Waterjet/Laser cutters in-house?

After looking at this Kickstarter project I was wondering… what is your opinion about this kind of equipment (Not only desktop versions) at team’s workshop (Waterjet/laser/even CNC) in aspects of safety, cost, space management etc…

One thing to keep in mind when purchasing these machines are the consumables (with the waterjet especially). Our lead mentor (also shop teacher at the school) looked into getting a waterjet but ended up going with our current CNC plasma cutter with water bed and exaust hood.

There were several reasons for the decision made, however the 3 main ones were,

  1. The Plasma uses only electricity, something we don’t pay for (the school does)
  2. The water jet consumes sand. This costs money and is very messy.
  3. The last and final reason being, we found out that were not actually supposed/allowed to bring sand into the school (I can’t recall the reason at the moment).

In terms of the laser, depending on what you buy and how powerful it is, they may consume gases.

There was some good thoughts on waterjets a few years ago when 359 had theirs installed going into 2014.

My opinion is that the Wazer is absolutely useless for FRC purposes (but cool as a technology demonstration).

It cuts ***REALLY ***slowly, the cutting area isn’t large enough for more than a few small parts, the cost to run it is high, and accuracy will be questionable compared to an industrial water jet. Maintenance will likely add up to more than the cost of the machine within a few years depending on how much its used.

You’d get a lot more mileage out of paying for $5000 (plus cost of consumables) of waterjetting from a legit vendor.

A legitimate water jet cutter is going to be $100-200k depending on how it’s optioned out, plus a **minimum **of $45/hr (up to $60+/hr) to run in power/abrasive/water/amortized maintenance. They are very finnicky and constantly have little problems that pop up that require you to stop and clean things out or perform minor fixes. When the pumps reach their service intervals you’re looking at a multi-thousand dollar rebuild. The mixing tubes/orifices are not cheap either and need somewhat frequent replacement. These are also enormously loud and messy machines. Glenn can speak more to his experience with ownership of one, but it would take a unique set of circumstances for a team to have a shop that is suited to owning one.

Legitimate metal cutting lasers for FRC use (1/4" aluminum) are so expensive they’re not even worth discussing. $200k-400k. Huge power requirements, though much cheaper to run than water jet due to fewer consumables and lower maintenance costs. These are machines designed to cut 4’x12’ sheets all day long as fast as possible and people who own them have to run the machine virtually nonstop, often for multiple shifts a day to make any money off them. Just totally in a whole other world than FRC usage,

While 2876 has none of this machines, I’ve spoken to many teams who have low-end laser cutters in their shops. While having one that cut metal could be cool, it isn’t worth it. Instead, teams will buy a cheaper (about 5k) laser cutter that can cut wood and (maybe) acrylic. They can test their chassis designs with these materials, and then send it out to be waterjet through a corporate connection or sponsorship if they want that exact metal chassis. A similar process can be used with mechanisms. This allows teams to have the benefits of the laser cutter (precision, rapid prototyping, etc.) with a smaller price tag.

The machine uses 20lb of abrasive per hour, so at the prices they’re quoting, that’s $20/hour by itself. Based on reading between the lines of the FAQ, you’re also going to use 30 gallons/hour of water, 1/25th of your cutting bed life per hour (no replacement price listed), and an unknown fraction of your nozzle life per hour (also no price listed). They’re operating at much lower pressure than a traditional waterjet, so the maintenance costs are likely to be less, the lower purchase price means that the amortized costs are going to be lower, and a large portion of the maintenance can be free student labor, but I still wouldn’t be surprised for the final running price to be in the ~$30/hour range. That said, an hour on this machine is going to get a LOT less done than an hour on an industrial water jet.

My real concern with Wazer is that there are no accuracy numbers, just a promise that “your holes will line up from part to part”.

The Wazer looks interesting. It would be nice to see the price of the technology come down, but there are reasons why the industrial machines cost what they do. Also keep in mind the first wazer production units are still about a year out.

This specific product is not that important, what do you think about industrial machines as well?

From what I’ve seen and heard, waterjet and laser cutters are prohibitively expensive and a bit unnecessary for the vast, vast majority of FRC teams. CNC mills and routers seem to be much more accessible, and popular among higher-resource teams. I don’t know enough about them to know what the the cost of running them is, but I assume they are cheaper than waterjet.

One thing I’ll throw out there is that I’ve been working with a CNC Plasma Cutter lately, and I think they could be great for teams. They typically run from $5,000 to $20,000. Parts often require cleaning and some post-processing after they’re done, and plasma cutting doesn’t hold tolerances as tightly as waterjetting, but there are ways around that. I think a CNC Plasma cutter could be a powerful tool in the right team’s hands.

AFAIK, 359 is the only team that has a production style waterjet in their shop. They’d be good people to ask for this.

Unless you have a pretty full set of other machines, the price that goes into a waterjet is probably better spent on the combined set of; manual mill(s), manual lathe(s), Drill press (etc…), 4x4 or 4x8 Gantry Router, and a VMC.

There is a cost to keeping any machine you buy in running condition. They really can’t be sitting idle and should see use each week plus maintenance & consumables so for a large portion of teams it isn’t something to keep in the shop.

If you have material and approach a few companies you can find some that will run their machine at a cost per hour (around $100 depending on the place) or if you send them the part files and quantities with the size of your stock they’ll give you a price for the batch. In 2014 we got a quote of $250 and 2015 was $400 for a batch of parts for our competition and practice robot with quick turnaround.

Having one is the dream but start talking with a few companies and be clear with what you’ll supply for materials and be generous with your timeline and you can find someone to get parts made.

