Hi,

This is a rebuild of a standard 15" hass projector I built a couple of years ago. It's been my intention ever since to re-build it as a vertical projector, and I'm finally getting around to it. What we have here are a couple of renderings of the enclosure plus some screenshots of the design as it currently stands in Solidworks. (Please ignore the floating objects in a couple of renderings - don't know what's going on there!). Nothing's been built yet, but I hope to get started in the next couple of days. Incidentally one thing that probably isn't clear is that there'll be castors on the bottom which will lift the whole thing a couple of inches off the ground, allowing air to escape from the bottom.

Suggestions appreciated! I'm currently trying to decide on a colour scheme. Choices are while acrylic with pine or similar light-coloured wood-vaneered MDF sides, or black acrylic with some kind of black lacquer on the sides. The black's my favourite I think, but I've no idea how to do a convincing black lacquer on the sides - that's a current area of research. One other thing I'd like input on is the choice of materials for the area round the bulb. I would like to use ply for all these elements, but I'm not sure how it'll respond to the heat. The safe choice I guess is MDF but I hate working with the stuff.

Any way, here we are:

Another pic

And another.

Incidentally the red thing on the back is a 24x2 LCD display which is connected to a PIC-powered controller I built for the last projector. It keeps an eye on the temperature and keeps the fans on till it's cool after switch off. It also retracts the lens after switch off, and moves it to its previous position on power up.

Produced a few parts last week. Hope to get a few days next week to get properly stuck in and make the rest of the internals. More soon!

More progress:

Some of the metal part for the bulb adjustment mechanism:



.

Inner enclosure:

And the adjustment mechanism in context:

Fresnel and LCD frames:

It's looking pretty sexy. I'm really envious of those of you who have access to CNC machines and the like.
Someday.... when I win the lottery...

Here's another pic of the bulb adjustment mechanism. The square bit holds the light socket, and has four bolts which are secured in the larger right angle frame. By adjusting the bolts in and out the bulb position and alignment can be adjusted. You can see this all assembled in one of the earlier pictures of the base.

Problems...

I've made quite a bit of progress in construction, pics of which I'll post later. But I assembled everything today to give it a test run and ran into a big problem. Basically the centre of the image is fine - in focus, the right way round, etc. But all you can see is the centre circle of the image - everything else is obscured. I tried removing all the focusing mechanism and holding the triplet in my hand, moving it back and forward -- same result. I also tried moving the mirror up an additional 50mm or so - again same result. The attached pic explains it better (incidentally in the picture you can see the focus mechanism still in place, but as I said I experimented with it removed too).

I'll post a proper solidworks pic of the opics set up shortly, but basically I've mimicked the setup you can see here in terms of angles etc:Diagram with angles

Anyway, I have no idea what's going on - any help is really appreciated!

Have you checked the fresnel lens? The 'rough' side should face each other with the LCD sandwiched in the centre.

Just curious what FL of the fresnel lens you are using?

Nice build, did you use CNC to cut your parts?

So, you have both of your fresnels installed and the image is what you are showing?

peter cyt: Thanks for the mega-quick reply. I was just about to call it a day (week actually since that's the next time I'll get to experiment) and I thought I'd do a quick check to see if anyone had a solution. Anyway, ran down to the workshop, flipped the fresnels round, and it works. Phew! Thought I'd made some huge design mistake.

Here's a quick shot of a youtube trailer (bear in mind this is moving footage, no tripod, plus the optics aren't adjusted, I haven't built the outer enclosure so there's loads of light-leakage, and there's no reflector or pre-condenser lens).

Yes, all CNC'ed. In fact you can just make out a shot of the CNC machine in front of the screen in the pic above, along with the old donor haas.

More pics of the projector below. Now to build the outside... Incidentally does anyone know anything about laquering? I want to make the exterior out of MDF and then achieve a nice reflective black finish - something I know nothing about. Any pointers would be great.

