Just a bump for Monday since there's so much good info in here.
Enjoy and anyone have any tips to add?
Photograph by Carl Heideman
Since that first rock was used to carve another rock into a wheel, humans have had the innate desire to turn raw materials into useful objects. Our evolving society has brought us from stones to metals to plastics, while tools have progressed from rocks to a myriad of more sophisticated devices like drills, grinders and welders.
While the craft of fabricating finished products is taught and written about widely, many useful tips and tricks are left undocumented. Here are some of our favorites; they should help the next time you’re fabricating the bits and brackets needed to make your project a success.
Make Paper Templates:
Cutting and folding steel is not a trivial task, and we prefer to do it only once. We’ll often make a paper template first to test our design for a bracket or part. Office file folders are a useful material for these templates—they’re heavy enough to mimic sheet metal, but light enough to be cut and folded easily.
A paper template allows us to rough out a design quickly, hone the measurements, and make appropriate changes as surprises come up. Then we transfer the template to our steel, and the result is often more functional and attractive. We’ve all heard “measure twice, cut once.” Our mantra is “measure twice, template once, cut once.”
Use a Scriber:
While pencil and permanent marker lines are easy to see, they’re rarely nice and crisp. We prefer to mark cuts using a scriber—also known as a dental tool—as it delivers thin, consistent lines.
The only time we don’t follow this rule is when a part might eventually be subject to severe vibration: any scratch in these parts could cause a stress riser that would eventually lead to a crack and part failure. Nonetheless, most of the time we’re cutting right on the line, so even in shaky areas it’s still appropriate to use a scriber.
Use Dividers to Measure and Mark:
We often need to create a part with a given width or length. Other times, we need to make marks for holes that will be a certain distance apart.
While we can use a tape measure or ruler to transfer these dimensions from one piece to another, we have found a more accurate and efficient way. We set a drafting divider or compass to the dimension we need, then scribe the line by dragging or swinging the divider. This method allows us to maintain very precise dimensions while scribing, increasing both our accuracy and speed.
Measure Holes From the Ends:
Most parts are mounted with two or more fasteners. To complete the job, the hole spacing often has to be transferred from one surface to another. People often try to determine the spacing between the holes by measuring from the center of one hole to the center of the other, which is very hard to accomplish accurately. An easier way is to measure from one side of one hole to the same side of the next hole.
Clamp Down Your Part:
When drilling, cutting or fabricating, always try to secure your part with clamps or a vise. Attempting to hold the part with one hand while fabricating with the other is dangerous and leads to a low-quality finished product. Just think about it: If the part is dancing around the table while you’re working, accuracy will suffer.
Work Your Way to a Larger Bit:
Drilling a large hole with a big bit is often slow, difficult and inaccurate. Here’s our approach for cleaner, better-centered drilling.
Start with a center punch, drill a pilot hole, and then step up to larger bits. For example, if we need a 1/2-inch hole, we’ll mark our spot with a center punch and then start with a 1/8-inch pilot hole. Then we’ll enlarge that hole with a 5/16-inch bit and finally finish with the 1/2-inch bit.
Cut Wisely:
When cutting bar or angle stock, make sure your blade encounters the least amount of surface area possible. Whether you’re using a hacksaw, cutoff wheel or powered saw, cutting on an edge with a small surface area will take less time and generate less heat than cutting on a large, flat surface.
Using an appropriate lubricant on your drills and saw blades will provide more accurate cuts and also extend the lives of your tools. Purpose-made cutting oils are available, but regular motor oil or even spray lube will work in a pinch.
Use Found Art:
Scrap metal yards, parts cars and the like can often supply helpful brackets and parts for your project. Modifying these components to your needs can save time when compared to starting from scratch. Why do all the work when most of it has already been done?
Save Your Mistakes:
If you make a mistake and have to start over, save the part. It might end up being the “found art” you need for your next project.
Right Angles Are Right:
Keeping things square will save you a lot of setup and layout time. If everything is either parallel or perpendicular to a line, accuracy will improve and measurements will be easy. You might lose some style points, but you can always add flair once you’ve finished the major fabrication and know that the part fits. Just carve off and smooth any unnecessary areas.
