Austin DIY HT Projects (1 Viewer)

[Jeff Meininger]

I learned two valuable lessons this morning...

1. MDF is heavy.
2. I'm a wimp.

Somewhere between the two 50# bags of sand and going through a stack of MDF sheets, I managed to really, really mess up my back. Really. Holy crapola. Ouch.

 

[Hank Frankenberg]

So, caterpillar, welcome to the rugged manly world of DIY, which requires muscles. Try Hank's universal cure: tequila. Quality tequila. Not the stuff in the plastic bottle on the bottom shelf. You'll be better in no time.

If you really need some help with cutting your MDF, let me know. Don't mess up your back further. I've got a 2-piece aluminum straight edge. Do you have a circular saw?

 

[Brian Bunge]

Jeff,
Welcome to the wonderful world of DIY! BTW, since I'm quitting my day job soon, I'm getting back on my workout program. But building subs and lifting MDF (I know, that's redundant) is a great for simulating deadlifts! Your back and hamstrings will be sore for days! It's called building "functional strength"!
Brian

 

[Hank Frankenberg]

Brian, these young guys are soft these days. Next thing you know, they'll ask me to pick up their MDF at Lowes/Home Depot as well as cut their cabinet pieces for them. Hmmm...another income possibility.

 

[mike_decock]

Speaking of MDF and sand, one of the things I'm really interested in building is a "sandbox". You know, a sand-filled box for resting components on, not something for your children or your cats .
Would any more people be interested in doing something like that at one of our meets?
-Mike...

 

[Jeff Meininger]

I have a tiny car, so I had the Home Depot guys cut the MDF sheet into four 2x4 foot panels so I could get it home. After that point, they became quite easy to handle.

I'll get the sonotube today, too. Then I'll have all of the supplies I need except for the terminal cup. I'll probably just try to find one of those at Radio Shack or tinkertronics.

Hank: I still hope to take you up on your offer to loan me a router / circle jig / jig saw. I promise to take good care of them. I'll only need the jigsaw for as long as it will take me to cut the tube to length.

I bought a 1-1/18" dowel that I want to cut into three equal-length "legs". The jigsaw might work for that, too... but I imagine a tablesaw or radial saw might produce superior results.

Again, Hank, any leftover 20" sonotube (~9 feet) or 3/4" MDF (16 square feet, unless I mess up and need to use extra) is all yours if you want it. I'll even store it for you until you need it, though I'll have to cut the 9-footer into two pieces for it to fit in my garage.

 

[Hank Frankenberg]

Jeff, I think we have a deal. Paul posted above that he is interested in a piece of sonotube. I don't need 9 ft of it, so why don't you send him an e-mail and ask what length he would want and then cut it for him when you get my sabre saw? You can pick up the tools any time - I'll be building a new little sub cube and a couple of monitor cabinets this weekend, but you can borrow my portable router that doesn't have the Jasper jig attached, as well as the masonite large circle jig and the sabre saw. Or, if you want, I could bring the tools to you and help you cut the tube and MDF.

 

[Jeff Meininger]

Hank: once the tube is delivered (anytime now), I'll give you a call.

 

[Jeff Meininger]

First day of sub-building went very well. I got the endcaps to fit in the tube fairly well using the "measure twice, cut as many times as necessary" method. The endcap/plug layers are glued, drying overnight under sandbags. I noticed that there is a gap between the plug and cap on one of them. Just a tiny tiny gap, but it bothers me since I don't know what could be keeping them apart. I noticed too late to do anything about it. Oh well, that cap will have no driver/port holes in it anyway. I might try to peel them apart tomorrow morning. If I succeed, then obviously the bond was weak and I can reglue. If I can't, I'll be satisfied enough after sneaking some glue into the gap with a sheet of paper.

Once I had all of the pieces cut, I did a dry-fit with the cut-to-length tube to see what the finished product would look like. It's gonna be great!!

Tomorrow will be consumed by:

1. Plug/cap gap damage control (above).
2. Routing driver and port holes in bottom endcap.
3. Returning tools (thanks Hank!!).
4. Sanding, priming, and painting.
5. Installing batting.
6. Installing top endcap. (I won't install bottom endcap until I order the driver.)
7. Assembling my base-plate/legs.
8. Trying to find ribbing material (sono sock). Struck out at Hancock and Hobby Lobby. Will try JoAnn tomorrow.

 

[JeffTodd]

Good to hear things are coming together for you. I went through this same process last weekend. I am still waiting for the driver to be delivered. I have yet to prime and paint the caps or install the port. I have it set up in the living room now to see how it fits. It took the place of a small table and it fits the role great! Now I just have to find a way to power it (I guess I got a little gung-ho).