One more. Incidentally I should mention the inspiration for the design is Sculptor's 15" projector - have a look around if you haven't seen it.

Hey that projector looks real good!!, in regards to your painting, im a automotive paint rep. my customers would sand it down quikly with 320grit (edges especially! as they will look "fluffy") if you are able to get primer, coat a few times as you will notice that custom wood soaks it up on the cut edges, sand using 500 grit untill you are happy that its straight! ( as Gloss Black is the worst colour for showing up imperfections!! ) its best to use a 125mm or 150mm round random orbital sander with "hookit discs" as it makes the job so much quicker and flatter! if you dont have access to this tool use dry sand paper and using a sanding block, sand in a "long kriss cross" action as this gives the finish a flat "glass" finish! as they say its all in the prep! once shes ready to color, if you could get a hold of "2 pot/2k gloss black". Our company sells PPG, so a good cheap gloss black is "2k Jet Black and Hardener" I don't know if you have that there in U.K As i live at the bottom of the world called New Zealand! it is a 2 Pot product so please use a vapour/mist mask . Mix product and put it through a spray gun, spray 2 x Med/wet coats let it tack off. spray last coat wet (not wet as in its dripping off like ice cream in the sun!). once it is dry (let it cure overnight to be sure) sand the paint down with 1200-1500 grit ( you are just knocking off the top of the orange peel/dry spray ) then using a buff machine and some cut and polish ( 3m xtra cut 05936 ) cut the panel, when you finish you will have a peice of custom wood that looks like Black Glass! My customer does so many of these as he is a kitchen sprayer and they love his gloss black Kitchens!!! hope this helps, oh.... ive just realized ummmm i was assuming you have a compressor and spray gun!!! hey if you use aerosols you can still achieve a good finish! just do the prep section and the sand the paint down section! and buff!

Hi Roobs,

Thanks for the suggestions. As you guessed - I have no compressor or spray gun!

So, assuming I go the spray can route, I:

1) sand the MDF with 320grit

2) Spray with Primer

3) Sand with 500 grit, preferably with orbital sander

4) Spray two coats (wet...?), let tack dry between coatings (gonna ask you about paints in a moment...)

5) One wet coat

6) Dry overnight

7) Sand with 1200-1500 grit

8) Polish/buff

So... Is that basically right?

Assuming I've got the basic idea, I have a couple of questions:

Paint: These guys mix up custom aerosols (site) - is that the kind of thing I'm after? And do I need to worry about a lacquer at the end? And can you get aerosol primer?

What's a wet coat?!

Umm, I think that's everything for now. Sorry if they're stupid questions - as I said this is new to me.

Thanks for your help!

-Luke

Hey just checked that link for you, yeah you will need a clear lacquer Over top it helps with making it look "Deep and Darker" as putting on a coat of just black,will cause it to look like it has hazing marks on it after you buff it.!
disregard what i said about med/wet coats! as this is more for use with a spray gun! i should do a tutorial on this!
And yes you can get a primer in a aerosol! this is the link to it " http://www.paints4u.com/ProductDetails.aspx?productID=3163 "
be sure to give it a few good coats of primer! cause when you sand it down you dont really want to rub thru!

and No! theres no such thing as stupid Questions!............only stupid answers!

I will have to paint my box gloss black aswell! i should post up pics of it as i go!

just yell out if you need more answers!

hey found the black you can use rather than make up a custom color! http://www.paints4u.com/ProductDetails.aspx?productID=3164
heres the link to the clear http://www.paints4u.com/ProductDetails.aspx?productID=3166

also check out the data sheets on the product for More clearer instructions!

Ok, that all sounds great. Do you have an idea how many cans of each I need? I need to cover a total surface area of around 0.7m^2 - that includes some scrap to practice on.

Thanks again!

Hey Luke not to sure, on aerosol coverage, as different brand paints have different tinter strengths. it may be a case of asking if you can return unopened aerosols. with our aerosols you could cover with two aerosols, of each. hope that helps! hows the progress coming along?

