Right now we are deciding what to spend money on for a super pit. We have got another rivet gun and a Bambu Lab X1 Carbon 3D Printer on the list right now. I wanted to ask if buying a mini cnc would be worth it, and if so what would be the best one? I also wanted to ask if you have any other recommendations for what a pit should have?
Invest in producing more spare parts, and bring some sheet metal and a jigsaw (and holesaw and etc) with the right blades to comp for that one time in 4 years that it will be needed.
I, and I think most mechanically-oriented FRCers, can make a flat part by hand faster than you could get one off a benchtop CNC mill.
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I’ll second this with regards to having the 3D printer in the pit. Producing more parts on demand in the pit sounds attractive, but printing tends to take too long for it to be viable. Unless something changes with R304 next year, you also can’t make parts while the pits are closed.
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I would be concerned about power consumption and noise complaints running a CNC in the pits, but if you can find away around this, go for it. That said I third making more spares before you arrive at the event, and bringing supplies to make basic repairs by hand.
As far as was to include, a full set of all the tools you use for assembly of your bot that never leaves the pit when you’re at home. You don’t want to be missing a wrench at comp, and it’s much nicer not to have to pack and unpack everything when you go to comps. We also carry tools and parts for anything common in FRC even if we don’t use that tool/part so we can help other teams especially alliance partners. If you have extra space, add more parts, be they specific to your bot or only for others. Lots of water bottles and a sharpie to label them. Stainless safety wire and wire twisting pliers can be a life saver for emergency repairs and modifications (shout out to 2767 on that one). I also like to keep some food around in case of students who skip eating until it is a physical impairment.
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A band saw mounted to a bench is the most valuable “premium” pit tool you can have imo. Sure the machine shop area at an event may have one, but the speed of just walking 3 seconds to your saw, using it, then about 3 seconds back into the pit is valuable. Other teams will want to have your permission to use it (make sure you post a “no steel” sign if the blade can’t handle it).
A set of nice blades, a flat surface (robot cart) and a half decent jig saw can handle anything beyond about a 10" throat band saw.
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is that legal?
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Not under current rules. Past rules had a gray area.
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+1 on bandsaw! A battery powered portable in a stand is actually much better than most small bandsaws. Loghter, quieter, can cut long stock, actually slow enough for metal!
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x1c is pretty darn fast if you print on ludicrous speed or mess with your profiles
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I like the 120V plug-in model so you can operate it with a foot switch. And the SWAG stand is the gold standard. Portaband Table Pro Model - SWAG Off Road
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Instead of purchasing a mini cnc, you could opt into getting a shaper origin (we’re sponsored) Shaper Tools. These are really useful in pits and u can cut p much all frc materials:
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For anybody considering getting this excellent bandsaw accessory, I strongly recommend getting the “choke out” trigger control kit. Otherwise, you get a velcro strap to wrap around the trigger to turn it on, and you end up handling the saw quite a lot with the motor running.
Depending on one’s expectations for accuracy, one may have to spend a fair amount of time making adjustments to get the blade perpendicular to the table. If one gets the miter gauge, it will also have to be adjusted to ensure that the fence is perpendicular to the track.
I added a larger fence to the miter gauge to the SWAG stand I have at home.
For the team, we purchased a corded portable bandsaw from Harbor Freight and one of the horizontal/vertical stands. This is a recently introduced product that the stores near me are having trouble keeping in stock. We just got it set up and it seems pretty solid.
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Just echoing others’ comments that a good band saw is probably a better choice than a cnc.
The number one thing people come by our pit for is to use our band saw. And ours is terrible. But they come back over and over.
The Bambu can print really fast so that’s not a bad choice for a 3D printer in the pits.
That all said, if your team really wants a small cnc, and has a use for the small variety outside of competition, don’t let us stop you!
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While I echo pretty much all the above comments, I have been next to a team that used a rather larger router in the pits before (it was pretty neat), so it wouldn’t be a first, but there is probably better use of that space/money. If you have the budget for a super pit I’m assuming you have the budget to trick it out, so I do think a Bambu would be pretty helpful with how fast it prints.
Edit: For anyone curious it was 217 at 2019 FLR, I think it’s the only time I’ve seen a team pump out more parts/upgrades at a competition then us which is saying a lot haha.
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A mini CNC for the pit? I see no real value in it. The parts you can make on that mini cnc are going to be extremely limited, and you’d likely be better of getting spares made prior to an event. My experience with my Nomad 3 Pro has been that I spend more time figuring out fixturing then giving up and just using superglue/tape than it usually does cutting. For the overwhelming number of FRC parts you’re better off with transfer punches, a center punch, a 2d printer and a decent drill press. (though, the speed of the X1C, you could probably print a drilling template in the time it takes me to usually remember how to use my 2d printer).
If it were me trying to spend some money on a pit set up right now I’d focus on usability first - do the tools you use have a place? Do you have adequate lighting and power distribution? Do you have a pit set up for off seasons that’s easier to transport so you can train students in using it in the off season?
Lighting, hand tools, labeling are all things that are chronically overlooked for “sexier” things like machines. But the reality is good labeling and lighting probably contributes more to consistent success.
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I could not agree with this more. My team (also sponsored) has used the orgin for a few years and its ease of use, portability and versatility have been super useful for everything from practice field construction to making new parts in the pit. I cannot recommend the shaper orgin enough. We even made a video with Shaper about this
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