Ideas for Skeinforge - Multiple Zones

There's work being done for multiple materials, which is really quite interesting... here's an extension and/or generalization of that thought:

what's being done:
  volumes get tagged in OBJ file, or use multiple STL files to define separate regions... tagging in OBJ is better because you can have arbitrary tags, e.g. color per object, color per vertex, etc...

  tags that match settings in Skeinforge would override the SF value.  e.g. a tag: infill_30 would be 30% infill.  if infill was absent, don't do infil.

  alternatively it might be simpler to have multiple profiles, however, the reason that's a bad idea, is because SOME settings should be accessible as adjustments to SF settings, but some are material-stock specific.  e.g. infill is an preference variable, a situation variable.  I might want multiple infill% on the same model, e.g. on a big flat boxy area, I can handle a 20% infill, but on a vertical tower, I might want it at 80%... or maybe on that vertical tower I want NO SPARSE layers?.... that should all be my choice... and those things should be definable within the OBJ.

  Another region could be support.  maybe I want support material under a specific bridge, but don't want it anywhere else.  why not just make regions that are filled with no perimeter, and only support material? Would be just better if an object can be designated as support material (in which case each layer from ground up could be essentially like a shadow of all the layers above it not looking at the other regions, only the region designated as support.   setting: region=support only, has support, no support.

ok that's a few thoughts, but the main pleading here is, to anyone developing multiple region capabilities, make sure to keep it generalized.  we are moving toward a need for more control over the entirety of the model, like variable infill% etc.

thanks for listening.

Another Idea for Skeinforge...

Cool:

Minimum Layer Time...  isn't very useful.  It slows everything down unnecessarily... or doesn't slow it down enough.

What is REALLY needed is a time to cool parameter for the material, and a cooling temp to achieve before printing over the same spot.

In other words, imagine if you lay down the plastic, at 185° C, and as soon as you lay it down it begins to cool... it shouldn't be exceedingly difficult to map the estimated temperature across the surface area, and then give the start position for the next layer priority to print on the opposite side.

alternatively, how about just adding a setting to the "fill" plug to flip-flop the start at from lower left only, to alternate lower left, upper right.

anyway... just a few thoughts.

IDEAS for Skeinforge

for Cool - it would be "cool" if you could have the extruder  head move such that the fan was blowing on some region - or orbiting some region, or criss-crossing over the whole model... but with the nozzle high enough it doesn't hit anything....

wonder if I could just add a relative hop-up in the cool start, have the print head start at 0,0 go to max,0 then max,30, then 0,30, then o, 60... etc....

silly for large layers I mean for tiny objects, all you need to do is have the fan blow directly on the top layer for a couple seconds, literally, and then do the next layer.

orbit sucks, and slow down doesn't do much at all.

Prusa Mendel is up and running - nicely.

OK I've been away for a while...

Prusa Mendel is up and running and doing so quite reliably - so far.

I've been broadcasting on http://www.ustream.tv/channel/peeringout

Anyway ;) just thought I'd share what I was up to.

Finally – The MK5 Plastruder… well, almost.

(almost meaning it’s going to ship in 1-3 weeks :( Uh, hurry up!… NOW PLEASE!!!! ) OK, so they’ve announced it!!! YAY this looks very promising, in a bunch of ways! nice… stainless steel.  NO STUPID BUTT SEAMS!!! nice.  Paxtruder inspired, without any STUPID IDLER wheel!!! NICE.  … I didn't see where the thermistor would go, and I’m very curious about using a relay board with the heater.

One problem I can really see with this is – since its still using the gear motor, and if it’s using the relay board, will it be able to hold a nice constant temp, and will it be able to cool itself down? – perhaps a modification of this design will be easy to hack.

I could see using forced liquid or air, to drop the temp of the hot end, when the temperatures are shifting.  And using insulation to reduce the load required to keep it at temperature.

