What do you prefer when connecting to pieces of metal together?(Poll)
 

Simply put! When attaching two peices of metal together, what type of connection do you prefer. I'm leaving the options: Welded, Bolted, Riveted, and Other. If you do prefrer Other tell us what that other is. These are the most basic forms of connection between metal peices in my experience, excluding when you connect: motors and air compressors and switchable parts. These parts are usually not welded on:) ...

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

Brazing

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

Bolted, since that's the only method we can use ever since the welding room turned into a school storage room.

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

It all depends.....

This year we used welding, bolting, riveting, press fit, and threads (threading the actual parts, not using separate bolts/nuts).

There is no "best way", because each part of the robot has different requirements for joining metal parts.

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

Well, I prefer hot glue and I think its the best way.

But seriously, I think it all depends on the metal, application and other requirements. Welds don't come loose like bolts but can still break.

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

I think it all depends on the situation. If you are assembling pieces of metal where nuts, bolts, cap screws, etc. CAN be used, then by all means use them. If the metal is a bit more intricate, then use welding. This all my POV, but it all depends.

(the only time I have seen riveting, however, is when we put the tread on the wheels. ONLY time.)

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

excellent points. and yes it does all depend. maybe the question should be which do you find you use the most? it would be more straight foreword. but yeah I think it all depends on application of the metal that is being joined.

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

What do we use most by number of parts? probably bolting.
What do we use most by total member weight? welding--our whole frame is welded.

That said, we sort of see their use on 3 dimensions: structural/strong, changeable/serviceable, and weight.
- Very strong, very changeable, weight isn't a major concern: bolt/nut it (with loctite another durable vs changeable dimension).
- Strong, still changeable, weight is a concern: consider steel rivets with backup washers. They're permanent (that how each of our pivot modules is connected to the robot), but if something does go wrong it's easier to change than welding.
- Strong, not changeable, regardless of weight: weld it! This can go for non-structural items too, if you feel like it. :)
- Less structural, possibly changeable (though not necessarily), weight independent: consider threading and bolting it (no nut) or aluminum rivets (with or without backup washers). Rivets are harder to change, but less likely to change on their own, and a little lighter (not to mention faster) if you're using a whole lot of them. Granted, the threaded hole vs nut trade-off can also come from location issues. i.e. can you fit a nut in there? More importantly, can you fit a wrench in there?

Of course there are exceptions to every rule, but this is usually what comes to mind first.

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

There are people who try to answer this question as their postgrad topic of study, and still don't have a definite answer. :p

I prefer a combined approach of all possible joining types given their advantages in specific situations. This being said, one of the most useful fasteners in FRC is the rivet, as it can do just about everything (but isn't necessarily the best at everything). Bolting and welding are just as valuable, if you are equipped properly though.

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

Finally!! Something I know about on this website. Well anyway I go to Aviation High school where we learn how to fix planes so I'm pretty familiar with the three you specified. So heres what I think:

Riveting- pop rivets (aka blind rivets/hand rivets) are good fasteners as long as theres no major structural or shear load on them(they will sheer off). they're easy to remove and install. Real rivets (which probably wont be used in FIRST very often) are excellent semi-permanent fasteners. they're reasonably easy to install and remove(though installation takes some practice and specialized tools) and they can take a good amount of sheer loads.

Bolting- bolting, and screws also, are good for anything you would want to remove constantly. my team used these the most this year on our robot since it was mostly a basic andymark everything. the good faster but they can get annoying when you have to use them in conjunction with moving parts.

Welding- lastly, theres welding. probably the best and most permanent (can something be most permanent?) fastener out there. just try removing a weld and see how far you get. downside is you have to get a little bit of training before you can properly weld. furthermore welding makes mechanical troubleshooting all the more difficult (depending on the application).

all that being said i would have to go with bolting most of the timesince its the best all-arounder. :D

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

It really depends on what situation each connection is going to be in.

I'm a huge fan of bolting whenever possible, especially if there's a chance that the metal in question is going to be unconnected or changed at any time. As long as you can easily reach both nut and bolt (unless you're ambitious and tap EVERYTHING), fasteners are great and reliable ways to keep those metal pieces snugly together.

While rivets are great for sheet metal and all, don't use them in high-stress or high-impact places...they can pop out (speaking from experience). They're easy enough to drill out if necessary, but I would hope that you don't use them with the intent of drilling them out every so often to upgrade or change parts. IMO, they're great for sheet metal (if used right -I'm not a fan of sheet metal after my experience with it this year), and fantastic for wheels.

Welding is a great option for parts that can't be riveted, and their structure is such that you can't easily bolt it together. As long as you don't intend to take apart those two little pieces of metal ever again.

Re: What do you prefer when connecting to pieces of metal together?(Poll)
 

In my opinion one of the better ways to fasten things is the bolt then weld technique. Bolt the thing together, get it to work correctly then weld it up and remove the bolts. This works very well for "add-ons" to the frame that are not an entire mechanism. Things like axle blocks and wheel supports. It also saves weight. Our rookie year we used the kit chassis for a while, but we welded it together, saved almost 8 pounds!

If it hasn't been made clear by now, each type of fastener has an ideal job and most robots will use multiple types. We have metal screws, nuts & bolts, threaded pieces and welds this year. In the past we have also used wood screws and rivets.