Tinijet — Affordable Waterjet Cutting At Home

While laser cutting remains the dominant force for rapid prototyping anything made of plastic, MDF or wood, the real holy grail is the ability to cut metal — something most laser cutters are just not capable of.

In the industry, this is done using extremely high-powered laser cutters, plasma cutters, or water jet cutters. All of which are very pricey equipment for a hacker. Until now anyway. Introducing the Tinijet, the missing tool for affordable water jet cutting.

We first covered this project a few years ago when it was just a university research project called Hydro — it’s since evolved immensely, and will be available for sale very soon.

While the following video is just a rendering, they demonstrated a prototype of the unit at CES 2016.


According to the spec sheet, the working area is only 300x300mm but it is capable of cutting up to 6mm aluminum, and 4mm thick steel or titanium. The operating pressure is a whopping 17,000 PSI or 1200 bar. We want one.

63 thoughts on “Tinijet — Affordable Waterjet Cutting At Home

    1. I remember the Hydro running around $15k for components but they couldn’t find a low cost pump to go above 10K, and they somewhat cheated and used shop air to power it (inefficiently). My calculations from then said they needed about 1KW of pump power. This may be more than that. I could back-calculate from their claimed cutting speeds. It also claims water filtration and a big enough tank to hold half a ton of water. It’s definitely not going on the second floor of my house. This one may be $20k.

      I haven’t seen evidence that Adam is involved in this one.

        1. You spelled garnet wrong on your PDF, btw.

          What feeds more abrasive into the 4 lbs of garnet mini hopper in after it runs out? Does it detect it has run out?

          264 gallons of air per minute at 87 PSI? What sized HP motor is needed to produce this?

          How much taper does this create?

          What orifices do you use? How easy is it to align and replace them?

          1. Hey WJ,
            Feeding by hand as of right now, about 20 mins of stock @60-80 g/min, working on external stock. 10 HP
            Not so much taper with the thicknesses indicated but I guess you would want to see pictures, working on that.
            0.008 ” DTI Slice 2 does not have a cartridge and it has a guarantee of perfect alignment.

      1. I did a few calculations. Mind the mixed units.

        With a pound per minute of garnet and a 0.15mm jewel, it looks like it may be in the neighborhood of 1KW nozzle power. This may vary as the quick and dirty calculator I used doesn’t go below 20000 psi and I didn’t mess with the mixing tube information.

        A 36 cfm 87 PSI compressor motor is about 5.5hp. Also, most compressors are 20% efficient to the exit of the pump, and may be 10% efficient in terms of useable power after taking into account the rest of the delivery system.

    2. just a minute…………..couldn’t you 3D print one using nuclear fusion, graphene and nanotech? 300×300? a joke, and by all accounts a very expensive one, go look at Keith Fenners turnwright machine works home made plasma profile cutter does the same job on a 1200 x 2400 size base for a fraction of a fraction of the reported cost. Just because you can, doesn’t mean you should!

        1. I own plasmas. Plasmas cannot do fine features or small circular holes, leaves the edges rough, introduces changes in temper, gives off fumes, needs assist gasses, the heat can warp parts and gives off UV and other spectral emissions. Cheap and quick though.

          1. You really should have left some details. Basically it’s using a conductive backer and the plastic just happens to be between the torch and the backer?

          2. Sheet of aluminum foil on top of the (very thin) non-conductive material will cut it, albeit with a large kerf. Plasma cutter turns the sheet of aluminum foil into a stream of plasma that cuts into whatever is below.

    3. It will probably be a lot more pricey than people think. Also, the waste from the cutting process is HAZMAT. You cant just put it down the sink… Not to mention water jets are noisy and need a lot of maintenance because of the nature of the process!
      I love how you go to the web site and you can sign up for marketing spam, or like them on social media, but there is nothing of substance there to see.

      At what point does it become superfluous to by your own, and you probably ought to just call a place that already has the gear to get something cut out… There are probably a lot of local sheet metal places within easy travel distance of any Maker/Hacker that would be happy to cut something out for you for a very reasonable price. Not only that, you can leverage their expertise to help make sure the parts will be exactly what you want, and come out with not only parts, but a local contact who can help should your idea become something truly marketable and need to be mass produced!

      1. Hey ! I take it you mean Hazardous waste ? It is only as hazardous as what you cut! If you cut lead then it will have lead in it.. Aside from that it is water and Garnett that comes from mining or from natural erosion. Oh and I ain’t no spammer !!
        Our experience is that the statement in your last paragraph is not always, meaning “rarely” true, on one or several of the accounts..