What makes a waterjet a better option than some kind of CNC router? For the metals that FRC uses, wouldn’t a router of equivalent price do the job just as well?
Just thinking about the lower operating costs and maintenance and the very-close speed of the cut, what makes a waterjet better than a CNC router in general? For the speed thing I’m just going off Youtube videos showing waterjets working and CNC routers working, so I’m not sure if I have a good grasp of the capabilities of a waterjet.

A CNC is limited by the bit dia. A watejet has a smaller kerf and do more detail. An industrial water jet is a lot faster. If cost wasn’t an issue, I would go with a waterjet. Or if pigs had wings. :] A $100,000 will get you a nice router, CNC mill, lathe… It doesn’t get you started on a waterjet.

I just had a couple of panels cut on a waterjet that could not be done on a router. But if a router was what I had available I would have adapted the design.

Good compromise, buy all those nice machines… then pay $100-500 a year for the few parts that need the smaller internal radii.

In a very broad sense, with some points not being of concern in FRC:

  • Workholding is much simpler with a waterjet. There is no lifting force and very little lateral force.
  • No risk of work hardening stainless or other alloys
  • Programming is trivial in comparison. No need to decide on depth of cut, width of cut, feeds and speeds, or to ensure the sheet is held down locally to avoid deflection while cutting. You select the contours, tell it which side to cut, the material type, thickness, and desired cut quality, and it does the rest. There’s some editing, but it’s a much less involved process.
  • Smaller internal features can be machined
  • Much thicker parts can be effectively cut (definitely not a FRC consideration)

Speed may or may not favor a router. If you have a good enough router that can cut full depth, it probably wins. Piercing start points for cuts is extremely slow on water jets. If you had a boatload of pockets in a part, a router may well cut it faster due to so many pierces. Feed once pierced is somewhere in the 40-90 IPM range for optimal cut quality on 1/4" Al for a water jet, depending on PSI and pump HP. We run full depth contours on 1/4" plate on our very rigid CNC mill at ~30 IPM with a 1/4" cutter and 55 IPM with a 1/2" cutter (both are pretty conservative feedrates).

A small correction… 1983 has an OMAX Maxiem 1515 “production” waterjet in our shop also. We actually had ours before 359. We moved into a new high school three years ago and I got to help design our “proto-typing” shop.
We just didn’t bring it up on CD.

We decided on a waterjet for a number of reasons, not the least of which was that one of our sponsors is OMAX (who make waterjets) Actually they are the original inventor of the technology and along with FLOW waterjets are located here in the Seattle Area.

OMAX makes a series of less expensive waterjets (the Maxiem series) that are well less than $100 K including everything. We paid full price for ours after obtaining a federal grant for our new school. I don’t think we paid more than $75,000

We do not find that the estimates of operating costs mentioned earlier are as high as stated. I don’t budget for anything for our waterjet and we have mentors that were trained at OMAX that do all of the operating. We have a source for free abrasive (its not really sand… it is crushed garnet) and we go through about a ton or a ton and 1/2 of abrasive a year. Even if you have to purchase it … a full year’s worth is well less than $1000.

We cut for many teams in the area and our shop is pretty busy during build season helping other teams cut parts and also showing how to do fabrication that utilizes the waterjet.

The only costs we have are water filters and electricity which is paid for by the school. The water filters are donated by OMAX and they also help with any maintenance. Occasionally we have a few other parts to purchase/get donated. The one large advantage of a waterjet over a CNC mill is that tooling is almost non-required other than the tip unit. Of course the mill can do things the waterjet can’t but it is also much slower.

Someone mentioned the rebuilding of the pump… which could be pricey but it is not that difficult actually and in the OMAX training (which is included with the machine) the trainees do a complete pump rebuild. The parts are not that much either.

There are definitely some quirks to keeping the abrasive flowing and some other light maintenance activities but the operation is really pretty easy. I am not saying it is as easy as a laser cutter (high school type) but it can cut literally any material and our machine can handle 5’ X 4’ sheets.

I chose the waterjet because I believe that designing in 2d CNC is a simpler way to start learning to design. It requires the student to think about the fabrication while designing and because we are in an Aerospace Industrial area… (50 feet from our shop is an airpark with the original 747 and 787 and a number of other planes from biplanes to WW2 bombers, and a Space Shuttle full scale demo from NASA is in a building on our same block)

If you want any other information regarding setting up a waterjet or using one I would be happy to respond. We have found it to be incredibly valuable to both our team and the 20+ teams that we have helped build their robots by cutting their designs on this machine.

thanks
and if you are in the area… come by and take a look.

3928 has a Flow Mach 2 waterjet in our building. We have used it to cut some of our parts since 2015. Due to the taper in the cut, we have to drill/ream out some of the holes, but it is still very convenient. I would not recommend getting one for only your team due to cost, but finding one that someone is willing to let you use works well for us. Thanks Iowa State!

If you have any questions regarding it, I will do my best to answer them.

This is great information, thanks for correcting me!

Do you the process would be repeatable w/o so much support from Omax?

I think it is repeatable. OMAX is very interested in getting waterjets into educational settings and I think they would be very receptive to helping.
They were actually working on a very small machine for that market but they do not have it in production yet. The issue is getting a small pump to operate it. The present pump is substantial and runs on 440 volts. If they can do something smaller it would rally help the footprint.

Of course it didn’t hurt that the main office is just 40 minutes away in our case but it is doable… if anyone is interested in pursuing this just message me and I can put you with the right people at OMAX

We use a CNC plasma cutter that we have access to from a sponsor. We use it to cut our chassis and this year some parts of our intake. The tolerances are fine for us, and it’s pretty quick and easy to use. It’s true that parts need to be cleaned up after they’re done, but that’s what freshmen are for, right?:smiley: