Been trying some CFD tests to see what speeds I can get out of a basic convergent divergent nozzle over temperature and if a defector to stop component overheating is effective and does not alter the speed. Not the best modelling but is good enough to see what temperature to air velocity I can get. Tested this one at 800c.by Madkite - General
By brother has one of those laser engravers/cutters. Bit fiddly to set up but works ok. Would need to work out the electronics and programming. I would still go with the full chamber of inert gas. Otherwise you may end up blowing the powder around too and wasting lots of gas on long prints. Its almost made for it already as you only have to keep a tiny constant feed to stop air coming in.by Madkite - General
The unfortunate thing with metals is as soon as you start looking in to it the problems to overcome make it complex. Firstly, its advantage of needing high temperatures to melt means you need high energy concentrations to melt it too. Difficult, expensive and dangerous are normally the result of this requirement. If you want to melt it then oxidisation is a problem. So you end up needing an iby Madkite - General
VDX you should film this stuff. Even badly shot wobbly vision videos can convey so much more information. Its also just great to actually see things. I intend to try and film what I am doing especially when testing for my own records as well as for the interest of others. You can so easily forget something that later is important but just seemed nothing at the time.by Madkite - General
Got any good links about the ceramics VDX. I'm an ignoramus when it comes to them. High temperature components are of grate interest to me. The best cost effective material I could manage was fire cement to insulate parts. Nicely made ceramic components would be awesome. Even just as heat shields.by Madkite - General
As I said I want a multi material printer. Metal printing is a big part of that but not the only thing I'm considering. Think more printed circuit board as well as metal parts. Technically I don't really belong in this category but I have nowhere else to talk about it. The final strength may also be a bit better than I'm making out as tests to repair aluminium aircraft parts with sprayed aluminiuby Madkite - General
Well lets see now. Pulley upgrade for my printer. Functioning improved whilst design. Parts for obsolete automotive switches. Christmas decorations. Headphone replacement parts. Phone case with closing lid. High tension coil cases for obsolete ignition systems. Gift boxes including one I proposed to my soon to be wife with. Prototyping parts to see fits before sending to be cnc macby Madkite - General
While cold spraying creates low malleability it also increases the tensile strength in tests when compared to other spray methods. Post heat treating can elevate some of this. Also the porosity of the deposited material has much to do with the material you are looking at and the precise parameters used. Copper can be deposited with very low porosity's and very high purity too when inert gassesby Madkite - General
My only concern is there are not really a lot of us. Just look at this thread. I'm really enjoying it as there is literally nobody out there who its ever worth taking to about this kind of stuff. They just look at be blankly. Though I'm going down a little bit of an esoteric route I will admit. But there its not even a handful or us. And we are all trying different things. Which is fantastby Madkite - General
Keep it open a couple of months perhaps and post links to it in the general section of this forum as it seems to be where most of the talking goes on. I might get a subscription or blob as I'm getting married next week so no need to ask how much money I have. lol. Have got the last main bits for the depositing head prototype coming though.by Madkite - MetalicaRap
If super high speed is not your concern then why not make a mirror positioning system. If you focus the laser with a fixed lens for a distance that is the distance of the mirror to the bed + the distance from the mirror to the lens then just have a flat mirror. Its not a huge machining feat to make up a gimbal type arrangement. Not for me anyway. Providing you design it with ease of machining iby Madkite - General
The power a mirror could handle would surly be a simple matter of how much light it absorbs over reflecting. Absorbing too much would make it get hot and cause components to fail. So it depends what kind of mirror it has and its properties to the wavelength used. But also are factors of accuracy of the reflection and its movement. Which I'm guessing would come down to quality of manufacturingby Madkite - General
Anyway whats wrong with space. I always thought of mirrors more than moving axes. Mainly because all those silly military laser weapons had huge laser so you just directed the beam with mirrors. They never seemed to think that if it worked and was used lots the perfect armor would be just another mirror! The mirror could be really light and tiny so only small, accurate and very fast steppersby Madkite - General
If you have a gas leak of either Argon or Nitrogen in an enclosed space and displace all the air you will suffocate. Anyone who does welding using any gas shielding should be well aware of this. To be honest there are no truly safe ways to concentrate energy in to a small aria. An inexperienced user can hurt themselves severely with almost any power tool. I can't see how you are really goingby Madkite - General
I like the depositor/ powder level position and the main chamber. The collection and recycling system looks good too. Its a nice concept. I have a couple of ideas/ suggestions though. If you want to reduce vibration then why not just direct the laser with a mirror that is moved by steppers rather than move a whole slide. The maths will be more complex to direct it but it will be a lot fasterby Madkite - General