        1. If you are cutting metal, the left overs will have large concentrations of very fine metal particles in them, or plastic, or what ever you were cutting. In most jurisdictions, they don’t take kindly to you pouring water with large concentrations of these types of particulate matter from industrial processes down the drain. In the very least it is classified as industrial waste that will have to be disposed of through proper channels. So maybe not necessarily HAZMAT, but not something that can be just gotten rid of by pouring down the drain.

          Also, as far as local places doing stuff for you, I feel sorry for those that don’t have any industry contacts that can help when this kind of specialized process is required. I guess I am fortunate to have worked in industry where I live, and know the local places, and what they charge. For me, and probably a lot of others, it is certainly a better deal to go to the local place rather than spend thousands of dollars on a machine that will limit my ultimate work-piece size to 300x300mm!

          As far as SPAM, I consider any marketing e-mail as spam, But I guess if they sign up, you cant technically call it spam… To each his own…

      2. The waste is not hazmat unless you are cutting hazmat materials. It’s actually one of the cleanest processes out there, you can use it to cut food, tampons, fabrics, PVC, etc as it doesn’t burn what it cuts.

  1. Did anyone get a video of this in action at CES? I’ve been wanting to see it in action, but havent been able to find anything yet. Curious how “affordable” you are talking here, all indications I have heard have this thing in the $30k range. Hopefully they’ll start selling parts for hackers to roll their own, thats a bit steep for most of the “hacker” crowd.

    1. Really the real trick here is the pump, but that’s true of all waterjet systems. It’s not easy to find a small high pressure pump with flow (and low pulsing). The waterjet heads are also not cheap, but they usually run about $1000. I was looking at water blasting pumps at one point in time. Never priced one out, such as the 20,000 PSI 5hp unit here:


      1. The heads, just the heads, run about $3000 to $3500, commercially. The on/off actuator is at least $1000 alone. Then there’s everything below that: the HP fittings, mixing chamber, mixing tubes, nozzle body, orifices, blast disc, body nut. Oh and the swivels run about $2000 each, too. Don’t forget, water is corrosive, so it is all stainless too. The HP lines that convey the water is generally priced per inch. Everything I just described is a wear part and is used up (at different rates, no less). A 40k PSI head, lines to it and swivel so you can move it will run at least $6000. You also still need a pump, XYZ controls, catch tank, etc. Granted, these are commercial prices but the machining isn’t free and there are limits on cost saving.

        1. The head and on/off actuator can run about $1500 (accustream.com). It may just be the supplier you’re working with, and you may get longer life.

          (PDF) This definitely helps illustrate the costs and frequency of replacement.

          However, I do believe that repair and replacement go with an exponent of the pressure, so 20KPSI will live a lot longer than 60KPSI given the same materials.

          1. Cutting heads that are designed for the lowest cost can run $1500, yes. That does not include HP tubing or swivels but you can find some older designs at that price point. And yes, 20k would last a lot longer than 87k PSI. But would also cut much, much slower so you have to calculate total cost per unit time.

    2. A new “cheaper” starter unit from Omax is, last time I checked, in the 100k range. Not even sure it’s intensifier based. $30k is much better but you would still be giving up a ton to achieve that.

    1. What are kids for. You sell one of them .. I know we would rather sell the wife..
      Just a ruff day at the office..

      But you are wright.. ( How much does a liver go for now days )

      P.S. Dont for get to fill out thoughs doner cards.

  2. Too small for any real applications. Commercial systems use hydraulic cylinders to produce 100,000 plus PSI. Those pumps do not cost near the 10K USD mark.

    I smell a crowdsource style ripoff….

  3. 17k PSI vs 40k, 60k, 87k PSI of commercial machines is going to mean a very slow or very jagged cut with abrasives. Where do you load the abrasive? Where does it go when used? You cannot water only cut metals of any appreciable thickness and it doubles as a cloud generator for the room if you try.

    They use upwards of a pound per minute of abrasive or more (per head), commercially. Once used, it’s now wet, partially used and fills up the bottom tank as a sludge that has to be removed to keep cutting. Also, every component in the pump and cutting path is a wear item.

    I love the idea of a “lower priced” unit but as somebody who knows commercial offerings and knows their limitations, this seems great conceptually but I don’t see how they have solved all of these issues well enough as of right now? Still curious about some of the actual technical details.

    1. Hey ! Lower pressure means in our case lower flow, which is a very important determinant of actual cutting power. Less water also means thinner abrasive in smaller quantities. Loading of abrasive is the same as on OMAX, at least early OMAX, you load a small tank that is above the cutting head. Thicknesses and speed are on our technical data sheet, but obviously those do not compare to commercial waterjets ! They do not intend to.
      I agree about the sludge, we have added spaces for entries onto the tank so that people can “hack” Tini and do automatic abrasive, and water removal for decantation and disposal.

