Jim S published a new build:

Read more about this build...

 

I've simplified the build vat and mirror assembly considerably. Here's the original concept:


And here's my newer, simplified version:



The next item on my list is to design the interface between the vertical portion of the machine and the flat projector mount. It doesn't seem like there's an obvious way to connect something to the end of a C-Beam. There are the 2 holes that line up with the stepper motor that I could screw to some angle or cube connectors, or 2 more like it on the front of the end-plate (where a cover plate would attach). Otherwise, I'd have to use a joining plate of some kind and hope that I can hit enough holes in the bracket to make a solid connection. What have others done to attach to the end of a C-Beam?

 

This is what I was hoping would go smoother. Is there a better way to attach to the end of a C-Beam than these methods?

 

Like that, eh?

Seems obvious now I was convinced that it was a puzzle for some reason.

 

I've already got a few of their parts on my list. My mirror holder will use a pair of their 45 degree angle brackets since OpenBuilds doesn't have anything that isn't square. Brackets - 5 Series, Angular Brackets, 135 degree Angle, 2 Slots｜MISUMI｜MISUMI USA

I was scoping out some of their mitered extrusions as braces, too. Plate Brackets｜MISUMI｜MISUMI USA

Thanks, all. I really appreciate the tips and tricks!

 

The design is still coming along nicely.

For those who don't picture what's going on, here's the nickel tour. Basically, the projector will shoot light at a 45 degree mirror to bounce the light upwards into the build vat.


The platform with the mirror and build vat can slide up and down the C-Beam to accommodate projectors of different dimensions.


I designed a subframe under the projector with two adjustable beams so that you can hit the mounting screws on different projectors.
You can also see how the 45 degree angle brackets attach to the lower beam of the vat assembly in this image.


The frame under the projector is attached to the C-Beam with angle connectors on the top and side, and with a joining plate on the bottom.



The joining plate on the bottom will will lay flat because I'm using angle plates of the same thickness in the corners of the sub frame, and I'll just stick rubber pads or something like that onto those plates to clear the screw heads and to give it something to stand on. (side note, I'm surprised that OpenBuilds doesn't sell leveling feet of some kind)



So the next step is to simplify... I overthought and overbuilt the mirror and vat assembly the first time, and now I'm sure that I'm doing the same with the projector subframe. What aspects of the box, the sliding mounting beams, etc could be simplified into a smaller parts count? I want to maintain the universal adjustability, and I don't mind overbuilding it, but I don't want to be ridiculous or overly complicated either.

The other thing that I have to figure out is which places it makes sense to use cast or extruded angle brackets vs the machined aluminum cubes and wedges. Is there a rule of thumb for which joints to use standard vs deluxe connectors on? I have to use the cubes where I've got 3D box corners, but plain old 90's could go either way...

Happy Friday, all. I hope you enjoy a nice weekend!

 

Here are some simpler views of the entire plan.

Isometric

Isometric


Side View

Side View


Front View

Front View


Rear View

Rear View


Top View

Top View


Bottom View

Bottom View

 

Nailed it, yep. DLP has a good black level, much better than LCD in that part of the UV spectrum, and the resin I use from MakerJuice cures between 365nm and 420.
Look up the LittleRP and Muve3D, that'll give you an idea of what's going on here.

My first build was a LittleRP with a $300 Black Friday special Acer projector rated at 3,000 lumens. The minimum projector modifications needed were just for the lense's zoom and focus, and with no other modifications needed I was exposing a layer every 6 or 8 seconds. After getting things up and running, and because I'm good friends with the chemist from MakerJuice, we set up a UV radiometer and started experimenting with other mods like evilc66 mentioned. By removing the UV filter and color wheel, I more than doubled my light output in the UV spectrum and was able to cure layers in 2-3 seconds depending on layer height...

Anyway, at work we use much larger projectors than the consumer grade toy that my LittleRP is built around. We replace them when they go out of warranty, so I've got 4 dual lamp Panasonics in the 6,000+ lumen range (real lumens, too - not the inflated number on the big box brand) so this projector frame is designed with that caliber of light engine in mind. The 'box' shape that the projector mounts to is a square made of 500mm V-slots, if that helps you scale it.

