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sanddrag 06-06-2012 20:55

Recommendations for purchases
 
I teach FIRST Robotics, Robotics Engineering, 2nd-year Engineering, and 9th grade Technical Literacy. I feel like I have almost everything I need to give these students a pretty good opportunity and experience. However, I may have an opportunity to purchase a few more things to really finish off the program so hopefully one day soon it will be rather polished. To describe what we have already would take me too long, but we're rather well equipped. We have all the basics and then some. I'm looking for suggestions for what to purchase to really enhance our FRC team or the classes I teach during the school day. What have you always thought "oh I really wish we had a..." ? The suggestions can be anything from large equipment to software to raw materials to consumables etc. I'd like to purchase things like motors, motor controllers, cRio, batteries, etc for FRC but it's hard to know what's legal next year.

Whatever I buy, I want it to be relevant, useful, learnable/teachable, and to last. I'm somewhat interested in re-vamping the 9th grade Technology Literacy curriculum with some new hardware/kits/activities/etc. It's a 9-week class. Currently we have about 3 weeks of computer history, 3 weeks of computer hardware and digital information, and 3 weeks of robotics programming.

CalTran 06-06-2012 21:01

Re: Recommendations for purchases
 
Well, if you have the resources, you could invest in researching drive trains. It's useful for the competition, and if you get one that your students really love then they can already have a general drive base year to year. Perhaps something that you can place "drive modules" into so you can trade drives quickly and get your students practiced in a variety of them.

BrendanB 06-06-2012 21:11

Re: Recommendations for purchases
 
If you haven't already I'd recommend investing in some 80-20 extrusion and fasteners. It makes prototyping a breeze and once you decide on a final configuration it is easy to switch out for box aluminum.

AllenGregoryIV 06-06-2012 21:28

Re: Recommendations for purchases
 
When I was in high school we had a course that covered multimedia engineering. It was mostly applied digital signal processing. I thought it was very interesting. It was through the Infinity project but I imagine you could come up with something similar.

If I had money to spare I think it would go with a CNC Router/plasma cutter.

Nemo 06-06-2012 21:43

Re: Recommendations for purchases
 
Off the top of my head, here are some of the things I'd consider buying if I suddenly had grant money that had to be spent before next season, and I was thinking of both FRC and the courses that can use robotics stuff.

Materials
-10 or 20 Victors
-Gearbox parts, including 2-4 sets of shifting hardware and a whole bunch of aluminum gears from AndyMark and wcproducts.net
-Aluminum in various sizes and shapes: sheets, box tubes, round tubes, round stock, T-slot extrusions, angle, etc.
-Polycarbonate sheets in several thicknesses
-Another cRio
-Extra sets of wheels of each type we are thinking of using on a prototype or a competition robot
-A bunch of polycord tubing
-A bunch of surgical tubing
-Pneumatic cylinders of sizes we don't have in stock

Computers
-Set of 6-7 laptops or tablets with good battery life for scouts
-Power inverter + more robot batteries for scouts + better charger
-Server computer
-One or two nice desktops specifically for CAD work

Tools
Hex broaches + suitable arbor press

Course Materials
One ton of Vex parts and controllers

Steven Sigley 06-06-2012 22:01

Re: Recommendations for purchases
 
Just speaking for electrical, it's easier to make a removable electronics panel on the robot (and makes for a fantastic board that can be utilized in numerous practice bots) if you have powerpoles, and especially so if you can get them with the chassis mount and plug like so:

http://www.powerwerx.com/powerpole-a...ch-4-sets.html
(The part the plug plugs into is pictured on the same page but is a separate purchase)

Or if you have kids that are just plain interested in learning about electronic components, this is a great way to get them started, it comes with two books, tons of projects, and numerous parts to get them started and help them understand how things go together.
http://www.radioshack.com/product/in...=Learning+kits

Boe 06-06-2012 22:06

Re: Recommendations for purchases
 
If you have the resources ($$$$) I would recomend buying a nice 3D printer. Our partner teams printer was very useful throughout the season especially for sprocket spacers and a fan duct for a shooter gearbox.

http://robotics.mnmsa.org/media/photos/

picture 71 shows the shooter gearbox fan duct, and prettymuch any pictures with the wheels wll show the sprocket spacers (all 20 of them :ahh: ) The sprocket spacers had to be a precise height so it lined up perfectly with our shifter's sprockets. We wouldn't have been able to get this result without the printer

AdamHeard 06-06-2012 22:29

Re: Recommendations for purchases
 
Quote:

Originally Posted by Boe (Post 1172995)
If you have the resources ($$$$) I would recomend buying a nice 3D printer. Our partner teams printer was very useful throughout the season especially for sprocket spacers and a fan duct for a shooter gearbox.

http://robotics.mnmsa.org/media/photos/

picture 71 shows the shooter gearbox fan duct, and prettymuch any pictures with the wheels wll show the sprocket spacers (all 20 of them :ahh: ) The sprocket spacers had to be a precise height so it lined up perfectly with our shifter's sprockets. We wouldn't have been able to get this result without the printer

Your mill could have easily matched that precision.

