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WO32 construction: Part I (Read 10035 times)
goldenk10
Ex Member



WO32 construction: Part I
02/20/06 at 00:17:03
 
Started cutting MDF last night. The process went quite fast. A friend of mine, who happens to own a custom car audio shop, offered to let me use his tools (table saw, router, etc.). We began work around 7pm and finished making all of the cuts we could at about 9:30pm. I CAD'd up the plans, and had all dimensions/angles before hand so there was no guess-work, or wasted MDF. We couldn't cut the holes in the baffles because my drivers still haven't arrived. Some folks are saying they spend multiple nights/weekends on this project. Just wanted to know if the project is end-loaded with respect to time. Here are a couple pics we took for the powerpoint presentation/report. More to come.



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60ndown
Ex Member



Re: WO32 construction: Part I
Reply #1 - 02/20/06 at 00:32:16
 
damn! you go speedy   Cheesy  glueing and screwing will take some time. i think i built mine in about a day, with a skill saw....finished!
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« Last Edit: 02/20/06 at 00:33:45 by 60ndown »  
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goldenk10
Ex Member



Re: WO32 construction: Part I
Reply #2 - 02/20/06 at 02:17:19
 
My friend, (the shop owner) suggested using his brad-nailer will speed up the process, and also maintains that the wood-glue will take more of the load than whatever type of fastener we use.

I intend to use screws on the baffle plates in case I ever want to swap drivers and screws on the lid to facilitate easy removal/maintenance. Other than that, the brad-nailer seems to be the way to go.

Opinions?
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gexter
Ex Member



Re: WO32 construction: Part I
Reply #3 - 02/20/06 at 03:23:46
 
I used a brad nailer and wood glue and clamps.
I glued and brad nailed each join then clamped it and waited for that join to dry before moving on. I made some braces that kept everything in position while it dried.

The brad nails and clamps just hold the wood while the glue dries.
Using a brad nailer is by far my favourite tool.

It amazes me that some of the members here can do a excellant job with just a ciculer saw and or jigsaw, and some liquid nails.

EDIT: the speaker and top should be removable.
Barbed inserts or t nuts on the lid and course screws to hold the  speaker baffle.

My opinion only
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« Last Edit: 02/20/06 at 03:26:08 by gexter »  
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goldenk10
Ex Member



Re: WO32 construction: Part I
Reply #4 - 02/20/06 at 03:36:45
 
Thanks for the construction advice. I feel a little better now about using the brad nailer. I have tons of carpentry experience, (very little finish work) but have never worked with MDF. Once thing I observed while sawing is that the dust is very fine. I have awful allergies and was sneezing until I figured out the dust was still all over me! Didn't stop coughing/sneezing until I got home and showered!

I think I prefer working with regular wood...maybe I just need a quality respirator? Good thing about MDF tho...no knots!

Do you have pics of the barbs you used on the driver baffle?
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nodiak
Ex Member



Re: WO32 construction: Part I
Reply #5 - 02/20/06 at 15:23:01
 
Thanks for the post, very helpful to see the cabs being built.

MDF is nasty stuff, will make you sick. Definitely use a good respirator, and when done for the day take the brad nailer off the hose , put on a spray nozzle and get it all off your body and clothes.

Don
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gexter
Ex Member



Re: WO32 construction: Part I
Reply #6 - 02/20/06 at 23:19:57
 
I use a respirator when I cut MDF and I wrap the base of my Table saw with a skirt.
I know its a no brainer but I have to say keep the goggles, ear protection and repirator on when blowing the dust off with high pressure. You may have it set at 80psi which can still cause damage.

on the barbs http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=081-1094

T nuts
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=081-107

borg ( home depot even has them)
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goldenk10
Ex Member



Re: WO32 construction: Part I
Reply #7 - 02/21/06 at 07:32:50
 
Thanks guys,

We actually had an air hose available, and used it between every third cut or so. However, the air just seemed to blow the MDF dust back up into the air. I asked about respirators...but was assured that they "wouldn't help". I don't know about that one. I don't do anything without safety goggles.

The barbs and the T-nuts are a great suggestion, I will definitely use those. I'm sure they have some at the shop. Before I complete the enclosure, I need the drivers, and before I can put the drivers in the enclosure, I need to verify their T/S parameters.

I have mapped out the horn expansion taking various measurements on the full-size blueprints. I hope to compare the expansion with the tractrix equation at some point this week. My hunch is a tractrix expansion, but I need to complete the analysis to be sure. Once I get through some other work this week, I intend to model the horn as a straight expansion in Solidworks. May not happen until friday. I expect the project will be completed by sunday. More to come.
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goldenk10
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Re: WO32 construction: Part I
Reply #8 - 02/24/06 at 23:46:48
 
I picked up my drivers yesterday from my friend's shop. I have spent the last 24 hours running 15 Hz sine waves through them to break in before testing TS parameters. I hope to test the drivers tonight to facilitate completion of my WO32 saturday evening. I will be using CLIOwin to test parameters. Has anyone used this software before?