      1. You still use 120 grit garnet though. So basically this is a small reduction in abrasive usage and a huge reduction in cutting output, all else equal? What size mixing tubes and orifice combinations? Are they COTS parts?

        1. 120 mesh, technically. And most waterjets have a small hopper right above the cutting head but what fills that up as cutting proceeds? Where is the bulk tank? 4 lbs would be only 3 and change minutes of cutting on a commercial machine. Yours uses less garnet per unit time and the cutting size is less than a sq ft but still? What are your garnet usage rates?

    1. It doesn’t. There’s really no comparison to 3D printers, which vary in how they operate. Waterjets cannot be “scaled down” to work like RepRaps can be. It’s not dorm room friendly and failures are significantly more noticeable. As great as that would be, it’s not really practicable to DIY a waterjet like you can some types of 3D printers.

  4. Warning signs this is more of a… Exercise in “entrepreneurial” and self promotion abound.

    1) The original inventor, a young 20-something has “gone on to bigger things” in the words of tinijet… What would be ‘bigger’ than turning your senior thesis into a startup company?

    2) The numbers dont really add up – as Waterjet has pointed out well

    3) There are renderings accompanied by schmaltzy marketing music bought from audiojungle.net or similar.

    4) Defensive brand manager is here promoting and defending obvious vapor ware as if it exists and has measurable properties that are in need of defending, as opposed to being renderings a third party did of some kids senior project.

    To me a few things are likely.. One is that this is a crowdfunding scam. The high ticket price seems to make that unlikely…. I actually think the people involved in this just wanted to design and render the machine – and now that they have done that, it seems fun to promote themselves using a cool design, however unlikely or impractical it actually is.

    1. I’m not certain the machine is viable (capabilities vs price), but they do appear to be “real”. There’s some prototype photos and videos on Youtube and their twitter feed that look fairly legit (not unfakeable though).

      While I can’t find much on them right now, it appears they’re based out of France and may be developing this in the OpenEdge.cc fab lab. I don’t see this as a scam as much as overreaching. However, they apparently had the prototype at Fab11 and another at CES. I still haven’t found any photos or video of either.

      Given my discussions with Adam during his internet stardom, this is a matter of parallel design, not collaborative. Tinijet’s comments support this. He wanted a 20000PSI electric multi-piston pump system to get away from shop air and to provide a smoother operation than his single acting pump (but keep costs down). That wasn’t found at the time, and any alternatives to the air driven high pressure pump were too expensive and had no chance of being used in anything but a full industrial setting.

    2. Hey !
      1) Adam did not invent waterjet cutting, I believe John Chang at Omax and others in the Seatle area did. He’s now building “robots that build rockets” @spacex and that is pretty big in my mind http://www.adamlibert.com/.
      2) Numbers: The stock of abrasive lasts about 20 min with a feed rate of 80g/min. Yes you refill by hand.
      3) I use the standard “add music” function of you tube. Sorry if the choice is not the best in your opinion. I am open to suggestions.
      4) If you found me Defensive, I am sorry, I was trying to share at best my point of view on the points that were raised.
      Thanks for the input !!

    1. Every tool has it’s place. It’s own unique strengths and weaknesses. Mills can rarely process 5′ x 10′ sheets of 4″ thick granite. Waterjets cannot cut partially cut through pockets and is somewhat slow. Plasma cannot do fine features. Lasers cost 500k and up. Mills require work holding, different tooling. Cutting edges dull. Everything has a set of what it excels at, what it’s ok at and what it’s poor at.

      1. It’s a cool demo, but I’m not sure what problem a 1’x1′ waterjet solves. We use one with a 9’x13′ table. THAT solves some problems! Cutting up large sheets without a heat-affected zone (it was specifically purchased to replace a plasma cutting table). If the waterjet were the same size as our mills, well, I could dream up some usages, but I’m not sure we’d bother.

  5. So we have now an upgraded version with a 1.5 kw direct drive pump, as some of you already know. We are offering the new version (direct drive) for the price of the old one (air pump) : (15 000 Eur) ex works. Get in touch or send us questions..

  6. Hi , what if you have two HP pumps or even three , you copple them together on a let say 3 KW reductionmotor . Then you make the outlet from the first pump to the inlet from the smaler second one by three pumps you do the same with an even smaler pump you triple the pressure don’t you ? There should be rubber hydraulic pipes who can handel high pressure . If you have a motor wiht electrical/mechanical brake and a relieve valve it could work maybe .
    For those who have things already laying around

    Just my 5cent for what its worth
    greetz from Belgium

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