Thanks for that. Interesting. The extrusion looks quite thick and I wonder how much problem trapped air is?by ablainey - General
Mikko Kosonen Wrote: ------------------------------------------------------- > > Dunno how good the product would be...I have seen > one extruder somewhere and its output was > like....dogs s¤#t LOL. I can imagine it. I think the big heated tank idea should work in principle. Downside is the really long heat up time, but if you are using it to make rolls of filament then its not aby ablainey - General
@Mikko Kosonen Thats really good. It proves the wood bit idea works, but I shouldn't need as much motor power and gearing as he is extruding at a much faster rate. thanks for the link!by ablainey - General
Pic of the view through the viewport of granules going past into the feed tube.by ablainey - General
Rather than add support to the can/hopper I found an old antisiphon bath trap in the shed, so decided to use it for the hopper as it splits in half. Cut the ends off the can and epoxied the trap in the middle (after sawing a few pipe connectors off it). It makes a really good vacuum chamber due to the tappered shape, thick walls and already had a nice 'O' ring seal at the join. (ive also added aby ablainey - General
@NelsonRap Yes thats it. Google Auger drive for more info on this kind of conveyor/pump/drive. Augers are used for lots of things like grain etc. Its really handy that we can use very cheap wood auger bits for auger drives.by ablainey - General
Following on logically it becomes obvious that we can use this method to support prints! Imagine prints with massive perfect 90 degree overhangs supported like this. You only need to pause the print before the overhang layer, ( could be done by adding a line of gcode to move the head to home etc). You then add your support to the bed and unpause the print.by ablainey - General
Copied from my post on BitsfromBytes forum as It will be useful for Reprappers with other machines: I ran off a multipart print today. 16 pieces of identical cable carrier. This was a no raft job on a non heated bed so typically about 20 mins into the job one of the pices came loose and the nozzle glued it onto the next piece writing them both off. At this point I had the option of letting it rby ablainey - General
Had a bit of time to do some more and here is some pics. First pic shows how the new granule extruder will be mounted above the printer. The reason for the height is so the silicone hose can move without causing much stress on the print head. Second shows a close up of the extruder. This is a 16mm auger bit inside a co2 capsule. with an outer gas tight chamber made from an aerosol can (just bitsby ablainey - General
I have been looking into the whole life without money idea for years. As said the Zeitgiest kind of idea is the only thing so far that really adresses the flaws in society, but it throws up new problems like the idoits that like to smash and burn for the fun of it. Can you imagine them in a world where no one claims ownership and all the people are supposedly living in peace and harmony? Demolitiby ablainey - General
Here is a link to the info and a pic so far. LINK scroll down to the pic then read the blurb for it to make more sense. Sorry if the explaination isn't all that clear. It should make more sense as I post more pics as it comes together. If you need a better idea of the principle, have a google for clay pugging machines whihc use a vacuum chamber to get air out of the clay while they mix it. Its abby ablainey - General
I have started to make a 3mm extruder that will directly feed a Rapman 3.1. This will be a vaccum air removed system (hopefully) that will be fed with raw granules or ground scrap. i'll provide links to pics and more details as soon as the pic uploads properly.by ablainey - General
I did post a link on a thread here about the recent use of a novel titanium alloy that can be blow moulded at plastic temps. Can I find the link? Can I heck! The first thing I thought of was if it could be extruded? Apart from metals I am now thinking along the lines of a printer that can put out carbon fibre or other high tensile filaments in thermoplastic. Maybe a frankenstien of a chopper gunby ablainey - General
Also you have the human quality control factor. If a part comes out really bad it wont be used for a new machine. On the flip side some parts will randomly come out really good and will definatley be used for a child machine. Statistically an average machine will print parts that vary in quality/accuracy. If this is output is plotted on a graph it will be a guassian distribution. with some reallby ablainey - General
Billy I have been working on writing a proper procedure for a few days. I am now suggesting 45deg for each initial turn as it shows any change much better, then turning less for fine tuning. 10 degrees is very acurateand good for fine tuning but any change may be hard to see as you have noticed. I'll have to look at the cupcake design to get an idea of how it is different to the rapman. The prinby ablainey - General
