Basic Mechanical Workshop

Hello CD,

Our team would like to host a basic mechanical workshop to teach the new members how to use a drill and rivet, etc. What i am wondering is what should be covered in our presentation. We would like to steer away from topics as the lathe or drill press. We would like to cover the basics only. Any suggestions?

Definety cover safety for all of the tools.

You should explain that “A flathead screwdriver is not a prybar”

I don’t know if your team had both regular and drill drivers, but if you do you sohuld explain the differance and the different setting on the regular drill.

Something has to open the paint

First comes first, as when learning any tool, is safety. Make sure everyone knows how to use the tool the way it was intended to be used.

Rivets are pretty self explanatory.

An incredibly important skill that is often looked over is measurement and precision with basic manufacturing. Things like understanding the offset on a tape measure, reading a vernier scale, scribing lines, using a center-punch, drilling and tapping perpendicular to the surface, etc.

You can pretty much build a beautiful well planned and neat looking machine with no special machines other than a band saw, a sander, a pair of cheap calipers, and a drill press if you plan accordingly.

The first one has been covered, though specifically rather than generally: what each tool is for.
Like many teams, we have a selection of saws. Each one is best for a specific range of functions. We have “chop style” saws, a large abrasive cutoff wheel, one with a blade for nonferrous metals, and one with a woodcutting blade (does both crosscut and ripping, though used mostly for crosscut). We have a jigsaw and a reciprocating saw, each with a variety of blades. We also have a cordless circular saw, and of course the dremel. Selection of a saw and blade is dependent on the material, direction and length of cut, and the required precision. Similar rules apply for drills (corded vs cordless vs drill presses) and hand tools (socket vs wrench vs pliers; hammer vs mallet; metric vs SAE (5/32" != 4mm). One of the main things that needs to be communicated is that the dremel and the crescent wrench are NOT the answer to every problem - I regularly refer to each of these as being the “tool of last refuge”.

As also mentioned before, how to use each tool, and how to use it safely. Explicitly say what can go wrong when the safety rules are not followed - stories about flying metal and broken bits and saw teeth and safety goggles doing their job make a much better impression (especially on teenagers) than a simple “do it this way.” Related: tool inspection, tag-out, and reporting issues with tools so they can be resolved. (Though an unreported broken dremel did more to get the kids to use the right cutting tool than the talks in #1.) Also, any maintenance for the tools such as oiling steel blades both for lubrication and preservation and tensioning/changing belts.

Where are the tools kept? How to find them efficiently, and the importance of returning them to their home so they’ll be there next time they’re needed.

Another thing to cover is measuring and marking pieces for cutting. This is especially important when doing a large number of pieces or when the marker and the cutter are not the same person, so that it is clear whether the cut should be on the left or right side of a line. We also have a bit during tryouts where we show how it is better to measure distances from a common origin rather than incrementally.

Bottom Line: teach them what to do and how to do it, but (especially early) spend more time telling them what NOT to do - and WHY.

Edit:

I thought so, too. I found out that you have to teach (at least some) people that the pieces being riveted have to be held tightly together, and the rivets have to be pressed into the pieces as you go; that you should place all of the rivets (or clecos if you have those) before you start setting them, and that rivets are most useful under shear, and are not the right fastener if the rivet will be under tension. A few don’t even seem to realize that the holes have to line up and the rivets won’t magically do that for you.

Edit2: related to several points above, and specific to versaframe work: Don’t drill a hole in versaframe without understanding why the pre-drilled holes aren’t in the place you need them. If the plans didn’t say to drill that hole, it’s more likely that you made an error somewhere else, and you’re only making things worse. This goes at least double if the hole is not along the centerline of the tube! We’ve had students cut angles too broad, then drill extra holes to make the gussets “line up”, resulting in a complete waste of both time and materials.

Talking about rivets, teach the importance of using the appropriate drill bit size and drilling it straight. With oversized hole or slanted holes the joints become loose. Over tightening the bolts on thinner tubes like 1/8" thick can cause structural weaknesses, using a flat washer may help.

+1 to safety and proper use of tools for their intended purposes. Also teach the difference between drills and impact drivers if you have them. Explain that an impact driver should only be used with impact rates bits/sockets, and should not be used as a drill.* Also inform the students on where bystanders should be when cutting, etc. to avoid danger from flying objects if something goes wrong. If you have a circular saw(AKA buzzsaw or Skilsaw), ensure that everyone is aware of the risk of kickback. Not really related to tools, but inform everyone where the first aid kits and fire extinguishers are, and keep those areas clear. Give basic use instructions for the extinguishers, just in case. This site has good information.

*Some impact drivers can be used for drilling holes. You’ll have to check your specific model.

There should definitely be a lesson on rivets about these things. Drilling the correct hole, making sure they are in shear only, setting them up before, clamping the parts, etc.

A lot of students have had no shop class or introduction to tools, as most middle schools have completely dropped those.

Safety Glasses Required in the Shop!

For Drilling:

  • Introduce them to both the numbered and fractional drill standards.
  • US fastener standards, particularly that there are both UNC & UNF at most sizes. (Good time to pass around thread gage and a few fasteners)
  • Introduce tap and drill chart, and hand out a PDF to all. Discuss correct tapping methods.
  • Probably a good time to a cover hex keys and wrenches as well.

Riveting

  • Introduce different sizes and grips of rivets
  • Standard hole size for the rivets your team uses.
  • Hand Riveter usage
  • Pneumatic Riveter Usage (as used)
  • How to Remove a Pop Rivet (undersized drill)

Since when are screwdrivers not ok as prybars?

I hope that was a joke. :ahh: In case it wasn’t (or someone else reads it and thinks it wasn’t), here are at least two reasons:

Screwdrivers are made from stiffer/more brittle material than pry bars. This makes them better ad driving screws, but more likely to chip, tossing chips around and/or sending hands flying into things than a real pry bar.::safety::
Most screwdrivers have handles made of plastic or other material which is not as strong as the business end. This is OK for a screwdriver, because the idea is to transmit torque from the hand to the shaft. When prying, the handle is the part most likely to break. Guess where the back end of the internal metal bar is most likely to wind up? If you didn’t answer your palm, you should try again.::ouch::

::rtm::

EDIT: and OBTW, both of these issues are even more likely to bite/poke you when used with cheap screwdrivers, which is what people tend to grab when using one as a prybar.

Another thing you might not think to mention is “how tight is tight enough”. We’ve had a few cases of enthusiastic rookies turning box tubing into an I-beam or drilling bolt-head-sized holes in plastic pieces by continuing to tighten a bolt until it won’t turn anymore, rather than stopping when it’s tight. People who aren’t used to using basic tools frequently don’t realize how much mechanical advantage the wrench is giving them.

The same applies to using screwdrivers as chisels/scrapers, especially when pushing them with a hammer.

Clamping!

It promotes safety by preventing your work piece from being thrown by power tools.

It also promotes accuracy such as when match-drilling. The holes won’t line up if the work piece shifts between holes.

I saw a t-shirt the other day that went something like:

The Stages of Tightening a Bolt

  • Loose
  • Tight
  • Very Tight
  • Over Tight
  • Much Too Tight
  • Loose

Go until you hear the crack, then back off a quarter turn. :]