 

[Colin Dunn]

I made a trip to Home Depot today and bought most of the stuff I need to build a movie screen. I thought DIY was supposed to be cheap ... I spent over $150 on materials needed to build the screen. (The edge moldings were fully a third of the cost here. The rest was MDF, paint, and some supplies I needed to control the paint mess.)
Hank: You've got mail...
Everyone: Here is the plan.
I bought a 49"x97" sheet of MDF, along with a 15.5"x97" and a 12"x64.5" section.
These three sections will be joined to form a large rectangle of dimensions 109x64.5.
Along with the MDF, I bought fluted trim moldings (similar to those seen around the inside of Nils Luehrmann's front door):
4 pieces: 3 1/8" x 48 7/8"
2 pieces: 3 1/8" x 57"
6 rosettes 3 3/4" x 3 3/4" (4 in the corners, one at the top center point, one at the bottom center point).
The trim moldings will take up 3.75" space at all edges, yielding a viewable area of 101.5x57 (a 116.4" diagonal screen in a 1.78:1 aspect ratio).
Tomorrow, I will do a "test fit" to make sure my meticulously calculated and measured dimensions really do work. A quick 'n' dirty trial fit of the MDF pieces is promising. Then I will begin to prime and paint the trim, so there will be no black paint splashed onto the screen material.
Oh, and it's about time for me to lay the Parkland sheet flat to prepare it for going onto the MDF...
---
Any suggestions for mounting hardware? I don't want to attach this screen to the wall permanently, but rather use some sort of hook system to hang it in place. The completed screen will probably weigh >100 lbs., so the wall-mounted hooks will need to go into studs. The screen-mounted pieces need to grip the MDF well without penetrating the wood for >1/2" (to avoid puncturing through decorative moldings or screen material).
I may return to the Depot tomorrow to get sandpaper and contact cement, and see what my mounting options are...
I may also get some more MDF cut to create a masking system. I've got plenty of extra black paint that I can use on the additional MDF, so I can matte for 2.35:1 and 1.33:1. (Probably won't bother with other aspect ratios, which are rare.)
A quick set of calculations shows I need:
2 boards of 6 7/8" x 101.5" for the 2.35:1 mattes. (I will probably get 4 boards of 6 7/8" x 50 3/4" so I can carry them home, and then splice them together with the biscuit joiner during the rest of the screen construction.) Result: a viewing area of 43.25"H x 101.5"W for 2.35:1 material.
2 boards of 12 7/8" x 57" for the 1.33:1 mattes. Result: a viewing area of 75 3/4" x 57" for 1.33:1 material.
Any recommendations for finishing MDF directly? I will put the same eggshell black paint on the mattes as I use on the trim. I know that's not quite as light-absorptive as a flat black, but I've got plenty of extra eggshell black paint to use. Do I need to sand the MDF before I prime and paint? If so, who has a power sander and can bring it to the meet???

 

[Hank Frankenberg]

Colin, compare what you spent to a new DaLite or worse, a new Stewart screen. Yes, DIY is VERY inexpensive
BTW, I just answered your e-mail.

 

[Jeff Meininger]

Here are some pictures of my sonosub building progress.
High-tech work table. Instead of C-clamps, I used a 50# bag of sand (not pictured) to weigh down the MDF.
http://boxybutgood.com/temp/sonosub/SubDAY1-001.jpg
Getting a straight cut on the sonotube was difficult. These little stringy runners would precede the jigsaw blade. They'd curl up, making it hard to tell if you were too far to the right or left of the line. I got the cut "straight enough", though. Next time, I'd draw the line and cut to one side of the line, not through the center of the line.
http://boxybutgood.com/temp/sonosub/SubDAY1-002.jpg
The bottom endcap and base-plate. Three legs are glued and screwed from the top, permanently fixed to the bottom endcap. Each leg has a hanger bolt (half bolt, half wood screw) sticking out of the bottom. These go through the base-plate, where a nut can be attached from the bottom to secure it in place.
http://boxybutgood.com/temp/sonosub/SubDAY1-003.jpg
Here's another shot of the endcap and base-plate. I'm using a simple radio-shack 2 binding post terminal. It requires a very thin panel since the posts themselves are rather short. I routed a circle using the smallest hole the jasper jig could create, then freehand-routed the material in the hole. I couldn't see what I was doing, so the hole was necessary to "feel" the limits of the area I was supposed to be routing. I used a dremel tool to go even deeper, since the terminal STILL didn't fit all the way through the holes. I'm slightly concerned about how thin the material is here... probably less than half an inch thick. Probably no big deal, though, right?
http://boxybutgood.com/temp/sonosub/SubDAY1-004.jpg
MDF is strange stuff. No matter how much effort I put into getting sawdust off of the cut edges (in preparation for painting), it's still dusty. What is the proper dust-removal method for this stuff? Toothbrush and swiffer cloth both collect lots of dust, but it just keeps on coming.
My next step is sanding the exposed edges and then painting. After that, there's not much I'll be able to do until October, when I'll order the driver.

