Waterjet/Laser cutters in-house?

[Tal_Esh]

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..

[cad321]

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.

[BrendanB]

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

[Cory]

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,

[anushad]

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.

[ahecht]

Originally Posted by Cory

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.

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".

[FrankJ]

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.

[Tal_Esh]

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

[Cothron Theiss]

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.

[AdamHeard]

Originally Posted by Tal_Esh

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

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.

[BrendanB]

Originally Posted by Tal_Esh

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

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.

[asid61]

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.

[FrankJ]

Originally Posted by asid61

What makes a waterjet a better option than some kind of CNC router?

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.

[AdamHeard]

Originally Posted by FrankJ

A CNC is limited by the bit dia. 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.

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

[Cory]

Originally Posted by asid61

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.

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).