Hey I'd like to think it was Dylan too.by aka47 - Polymer Working Group
Mag tape used to be the favored data carrying medium for Key Cards and Credit cards etc and suffered like all magnetic media from its suceptability to corruption from stray magnetic fields. Not very durable, and once corrupted in situ will be a pain to reconstitute. It was once standard practice for Hard Disk Drives that had Voice Coil Actuators to dedicate one of the platter surfaces to a magnby aka47 - Mechanics
BTW Vibrating a mass of mixed sizes of powder grains, effectively compacts and sorts it a touch. Not necessarily what you want. I am sure it does liquefy for the duration of the vibration (like patting damp sand and watching it flow into a puddle and away on the beach). But when you take away the vibration the fact that it's presence has "Sorted" the grains into the most dense formation is likeby aka47 - Polymer Working Group
Umm the heating/warming up just before dispensing was to make the ethanol evaporate quicker.... Baking the Epsom Salts in the Oven at 210 DegC converts it into it's anhydrous state. My plan when I get the ingredients is to pestle and mortar the stuff as it comes out of the packet , initially grade it with an icing sieve. Re grind anything that won't go through. Bake the powder in the oven at 2by aka47 - Polymer Working Group
From what I have read about how digital calipers work it should be possible to make them without the caliper. ie just PCB/s. aka47by aka47 - Mechanics
But introduces the spectre of irretrievable blockages in the fine bore of the nozzle. Your support blocking up 11 hours into a 12 hour run is going to be something I think you might want to make so unlikely as not to be worried about. I know I do. If that happened I would need to go out for a couple more bottles to drown my sorrows. aka47by aka47 - Polymer Working Group
I am not convinced that it is fully needed yet. Ethanol being an alcohol has useful degreasing properties. The initial idea is to have a paste that contains some water. enough to encourage initial crystallization but not enough to encourage the stuff to set solid in the feed line/syringe. Ie enough to have the crystallization process started but suspended due to lack of any more water. Crystalsby aka47 - Polymer Working Group
Thanks for that Blerik I was wanting to be sure that the Step + Driver servomotor controller board with additional high level access wasn't already duplicated elsewhere (would have been a waste of effort). Cheers aka47by aka47 - Mechanics
Thanks for that Blerik, much apreciated. Something that's not clear in my mind. Or at least I think it could be but am not sure. EMC2 can control directly at PWM level for Servo Motor Control, (The thing I am currently working on) The Current RepRap stack has no Servo Control capability at all... ie no PID or Positional Feedback ... Is this true ??? cheers aka47by aka47 - Mechanics
Sorry for the lack of visible progress on this front for a little while. I have been distracted into getting some sort of test bed up and running, repairing some of my machine tooling and scraping together some access to machine tools I don't have. As well as begging borrowing or if desperate buying bits and pieces to look at whilst designing in my head (It really does help the process of visualby aka47 - Mechanics
Anybody experimenting post your results & methods back here, at the moment it's just ideas and will need a bunch of folk to verify/modify or discard before were done. Re patents from my reading of the links above they all pretty much seem to be down the aggregate, binder and plasticizer route. Rather than the Plasticizer & Crystalizer suggested as a possible theory here. Further my unby aka47 - Polymer Working Group
If the trials work out you could always go for lab grade and add water. Don't know if this is any cheaper though and you have difficulty getting it supplied in the UK as a member of the public. Just about anything chemical and lab grade is subject to an excessive amount of paranoia in the UK these days. You could use cheap vodka you just have to put more epsom salts in it. I guess if it worksby aka47 - Polymer Working Group
Yet more excellence..... Demented seems to be getting along well too. aka47by aka47 - Shape Deposition Manufacturing Working Group
For stabilizing your joints if welding is proving to be tiresome you might want to consider aligning it, clamping it and then drilling a hole through where you can hit both bits of pipe (Union and threaded pipe end). Then put a self tapping screw through to hold it. It doesn't need to go all the way though both sides. Just one side but both bits of pipe. The advantages (although it is a chew toby aka47 - Mechanics
Yup, nothings forever. Given the maltreatment my kids manage to dish out to whatever there current in thing is, I cannot honestly see lightweight CNC kit coming anywhere near the peak shock and G forces kids manage to dish out to Skateboards. 48 Kilos of juvenile dropping 0.5 to 1 meter complete with skateboard apres grind, is quite a high peak loading. Even distributed across that many bearingsby aka47 - General
By George I may have it, but it's not catching...... The Vodka Method.... Epsom Salt or Magnesium Sulphate, available from most mosts chemists even in the UK. Great as a desiccant, barely dissolves in ethanol, can be made anhydrous by heating to 200 Deg Centigrade (Within the range of the average oven) I think I might try this later. just for fun. The cleanest Ethanol based spirit I know ofby aka47 - Polymer Working Group