Whatever the issues that may have room for improvement, the MK5 is SURE to start flying off the shelf!!! GO MBI, I’m psyched.

Cost, $185 – worth it? (comparatively… HELL YEAH!)

edit: finally got the page to load (unavailable earlier… too much traffic? maybe)

http://wiki.makerbot.com/plastruder-mk5 and there’s the thermistor! COOL.

GO BUY ONE!!!

PS and for what it’s worth – their latest design is doing the single most critical smart thing possible – guiding the filament all the way through with PTFE tubing INSIDE the metal structure!!! kick ass… been working great for me in my rigged up design for a few months now as well and it sounds like they’ve been testing it for at least as long! SWEET!

BUY? ---> http://store.makerbot.com/plastruder-mk5.html

 

It’s all developing nicely, but… just catch up when a great path is found, try to keep up at the head of the pack, or try to forge our own path?

I don’t know why I am this way, but I am.  I’m not outwardly competitive.  Logically I simply love the idea of the entire community moving forward as quickly as possible, and benefiting everyone.  However, on more than one occasion I read someone’s blog post and I get that twinge of '”crap, are they going to post the idea I had before I get around to it?”  I get that competitive urge of I need to make sure my idea is out there first!…  but really, I have to remind myself, as I do, that this endeavor is NOT so any one person can go down in history as having discovered “the best way to print”, it’s for ALL of us to be able to print reliable useful items.  Coming from a traditional product design background, the idea that we’re all in it together is a little foreign, so it takes some getting used to :)
Anyway – it was just an idea that I keep coming back to, and that is – you don’t have to be first with the idea and it doesn’t matter if you end up re-doing someone else’s work.  Re-doing the work, validates it.  Posting about it as well gives others more experimental data to work with/from.  And the fact is, even the best of us aren’t necessarily documenting every single step of what we do.  (sure some are)
The overall point here is a reminder (perhaps only to myself) to enjoy “MAKING”, it’s why I started this in the first place.
So, whether you want to lead the pack or follow the well worn path – make sure your end goal isn’t about others, but rather about what makes you excited.  That excitement is what will have you producing your best work.  Competition is a good thing, as long as it’s in the spirit of fun and sharing… at least as far as this project goes.
Big thanks goes out to the pioneers of RepRap.  And a big Kudos goes out to those that have built their lives around bringing it to people! Hats off.

It’s about time I post a photo of my setup! (yes, it’s with me in a hotel, thanks to my handy Pelican Case!

Sounds like the MK5 actually will be a lot like this - without the long barrel

sounds like the MK5 hot end will have a seamless pathway all the way to the melter... even if there's still a PTFE  insulator - which I'm not sure I get yet... WHY use PTFE - WOOD is cheap-and hard-dimensionally stable - and unless I'm mistaken, won't burn at the temps we're working at.

Though, please, someone correct me if I'm wrong here.

So there's the PTFE tubing that guides the filament all the way down to the hot end from the supply and filament driver - cool, but hey - what about reel changing? do we have to un-thread the entire length? hmmm... sounds not so great.  do they hope we'll spend $100 each for a spindle + another $100 for each filament driver + another $50 for a controller for each color? or are we expected to push 2 feet of filament through the tubing each time we want to change colors.

if you aren't familiar with the mk5 concept - or the bowden extruder, it's basically pushing the filament driver away from the nozzle - which is cool in some ways.  It makes the nozzle end very light-weight, and smaller by a lot.  however it's a long travel from the driver to the hot end.  so there's compression of the filament (although I dont' think that's a huge problem) but material changes is more problematic.

