible, mainly to keep the top of the main roll hoop as low as possible. The curvature was easy to make by just bending the steel by hand and fitting it by eye to the frame.
Attachment points are carefully spaced more than six inches from each other to comply with the F1000 rule outlawing stressed panels (with certain exceptions). It would have been much easier to just weld each piece to the frame tubes below it, but I don’t plan on this counting as the stressed belly pan. A stressed belly pan will be added to the planar bottom of the car. Making the seat bottom removable gives the advantage of easier access to the triangular compartment below it for mounting the fire extinguisher and whatever else will fit, and I can also replace the seat bottom later with a carbon fiber and kevlar version to save weight. At the moment I’m appreciating the fact that certain important body parts will be protected by two layers of steel in the event of a crash.
First two pieces clamped in place and ready to tack weld
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:
Repeat everything four times. Final result: four lower A-arms
Starting with the spherical bearing cups, face and cut outside diameter
Cutting the internal diameter on a bearing cup. This is a press fit, so it has to be cut as perfectly as the tools will allow.
My boring bar won’t fit into my new quick-change tool holder, so I had to cut it down to fit.
Boring bar now fits into tool block.
Cutting the groove for a snap ring. I wasn’t sure I could get the press fit perfect, so I included provisions for a snap ring
Snap ring in place for a trial fit.
Using the cutoff tool to cut the part off the stock
Bearing cup, spherical bearing, snap ring, and ID gauge for cup. I don’t have an internal micrometer, so used my external micrometer to cut a gauge to the precise length for the ID.
I ground a carbide cutting tool for the boring bar to the correct width to cut the snap ring groove. It took a lot of grinding. Carbide is really hard!
Starting the rod end receptacles that will be welded to the legs of the A-arms. Face and cut OD on lathe.
Cut step to fit inside A-arm tube.
Use center drill for accuracy.
Drill hole to be tapped for rod end
Using cutoff tool to part off
Tap for 3/8-24 left hand threads. A later version of the A-arms may have easy rod-end adjusters, so I’m using left hand threads here, too.
Cutting a chamfer on the face of the rod-end receptacle. Looks better, is lighter.
Four finished rod-end receptacles
Setup for tack welding rod end receptacle into A-arm tube
Tack welded in place
Welded all the way around. Holding the tube in a V block makes it easy to turn while welding
Made 2 aluminum bushings to fit inside the bearing cup and locate it on the jig
Rod ends are held in jig for welding.
A-arm jig is made from printed drawing glued to plywood.
Spherical bearing cup fully welded to one leg of an A-arm
Both legs of an A-arm fully welded to a bearing cup
A-arm bearing cup braces marked and cut
Bearing cup braces in place and welded
Pushrod mount in place and welded. These pieces were made with the patented (not patented!) technique of printing on sticker paper, cutting with a plasma cutter, grinding to exact shape.
Spherical bearing is pressed into place on my home made hydraulic press. Custom bushings were made to only push on the correct places, like not the ball.
Anti-intrusion bar test fitted
Anti-intrusion bar fully welded. Weld shrinkage is a problem here.
Welding distorted the bearing cap enough that I had to recut the bore. First, find the center of the hole.
Next, use a boring head to cut the hole to exact dimension. Very tricky; had to use 1/2 the smallest tick mark on the boring head. Total overlap for press fit is around 0.001″
Repeat everything four times. Final result: four lower A-arms
I’ll be needing a press to insert the spherical bearings into the control arms and to insert the wheel bearings into the suspension uprights, so I took a couple of hours and built a simple hydraulic press. It’s just a strong steel frame that will give a small 5-ton hydraulic car jack something to push against. It’s taller than it is wide to be able to press items of different sizes by turning the frame on its’ side. Regarding painting, I’m finding that, with modern paints, I don’t need to use primer. I just clean the metal with a wire brush on a variable-speed angle grinder, clean it again with acetone and paper towels, then spray the topcoat on directly. This gives a thin, hard coat that sticks well.
4 x 2 x 1/4″ C-channel steel marked for cutting with the plasma cutter
Plasma cutter makes short work of cutting this thick steel. Each cut would take more than 1/2 hour on a 12″ abrasive cutoff saw, but takes just seconds with the plasma cutter.
Jigged and clamped, ready for welding
Crushed a few things to test it. Can exert some pretty good force.