Sneak Up on Your Solution:
While this might seem counterintuitive, taking the extra time to occasionally test fit your part will often save time. Doing so helps to catch mistakes earlier. After all, it’s pretty disappointing to make a beautiful bracket that doesn’t fit.
Get Benched:
A good bench vise makes a great bending tool. Sometimes, holding a part in the vise and bending it over by hand or with a hammer works well. Other times, it’s best to fold a part using the jaws of the vise. Either way, using the jaws, edges and clamping force of the vise will improve your parts.
If You Need a Welder, Find One:
If you’re not a competent welder, that shouldn’t stop you from fabricating complex parts. You can always tack weld things together, but be sure to have a professional or a talented friend finish the job. Welding can slightly change the shape of your part, so you might need to make some adjustments after the pro is done.
Radius the Corners:
Looking for a nice finishing detail? Radius the corners on your pieces. Use a washer to mark off an attractive radius line, then sand or grind the part to that shape.
Use Bolts Properly:
Bearings, rod ends and other moving parts should not ride on the threads of a bolt or stud, only on the shoulders.
And, of Course, Keep It Safe:
Wear the right protective gear when you’re working. Protect your eyes, ears and limbs at all times and wear appropriate clothing. Stay away from clothes that fit loosely or have holes.
Just a bump for Monday since there's so much good info in here.
Enjoy and anyone have any tips to add?
Drilling is such a pandora's box. I've had a guy at a machinist's supply house tell me not to step up drill bit sizes because it loads one point on the cutting edge of the drill bit excessively when that loading is supposed to be spread over the whole cutting face. I get it, but i've never had bad results doing it. The one exception i can think of is that when each size of bit only has to cut a small amount of width it can end up self-feeding too aggressively and sucking into the part and stalling which is usually when parts crack and bits snap etc, but it's manageable. I think the main thing for that is that going slow on rpm seems like being careful but is actually counterproductive since most cutting bits and bobs are less likely to 'catch' if they're moving faster.
One thing i failed at recently was preventing some carbide burrs from loading up with aluminum. Wish i'd looked for a helpful refresher before i started on that one.
Today I traced around a large-ish washer to give myself a target line for belt sanding a sharp outside corner smooth. Thanks, Carl!
stuff like this is how GRM has made me a better mechanic. Also you forgot weld it strong, grind it pretty.
Re-use/recycle/re-purpose.
Unless it's complete and utter, rusted, mangled, melted, rotted, etc trash, save it. Metal scraps, hardware, wood, even plastic can turn to be useful down the road for other projects, whether as parts , fixtures, or assembly aids.
An old BMX handlebar turned upside down and welded to short brackets made a perfect front bumper for my John Deere riding mower. Plastic cap from a small butane refill cylinder was perfect for capping off the open end of my hydraulic floor jack handle. Plastic cap from a spray paint can cut in half makes perfect wheeltubs for the bed of a model truck. Old center link from a Jeep steering linkage is handy as an extension when I need some extra leverage turning a wrench. Old 3/8" long socket extensions work great as a good strong punch to knock things loose or straighten out bent things that are hard to reach. Old bearing races and broken shafts make handy spacers or supports when using a hydraulic press to push things together or apart. Old valvetrain pieces (valves, springs, keepers, lifters, rockers, etc) make cool chess men for a custom gearhead chess set. An old Winston Cup piston, used NHRA aluminum connecting rod, old long 3/8 drive spark plug socket as a piston pin, and an aluminum R/C car wheel makes a pretty cool desktop clock. Unused, extra pieces of thick guage sheetmetal wall purlins/brackets from a metal building frame make perfect jeep-style trailer fenders with a little cutting and welding.
Disassemble small parts inside a plastic bag, especially if there are springs or springy things known to be included. It's way easier (way) to find them in a bag than under your SOs stuff after the part hyperspaces across the room.
earlybroncoguy1 said:Re-use/recycle/re-purpose.
Unless it's complete and utter, rusted, mangled, melted, rotted, etc trash, save it. Metal scraps, hardware, wood, even plastic can turn to be useful down the road for other projects, whether as parts , fixtures, or assembly aids.