I'm thinking it'd be better to have the filament driver as close to the hot end as possible - and just insulate it better... again - I SAY use wood, not PTFE.  It's serving me well, and I've NEVER had even a hit of burning wood smell... so ***DISCLAIMER*** I personally have never noticed any risk of fire hazzard from the wood, and it doesn't expand or fail like the PTFE - BUT!!! I also have no possibility of leaking plastic into the wood threads or anything - there are no seams in my set-up.  I have a thin (1/32" wall) PTFE tubing that runs the length of my wood insulator and down into my 5/16" - 18tpi hollow tubing that has a 3/16" bore - which fits this 3/16" OD, 1/8" ID PTFE tube like a glove... in fact I had to shave the tubing down on the outside with a perpendicular exacto blade (like how you'd scrap the top of your nail to check the sharpness of a freshly sharpened knife)

anyway - .... I really need to post a drawing of my hot end.  picture = 1000 words, and somehow my 1000 words is only worth 3 pictures of around 25% clarity.

can't wait to see the final mock-ups of the MBI Heater Barrel... Although I think there are still issues to solve, and I think they are not 100% goal oriented on ideal for end user, but they are trying to run a business... so it has to be cost effective (for them) to sell this.... so some of their decisions make more sense when you look at it from a business point of view - and I can in NO WAY fault them for that.  Doesn't mean that I think it's pointless to design my own hot end either. :)

Another Rambling thought on why heat sinks are a bad idea...

A lot of people have trouble with the filament getting "stuck" and not pushing through.  The filament pushing mechanism doesn't have a lot of push before it fails, temporarily, or permanently.

what happens, from what I can see, is that the filament melter opening gets hot, and melts the filament as it's going into the opening, and that allows the filament to mushroom around the barrel go down the threads of the PTFE which expands with heat anyway, and then contracts when it gets cold.

If we let the whole thing heat up a while, I'm pretty sure the filament would probably move through ok.

But then people started sinking the barrel to pull the heat away from the top end to prevent the mushrooming in the first place.   good idea, but I think it adds another problem.  --- metal, brass, is HIGHLY conductive, and ABS softens at even relatively cool temperatures.  Not to mention that it's going to soften up the length of the filament even without help from the brass.

well -
stop trying to sink the heat away, in fact, get as much heat as you can near the filament opening
stop trying to use PTFE which is a bad insulator, not dimensionally stable, and all around silly.

WOOD is a much better insulator - and with a smoke point well above (please someone correct me if I'm wrong) the 250°C that we're looking at, shouldn't be a risk.
WOOD is a much more stable material - takes threads easily, and holds them without stripping out so easily.

So - as an experiment, I'm about to try and use the makerbot heater barrel in a WOOD barrier.  It will eliminate the retainer rings, and hopefully insulate the filament pusher completely from any heat, and keep all the heat inside the block so that the filament will simply soften and push through.

-------

will let you know how things progress.... personally I still like the barrel I'm currently using that is PTFE lined, so there's not a single seam in the pathway.  That's right I said PTFE - but it's not structural, it's simply a lining.

There is one other experimenter I've seen using a PTFE lined heater barrel - and the only problem I had with their set up was that it was overly complicated and required a lathe - which I don't have.

anyway - onward and upward!

don't sink the heat - it's wasteful!
insulate the crap outta the barrel and make it EASY for the extruder controller to get it as hot as needed.

Designing the new extruder

In order to minimize the design of the extruder, it is necessary to outline what is needed.

A Supply of plastic

A Device to transport the plastic to the extruder

A Device to liquefy the plastic

A Device to direct the molten plastic into a fine stream in a precise location.

- I have ideas swimming around my head as to how to solve thiese problems, so it's hard to prevent what I BELIEVE to be an intriguing design path from influencing the bare-bones minimum description of what's needed.

- Let's look at the extruder component list above and think about it - is everything needed? is there anything missing?

supply of plastic - seems pretty general to me. could it be something else? perhaps its not plastic, ok so "SUPPLY OF MATERIAL"....

A Supply of Material

A Device to transport the plastic to the extruder

A Device to liquefy the plastic

A Device to direct the molten plastic into a fine stream in a precise location.