Yes I think they are pretty similar (I havn't seen inside a cupcake), teh RapMan is 4 threaded rods in teh corners, pulleys at the bottom of each with a single belt that runs round the outside. If you can loosen the nuts etc in the cupcake so you can manually turn each threaded rod then it should work. the idea is to take the periodic thread error of the rods which translates as a cyclic verticaby ablainey - General
I just worked out how to fix the Z wobble banding in RapMan prints with no new hardware or software tweaks. See Rapman Forum and scroll down to the pics (or read it all if you want to know the how and why). This may also be applicable for other repraps with banding opr quality issues caused by threaded rods. ALby ablainey - General
Had some idle time so ive been pondering extruders and had a few 'Blainey Extruder' ideas: 1) What about a needle shut off nozzle? This would open up some possibilities like a nozzle that can take its melt from multiple sources. For example two feeds of different colour/material. Both have needle shut offs and are 'Y' connected to a single nozzle outlet for printing. That way you dont need any eby ablainey - General
ElectricMucus Wrote: ------------------------------------------------------- > ablainey Wrote: > ------------------------- > > ooh, I Have now! > > > Well, thanks. > I actually thought of a piston driven mechanism > either fed using air pressure or gravity. The > problem is even if you squash one pellet while > melting you could still get air coming out of theby ablainey - General
ElectricMucus Wrote: ------------------------------------------------------- > heavier and more expensive unless one has a genius > concept on how to extrude the pellets one by one. > ooh, I Have now!by ablainey - General
Just thinking about a few ideas. What about having a dualhead printer. One extruder putting out the outline using good quality high tolerance filament. While the 2nd does the infill using cheaper stuff? Workable? Worth the effort in cost saving? probably not, but it might be a solution if we staret making our own dodgy filament from recycled milk bottles.by ablainey - General
How about a good old clock gauge measuring the filament as it goes in. I am sure i have seen digital gauges with RS232 out. We could adjust feedrate based on measuring the pressure of the melt or I would expect the temp to also vary if the diameter changes,; Thinner = higher fatter=lower due to increased volume of material to be meleted. so we may be able to use that or a combination of both theby ablainey - General
But do we really need filament to be so accurate? After all we melting it down again and re-extruding it anyway. Surely a supplier will realise that they could knock out cheaper filament with lower tollerances and corner the printing market.by ablainey - General
Can anyone see where I am going with this? Mwahahahahaha......Mwaahahahahhahahahaaaa AARrrrrrrrrrrrrrrrrrrrrrrrrrrrrghggh. And relax.by ablainey - General
Yes you can spray from up to 16 inches away to get a thin coat. It still has lumps and bumps and is a much wider coverage area. You could probably narrow the spray but I think the problem lies with both the mixing and the fact that random spray is generally globular by nature. (Look at the universe!) It may be possible to change the mix ratio or add a third part (filler) to reduce the expansionby ablainey - General
Where can I find info of the various nozzles out there? (just the nozzles not the extruders) I am after some info with measurements and angles to compare so I can see what designs work and what doesn't. Ideally including internal presures if anyone knows. Is there any form that seems to work well or is it a case of anythign that will squirt plastic is ok by us! ? The reason I am looking is toby ablainey - General
This is somthing I am interested in and have thought about for car modelling and large mould making. I also wondered about PU foam as I have used it many times before and have used very quick curing "spray on" which goes off in 15 secs max on a warm day. Which would be perfect as it comes in presurised tanks and is extruded or sprayed though a disposible mixing nozzle. The trouble as mentioned iby ablainey - General
Oh well I have taken the plunge, no going back now. Just ordered a RapMan 3.1 from Bitefrombytes. Costly little blighter so shhhhhhhh dont tell the misses! Anyone using the RapMan?by ablainey - General
Thanks for the replies. Thinking about comments on the timeframe needed to get up and running, tweaking, things breaking etc. If you could do it all over again would you buy a fully built machine? (I know they are expensive) That is from the standpoint of all the time you have invested in building and getting it running (equated to money for your time) vs out of the box up and running + the extrby ablainey - General
Thanks. After reading about the clonedel parts and looking at the quality. I am pretty convinced I can do better. For starters why no holes? Yes shrinkage is an issue, but easily allowed for in moulding. And the parts being sold are rough and still need finishing. Now I am thinking that getting a full mendel kit and turing out better cast parts is a strong contender. Can I get better than this kby ablainey - General