Ok - thanks. I'll ask the supplier if they can offer any advice - failing that I'll buy two of each and see how I get on. In any case I'll find an application for them eventually if some goes unused.

No progress on the structure as yet. I'm mulling over doing without the aluminium strips that currently hold the perspex front and back in place (see renderings!), and instead having them flush with the sides. Basically if the sides turn out well enough it would look pretty cool I think. With a slight redesign I can wait until I've made the sides before having to commit myself to either route, so that's next on the to-do list.

One thing I have been working on is the controller. It's based on a PIC16f887a microcontroller, and it monitors temperature and controls the stepper motor which'll drive the focus mechanism. Plan is it'll note the user-set focus position, then when you flip the off switch it keeps itself powered up (thanks to a relay in parallel with one pole of the power switch which drives the 12v transformer), waits till the projector's cooled sufficiently, then retracts the lens and turns itself off. When you power it back up it'll move the lens to where it'd been previously. I've been hooking up the funky red LCD (see renderings again) and also sorting out control of the fans, so that it can regulate the speed with PWM if they're running quicker then necessary. I've also been contemplating one utterly unnecessary but potentially extremely cool feature (well, to me anyway): Namely using an ultrasonic sensor to automatically focus the projector. The question is what kind of sensor resolution would be sufficient. For ~$25 I can get a sensor with inch resolution, but I'd need to spend ~$50 for cm resolution. It's a question of whether inch resolution would be good enough (to clarify I'm talking about measuring the distance from the front of the projector to the wall). I'm not sure whether the ratio of coolness vs utter superfluous-ness warrants $50 of expenditure.

Anyway - you asked!

I have another question actually - can I do the buffing manually or do I need some kind of power tool for a decent result - can I maybe get something for my drill? Also the cutting solution you mentioned - is that the same kind of thing as T-Cut (I already have some), and do I still want to do this given I'm going the aerosol route?

Thanks again.

hey luke you can do the buffing by hand, but it will take a while!! but it will look soooooo good!!

Ok, cool. I ordered the paint yesterday (went for two cans of each - can always buy more if necessary). Hope to make progress on the enclosure this weekend - will post progress!

remember to use a circular motion when polishishing! and that t cut looks ok, if it still looks a lil dull use a canuba wax after as well!

Progress! Here's what I managed this weekend:

And an in-situ shot. Haven't actually screwed the thing together yet - just made the sides.

And another

Also here's the cyclonic dust extractor I whipped up prior to getting stuck into the MDF. Formerly two Ikea bins. Total cost Ž£3.18 (I already had a broken vacuum cleaner that provided a spare hose and pipes. Seems to work pretty well. You can see the dirt spiralling round the clear bin - very gratifying.

That is totally rad, dude! Been trying myself to come up with a way to build a cyclonic dust extractor. You, once again, make things look too easy... great craftsmanship! I'm curious to see the inside of your cyclonic dust extractor and any baffles that you might have included. Would you mind expanding on this little: how you built it / put it together / would you change anything about it... ??? Is it really as simple as putting two Ikea bins together with the wood top and the spare hose / pipes???

Thanks,

David

Here's some pictures of the construction process

More pics

As you can see I cut the bottom off the white bin, then cut the resulting cone straight down the side. I cut a hole in the bottom for one of the vacuum tubes, and used a wooden cylinder to help secure it. This assembly formed a new top for the white bin. I cut a piece of MDF for the bottom - it sits just inside the red bin. Everything's hot glued into place, and seems pretty robust.

The geometry of the top cone was determined purely by using it's bottom as a new top. It may be that a different angle would produce better results. Certainly it seems to work reasonably well though - after cutting out the sides for the projector the red bin had not insubstantial amount of dust, while the vacuum cleaner bag had only a small amount. Apparently some designs collect pretty much everything, so I may experiment a little more to see if I can improve results.

