/diy/ - Do It Yourself

I realize I'd have to put some diagonal supports as well, but I just didn't have time to model it correctly yet lol. Also, sorry for my english, it's not my first language

Have you ever seen a swingset? Make it an a-frame like one of those and you can build it out of normal materials like a 3/4" dowel, instead of needing a space age carbon fiber nanocomposite to make that tron walker without flexing and/or falling over.

>>2423367
That's a good suggestion, but I would need really long dowel rods and it would wobble around a lot (or it would be way too heavy and expensive if I used metal rods). Also keep in mind that it needs to be on top of a table, and the projector needs to be hanged in the middle of it.

With that in mind, the material is still a problem. The structure you propose would be a great solution if I could make it a solid mount or if I could rely on the table structure to hold it, but it needs to be dismantled for transport and it needs to be adjustable to fit a different table if needed (yeah, that might be a big complication, but I'd like to try and find a solution that accommodates those parameters if possible).

I could get a solid enough structure with 4 a-frames (2 on the table ends and 2 on each side of the projector) maybe, but it wouldn't be very efficient and it might affect the projection on the table.

And lastly, just to clarify, budget wouldn't be a problem if I knew it would be a final solution, but the structure you propose still doesn't convince me enough to risk buying all the materials and hang a projector that might end up in the trash if the mount fails. Thanks for taking the time, I really appreciate it and I'll keep your suggestions in mind!

>>2423335
what kind of school wont let you mount to the ceiling? i call bullshit

Look up gantry crane structure and mount with c clamps to table. Fucking useless zoomers

>>2423335
PVC pipe and fittings are cheap and can be made into a mixed structure where some are glued and some not.

>>2423413
The schools where you live let you drill holes on the ceiling? That must be nice. In any case, where I live the college buildings are public property and I'd need a permit to do something like that which is kinda impossible to get. Thanks tho.

>>2423416
>Fucking useless zoomers
Your suggestion is basically the same as the a-frames problem and I've already responded why that wouldn't be reliable. I'd have to either use materials that are too heavy for a table mount or too wobbly for that height. In any case, thanks again for the suggestion. Also, calling a college student useless is kinda dumb, I'm learning how to do stuff, and the mount I'm attempting is pretty much a new concept, I haven't seen a projector mounted like this anywhere, except those little projectors that have no problem being mounted on a single arm with a C clamp (not my case, it would definitely collapse).

>>2423453
That was my first intention for the build, but they would probably wobble and if someone bumps it the table will go to hell lol. But now that you mention it, I could fill the PVC pipes with something to make it more stable. I'll look it up and see what I find. I'll also revise the structure I have right now with the suggestions people made before, I'll post here if I get a structure that convinces me enough. Thank you!

>>2423387
>it would be way too heavy and expensive if I used metal rods

Can I ask why you are determined to attach this to a table rather than using a steady tripod? Will you be taking the table with you, or does it need to attach to whatever random table they have? What is live "video mapping", and do you have to use a projector to do it? Or do you just need a large horizontal display surface ( like a LED screen )? Have you looked at using a jib crane? Why do you have to use a heavy projector?

>>2423536

Thanks for the reply, I'll try to answer everything in a way that makes sense.

>why you are determined to attach this to a table rather than using a steady tripod?

A tripod wouldn't be viable because it's supposed to be mounted on a classroom for a public presentation, with people coming and going. A 2 meters tripod wouldn't work on top of a table and a tripod taller than 3 meters (to account for the table's height) just wouln't hold the projector steady even without anyone bumping into it.

>does it need to attach to whatever random table they have?

It needs to attach to whatever random table I get if possible. I could bring my own table but it would be way more interesting to mount it on site (and also save me the transport cost lmao).

>What is live "video mapping"

Video mapping (also called projection mapping) is a technique to project onto objects instead of a screen. In my case, I'll be making an augmented reality tabletop game.

>do you have to use a projector to do it?

I have to use a projector because the assignment is to use video mapping (which requires a projector) to make an interactive presentation with simulated physics.

>Have you looked at using a jib crane?

And a jib crane still has the problem of stability when mounted on a table, unless I could drill onto the table to attach it. I'm trying to avoid any permanent mounts.

>Why do you have to use a heavy projector?