Perhaps this is too specific still... if we change to "Material" then perhaps there is no need to liquefy the material... what if it is liquid already (e.g. epoxy, or silicone, or frosting)...

OK so -

Simplest version is

A Supply of Material and a way to direct the material to a Specific Location.

I think something's missing...

A Supply of Material and a Pathway to Direct a Specific Volume of Said Material to a Specific Location at a Specific and Variable Rate.

--- I like that....

One last thing - that's optional is processing the raw material.

A Supply of Raw Material(s) and a Pathway that includes any Processing, and Directs a Specific Volume of the Processed Materials at a Specific Rate to a Specific Location...

So - interesting - Specific - means that's an important aspect to control, either through design or actually on the fly needs to be controllable.

1) Raw Material Supply (Hopper for Pellet Plastic, a Spindle for a Spool of Filament, a Chamber for Frosting-Like Materials, a Pair of Chambers for a 2-part epoxy)

2) Processing

• Pellets need to be dried, melted, degassed, and homogenized, possibly colored, then if they are thermoplastic, then they need to be made molten by heating or perhaps by u/s vibration, or pressure. Injection molding uses a combination of pre-heating and pressure to inject the plastic and retain the best mechanical properties. Melting plastics with heat is not necessarily the ideal way to liquify them, but it's working - so we can use it for now... but consider there may be better ways that produce superior output.
• Filament might need to be dusted/cleaned, possibly pre-heated, possibly oiled (for materials like PLA) - similar to above the filament needs to be liquefied, but we don't have the opportunity to compress it and use pressure the way we can with a screw. However, nothing says we can't use u/s pressure. we'll see... ( I just had a thought of sandwiching the filament between an ultrasonic plate, and a a stationary plate that contains the nozzle-outlet... feed the filament into the u/s pressing chamber and vibrationally smash it through the nozzle a droplet at a time. -
  
  
u/s extruder head - just a thought


• Frosting-Like materials might need to be mixed to a smooth consistency, and perhaps degassed as well, perhaps coloring as well, but that would essentially make it a 2-Part material - see below.

• 2-Part materials would need thorough mixing, possibly coloring, degassing?

3) Specific Volume of Material

• Pellets would need some drive mechanism that accounts for their granular nature, and the fact that they will need to be degassed... the "specific" part would mean it would probably need to be a mechanism AFTER the processing, so either the hopper is gravity feeding into the dryer aparatus, etc... or there are 2 feed mechanisms... possible more
• Filament needs to be driven either by a pinch-wheel, pax-style, or some other mechanism. Perhaps though, there is another method that is more controllable - this could use more thinking - keeping in mind tolerances and avoiding situations where precise construction is required. Best design = Design that anyone with half a brain and limited tools can make it.
• Frosting - I'm going to stop considering frosting, it is a much larger task than I care to take on right now.
• 2-Part Materials, same as above - both of which I may come back to in a later post.

ok time to get back to work - will work on this post later - feel free to leave comments if you think of anything to include... certainly I'm open to suggestions.

Some thoughts on the HOT end.

A few thoughts on the heated end.

larger thermal mass is better - just like a flywheel - the thermal mass holds the energy ( heat ) better - so when the heat is transferred rapidly to the filament it doesn't suck ALL the heat out - so the heater barrel can maintain the proper heat without dips...

a heat sink is a BAD thing....

on the heater barrel, but not on the fillament channel

i.e. it's good if the inlet is coolled, but it shouldn't be connected to a highly conductive (thermally) part...

the heater barrel should not have to waste ANY energy heating what shouldn't be heated...

(the boards are taxed enough - so improving the efficiency by keeping the heating where it NEEDS to be is better, and not heating anything else (the room, the cold channel etc) is CRITICAL!

you should be able to heat the heater barrel with a minimum of energy and insulate it to keep it hot as well.

HOWEVER - because support material can now be used in the same material, there needs to be a way to COOL the barrel quickly as well... in order to speed up printing.

