BIGGER & more accurate?  

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dm.r
 dm-r
(@dm-r)
New Member

After reading your scores and prices in the Make printoff, I am tempted to order as soon as some anticipated cash gets here. It looks like just what I can use now - and just what I MIGHT be able to use in a major rebuild if you don't get there first.<g>

What follows is spoken from a point of true ignorance - well, at least it seemed like a good idea for slightly more than 3 million of the voters in our Presidential election - I neither like the electoral "winner" of the race, but it seems like a good place to get a discussion going here - regard what I say as based on very limited data - and tell me where I'm wrong, or maybe even right.

There are several projects I have in mind for a printer - and most require a larger build space than ANYTHING on the "hobby" (under, say US$4,000 can do, and none that can do it for anywhere near my income level.

The Prusa *looks* ideal for taking several "simple" (that is, simple until one digs into it) to make a really large printer, say a volume of 1/2 meter in all directions This would require: replacement of the frame and guide/threaded rods with longer ones, possibly replacing the frame itself with modular aluminum (it *looks* like z, and probably x are already moving on high-accuracy bearings - I don't know if the steppers driving them could support such a larger and {see below) modified y system.

The hardest upgrade would probably be in the print table, which might need up to a dozen circular "zones" to keep things at the right temperature during a big build.

(also quality improvements might slow the rate of building further - I've always been the guy who wants to see smaller- and smaller than that - holes in (possibly custom screw-on) nozzle tips on the hot end of things. So it takes two days of feeding in a larger reel of plastic and making sure things are going well - incidentally, I find the price of fiber from ALL sources appalling - a bunch of well-scrubbed soda bottles or cleaned up auto accident remains, an appropriately-bored nozzle on a very basic print head, over a cooled area and a tension-tracked takeup spindle should provide an endless supply of low-grade fiber good enough for initial runs - incidentally, has anybody ever checked out the price of fiber in 100+KG reels? Splitting it up for a large enough group of home-scale printers should (again from a point of TOTAL ignorance) into low-cost fiber. There MUST be some industrial user of, say ABS fiber, who loves to be able to say "made from 90% post-consumer waste - and I've seen what kind of precision weaving thread is made from said pop-bottles, as I once described the process of what they're good for "and if bad taste returns, leisure suits).

The most difficult, accuracy increasing and costly improvement would be 1) getting rid of the accursed, stretchable, slipping plastic toothed tape moving the head and using the same high-quality threaded (possibly ball-race) bars they use to move everything else? They say to me 'look at the accuracy of ink-jet printers' - the best of which are 10 times less accurate than the data my camera's sensor sends.

It WOULD mean the possibility of a counterweight on the opposite side, but would also open the door to two-head printing!

So, challenges, idea, and pointers to attempts and successes are welcome, while I await the cash and the 6-8 week backlog on orders!

dmr

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Posted : 29/12/2016 12:47 am
david.w8
(@david-w8)
Eminent Member

I've had the same thought, at least regarding increasing build volume. Probably the easiest to modify would be the Z-axis, using some aluminum extrusions to build the frame up or just getting a larger one cut somewhere like bigbluesaw.com or any other water jet/laser cutter. Personally I would find even one axis being larger quite useful, but for now I just use the Fortus at work for larger stuff 😉 The Prusa prints look nicer though, and all for only 2% of the cost of the Fortus. Make 3D printing great again.

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Posted : 29/12/2016 3:23 am
david.b14
(@david-b14)
Honorable Member

Some data points for your consideration.

As your print bigger objects all parameters go up exponentially:
- Time to print object
- Success rate
- Probability of breaking the 3D printer
- Cost in terms of material ( strength for different type of filament )

I want to create bigger objects so here is my approach.
- User the MK2 to make parts for bigger things
- Use the shaper origin ( https://shapertools.com/ ) which basically use you as the x and Y stepper motors


http://hackaday.com/2016/08/25/hands-on-the-shaper-origin-a-tool-that-changes-how-we-build/

- Build a larger 3D printer that is optimized for huge 3D parts since the materials will only be around $300, like the one below. You could replace the picture frame with a door frame.

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Posted : 29/12/2016 2:05 pm
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