Waterjet cutters for small FRC team

Does anyone have any recommendations for waterjet cutters or any of the like? We’re looking to see if we can add one to our shop.

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Find a sponsor with one. They aren’t cheap to buy or operate.

It’s my understanding you’re looking at $100k+ for the machine, and ~$60/hr to run.

If you have that kind of cash available, you’d be better off paying the $150-250 an hour and design efficiently. 10 hours of waterjet time is a LOT of parts.

Obviously sponsored is better, but sometimes you need to pay to get things cut (which has some BOM effects, but per part is still often cheaper than COTS).

If using outsourced cutting you definitely need to communicate the team’s needs, and figure out a communication method/schedule so that you’re both not wasting each other’s time during season.

For example our waterjetter cuts on weekends for the first 3 weeks of season, and we know if we get him files by friday morning we will get parts before sunday night (sometimes friday even).

Get a CNC Router instead, they’re SIGNIFICANTLY cheaper, and more versatile than a waterjet (since you don’t have to cut all the way through material). There’s an extensive thread discussing them here.

The school engineering lab we work out of was able to get a grant for one of these:

We have it, but it has not been hooked up yet. I’ll report back in a month or so once its up and running. The cost was about $18,000 and required garnet abrasive to operate.

We are hoping this will work well for making gussets, plates etc since it is limited to a 12in x12in cutting area. The workflow we have use the last 3 seasons is design in CAD with prototyping out of cardboard. take the CAD and lasercut it our of 1/4" plywood or MDF and then send out to waterjet the parts out of aluminum. Hopefully we will be able to do it all in house now.

Was just about to post this link, haven’t used it but have been eyeing it for a while now. Dying to hear how it works!

Do you know the feedrate of this in 1/4" aluminum?

It’s my understanding that they are significantly slower.

From their software, and a sample DXF:

           Material: Aluminum 6061
     Machineability: 215.3 (Metal)
          Thickness: 0.2500 inches
        Tool offset: 0.0135 inches
           Rotation: 0º

           Estimated time for path:
                  About 25 minutes.
         Estimated abrasive needed:
                       About 6 Lbs.
            Pierces: 25

              Width of path: 5.2981 (inches)
             Height of path: 4.4266
        Length of tool path: 80.1993
          Length of cutting: 61.1649

(Values reported after tool offset applied.)

If my math is right, about 2.4 ipm. Not super fast, but we are hoping to be able to set it up, let it cut and then come back when its done.

4.55ipm at “Quality 3” of 5

EDIT: Sniped, the numbers from their software are probably much more accurate than what they advertise on their website

I’d be very interested to hear your thoughts on it. I looked into one for my prior workplace as a small format jet to supplement our two other jets, but our expansion budget took a big cut and we weren’t able to get the fun stuff anymore.

Factoring in a router taking multiple passes, that speed is comparable to a very unoptimized router.

Just to be sure we’re not ignoring some crucial requierment from your end: Any particular reason you singled out waterjet’s to start?

As others have mentioned here, they’re kinda unweildy, especially the upkeep and maintainence. CNC routers, plasma cutters, or even laser cutters are easier to work with.

We were thinking of laser but it could be a safety hazard. We build in the same room as the technology classes work in.

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Waterjets are also disgusting machines. They don’t put off fumes but they do make a huge mess.

To add to this, the aggregate isn’t just your everyday sand, it’s usually imported from somewhere like Australia and can’t be reused. The costs add up quick.

As Cory mentioned above, Waterjet machines are not clean by any measure. In the lab that our waterjet was housed in when I attended university almost everything was covered in a fine dust from the particles of cutting abrasive that went into the air. This is even with a machine that you could fully close off from the room around it with a full hood enclosure.

I would recommend a router.

We use the same room as our tech wing, and have no issues with laser jet cutting being an issue. Just like a lathe or a wielder, as long as people are properly train when using them, there really isn’t a major issue, unless it’s a school policy.

We do, however, choose not to run it unless someone is supervising the machine, so it is typically used only during meeting times.

We are one of the few teams with an industrial waterjet in house (GM owned, not team owned). If I did not have access to this I would not consider buying one. I would buy a CNC router due to the versatility and significantly lower operating costs. We also cannot cut gearbox plates on our waterjet because the tolerances aren’t high enough. We end up machining those on a mill anyway.

The ability to walk away from your water jet very much depends on the parts your cutting and the setup of your slats that hold the part in place - I very rarely if ever walk away from ours. We often have an issue where small cutouts will not fall through the slats, then “waves” of water created by the jet will lift the cutout pieces and move them. This can ruin a part if they land in the cut path, but can be even worse if they get caught in between two slats with one side of the part lifted - this means they are potentially in the path of the head of the jet and can break the nozzle. These nozzle are carbide and are not cheap. To avoid this I pause the water jet when it’s finished and make sure to clear any lose parts - this also helps to make sure our parts don’t end up in the tank.

For the cost of buying, installing, and running a water jet I bet you could get a 5x10 cnc router, a 5x10 cnc plasma cutter, get them both installed and tooled and still have enough money left over to run a team for a few years.

359 had a nicer(?) waterjet installed in 2013. Their total project cost was on the order of $250k.

I would be interested to hear from 359 if they think it was all worth it, what they’d differently, and how it has changed their build.

We do have students in tech classes that shouldnt have the privilege of being there. Kids can be obnoxious and random play with machines. We did have a fight break out. Fortunately, it didnt have to do with machines being broken. Unfortunately, there was blood. We had to get everyone to calm down. We’re just afraid of what a new machine might also bring. If we do get one, though, we’ll surely keep it unreachable.

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