Incidentally I studied this for inspiration.

If you decide to give this a go one thing to watch out for is that the ribs and base of the bin can be quite brittle - I found keeping the jigsaw at max speed while cutting slowly prevented problems.

Here's the top with the wooden cylinder.

Hi roobs (or anyone else with painting expertise),

I have a couple of paint-related questions:

1) At what stage do a do the buffing - after the black paint, BEFORE the lacquer, or after the lacquer?

2) What kind of cloth do I use to buff?

3) Do I sand my last layer of laquer before buffing, or do I just leave the last coat alone?

Hope that makes sense! Currently preparing the MDF for painting...

Thanks,

-Luke

woohoo!

Progress last weekend:

Did a lot of work preparing the sides. The sides are both made from three pieces (I can't cut a large enough area on my router), and they're joined together by ribs running along each side which will also support the acrylic 'skin' - you can see these in the pictures above. There's a slight lip where each piece meets, and if you press in the centre there's a bit of flex. Obviously this wouldn't do my painted finish any good, so I disassembled the sides, sanded a 2-3 mm chamfer on each piece where the join was, then reassembled the pieces with wood glue between the adjacent edges of the flat pieces. Once that was dry I filled the gap the chamfer produced with car body filler, waited for it to dry then sanded the ridges flat. The attached pic shows the result of all the labour. I also sprayed liberally with polyurethane varnish I've read works great for sealing MDF.

I also found this thread on diyaudio.com detailing how to produces a glass like black finish on MDF. It's worth checking out just for the pictures (not the first one - look further down). But to save trawling through it all, the basic method is: 10-14 layers of primer, 2 coats of colour, 10-14 of lacquer. Then polish! What he details in the first post is the polishing process, not the painting! Apparently the deal with 1k paints is that they need a month to harden before they can be polished, so I plan to get the painting done asap.

Anyway, here's the pic:

And a close up

Also I built this. It's a fan vent for the bottom of the projector, so air can get out but light can't. It's made from 1mm sheet ali. Because I don't have a sheet metal brake I cut the metal along the folding lines with a ball nose cutter on my router, then used my workbench as a kind of improvised metal brake. The gaps I filled with car body filler again, then I sanded it and painted everything black.

Painted:

Work continued this weekend on preparing the sides for painting. To be honest I had actually planned to do all the painting, but I realised I should really finish the aluminium edging and acrylic skin first, which took a lot longer than I had hoped! The plan was the acrylic would be held in place by the aluminium edging. What I realised was that the acrylic was far too stiff to be held in place just by the ali, and it'd have to be screwed in place too. In addition when I started fitting the ali I realised that it was highlighting the slight irregularities in the edge of the MDF (thanks to sanding etc), which aren't usually noticeable to the naked eye.

So I decided to forget about the ali and paint the edges of the mdf black too. This necessitated a whole load of extra preparation - basically I think if I just painted the edge of the mdf it'd soak up tons of paint and look rubbish, so I decided to coat the edges with a thin layer of car body filler to provide an impermeable layer for the paint. At the moment I'm about halfway through the process. Hope to finish it next weekend.

There's nothing to stop me adding the ali later if the painted edges don't work out. I'm open to suggestions on this point!

Here's a pic of the rear acrylic skin fitted (sadly camera batteries died just before I could take a better shot properly showing the glossy shininess of it, but it looks pleasingly like the renderings at the beginning of the thread):

hey that is looking real good!! just got back on to my project, got my first pic on the wall! brother was amazed and nephew and brotherinlaw....and the one opinion that really matters... the wife thought it was a amazing! finally after building it in the lounge as i got no workshop! will be painting it real soon now!
just needs cosmetics done now! in regards to your mdf edges, if you sand them with 500 grit sand paper they get really smooth they dont soak up alot at all!
ill have t send you pics of my box, ive sanded the edges half round and they shouldnt soak up much!