Hazel 1919 Unfortunately there is little information and that is hard to find about the normal coting process alone. I'm in a whole new realm of unknown. Where I quite like it. Am making a video with the parts I have as am stuck till the bit come. But try this for an insight and see attached. There are lots of factors but its promising from my perspective.by Madkite - General
Just ordered last parts for test rig. Will take a while as some coming from China but when I have them all it shouldn't bee too long.by Madkite - General
Lowery the velocity, then a metal tattoo!!! Someone else can test that. At the speeds I'm aiming for it might be stopped by the bone. I don't intend to find out the hard way. Of course the nice thing with it is to slow it down all you have to do is lower the temperature. Though it means the lowest speed would be about 300-350 m/s without refrigerating. Things like aluminium need 800 m/s+by Madkite - General
Thought it wouldn't work. But I'm far more up with gas systems. Not that for a complete system mine will necessarily work out any cheaper or safer. It would however negate the need for inert gas. Urrrr dread to think what would happen to someone's hand if it got in the way of metal dust traveling at 1000m/s. Nasty.by Madkite - General
I'm going for aluminium for starters as its good for making lots useful of parts. But as my ideas are a little out there its worth thinking on other lines. If lasers really are too costly and considering they have been around for donkey's years they probably wont get cheep any time soon. Perhaps some other less perfect approach could be tried? And I'm not the kind of person to shy away from crby Madkite - General
I see. I'm not up with lases so forgive my ignorance. So its really a ratio of watts per mm squared for a selected wavelength? But what about fusing to an object witch had quite a bit of mass to conduct the heat away? Its one thing to weld to a thin plate but to weld to a large lump of metal needs much more power. Up to a point of course.by Madkite - General
How powerful laser is required? A sealed chamber filled with argon would be best as it would use a very small amount and prints can take a long time. But anyone with a TIG welder has argon. Its not that hard to obtain. Looking at the price of Co2 laser tubes if it needs lots of power for metal then it going to be really expensive and the life span of these tubes is not spectacular either.by Madkite - General
Jasper1984 Isn't that how shapeways does it? That may be a good option. To build the part and stick the metal dust together with a binder then cast it together filling in the gaps with a little extra material than runs in the space left by the binder in the mould. I have a small furnace capable of 1200c so its an option.by Madkite - General
I need to get it all built first. And get a small beam. But I will be testing after that. Probably short tests as I don't think my compressor is up to the supply requirements but enough to prove the concept. As far as I can see as long as the jet hits a surface at right angles then it will join. Multiple layers can be built up and are by the current tests. Plastics have been tested already anby Madkite - General
I'm working on it but on my own tack. I have decided to investigate hypersonic powder deposition as a building method. With this method you could deposit plastic and metal all with one system. The problem is creating a collimated stream of particals. That I have been working on and am now building the test rig. And yes its a little ambitious and nobody has done it for this before but I fby Madkite - General
My metal plastic multi material printer project had me thinking about a kicksterter in much the same way. I'm trying to build a hypersonic powder deposition system that at minimum will do a number of metals and plastics. Assuming I can get the system to work and show its a viable idea then what would I do. The problem would be I do not have the programing or electronics expertise to constructby Madkite - MetalicaRap
It is also a consequence of open source hardware over software. Software is effectively free to copy or the cost is so small its irrelevant. This makes it very easy to proliferate and free for anyone wishing to acquire it. Open source hardware requires matirials and manufacturing. It makes proliferation difficult without some businesses set up to sell large numbers of the parts or complete itby Madkite - Developers
As I thought. Nothing to help an open source project. It would be very hard for any individual to afford all that patenting unless they were quite wealthy. And a waist of crowdfunding. The system does favour big business or the wealthy. If there was some kind of open source license for this kind of thing then they at least could not claim prior art. Though as you point out it would probablyby Madkite - Developers
Actually this raises an interesting question. Lets say one of us comes up with a novel patentable thing for Reprap that might be worth some money if patented. Apart from patenting it yourself, what could you do to keep it free for people to use? Can you prevent somebody patenting it and stopping its free usage without patenting it? Otherwise if we did invent anything new and potentially valuby Madkite - Developers
Well I'm intending to test my idea out. If its successful I can streamline the whole assembly in to one neat nozzle heater powder injector. Its all seperate bits at the moment to allow easy swaping of parts for testing. Obtained some tungsten wire for the heating element to try and achieve the maximum temperature I can. I'm not sure you could make things propitiatory in the 1400's. Just keeby Madkite - Developers