Basically because it has to be a decent projector. If I use a small and light projector it might not be visible enough. We won't get a completely dark room to mount it.

I've modelled a new possible structure using a-frames. The problem is that I can't imagine it being sturdy enoguh at a 2 meters height over a table. I might get a better support from the table if I put weight on it, but still if the structure wobbles it's very likely that the projector will fall.

From the suggestions made, I thought about building it from PVC pipes, filling the bottom pipe with concrete and using clamps to hold it onto the table. The top rods would probably be dowels.

Is there a chance that this works? What's the chance of it failing? Is there any other material I could use that would help me with it? Thanks!

>>2423546
>a tripod taller than 3 meters (to account for the table's height) just wouldn't hold the projector steady

I have a hard time believing this, but I'm assuming you have tested it.

>a jib crane still has the problem of stability
You don't mount a jib crane on the table, you mount it next to the table. They are stable enough for video cameras.

How large does your project area need to be, and what is the necessary height of the projector?

>>2423555
What you are doing is making the stability of the projector dependent on the table. Unless you have a concrete table, that will almost always be less sturdy than just continuing the A-frame all the way to the ground. I'm not sure why you think an A-frame isn't sturdy enough.

>>2423557
>What you are doing is making the stability of the projector dependent on the table
Yeah, that's the big issue here. Would a 3 meter a-frame made out of dowel or PVC be enough to hold it? Because if it is, I'll just mount it on the floor, I haven´t done anything similar (out of those materials), so I'm not sure about it.

>I have a hard time believing this, but I'm assuming you have tested it.
I haven't tested it on an expensive profesional tripod (which is kinda out of reach for this project), but I've tested it on common camera tripods and projector screen mounts. Anything over 2 meters needs a huge tripod and a sturdy metal pipe as the main column (sorry, I don't know the english term for the vertical rod of it lmao). That would need too much space and would leave the projector far from the table.

>How large does your project area need to be, and what is the necessary height of the projector?
I really don't have a defined project area, but about 1 meter, which means having the projector at a 2 meters height.

Maybe a jib crane made out of wood solves this? But again, a 3 meter high wooden structure wouldn't be very movable.

Sorry if I'm being annoying with all these things I keep bringing up, I'm hoping for an ideal situation that might not be possible but I'll go lowering my expectations as I get arguments about why they don't work.

Again, I haven't seen any mounts that accommodate my idea, so it's completely valid to tell me that I'm just being dumb and it's not possible. I'd just like to know why so I can learn in the process.

Are you already married to a particular projector? consider a short throw projector model that is just sitting on an shelf next to the table. Incline it downwards with a little ramp, and it will have some fine tuning menu to correct the picture to very near a rectangle.

>>2423575

Why use dowels or PVC? Can't you just get 2"x12' studs in your country? you're making the same structure as a gantry or sawhorse just bigger.
theyre strong enough for carpenters and machinists to trust them to hold literal tons of weight. Don't use stupid 3d printed joints, you dont need them. Use bolts, nails and screws and glue.

>>2423586
>you're making the same structure as a gantry or sawhorse just bigger
Except that to make the exact same structure I'd need it to be a lot bigger, because of the height (it would need additional support to be sturdy). I agree on the bolts and nails part, the 3D printed joints thing would've been just a complementary support for them.

>Can't you just get 2"x12' studs in your country?
I could, but it would be way too expensive to just do it as a test (also I'm assuming it'd be mounted from the floor which also makes it hard to transport). I'd need to plan a structure that ensures a good support.

>>2423582
>Are you already married to a particular projector?
Basically yeah. I already have a projector and it isn't worth it getting another one. Also the mount you're proposing would be great if it were going to be on an empty table, but since it's meant to be for projection mapping the angle shouldn't create shadows from objects placed on the table.

>>2423555
You really need a table?
You cant project it into the floor?

>>2423335
Use one of these things and proyect it into the floor.
If you want to be "nicer" tape some white cloth to the floor.

>>2423615
>Use one of these things
Indoors on a classroom? I might be able to assemble it, but getting it to the 2 meters height I need would be impossible. Even more so if I wanted to project it on a table.

>tape some white cloth to the floor
It won't be projected onto a screen or the table itself either. The projection will only affect the game pieces.