(cold support layers don't stick to cold object layers

so

the interface/support material is best laid down at about 20-30 deg colder than the object material, and the first layers (touching the support layers) should be about half way between the cold support and hot object layers.

it makes support removal OODLES better

EDIT:

Thanks for the comment, you're right - water cooling is something I was thinking about - but of course this is a DIY type thing, so water + electricity + human error = BAD SITUATION! :D hehe... so I was thinking it'd be better to move some air in there - through some copper piping or something like that.

I'm travelling right now with the bot - so I don't have access to all my tools - but plan on experimenting virtually in CAD.

I have a hot end that is working REALLY well - save the long heated channel - which I will be shortening eventually when I can make a coolable thermal block (instead of a long steel hollow tube). hmmm.... liquid cooled - I wonder if I could use some pieces from a liquid cooling system used for cooling overclocked PC hardware - certainly those are designed for liquid SAFETY! - maybe liquid cooling of the hot end IS possible!

Again, thanks for reading - I'll try and post more often!

UPDATE - this is working REALLY well - the pressure adjustment SUCKS but otherwise - I literally only have to adjust it if I'm changing filaments (which means they change diameter slightly) I'm working on a replacement assembly for the filament extruder body - will post pictures when it's closer to done. My main goal is to minimize EVERYTHING! pathways, plastic used, size, etc... can't wait to share!

OK - the theory was sound.

In practice? - yay, it works!

The following is a rigged up kinda like the paxtruder teflon idler not-a-wheel, wheel.

Prototype version - (note there are actually 3 pieces of scrap PTFE tubing, 2 for stabilizing, and 1 pressing against the filament - and this only worked for a while before the tubing started slipping)

Above is the current and PERFECTLY working version - a relatively simple retrofit of the MK4 Plastruder. The tensioning mechanism leaves a bit to be desired, however I have yet to have to adjust it and it's going on 2+ weeks of good printing (basically it's 7/3 right now and whenever I first posted the original post... ) --- also note the makeshift needle that shows if my motor is turning... it's just one of the little cone/piles of filament popped into the bearing hole. works like a charm.

Basically I flattened a piece of scrap PTFE tubing from the stuff I'm using to line the heater barrel. WOW this works - um... 100,000,000X better than the idler wheel IMHO.

the piece of flattened PTFE tubing on the near side (and another one on the back) prevent the idler from getting pushed to one side by the filament... and yeah that's a printed (failed) IDLER wheel.

Above and below here are the mocked-up extruder with PTFE lining.

• 5/16"-18 threaded hollow steel pipe (3/16" ID, and right now it's 5" long... TOO long. I need to shorten the actual "hot zone", but this proved a point.
• 3/16" OD, 1/8" ID (3.125 mm) PTFE tubing... with about 0.002-0.005" shaved off the outside to allow it to slip inside the hollow tubing without having to FORCE it in - which doesn't work when it's net fit.
• the rest is just for mocking up the extruder (the wooden blocks actually work really well over the metal - they insulate and really don't get THAT hot. (of course it's wood - so if you use wood on a heater barrel - do so at your own risk, as I didn't build your heater barrel, I don't know it's risks.

Yeah, I KNOW WAY too much plastic - but at the time it was better than NO plastic :D

Extruder Problems...

The Plastruder MK4 has, honestly, been nothing but problems...

For the filament pusher end, I've got it relatively working as long as the heater barrel assembly doesn't get all jammed up... but it DOES get all jammed up.

When it gets jammed up - the generous forces from the pinchwheel motor can crack (easily) the idler wheel when there is too much forces backing up. so the filament when it buckles tends to like to force the idler wheel sideways and either crack it loose from the bearing - or worse CRACK it, because it's ACRYLLIC! (has anyone tried making the plastruder out of lexan? expensive, a little, but, uh... not as expensive as repeatedly rebuilding and replacing parts on the acrylic version... just a thought.

anyway - when I first started building the cupcake and plastruder - I thought the whole heater barrel design was just STUPID. Of course - as I've mentioned before it's not stupid, it's just a complicated problem, the way it's being solved. and trying to make a 3mm diameter tube/guide that is COLD, and butts right up against the 3mm diameter HOT, is TRICKY.

