As the question states, what are your methods of cutting the VEX metal(including aluminum). We use a grinder which results in quick but, frankly terrible cuts.
We use a Dremel with a thin cut bit or a pair of metal snips if the battery’s dead. I like the Dremel because it’s easier but you get metal shavings every where is the only downside.
My team typically uses either a dremel or for small light stuff a Hacksaw.
For detailed parts - dremel
For bigger, less intricate parts- hacksaw
Dremel for a majority of it. We do have a bandsaw now that we also have.
Also a mini-tablesaw.
We usually use a band saw and carefully grind the cut to make it smooth. For trimming parts on the robot its done carefully with a dremel.
For both steel and aluminum parts such as C-channel, angle pieces, etc. they use a hacksaw. The parts are then deburred with a file and finished up with sand paper. Do not use a grinding wheel on aluminum: the soft aluminum metal will melt at the contact point and then amalgamate itself to the carbide of the grinder - its messes up the grinding wheel.
For cutting the shafts, I have them use bolt cutters and finish the cut ends with a file and sandpaper.
For cutting aluminum bar, they sometimes use tin snips and file down the resulting sharp edges.
I have the kids remove the burrs on both the cut piece they intend to use and the cut piece they are putting back into the supply box - I don’t allow sharp points floating around.
Dremels are rarely used - the flying dust is not good and I don’t feel my middle school kids are experienced enough. Also a lot of schools nowadays will not allow kids to use power tools.
Safety glasses are required and I teach them not to rub their eyes when working with metal since the metal filings and dust can get into their eyes that way.
Hacksaw and file are what I always use for both aluminum and steel.
A Dremel isn’t very exact and not really necessary, and an angle grinder is overkill for the thin parts. A hacksaw with a decent blade, installed the right way around, and used with proper technique goes through metal very easily and quickly, especially aluminum.
For axles I’ll use a hacksaw as well, and then use the disk on a belt sander to round off the corners and edges of it so it fits through parts smoothly. I doubt it makes a huge difference, but using a piece of cloth or paper towel when clamping them prevents the teeth of the vice from making the surface rougher.
Occasionally I do also use tin snips for the 1 bar or plate, but I find it curls up the corners a little bit, and isn’t as neat as a hacksaw. And you can cut though the 1 bar in 2 or 3 strokes anyways.
It’s important that however you cut your metal, you file or sand it afterwards and get rid of all sharp edges, both on the piece you are using and that goes back in the bin. I use a wide, flat file, and sometimes a belt sander. Tip: Buy a file that is just a bit narrower than the inside of a 1x2x1 C Channel.
We use a band-saw for just about everything. And file afterwards.
However if it’s a small piece and we’re impatient, tin snips might be used.
Also on occasion we use a dremel if the piece is easy enough to cut with it.
(I’ve seen a person in my club cut an axle with a triangular file. )
We use a band saw for both metals. We also have a belt sander to smooth everything down. Since all of that is hard to travel with we also have a dremel with cut off wheels, carbide tools, and sanding wheels in case we need to do something at an event.
Thank for all your input! We’ll have to try some of your ideas. Do any of take your parts to a shop for cutting?
We have two benches for our cutting station. We leave some safety glasses at the station so there is no excuse for not wearing them.
Station 1 - vice and hacksaw or Dremel
Station 2 - Chop saw and (low power) grinder/buffer
Anyone using the Dremel, or grinder needs to wear a face shield. Not that expensive so I strongly suggest getting these for Dremels and chop saws. I’ve had personal experience with getting metal in my eye. It’s not fun.
We bought this cheap chop saw at Harbor Freight (coupon made it cheaper too) and it works great on 1x2x1 c-channel but not as well on larger pieces.It won’t hit bigger items in one chop. You can buy a bigger chop saw if you want that level of cutting. The clamp mechanism does not like the flat pieces very well either. But for 1x2x1 and frame rails, it works very nicely.
[http://www.harborfreight.com/power-tools/cut-off-saws/6-in-cut-off-saw-61204.html
The chop saw has been a real asset. Cuts take out a bit more metal than a band saw or hack saw but it is mighty fast. We went through 2-3 blades in the 3/4 of a season we had it. It leaves more metal shavings about so clean up is imperative each build day.
The grinder does not smooth out as easily as hoped either due to the shapes of the pieces. Hand filing is still done on the majority of cuts.
We also have some clamps and an jig saw for plexi shapes and long cuts. But that is seldom used.](http://www.harborfreight.com/power-tools/cut-off-saws/6-in-cut-off-saw-61204.html )
One thing I forgot to mention is how we clamp in C Channel. If you just clamp it in the way it is it will bend a bit and get a slight curve. There are tricks with clamping it on an angle and the like, but the easiest way is probably just to find a small piece of wood and put it on the inside of the C Channels. I used a 1"x1" (actually 5/8" x 3/4") piece of wood, but anything around that size works.
Also, having a small shop vac around is really helpful to clean up after every cut so metal dust doesn’t get in everything.
As for safety, using common sense is the best approach. Wear safety glasses if using power tools, make sure the sparks fly away from you and others, don’t put a running or slowing machine on a power cord, etc.
Before we actually got proper tools, someone (no names, but anyone on our team should know who;)) managed to lose the hacksaw, so we cut a plate with an odd mix of clamping, bending, and a wood file.
I find this thread very helpful for our team. Thanks everyone. Cutting parts have always been an issue in my team, mainly because our mentor runs three robot classes a day and he needs to make sure that enough standard parts are there for seventy people building robots. We are really looking for a safer way than requiring our mentor to use extremely dangerous power tools to cut parts for us.
Grinder, table saw and hack saw are tools we used. Most of our team members first think about grinders when it comes to cutting structure, which in my opinion makes more dangerous edges. When cutting a lot of parts our mentor uses a table saw, and i still doubt the safety. We only use hacksaw for shafta, and i guess we need to use them in c channels as well. A lot safer than seeing sparkles everywhere!
We use a Dremel for everything. Someone tried using a bandsaw once and it didn’t go well. Nobody got hurt but the c-channel somehow got warped and became unusable.
I use a band saw to cut just about anything. Did you have the wrong kind of blade? Was the cutter inexperienced?
We use a dremel sometimes, but most of the time we just use a hacksaw. We use a metal file to smooth off the rough edges. The problem I have with the dremel is the dust and sparks that are generated–I know that I can stay out of the way, etc, but I don’t want the dust floating into my electronics.
For cutting polycarbonate, recently I have taken to using a jigsaw with the piece firmly clamped.
My team uses a bandsaw, dremel, or hacksaw