>>2423644
Those things are already like 2 meters high. You will only need to add like 70 centimeters or whatever the table height.

>>2423335
They sell these, google "artograph projector stands". They've been around years. They're cheaper than the raw materials for your typical /DIY over-complicated, over engineered solution.

>>2423644
You are stupid or what?
Those things are already like 2 meters high, unless you expect to attach the projector to the bottom of the post you only need to add like 70 centimeters or whatever the table height is. Or just place it on top of other tables, and there you go.
I know you want to over complicate your life to impress your teachers, but dont do that, teachers will look at you like a weirdo, teachers tend to like simple, clever solutions

>>2423665
>They're cheaper than the raw materials for your typical /DIY over-complicated, over engineered solution.
Yeah but a stand like that is impossible to mount at the height I'd need. It's meant for a different type of projector. I might be able to use something like that mounted onto a tall stool or something like that (kind of a small wood tower to boost it's height). I don't know how I'd keep it stable but maybe some weights on the base would be enough. I'll take some measurements next time I go to class to see if it would work. Thank you!

>>2423671
>You are stupid or what?
The insults are really not necesary.

>Those things are already like 2 meters high
Yeah, but the structure has a rod going up an extra 60cm (50-80 depending on the model). That's 2,6 meters, plus another 60cm for the table (assuming I'm using a small one) for a total of 3,2 meters. A common classroom roof in my school is about 3 meters (maybe even less). That just won't work. I really appreciate the effort to explain it tho.

>I know you want to over complicate your life to impress your teachers, but dont do that, teachers will look at you like a weirdo, teachers tend to like simple, clever solutions
It's not about over complicating to impress. It's more about the mount being part of the presentation (as it should be a simulation for a real job). I don't go to college to make my teachers happy, I do it to challenge myself and learn in the process.

Over complicating implies that there's a simpler way of doing it. The simpler ways that came up so far would affect the quality and even the nature of the presentation. That's not a solution, that's a hack at most.

Again, I really appreciate the feedback and even the negative comments as long as they're explaining why my idea is stupid or not possible. Thanks!

>>2423688
Oh, you're autistic, I didn't see your autism updates for a ridiculously and needlessly tall mount. Which you're not going to do, anyway. My bad.

PUT IT ON THE GROUND.
Mounting to the Table complicates everything. You have to think about the rigidity of the table and about people bumping the table, the ground is easier.
If you don't want to buy a prefabbed solution, build an A frame. If you want to be able to disassemble it, wood is a bad idea, I'd use Steel tubing , weld the side structures and the middle Structure separately and bolt it together on site.
Won't be cheap though

>>2423710
>Which you're not going to do, anyway
If I end up not building it, it'll be because someone came up with an actual simpler sollution. In any case, the results will be posted here when I have it.

>>2423714
>the ground is easier.
Yeah, for an A frame it's a lot easier. So far this might be the best option I have.

>Won't be cheap though
Yeah, but it's a very feasible and not too complicated solution. I'll consider it as a last resource if I don't find another solution in a day or two. Thank you!

If anyone has any other ideas I'd really appreciate it.

>>2423688
>the structure has a rod going up an extra 60cm

Well, remove the rod.
Are you studying medicine, law or something like that?

youre not gonna 'rig' this

get a sheet or two of plywood and make a decently sold gantry with wide planar posts

>>2423527
>permit
unlikely, go ask for permission

Apart from the "reinventing-the-wheel"-thing with the frame-geometry: Has threaded steel piping + fittings (the plumbing stuff) already been discussed? Easy to get, easy to transport/assemble/customize, quite sturdy if 3/4"- or 1"-pipes, still "cheap"/affordable (at least in comparison to proffesional stage rigging) and can be put on a table as well as directly on the ground.

>>2423740
>Well, remove the rod.
For someone who goes around insulting people about their intelligence your comment is very surprising. In any case, there are some of those that come without the rod, but they're hard to find and expensive (not that the ones with the rod are any cheaper). I'd rather build a stronger and cheaper metal structure myself.

>>2423877
>get a sheet or two of plywood and make a decently sold gantry with wide planar posts
That idea is starting to make its way into my head, painfully and slowly as I forget about my dreams lmao. I'd probably use some steel pipes tho. Thank you!