 

Trying to finalize the design and BOM today so that we can start ordering things.

Before I'm committed, maybe in more ways than one, does anyone see glaring errors or obviously over-complicated parts that I should take a second look at? What would you change?

Since the last update, I've figured out a way to add some leveling feet that I can run into an extrusion T-Nut and then tighten with a jam nut to install Table-Top Bases｜MISUMI｜MISUMI USA I've modified the lengths of a few pieces on the Vat holder so that I can order them cut to length in whole millimeters, and I've added a pair of handles in an effort to keep people from grabbing the C-Beam to move the machine.

 

The limitation to continuous printing is more related to the build vat's membrane material than the power of the projector. Each layer that you expose will stick to the vat floor, and most of each layer's print time is actually the mechanical cycle time of raising the build platform to unstick the part, returning it to the right spot for the next layer, and then pausing for a second to let the resin flow and equalize (it's viscous and will bulge the membrane if you go too fast).

The thing that makes CLIP and some of the other continuous printers revolutionary is that they print without sticking the part to the build vat. This allows them to do a continuous pull without all of the rip and dip that the processes before them required. Other continuous machines print top down and submerge the part as it prints instead of pulling it out of the resin. Both techniques raise questions about their viability. Like I mentioned before, the resin is thicker than water - more like motor oil, and there's speculation on whether or not you could run a continuous print without causing resin starvation on parts of a certain surface area.


Anyway, last week ended frantically with an unplanned support call from Chicago, and then I was at the MakerFaire in Detroit all weekend, so I haven't finished the design yet. Hopefully the design will wrap and parts will be ordered this week.

Here're my Detroit MakerFaire pictures, if anyone is interested. The MakerHive - Photos | Facebook The MakerHive is my local makerspace, and I do our social media.

 

There's always next year. I've gone 3 times now, and it's always amazing. It's a great place to bring the kids, too (depending on their age). Hard to go wrong at The Henry Ford.

 

Started ordering parts today. I'm pretty confident that it'll at least fit together the way that it looks on my screen. If there are any gotchas or pitfalls in what I've already created, the parts are individually cheap enough that I might as well find out by starting to build it. Pictures coming soon!

 

Parts are arriving!! I've got a beautiful pile of aluminum on the workbench, and I'm excited to start taking pictures and assembling them. I also bought a tap/drill set with an M5 in it from harbor Freight and some tapping oil, so it's just about time to start turning some allen wrenches.

I did have a quantity mixup on some L brackets and a funny motor that I emailed contact(at)openbuildspartstore.com about yesterday, so hopefully I hear back soon. I've never had a bad experience with OpenBuilds though, so I'm sure they'll respond sometime this week and take really good care of me.

In addition to the OpenBuilds structural parts, I've got a few pieces that were cut to length by Misumi (I want people to be able to build it without special tools or saws), a custom sized mirror from firstsurfacemirror.com, the SeeMeCNC flex-vat and build plate, and the arduino shield from LittleRP. I'll also throw a TMC2100 silent step stick on it, and have been working on the Raspberry Pi NanoDLP image. I'm debating on whether or not it makes sense to add a shutter. Most of the projectors that I intend to use will already have one, but not everybody else's will. I'm trying to find that right balance between being universal and keeping it simple.

I do still need to order my gear reduction plate from OpenBuilds, but they're not available still. Does anybody have the inside scoop on how soon those might become available again? I know that they're working on adding a bearing, but I don't know what the timeline is... Luckily I'll get by without it, but I do like the idea of removing the flexible coupling, doubling my step resolution, and having a big pulley to turn like a knob for manual positioning (don't really need or care about the torque advantage in this application, a Nema23 is overkill to begin with).

Anyway though, hopefully my next post will have some pictures and build stories!

 

That's awesome news, @Mark Carew You guys really are the best!