So, and we'll see if it works out, but, my thought here is use a larger diameter heater barrel, and line it with PTFE tubing. 3/16" OD and 1/8" ID. The PTFE tubing will provide a non-stick surface that, hopefully, has no problem being heated to 240-250°C (since it's upper limit is 260° C) .... I still need strength and stability leading in to the heater barrel, so I'll still be using a PTFE insulator spacer, but this will not cover much if any of the heater barrel. I'm actually hoping to butt them together. I might dog-point the end of the barrel by 3-6mm just so it's easy to center, but I don't need a compression fit between barrel and PTFE - so I don't really need to even clamp the PTFE to the hot end... it's more like a sleeve for stabilizing.

Also I want to have as little metal on the heater barrel assembly, I want to keep the thermal mass as small as possible and keep as much heat right at the nozzle. So I'll be using a pair of thin nuts and a single small 3mm thick plate of aluminum (similar to what Charles Pax is using on his paxtruder - which is pretty nice looking, and if there were a kit, I probably would have tried that first, but... I'm excited to try out my experiment here.

Of course - I can already see there MAY be some problems with the design, and will follow up and to let you know if any of them pop up...

• what if the PTFE lining wants to push out? (hopefully the PTFE insulator/spacer will help prevent that, but I don't know - I also have some glass filled PTFE which should prove stronger and more stable than standard PTFE, we'll see )
• what if the ABS / PLA squidges between the PTFE tubing and works it's way up and out the top of the barrel. that's no good.
• what if 240°C PTFE tubing is too close to it's maximum limit and is weak and gets CHEWED to shreds by the filament with it's teeth created by pinch-wheel?

there are probably a few more things that could go wrong - we'll just have to see.

until the parts get here - I'll be workin' on real work :D

Cupcake is Alive!

ok - well it was for about 3 prints.

Here's the short - and soon I will update with some pictures of the process and post some vids on Youtube. But for now - the long and short:

Cupcake cartesian bot - brilliant, few flaws in the design and went together SO easily. There were a couple of things not well illustrated in the online instructions that caused me to worry a little but when I went with my gut, all was fine.

The electronics and Replicator G work REALLY well to control the bot. I wish you could do absolute positioning in the remote control - but meh - whatever.... good enough. I feel like I should probably add an end stop for the Z axis - WAY too easy to hit that down button one too many times. (BE CAREFULY you can dent your little build platform if you're not careful.

The plastruder on the other hand - is fundamentally not flawed but the assembly of it is riddled with bad practice. things that need servicing require almost complete dismantling - this is just bad. So I'll be re-designing and working out my own.

I had to rebuild the extruder after only about 2 piles of plastic and a couple rafts because the idler wheel cracked. But I sandwiched the sucker between a couple discs of >PC< ,,, from a DVD heh.... nice - used some JB Weld to bond it all up and since then - BRILLIANT no flaws, and no chunks bitten out of the filament. However in the reassembly, the stress of screwing and unscrewing the M3 screws - some of the acrylic (GRRRR) developed little cracks and I am pretty sure if I disassemble the thing again - it's going to fall apart... for this I HATE ACRYLIC! it's Terrible - no thanks I don't like it... ick! For an extruder that takes these kinds of forces - it's just silly. (yes I know there are plenty of parts out there made from acrylic that work just fine - doesn't mean it's the best material for the job, by any means.

I've been looking at the Paxtruder - and while it looks interesting and potentially a lot better... meh - it won't be MY design so I think I'll do the extruder as a ME project!