An old BMX handlebar turned upside down and welded to short brackets made a perfect front bumper for my John Deere riding mower. Plastic cap from a small butane refill cylinder was perfect for capping off the open end of my hydraulic floor jack handle. Plastic cap from a spray paint can cut in half makes perfect wheeltubs for the bed of a model truck. Old center link from a Jeep steering linkage is handy as an extension when I need some extra leverage turning a wrench. Old 3/8" long socket extensions work great as a good strong punch to knock things loose or straighten out bent things that are hard to reach. Old bearing races and broken shafts make handy spacers or supports when using a hydraulic press to push things together or apart. Old valvetrain pieces (valves, springs, keepers, lifters, rockers, etc) make cool chess men for a custom gearhead chess set. An old Winston Cup piston, used NHRA aluminum connecting rod, old long 3/8 drive spark plug socket as a piston pin, and an aluminum R/C car wheel makes a pretty cool desktop clock. Unused, extra pieces of thick guage sheetmetal wall purlins/brackets from a metal building frame make perfect jeep-style trailer fenders with a little cutting and welding.
That is the way I feel except for the storage issue. Sooner or later you run out of space for those scraps and odds and ends.
Plus the temptation to use the wrong piece because you have something close that you can make work. I've spent the last 3 weeks clearing a space to work on my next car. If I could eliminate all the left overs, spares, and odds and ends I'd have 1800 square feet to build it. Instead I'm working like a pack mule to get 200 square feet
Something I learned a long time ago, when drilling use a center punch then while drilling rotate the drill so the bit travels like a cone. It helps keep you in the punch and not traveling off center.
Here's a little tidbit. Hammering metal on a flat surface makes it bow. Sometimes this is to your advantage and a lot of the time it's the opposite of what you thought you want.
Keep your empty beer cases. Break them down flat and put them somewhere. They are the perfect material for templates when making complicated sheet metal patches for floor pans and such.
thanks for the advice,very helpful!
In reply to Vigo (Forum Supporter) :
When drilling a pilot hole, you are supposed to only drill it as large as the root diameter of the final hole's drill bit.
This is great until you break all of your 3/64ths drill bits or whatever.
I think this is the magic of the Hyperstep drill bits. They drill their own pilot holes.
In reply to Pete. (l33t FS) :
That's interesting. I was trying to think this through the other day as to what was ideal for pilot and steps up from there and got hung up on the notion that the difference between steps would be guided by the difference in surface speed between the existing hole and the new diameter. Like if you jump from 1/16" to 1/2", the worry is that you could be cooking the outer edge while not cutting effectively at the inner edge due to the 8x speed differential. Nevermind the ridiculocity of moving drill press belts every couple of sizes. Overthinking for the... hm, I don't think that's a win...
I didn't know about the Hyperstep bits, though I think expensive, proprietary bits are beyond my willingness to cope.
In reply to Jesse Ransom :
They are not all that expensive. IIRC it was $350 or $400 for a set by 64ths up to 1/2".
For comparison, the last set of normal drill bits I bought (not counting disposable Harbor Freight junk good for cutting anything but steel) was also about $300, in the early 2000s.
I know, "but my $20 Harbor Freight bits work just fine". And I am sure 500 treadwear all season tires "work" when autocrossing or driving in cold wet weather. Sure you take a lot longer and are going to have some mishaps along the way, but that's life right? It's acceptable until the first time you use something properly built for the job at hand, be it dodging cones in a parking lot, or driving on a salt flavored Slushie, or putting a hole exactly where you want it, making long curly shavings in the process, at amazingly fast speed, through anything including hardened bolts. After that you won't go back 
In reply to Pete. (l33t FS) :
That's a compelling comparison.
Hrm.
If you make a sheetmetal 90 deg. bracket, put a crease in the crown with a chisel. Stiffens the corner immensely.
earlybroncoguy1 said:Re-use/recycle/re-purpose.
Unless it's complete and utter, rusted, mangled, melted, rotted, etc trash, save it. Metal scraps, hardware, wood, even plastic can turn to be useful down the road for other projects, whether as parts , fixtures, or assembly aids.