I have never personally owned any HT stereo components. In my small shared student apartment, I have a "vintage" solid state Realistic STA-820 Stereo Reciever (circa 1977 -- Dad's reciever from college Smiley), some crappy "Boka" computer speakers, and some hand-me-down "Acoustic Monitor" full range cabs with junk-drivers in them.

I am really looking forward to building an entire home system, using the WO32 as the base. The anticipation is building. More to come.
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60ndown
Ex Member



Re: WO32 construction: Part I
Reply #9 - 02/24/06 at 23:59:07
 
[quote author=goldenk10  link=1140398223/0#8 date=1140824808]I picked up my drivers yesterday from my friend's shop. I have spent the last 24 hours running 15 Hz sine waves through them to break in before testing TS parameters. I hope to test the drivers tonight to facilitate completion of my WO32 saturday evening. I will be using CLIOwin to test parameters. Has anyone used this software before?

I have never personally owned any HT stereo components. In my small shared student apartment, I have a "vintage" solid state Realistic STA-820 Stereo Reciever (circa 1977 -- Dad's reciever from college Smiley), some crappy "Boka" computer speakers, and some hand-me-down "Acoustic Monitor" full range cabs with junk-drivers in them.

I am really looking forward to building an entire home system, using the WO32 as the base. The anticipation is building. More to come. [/quote]

sounds like your covering all the bases. Sad
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J_Rock
Ex Member



Re: WO32 construction: Part I
Reply #10 - 02/25/06 at 00:31:56
 
So where part 2?

Also on the whole MDF thing, do you guys not cut with dust collection system of some sort?  Not only does dust collection keep the dust away from your nose, but it also allows machines to make better cuts.

I may be used to the MDF dust too, cause I never sneeze when I cut it. Although I can bet next MDF cut I make I will sneeze cause I said this...
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60ndown
Ex Member



Re: WO32 construction: Part I
Reply #11 - 02/25/06 at 03:07:08
 
mdf dust is VERY VERY bad for you.poisonous
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nodiak
Ex Member



Re: WO32 construction: Part I
Reply #12 - 02/25/06 at 05:35:21
 
A while ago I started only cutting it outside, wearing a mask. It is poisonous, some have said they get nose bleeds from it. I don't have a reference but I remember reading how the super fine dust stays in the lungs longer than plywood dust.  I've had headaches from it for sure.MDF BAD! I started using more Baltic Birch ply recently as recommended by some older wiser speaker builders who consider BB to have a more natural lively sound quality. I'm trying it out on some subs. Maybe that inert quality of mdf is too dead?
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goldenk10
Ex Member



Re: WO32 construction: Part I
Reply #13 - 02/25/06 at 07:44:26
 
Wow, I had no idea MDF was so bad for you (poisonous?!). I am glad we are 90% done with the cuts. Tomorrow, we just need to cut the holes in the baffles to mount the drivers.

The saw does have dust collection...I think the bag was at capacity Undecided.

Part two should hopefully come tomorrow night. That is when we plan to "glue and screw". I'll get pics up ASAP. I went and tested the TS parameters of my drivers this evening.

Here are the results:


Published Values For Dayton 295-550 vs. (measured) values

Fs---------30Hz---------(27.6691Hz)
Qms-------8.0-----------(5.8588 )
Vas--------52.10 L-------(55.7692 L)
Cms-------.33 N/mm------(.3595 N/mm)
Mms-------82g-----------(92.0244g)
Rms-------2.0 kg/s-------(2.7307 kg/s)
Sd---------332.1 sq. cm.-(333 sq. cm)
dBSPL------88.5 dB-------(88.603 dB)
Qts--------.30-----------(.2488 )

Those are most of the relevant numbers. I did the other driver too, it's numbers were similar, with a slightly higher Fs and Qts. In any case, both drivers measured close to spec, so I am pleased.

We used CLIOwin 6.5 and did the tests over a period of about 30 mins...taking our time and retesting to make sure we got good data.

Instead of putting the drivers in a fixed volume enclosure, we added weight to the speakers. It was pretty ghetto. We took nickels (5g each) and taped 4 of them with packing tape to the woofer cones.:P. Others there were doing the same, so we figured, what the hell....and because the numbers were close, I think taping nickels was effective for my purposes.

After testing two dayton drivers and having their actual TS parameters be close to published values, I would say it is fair to trust the numbers from them. Yay Dayton!

PART II coming VERY soon!
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qpalzm
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Re: WO32 construction: Part I
Reply #14 - 09/30/06 at 12:05:33
 
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