User talk:Another W.Smith

WHY IT UIS GOING TO TAKE ME A WHILE TO SAVE UP THE CASH FOR A PRINTER (and why you should consider doing it too)

My first, still-non-working printer is a half-finished Makerbot Cupcake, unfortunately inherited when a good friend died of a horrible cancer.

I'll be working to try to get it working, because I need a spare self-destruct gear for my RO-19 Teletype (as used for about 60 years by Associated Press and United Press/International News Service) With a 1/3 hp motor in the base, and what looks like an old typewriter above, any kind of jam in the keys would leave behind nothing but a twisted wreck of keys and bars if it weren't for a phenolic gear in the path between the motor and delicate machine. So ... yep, made an entire newsroom smell of burning formalin when they went, but saved thousands of 1940$$ worth of gear. Needless to say they're out of production.

The second reason is (and I know I'll blow the spelling, is to reproduce the Antikytora machine, a re-Roman Empire orrey capable of keeping three calenders in synch, predicting solar and lunar eclipses (but not whether it will be visible in your area) and the four event cycle leading to the Olympic games.

That's when I knew I'd have to build my own - because I'm not into hand-cutting brass gears, nor do I like anything on the market, machinewise.

WHY? You're all trying to build something that should be capable of repeatedly building accurate copies of gears, with paper-thin z-layers.

The big Point of Failure: Everyone is trying to build towards this kind of accuracy with hardware-store accurate threaded rot, and plastic connectors where industry uses steel. That's the way to go, let it shake andleave things loose tio compensate for bad sloppy equipment.

AFTER speaking with reps from several companies selling parts needed for our building lists, I realized,my concept of a rock-steady all metal (no plastic connectors or plastic supporting hollow tubes holding the YZ mechanism up there, and the drivers, etc.

It'll cost $less than $2K, not by much but: 1- dump the hardware store threads for hyper-accurate ball screws: Nuts (which attach to moving XYZ platforms "pre-loaded" with precision ball bearings matching the screws) and screws cut to fit exactly that particular set of ball bearings. Hold one end with the stepper and a "pillow block support, and the far end with a good quality bearing cap. Only problem is they can range up to $250 per for a 14"cubed machine - but YOU ONLY NEED FOUR. Build your frame out of 40 mm Al extrusions, maybe using 20 on the YZ arm (see Bukobot design for where I'm starting from and where I'm heading. Also NO belts,synchromesh wire, or anything else. Bolt proper supports and slides on your system, as accurate as ball screws (now this doesn't mean your YZ riser on the firm gantry might have a secondary support from nylon bearing wheels used to cut the tension on a pair of ball-screws, seating them between carriage and grooves in the gantry posts.

Too heavy for $15 synchros - probably - you are going to need on a 14" square X platform to move kilos of material around, and you'll want your other synchros very well made, and set at .9-degree steps.

Unless you are going to use precision shafts, forget the tubes supporting the y-slide of your extruders. replace w/20mm extrusions carrying a light aluminum carrier back and forth - OH THE WORST MATERIAL - No WOOD anywhere - unless you want to rebuild the whole carefully-aligned wooden structure every time the relative humidity changes.

And invest, if need be in either time adapting software, especially slicers, or money in prefab'd stuff.

Oh, <btw> the machine will be a lot slower than what's on the market today - you an only push so hard on a ball screw, and your steppers are going to be making at least twice as many steps. So get a cheap laptop with a camera, and a few extra smoke detectors, and run the machine at night - watching it on another computer in the bedroom, that comes on if something goes wrong. So what, you use robotic machines because they can work 24/7 on their own. Perfect precision output, with accuracies equalling powder machines or liquid monomar machines are possible - if you just use the right parts.