Just had another quick set of thoughts. What about making a paste up from a salt (ie water soluble) in its crystal form whetted with a volatile that the crystals don't dissolve or react with. Effectively using dissolvable crystals as aggregate. If we could find such a salt and the basic crystal shape was closer to a sphere than say a cube then we should have the basis for a paste that is easierby aka47 - Polymer Working Group
I know this is slightly at a tangent to the current but I have just been looking at some electrical gear (putting more lights in the loft) and couldn't help but notice the knock-out portions. This might help with some of the things we need to do (certainly not all or even possibly the majority). Basically add in thin easily cut sections into the master drawings as supports. I am thinking predomby aka47 - Polymer Working Group
Sebastien I have scraped together enough cash to order up the parts I need to repair my drill press. (castings shattered irretrievably) so hopefully I can do some more playing with bearing trucks etc when the parts arrive. In the mean time, thinking about the trucks Patrick was making up with aluminum angle do you think there is any mileage in RP'ing these as a triangular prism bar shape with fby aka47 - General
Demented sir Soldering Iron element looks like a viable suggestion. I too have been musing on that one and can see two potential downsides one of which probably isn't. 1. Most soldering iron heater cartridges are mains powered. (Although I did poses once a 12 v soldering iron I got from a model railway shop) 2. in binding your cartridge to your print head your element would be making contactby aka47 - Mechanics
Most excellent dude. Given that it takes a certain amount of heat energy to convert the solid polymer to fluid, and a higher extrusion rate (1mm) takes more heat energy for the same head speed. Could your temperature thing be that the rate you are using up the heat your heater is generating is greater than your heater can generate it ???? (I actualy don't know here, just freewheeling ??) Cheerby aka47 - Mechanics
Interesting links, I can't help but think that concretion is something of a double edged sword. I that you have abrasives, setup time and shelf/tool life to consider. Taking all of the previous gives you a very limited window of opportunity for repeatable success. Having said that I can certainly see the appeal and experimentation may indeed yield a mix that works and can be delivered by a relatby aka47 - Polymer Working Group
Terrazzo NB this is all about marble chip flooring, however if you substitute Granite for Marble you won't be far out. When casting V Large pieces including larger aggregate sizes in the core of the piece will substantially reduce cost. (Possibly using a two stage process) plain old concrete could even be used in a core slab. drastically reducing cost but getting the same finish results.by aka47 - Casting and Moldmaking Working Group
OK What looks like a useful supplier of Resins and molding compounds in the UK (As well as other bits and pieces including carbon fiber) Note I have never tried pricing or buying form these folk I just found them on t'internet but they do appear to retail. Their sr-ca-85 and sr-1690 sd-7160 seem to pretty much fit the bill, and they do silicone molding stuff too. They have good data sheets oby aka47 - Casting and Moldmaking Working Group
Viktor Which epoxy is the favored one and are there some useful example recipes somewhere ?? cheers aka47 PS Ripping apart I would have to go for Ramstein.by aka47 - Casting and Moldmaking Working Group
Yup fair point, solid it is then.by aka47 - Polymer Working Group
For an ideal but as yet unspecified support material what propertied do we really need and what do we want. Lets split the problem down into two parts.......... Support The extruded/deposited support material must have sufficient viscosity/strength to support a specified mass/weight/quantity of component plastic extruded over the top. It may not actually have to be fully solid at all, it justby aka47 - Polymer Working Group
I think the support material question is one that is going to keep on popping up. I haven't seen any suggested yet hit hit the "YES" what great idea button. It isn't that folk aren't coming up with great ideas, because they are. The nearest i got to YES factor was the suggestion above of glycerin soap extruded as a wax. Maybe we should be looking at Salt Compounds I think Icing Sugar has beenby aka47 - Polymer Working Group
Kraftwerk were very good. TransX (Living on video) were better. League Unlimited Orchestra were the best. Given that it's Germany though it's more likely to be Tangerine Dream. I can definitely see a lot of mileage in the Stone base (Y Axis), Stainless steel gantry (X Axis) and Aluminium Z axes though. With the Gantry set into the base. All shiny and custom. I wonder if my wife would letby aka47 - Casting and Moldmaking Working Group
OK First off I think I need to say that the current design etc is great for what it is intended for and probably does'nt need much if any modification whatever. Having been doing a bunch of thinking re improving the thermal capabilities of the current to make it more suitable for higher temperature plastics (Maybe even PTFE....) I have some ideas to contribute and offer up for shooting down.by aka47 - Mechanics