The biggest problem with the extruder is the PTFE insulator it's nothing but trouble and you can't tell if it's failing until it's failed REALLY badly. there is actually a lot about the hot end I don't like, but in fairness - it's a complicated problem (I think) to solve. That is - heat up the nozzle and enough of the barrel, hold the barrel against something that protects the extruder and doesn't wick heat away from the nozzle and can withstand the pretty intense pressure from the extruder.

So - I'll try and post some images and vids from the build - and once I've done that I'll start posting my progress as I design my new extruder!

PS> Frostruder got here today - uh .... yeah it's a bit EXPENSIVE for what you get - but hey... the guys at makerbot deserve to maker some $ ? So support them! I did.

Idler Wheel thought

So - the Idler Wheel - I was reading the instructions on makerbot's wiki, and one of their suggestions is a double wide idler wheel. I didn't really want to deviate from the standard way of making the extruder - so ... I thought - hey, when I'm all done - maybe I'll PRINT myself up a better idler wheel, with a nice concave surface to prevent the potential filament popping off sideways. which is the reason some folks do the double wide.

just a thought - I don't have a printer yet, so it's all just thoughts and dreams.

EDIT (As of today, Jun 9th, I have decided/agreed that Charle's Pax's Paxtruder, at least the element that puts pressure on the pinch wheel, is TOTALLY superior to the idler wheel - which NEVER worked for me)

Back in Business.... after a few months down...

OK, so I lost my hard drive - WAY back in Feb.
I got busy with work - and just didn't have a lot of time.

Waited, apparently, long enough that the supply hiccup is no longer an issue.

I ordered my Makerbot Cupcake CNC.

I guess I'll post me work on it here.

It will be sporadic, I think - still slammed with work, but excited to get this 3D printer up and running.

As another bonus for waiting - the Cupcake shipped QUICK - not in 8 weeks as was the old lead time - but same week (next day for me actually)

Another bonus is the heated build platform - I can't wait to see how that performs.

so - here is a picture of the first 4 parts I've constructed for my Plastruder MK-4. I still need to order the MK-5 pinch wheel... looks WAY better out of stainless, and they claim about a 100% improvement in pulling strength.


... ok - Clockwise from upper left - Big Dino, Wierd Dino, Idler Wheel, and Heated Barrel (no shorts, and all seems ok)...

BRIEF POST!

On Friday Feb 26th, at about NOON! My Seagate ST3500320AS Main System HDD decided to go belly up. Yes, I've found the firmware patch and applied it, no it's not bricked - well I THINK it's not... Bios sees it, but it's got bad blocks and the Seatools for Dos diagnostics says "SMART Tripped" - return for exchange using diagnostic code DDBLAHBLAH... YAY! >> Grumble <<

Anyway, long story short - hard drive died, and the last month's work on reprap is well only remaining in my brain and on GOOGLE DOCS etc - oh how I am loving that right now.

So - will start posting whenever I can. I keep telling myself "at least my brain didn't crash" (yes, knocking on wood right now)

Hardware: Just ordered my ball bearing kit...

Just ordered my ball bearings kit from www.VXB.com

They are AWESOME! processed and shipped same day, and have excellent pricing. Since I'm not going to be redesigning the whole mendel from scratch now - which would actually be a waste of time that could be spent PRINTING things - I decided to order the reprap kit from VXB. Sure the 624s are about $1 /ea and there's 48 of em in the mendel build, which is about 0.60/ea more than the 608s if you buy in a lot of 100 pcs. but they are much smaller and here's the big thing. 608s have an ID of 8mm... M8 bolts aren't cheap. you're better off spending $0.60 more per bearing and using M4s, than if you purchase the 608s and having to use expensive bolts.

Still - for things like hobbing an extruder bolt, and other potential uses (home brew micro lathe anyone?) I picked up a set of 16 extra 608s. never hurts to have cool hardware lying around when you have a brilliant idea.

so that should arrive early next week - probably right about the time I'll get a big project at work and won't be able to touch anything.