Akash Rastogi 06-06-2012 22:41

Re: Recommendations for purchases
 
I've always thought that many teams overlook the automation of a robot by a large amount during build season. I think purchasing sensors (VEX or any other sensors) would be a smart choice and to teach a few weeks just about automation techniques as well as sensor integration into a design/system.

sanddrag 06-06-2012 22:50

Re: Recommendations for purchases
 
Keep in mind we've been doing FIRST for 12 years now, so we've accumulated a lot. Nearly all the things listed in this thread we have already, but please keep the ideas coming! There were a couple things mentioned that we don't have yet. I'm also interested in things for engineering and technology classes which teach students from the general student population (not FRC specific).

Boe 07-06-2012 01:26

Re: Recommendations for purchases
 
Quote:

Originally Posted by AdamHeard (Post 1173000)
Your mill could have easily matched that precision.

i guess... we have a manuel mill though so it would have been alot harder

EricH 07-06-2012 01:37

Re: Recommendations for purchases
 
Quote:

Originally Posted by Boe (Post 1173035)
i guess... we have a manuel mill though so it would have been alot harder

Nah, not a lot harder. Just means you have to take a bit more time and care, that's all.

Here's a CNC comparison of tolerances. I'm speaking for a shop at my college here, but the absolute best they can get out of a high-quality 3D printer is a .007" print head (at least, with what they have), but they typically run a .010" head. Figure at least .0035" of "slop" with the smaller head. The CNC machines can go to .002".

Now, let's say I'm on a manual mill. I can't consistently get to .002" of tolerance--nowhere near enough practice. But I can hold .010" just fine; more than likely I can hit .005" without too much stress. And that's me--I have limited mill experience, and I'm a bit rusty. A shop teacher who's been doing this for years could probably hit the .005" just about every time it's needed, and tighter if absolutely needed.

Of course, the "if needed" part begs the question: How tight does your tolerance really need to be? .100"? .010"? .005"? .002"? Tighter? Looser? And that's not a question that is easily answered. Just trust me on that one. I had to wrestle through that on more than one occasion this last semester. And only on a couple of parts...

Boe 07-06-2012 14:17

Re: Recommendations for purchases
 
Quote:

Originally Posted by EricH (Post 1173037)
Nah, not a lot harder. Just means you have to take a bit more time and care, that's all.

Here's a CNC comparison of tolerances. I'm speaking for a shop at my college here, but the absolute best they can get out of a high-quality 3D printer is a .007" print head (at least, with what they have), but they typically run a .010" head. Figure at least .0035" of "slop" with the smaller head. The CNC machines can go to .002".

Now, let's say I'm on a manual mill. I can't consistently get to .002" of tolerance--nowhere near enough practice. But I can hold .010" just fine; more than likely I can hit .005" without too much stress. And that's me--I have limited mill experience, and I'm a bit rusty. A shop teacher who's been doing this for years could probably hit the .005" just about every time it's needed, and tighter if absolutely needed.

Of course, the "if needed" part begs the question: How tight does your tolerance really need to be? .100"? .010"? .005"? .002"? Tighter? Looser? And that's not a question that is easily answered. Just trust me on that one. I had to wrestle through that on more than one occasion this last semester. And only on a couple of parts...


I see your point it, it would probably take about the same time on the mill, or on the printer. I would recommend having both at your disposal because while other parts are being made on the mill we could easily print our spacers at the same time

R.C. 07-06-2012 14:34

Re: Recommendations for purchases
 
Quote:

Originally Posted by Boe (Post 1173088)
I see your point it, it would probably take about the same time on the mill, or on the printer. I would recommend having both at your disposal because while other parts are being made on the mill we could easily print our spacers at the same time

Printing spacers is really a waste of a 3D printer, as you can buy spacers much cheaper than it takes to make them on a 3D printer. You could make them on a lathe even cheaper.

If you wondering where to get spacers from, McMaster sells a really nice set of plastic spacers that we dye black (stolen from 973). Really helps putting together a robot and saves a ton of time/money.

A 3D printer IMO is best used for low stress hard to find/get/make parts. Its also great for crazy pot mounts, plastic gears that are not taking load. etc...

-RC

IKE 07-06-2012 15:29

Re: Recommendations for purchases
 
You might want to look into these guys if you would like to teach teh kids about controls:
http://www.quanser.com/english/html/..._homepage.html

they ahve some pretty neat platforms to do controls experiments from.


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