An old BMX handlebar turned upside down and welded to short brackets made a perfect front bumper for my John Deere riding mower. Plastic cap from a small butane refill cylinder was perfect for capping off the open end of my hydraulic floor jack handle. Plastic cap from a spray paint can cut in half makes perfect wheeltubs for the bed of a model truck. Old center link from a Jeep steering linkage is handy as an extension when I need some extra leverage turning a wrench. Old 3/8" long socket extensions work great as a good strong punch to knock things loose or straighten out bent things that are hard to reach. Old bearing races and broken shafts make handy spacers or supports when using a hydraulic press to push things together or apart. Old valvetrain pieces (valves, springs, keepers, lifters, rockers, etc) make cool chess men for a custom gearhead chess set. An old Winston Cup piston, used NHRA aluminum connecting rod, old long 3/8 drive spark plug socket as a piston pin, and an aluminum R/C car wheel makes a pretty cool desktop clock. Unused, extra pieces of thick guage sheetmetal wall purlins/brackets from a metal building frame make perfect jeep-style trailer fenders with a little cutting and welding.
Until you can see that you are no longer going to finish everything you'd like to. At that point start giving or tossing stuff away.
Don't burden your family to dispose of scraps.
In reply to Carl Heideman :
Off the subject but perhaps you have an opinion.
A friend of a friend threw a con rod through his block.
Magnafluxing revieled 2 cracks beyond the hole, none going any place critical. Can I just put the piece back in the hole and braze the cast iron block? He's got a kitchen oven to heat the block up to 400 degrees and complete access to both sides.
It's a driver quality engine not intended to race.
In reply to frenchyd :
I think the plan you're describing might work, but I've never done it so I can't offer any experiential advice. I have brazed up minor cracks in water jackets and feel that JB Weld has been easier and just as successful.
For a hole in the block, I'd find a new block unless it's super rare. And if it's super rare, I'd probably find someone who's done it before. But I guess there isn't much to lose to try it on the holed block.
In reply to Carl Heideman :
Yeh it's rare, MG only made 6000 in 1955 about 1/2 came here to America. Plus it's a numbers matching engine.
It's not really stressed and it's well away from water jackets or cylinders.
The thing with brazing it back together is you run the chance of warping the block all to hell. I have seen it done to put a rare Buick block back together, lots of peening while it cooled and it needed to be completely remachined. I would like to say it sat for a while "finding itself" before being machined.
If the cracked out parts are non structural I almost wonder if metal stitching would work. Probably more expensive and time consuming.
When I was about 7 a 1948 Chevy was left over winter with water instead of antifreeze in the radiator. The owner had abandoned the car when it wouldn't start. Luckily he left the signed tittle in the glove box.
Anyhow with the guidance of the local hot rodder we neighborhood kids pulled the engine. Put it on a wagon. Then 8 of us tugged it 3 blocks up and 2 blocks over to a welding shop. They welded it back together and we kids spent the rest of the summer getting it back in and running ( I wish I remembered his name.).
But I remember his 1927 Model T hot rod. Yellow with
Wee
Weary
Will
ahead of the drivers door.
He also later built a 1950 ford. Chopped, channeled, sectioned, and narrowed with a 270 Offy running on alcohol that one was always in primer.
Frenchy,
I have successfully welded a block with a stick welder and nickel rod . I didn't heat the block and beveled where I was welding. It was a Ford Cortina block and it lived im my Turner for many races.
A few more additions, mostly painting/detailing related:
Consider using paint "pens" or Sharpies when adding small details to paint projects - they're quick, easy, precise, and available in just about any color. No searching for just the right size brush, dealing with paint drops, cleaning afterward, etc.
Going to spray paint something? First, shake the hell out of the can, until you hear the ball rattle, then shake some more. Make sure the nozzle is clean - if not, a few swipes with a small steel brush will unclog the nozzle. Hang whatever you're going to spray from an wire old clothes hanger, straightened out and small hooks bent into the ends. Make sure whatever you're going to paint is CLEAN - paint won't hide things, it'll magnify them. I spray Windex all over the part I'm about to spray, then blow it dry with compressed air, or an old hair drier. Windex is mostly ammonia, does a great job of cleaning and degreasing, and evaporates quickly with no residue. I've used it for years.
After painting, let the parts sit out in the direct sunlight to help the paint dry faster.
Need to clean up some old, rusty bolts? Chuck them in your drill, head over to your bench grinder with a wire wheel, use the drill to spin them slowly against the spinning wire wheel to clean the threads, shank, heads, etc. WEAR EYE PROTECTION.
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