... next, I'm planning on placing my order at Mcmaster tomorrow to pick up some of the other hardware, studding, and bar stock.

Probably will try and put together a Mouser order too - more than one project going on that could use some parts! but that's another topic altogether.

Electronics: Phase 1, procure electronics.... #@#$%^&

Everything is out of stock EVERYWHERE, so I picked up an Arduino Mega (Makerbot.com says that's the platform their moving toward anyway, so yeah, by the time I figure everything out the WILL... right?... have firmware compatible with the Arduino Mega!... hopefully anyway... not to worry though - the firmware is not horribly complex, so if I have to hack it together for myself, I will.

Also picked up 4 - NEMA 17 Stepper motors from www.TrossenRobotics.com
Also picked up 4 - EasyDriver Stepper Motor Controllers from the same - they are the ones made by sparkfun (VERY easy to use)

Once I have a hardware platform up and running, I'm probably going to pick up a couple of Arduino Pro Mini to use for the controllers. 1) they are based on the ATMega328, so pleanty of RAM for a MOBO and Extruder controller and 2) they are FRIGGIN CUTE AS HELL!

In all, my mobo with steppers and extruder controller with stepper will be smaller than the makerbot's mobo and extruder without stepper controllers. (bothacker has built a Seeeduino shield and is using the same stepper drivers as I am... so this is along the same lines I'm working toward)

that's it for now - will keep posting my progress.

This shall be a journal of the research and building of my rapid prototyping robot...

Like many who have come before me, I will document the experience of building my very own 3D printer. It's a very exciting time we live in, where we can not only build a thing that can create physical objects we can interact with, but in fact it can create copies of many of it's own parts. I was skeptical last year when I first happened upon reprap.org. it reminded me of the "build your own hovercraft" that was the regular last page ad in popular science - no I NEVER saw one of those things around. I discounted it as pipe dreaming!

Well, I was wrong. I have seen a Darwin printing in person. I have seen hundreds of videos of things being built. I am now, actually, confident I will have my very own 3D printer within the next month or so - otherwise it will be a much longer time - since I will be heading to the bay area for a month! (I'm hoping to bring a finished, working, 3D printer with me - to show off I guess.

A little bit of background here.

In January, I revisited the reprap.org web site, and makerbot.com since I had seen them in wired magazine. Finally some credibility to the whole thing. It only took about an hour or so and I was convinced I would have one of my own.

After a few more days of browsing and researching, becoming increasingly overwhelmed by the enormous number of directions and general over abundance of information, none of which could easily be discerned as "current and viable", I did what I tend to do - I decided to design my own - I'd leverage all that had come before me, and I'd build a repstrap of sorts, perhaps a McWire type - but nicer looking or whatever.

I also realized I'd have to spend some time experimenting with implementations of drive mechanisms. I am no expert on these types of things - well I know a lot more now than I did a month ago...

I actually asked my mom to send me all my old Lego (THANK YOU FOR NOT THROWING THEM AWAY!!! Golly they're expensive now :) I built a number of transport mechanism contraptions with them to figure out how to use the stepper motors and figure things out about using a lead screw (tooo slow) and how a cable drive really is a better way to go FAST anyway - posted on youtube if you wanna see them.

http://www.youtube.com/user/cakeller98

Anyway - enough babbling. after several experiments, I realized that, for a reprap style 3D printer - that's efficient, and fast - mendel's basic design is the way I'll be wanting to go. I don't have access to a rapid prototyper at least not enough for ALL the mendel parts. They estimate 50-60 hours worth of printing to get all the parts. Andres Huertas has the first Darwin (I know of) in the area that's actually printing. He said he could help out a bit - but really, he's just getting started, so asking a favor on that magnitiude would require a LOT of bear and pizza. Beside, where's the challenge in doing things the way everyone else did!?!?

So I'll set out to build a mendelbot-repstrap. Let's see how it goes!