>unlikely, go ask for permission
I literally had to fill a form and leave my signature to get a table on the hallway for a couple of hours the other day. Also even the teachers said that getting permission to mount stuff on a wall or ceiling wouldn't be very feasible. It's not that easy lmao. I appreciate the encouragement.

>>2423891
>Has threaded steel piping + fittings (the plumbing stuff) already been discussed?
Someone suggested steel piping for the mount. I already had a look at prices and it would be affordable. It solves most of the issues, but I would still have to mount it on the floor because any movements on the table would cause the heavy structure to collapse or even break/flip the table itself.

Mounting it on the floor with any of the structures that you guys proposed is probably the best option here. I wanted to make something different, but I guess there's a reason why no one does it that way lmao. In any case, thanks for all the suggestions and I'm still open for ideas and discussions about it. I probably won't even start getting the materials until next week (I have a couple of deadlines and an exam coming up). I'll post a few designs for a ground mount when I get the chance to model them, I'd really like some opinions before I make a final decision.

>>2423335
just build a FTIR (frustrated total internal reflection) table. it also acts as a touch screen. the software is open source, you just need to mount a webcam next to the projector to pick up touch inputs. a thick sheet of acrylic with an opaque back projection screen like a sheet of vinyl treated with a compliance layer made of silicon applied to it. IR leds lining the edge of the acrylic glass shine ir light into it, when someone touches the screen, ir light bouncing around inside the glass gets reflected by your finger touching the glass out of it, so it gets picked up by the webcam as trackable blobs of light. you could build this into a box, the projector would be hidden away inside the box since its a back projection system, and hands would not cast shadows onto the table as they interact with it. it has a low center of gravity and wont topple over or wobble around. you can additionally use 2 mirrors to bounce the image twice to increase focusing distance, to allow even larger projection surfaces. ive seen ones half the size of a ping pong table

these dj setups work the same way , but its also easy to DIY into a enclosed box https://www.youtube.com/watch?v=OVMmmwginGw

https://www.youtube.com/watch?v=Cxi3dzYvOn4

https://www.youtube.com/watch?v=mB9_Tut-WG8

>>2424119
That's a really cool idea, and I've seen a few examples like that in class. The problem there is that the projection doesn't map onto anything, it's just a screen. I need to map the projection onto real world objects for the assignment.

Thank you so much for the explanation and the videos! It's some great information for another similar project, you got me interested in attempting a build like that lol. I really like this kind of things.

>>2424135
ah, you do projection mapping, i see. i thought you meant a real map at first

Update: I've come up with another solution that might work. It would affect the presentation so I'm still not sure about it but it's an option. It would be safer and a lot easier than building a metal frame for the projector.

The idea is to mount the projector in between two tables, then using a mounted mirror to reflect the projected image onto the table. The mirror would only need to be lifted about 1 meter instead of 2. That (and the distribution of the weight) should allow for it to be mounted on the tables and I suppose it'll be somewhat stable. The structure would be made out of wood, I might consider steel pipes depending on the weight of the mirror, but building a prototype out of wood would be cheap so I might give it a try.

Also the projector (except the lens) and the gap between the tables would be covered, so that space would still be used to project.

And just to clarify, I've already tested it by holding a mirror on top of the projector and it seems to work great. I'd just need to get a mirror with the exact size (or a bigger one and cut it) to test the weight and see what I can use for the mount.

Again, any opinions would be appreciated!

>>2424724
dude
make something beautiful and simple with good birch finished plywood
for all this shit talking you havent even mentioned once how your projector can be mounted

Am I missing something here? Why can't you just do this?

>>2425302
because those are just pixels my man

>>2425262
>for all this shit talking you havent even mentioned once how your projector can be mounted
In the mirror example i'd just put it on a stool lmao it's not that hard. Any other mounts would require a mount plate that I already have and some screws.

>make something beautiful and simple with good birch finished plywood
That's the idea here, any wood strips would be strong enough to hold the mirror in place. Thanks for the suggestion.

>>2425302
>Why can't you just do this?
Well, because a projector doesn't hang from thin air basically? As I already explained I can't mount stuff to the ceiling, which limits my options a lot. I'd be happy to do it if I could, I even have the mount for that.