 

[Colin Dunn]

I did the test fit of all the pieces of my screen. Everything seems to fit together well, even the trim pieces around the edge. The only exception is a slightly out-of-square cut on one trim piece, but the error will likely not be visible at viewing distance.

I have taken pix of this stage of assembly, but the batteries in my digital camera died, so it will be a while before I can retrieve them and post...

Hank: More mail headed your way soon...

 

[Harlan B]

Hello everyone!
I'm new to HTF (I'm a long time member of HomeTheaterTalk.com)
In fact, My DIY project started over there...
But, I heard from a friend that ya'll Austin-ites might have some spare Sonotube,
Jeff, others??? please?! I can pick it up... drop me an email or a post here if you've got enough to spare. I'm more than willing to pay my share of the cost of the Tube...
If you do, I'd love to have some! I'm trying to get my DIY SUB Sonotube design in under $400, and my budget is tight... (I already bought the Tempest Driver and AVA250 Amp)
To keep dibs on my project; follow the thread over at htt:
http://www.hometheatertalk.com/ubb/F...ML/001594.html
Thanks,
Harlan

 

[Jeff Meininger]

Sorry, Paul Laiming has already spoken for my tube. The two places in town that sell sonotube are...
1. Shepler's (http://www.cmcsheplers.com/location.htm)
2. Texas Contractors Supply (http://www.texascontractors.com/austin.asp)
I'm not sure if shepler's will sell a partial tube. They didn't have the diameter I was looking for, so I never asked. Though I had to buy a full tube from Texas Contractors Supply, I was pleased with their price and their VERY affordable to-your-door delivery.
Staying under $400 is going to be a close call in your case, having already spent $350. So far, I've spent $137.06, and I still haven't bought the driver, amp, or flared port kit. I was really hoping to spend less than this on the enclosure materials, but "oh well". I know in the long run that it's still a bargain for a sub. But when the budget is tight, the budget is tight.
Most of the unexpected anti-money has come in the form of spray paint. I had no idea how much I'd need for two stinkin' endcaps and a base plate. Yowza. My suggestion to you would be to buy cheap paint in a can and a cheap brush (but not a foam brush). I wish I'd have gone this way, since the texture of the brushstroke can "smooth out" and cover up any imperfections. Certainly cheaper, too. Kilz primer spray is nice, though, and worth the money for getting a nice sanded surface.
I'm over-budget enough so that I probably won't be able to afford the driver and amp until later in October. So I'll have a completed, driverless, ampless sonosub enclosure sitting around for a while. It will be silently mocking me. I'll wake up in the night thinking I heard 105 dB at 20 Hz, but it will just have been a dream.

 

[Jeff Meininger]

Mark Hayenga: on page 2, you said I should finish my sub in crushed velvet. In an effort to avoid sewing, I had already decided on going with ribbing (stretchy tube) material. I tried to dye the material to the color I want, and got so-so results. I'll live with it for a while, but crushed velvet probably already comes in the color I want, and would look very nice. Are your subs covered in crushed velvet? I'd love to see a photo.

 

[Hank Frankenberg]

Mark: you MUST bring a crushed velvet something to the meet Saturday. If you don't, I won't be inspired to do a cabinet in faux leopard fur

 

[Jeff Meininger]

I really hope I can make it to the meet on Saturday!!
Here's a picture of my future sonosub next to the current noisy 8-incher.
http://boxybutgood.com/temp/sonosub/SubDAY4-001.jpg
As you can see by the highly irregular sheen on the baseplate, I either don't know how to sand or I don't know how to spraypaint. Same goes for the top surface. The camera flash makes it look worse than it really is.

 

[Jonathan DA]

Jeff,

Spray paint is a royal pain to get an even finish with, and white is even worse because it requires more coats than most colors. Did you prime the tube and plates before painting them? If not, do so and then repaint. After the first coat of paint dries, wet sand it by splashing some water on the plate and then sanding with a sanding block and a very fine grit sand paper (600 is a good start). Repeat the painting and wet sanding process about 5 times, increasing your grit up to about 1000, and you'll end up with a smooth paint job. It's not an elegant solution, but it works if you're patient.