Pre-season purchases

[CalTran]

Check your batteries as well. If you don't have at least 3 chargers and 4 batteries, I'd stock up. How's your pneumatics supplies looking? For our team, last year we basically hit our pneumatic limit simply because we ran out of solenoids. There's also the usual zip-ties, duct tape, WD-40, and Loc-tite to have handy. Some extra wires/connectors would be helpful too

[sanddrag]

#25 chain is a pretty safe bet. I wouldn't get much of anything else pre-season unless it was tools.

[Ninja_Bait]

We're buying zip ties, pool noodles, basic electronics parts, stock metal, and rotary tool accessories. (There's also some vector drive parts on the way, but not many people need that. )

Definitely buy more of what you use up (duct tape, zip ties, bolts etc.) and some more batteries. Also think about getting the new little cRIO.

[Peter Matteson]

Originally Posted by Nemo

You could start with things that you are nearly guaranteed to need:

Bumper materials (noodles, fabric, plywood, fasteners)
CIM motors
Wire
Fasteners
Jaguar and/or Victor motor controllers
Controllers (gamepads / joysticks / custom controls of your team's choice)

Items bolded by me are things to be cautious about ordering. These are items that can easily be eliminated from the kit without warning no matter how likely you think they are. Proceed with your own caution when purchasing these until we see the 2012 rules.

Originally Posted by CalTran

Check your batteries as well. If you don't have at least 3 chargers and 4 batteries, I'd stock up.

What battery will be competition legal this year?
We're on the 3rd or 4th different battery in my tenure as a mentor so I would never reccomend a team with limited resources buy them until the season starts.

I agree with folks saying stock up on tools, fasteners, and raw material. Those are items you can use no matter what. Anything like controllers, other than the FRC specific cRIO that we know is coming, is at risk of not being in the rules if FIRST decides on a whim to eliminate it. I can think of many kit items and rules that were thought unchangeable over the years that we were proven wrong on.

[Al Skierkiewicz]

Carol,
Now is an excellent time to buy into tools. If you have the basics, then I would add the following...
Flush cutting wire cutter
Chain Break
At least one multimeter. (Some nice ones are still available for less than $50)
A set of both English and Metric Allen wrenches.
A nice machinist's square
A good hacksaw with several blades
A couple of files, or a set including different lengths and cuts
A couple of drill sets
Pop Rivet tool, rivets (different lengths and material) and several of the correct size drills for installation and removal.
If you are thinking of using Anderson Power Product electrical terminals, then crimping tool for such connections. (Search Anderson here on CD for recent discussions of tools and terminals.
MCM Electronics (www.mcmelectronics.com) has nice zip cord wire. Get a 500 ft. roll of #18, #14 or #12, and #10. You will have it for years to come and it make wiring easier as the red and black wire are bonded together.
Ty-wraps of varying sizes and lengths.
Heatshrink for wire insulation in various sizes.

[roystur44]

A good purchase would be a roll away tool box that is labled where the tools should go. Training the students to pick up and put back the tools after use is high up on our training list.

Having a nice transport cart for the robot is a good off season project.

Organize your wiring tools you use to make pwm cables, molex crimpers, heavy gage wire strippers.

Battery load tester

Rivnut gun, pneumatic pop rivet guns, small arbor press for bearings.

Roy

[thefro526]

Originally Posted by Peter Matteson

What battery will be competition legal this year?
We're on the 3rd or 4th different battery in my tenure as a mentor so I would never reccomend a team with limited resources buy them until the season starts.

I've always wondered why FIRST is so hesitant to release the very basics of the KOP in the Pre-Season. I can't imagine that a team would gain a substantial advantage by knowing what speed controllers and battery models would be allowed next season.

One of my favorite things to stock up on in the weeks leading up to build season are prototyping materials. Wood, PVC, Small Wheels, etc, that can be thrown together into a quick prototype on Saturday or Sunday are always nice.

[ebarker]

If you really want to squeeze a dollar and maximize your purchase I'd recommend that you do the following exercise, which happens to be something we did over the summer.

1) Using an excel spreadsheet we created a table of everything in the KOP plus everything we had bought the past few years.

2) then we did an inventory of all of our raw parts, with cost. great exercise, you can learn how much money is laying around.

3) then we made another spreadsheet of our master wish list. this includes tools, parts, machine, trailer, shirts, everything. It is a huge list.

4) Then you do nothing.

5) Sit on this information ready to pull the trigger on purchases, but only after you KNOW you will need it, not THINK that you need it.

After all, the only thing you can assume about next year is a cRio and a Microsoft Kinect.

Just in the past few months we have saved a ton of money by doing nothing because we ultimately determined other solutions or that we didn't really need it right now.

Planning is more important than spending right now !!
.

[Mark McLeod]

Engineers can be bought....

[Al Skierkiewicz]

"I can't be bought but I can be rented..."
Quote from my Physics 101 instructor. ca.1970

[ebarker]

Originally Posted by sanddrag

#25 chain is a pretty safe bet. I wouldn't get much of anything else pre-season unless it was tools.

Why is #25 safe ? Not very many people use it. The KOP is #35. So far we have never bought that in 8 years. Then again we have never had a winning robot either !

[BrendanB]

I've heard mixed on 25 vs 35. Pros to 35 is that it very standard on high torque applications such as arms and drivebases and since it is larger, it is easier to work on which comes in handy if you blow a chain the finals. 25 is smaller and lighter but it is a pain to work with in a timely manner with how small the master links are. Great for small applications such as rollers, set and forget.

I have heard of a few teams using a combo in their drivebases to save weight. Use 35 chain to drive the the middle set of wheels in a 6wd and have 25 spanning to the front and back. So even if you blow a 25 chain you can still drive your main dropped center wheel. To save such a small amount of weight I'd rather just drill a few holes but if your aim is to use as little weight as possible from the start of the design it isn't a bad idea.

For me, 35 as much as possible. Less spare parts to plan ahead for and I know when properly tensioned it will be consistent and an easy fix if something goes south.

Pre-season purchase? Kinects!

[apalrd]

The great 35 vs 25 debate.

We have used only 25 in the drivetrain for many years now. Last year we lacked 35 completely, and the year before we only had 35 on the lift arm (an extremely high load application).

We also don't use master links where we can avoid it. We use the Dark Soul chain tool to create seamless drive chains.

That said, we use only 35 for OCCRA (as required by the rules - no 25 allowed in OCCRA). This is mostly a precision issue. If the robot can be built to reasonable tolerances, then 25 is acceptable. With the quality of craftsmanship in OCCRA, 35 is a stretch for most teams for most things.

If you can build things precisely, 25 will work fine for almost every FRC application including drivetrains. If you can't, then 35 will let you be much more sloppy.

[Chris is me]

Originally Posted by ebarker

Why is #25 safe ? Not very many people use it. The KOP is #35. So far we have never bought that in 8 years. Then again we have never had a winning robot either !

I think he meant "your team's preferred method of power transfer".