Now lastly for a general update: I think I'm almost decided about the mirror mount, I'll consult with my teachers on thursday to hear their opinions but I think it'll work.

I'll post an update soon, I have been busy with exams lately. Thanks for all the suggestions.

>>2426948
>Well, because a projector doesn't hang from thin air basically?
Can you not see the color red or something?

>>2426997
Are those red lines supposed to be supports? Have you ever mounted anything onto a table? The slightest bump would tear that appart or make it fall off, even if it's made out of steel pipes as someone suggested. It's supposed to be 2 meters above the table, and I can't nail/screw it to the table. I don't think clamps would hold it in place, it would be way too heavy and it would easily turn the table over if someone bumps it.

>>2427069
>it would be way too heavy and it would easily turn the table over if someone bumps it
The same would be true for every other design you've posted, only probably less so in this case. A pyramid is a very stable shape.

>>2427076
That's exactly why I haven't built or decided on any design yet and why I'm asking for help. What you proposed isn't a pyramid, it's just a tripod with an extra leg. In any case, no matter how stable the shape is, with that build if (when) the table gets bumped it'll flip over.

>>2423335
What kind of retarded college let you in when you cant even figure out elementary school bullshit like this

>>2427091
>it's just a tripod with an extra leg.
That's a pyramid.

I thought I posted about this, but maybe it didn’t go through. I think you are going about this the wrong way. You should put together an MVP minimum viable product, and then iterate. Maybe you have done this already, but I suspect you have not.

Before you go any further, you should hang this projector from the ceiling ( or a ladder or whatever )pointed down and test the basics. How dark does the room have to be. How much jostling ruins the experience. Does the projector overheat when rotated at that angle. Etc. is it even an interesting experience for people?

The stand is arguably the least Important part of this entire project.

What about something akin to a portable basketball hoop, or standing lamp? Free stands from the table, stability is dependant on putting enough weight in the base. Would have thought good PVC piping set into a bucket of cement would do the job if you're making the thing? I presume it doesn't have to be adjustable because you can just focus the projector to fit the table?

>shitty pic rel

>>2427092
>you cant even figure out
I can, I know simpler ways of doing it, but that would make for a shitty presentation. That's the whole point. At least take a moment to read before calling someone a retard.

>>2427098
>That's a pyramid.
"A pyramid is a 3D polyhedron with the base of a polygon along with three or more triangle-shaped faces that meet at a point above the base." A polyhedron has faces, not just edges. So does a pyramid. So no, the lateral edges of a pyramid are not a pyramid.

>>2427139
>The stand is arguably the least Important part of this entire project.
The rest of the project is being work on separately. The projector overheating isn't a problem with mine at least. The light of the rooms has already been tested and the presentation will be done on a room that allows for even a less powerful projector than mine. The stand is something everyone else is overlooking or avoiding by choosing different projection angles (which I really don't want to lol). Thank you for your suggestions!

>>2427157
>What about something akin to a portable basketball hoop, or standing lamp?
That was the first idea someone suggested to me. The problem there would be transport. It would probably work great, but if I have to get that thing to a second floor I'll be in a problem. Thanks for the suggestion!

have you ever heard of a mirror op?

>>2427512
this put the weight at the ground, you want it portable and stable do not make it top heavy.

>>2427531
Yeah, just hang a ~40" mirror above people's heads instead. Much safer.

>>2427589
what is curvature.
convex should work

>>2423335

a banner stand is the thing you want.
it folds all up into a small area so you just sling it o'er your shoulder and walk away with it

>>2427646
>banner stand
Never used one, but it seems to have a complicated structure which would obstruct the projection.

>>2427512
I've literally posted about using a mirror. It's not without complication, but it's a solution that would still be nice for a presentation.

>>2427589
It's actually a lot safer than putting a 3 meters metal rod over their heads. If the mirror falls (which is unlikely since it'll have more than enough space to even be moved) it wouldn't be even near to anyone's head. I could put some thick blankets on the side of the tables just in case, but I don't even think that would be necessary.

>>2427531
>this put the weight at the ground
You mean the weight of the projector? In that case you're right. The mirror would still be mounted on the table, but it shouldn't be a problem as it would have a better distribution.

>>2427628
I actually didn't think about that. It's a really nice idea! Thanks