HELP! I have a junker to rebuild!!

[blissiictrl]

Hi all,

I tried advertising it for sale a while back but I couldn't get rid of it, so here goes.
I bought a Muve DLP a few years ago, a DIY kit, and could never get it to work. It had consistent Z-axis issues where it wouldn't zero properly, the build plate non-stick cover was problematic etc. and I never got further than half a (small!) print finished before it stuck to the vat.

Basically, seeing as I can't get rid of the kit, I decided to either turn it into a CNC mill or 3D printer. I already have a replicator 2, but I want to turn this into something more like a higher build volume printer for prototyping or building (for example) costuming part blanks for moulding, that sort of sized thing. My plan is to build something with a reasonable build area (bigger than the replicator), maybe 350-400mm cubed?

The current list of parts I have available is as follows:

Aluminium Extrusions (all are a Misumi HFS5 profile unless noted otherwise)
2x 240mm
4x 320mm
6x 322mm
2x 360mm
2x 415mm
10x 460mm
2x 312mm (HFTF5-2020 profile, door)
2x 410mm (HFTF5-2200 profile, door)

Microrax:
2x 60mm
2x 100mm
2x 160mm
1x 300mm

Bunch of screws, bolts, nuts, washers etc (arbitrary, I can buy these as needed but most are in M3, M4 and M5, with some M6)

2x M8 threaded rods (I didn't get the chance to measure but I think these are about 3-400mm long iirc)
A bunch of sliding blocks
2x shaft couplings
2x linear motion guides

A bunch of brackets and angles etc.
2x NEMA 17 steppers
Arduino Mega-2560 and RAMPS 1.4
A ton of cabling
Microswitches

Basically if anyone has any ideas they would be greatly appreciated!
I would likely run it similarly to the Makerbot, with a more solidly supported build plate. Possibly supported in all 4 corners, using 2x Z-motors central to each pair of corners (L/R) that utilises a dual-pulley and belt system.

pulley.jpg *excuse the crappy drawing!!

I'm just trying to come up with ideas at this point but realistically I want something with a reasonable build area and am willing to spend a bit extra on electronics or boards to make it work.

Dual extruders would be pretty cool too, but not necessary. The ideal would be to run primarily PLA with a dissolvable support.

[curious aardvark]

you've got enough there to build a decent size delta.
The 10x 460mm extrusions would be fine - use three for height and the 320's for top and bottom pieces.

Whatever you do you'll need a another couple of stepper motors.

[Trakyan]

Since CA will take up the delta camp, I guess I'lll represent cartesian. Both are good choices, but if you need it to be easy to troubleshoot and calibrate cartesian is a winner for me. If you need lots of Z height, deltas are an easier choice to implement. However, if you want lots of XY room then I'd go cartesian, the diagonal rods on a delta get a bit wobbly as they get longer (for more XY room). Deltas also get tell pretty fast, both increasing your XY or Z print areas requires a taller machine and you may not have room for this.

If you do go for a makerbot style cartesian printer with a moving bed, your idea of two leadscrews is great, but do not support it at four corners. Three guide rods at most, any more and you are over constraining and it will be more likely to bind up (and I'm guessing you'd had enough of that already with this DLP?). Two guide rods should be enough, too, as long as you position them at opposite ends of the bed so it's not cantilevered. If you take this last route, make sure you have a driving lead screw on each side or it will also probably bind up.

Depending on how (relatively) small or large you want to go, consider different motion systems. On a relatively small (desktop) machine where the motors would make up the majority of the moving weight on the gantry, try making them stationary like in coreXY or sli3DR. If you're going BIG, and the motors would make up just a small portion of the gantry's weight, don't bother trying to make them stationary. Maybe even go for rack and pinion drive like on some CNC mills. You'll get negligible increase in moving mass in exchange for not having to deal with belt stretch or routing.

[curious aardvark]

Actually I'm going to suggest an I3 cloneas well - check out autowhiz's build from scratch: http://3dprintboard.com/showthread.p...ted-3D-Printer
Awesome build - but only feasible if you already have a 3d printer (or in autowhiz;s case about 6) :-)