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Discussion Starter · #1 ·
Hello there.

I have an idea of making speaker from one piece of wood log.
Do you think it is a good idea? And will be result worth of doing it?

process is - cutting out the inside, so in result i will get "one peace" cilinder.
The problem is to get ideal material/wood log without any scratch/breaks in log (broken structure of the cabinet, unlike MDF which is ideal here).
And of cause due to time and outside temp/etc parameters it can spin/break... :hide:

PS: i can get some materials, just to test firstly how it is difficult to make cilinder at home (DIY)

Thanks for listening and comments :whistling:
 

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turning a log into a cylinder is easy on a lathe, but there are a lot of but comments that are but to follow.

1) ... a lathe big enough to do a proper speaker is expensive. To use an 8" woofer I am thinking you will need to start with an 18" log (debarked diameter) turned on the pith.

2) ... Finding a central pithed log is easier said than done. A couple of inches off center for a log that big isn't going to be too hard to find, but they you are looking at needing a bigger lathe and the price for big lathes goes up exponentially in relationship to their turning capacity.

3) ... There are only 2 lathes I would actually recommend even trying a log that diameter with Oneway 2436 with a bed extension ($5500) or a Vicmarc VL300 with a 3hp ($4400). In my opinion for a project this size go with the Oneway. I have a the Vic and even at slow speeds turning a 20" x24" is a very delicate and scary thing and I have been turning for 15 years.

4) ... after the investment in the lathe you need lathe tools. Unfortunate what you are talking about is a very specialized project so things like the steady rest for hollowing will have to be custom made. Of course that can be done in the woodshop and is fairly easy. An extended tool rest and special holowing tool able to hang way off the end of the rest without snapping are probably going to be pricey unless you already are a machinist and can do it off hours at work. Expect to spend another $1500 to $2000 for tools and accessories.

5)I would also suggest you get some training and working your way up to the big log. A lathe is quite possibly the most unpredictably dangerous tool in your shop. When a work piece decides to explode or come unmounted there is no predictable trajectory. A full impact resistant poly faceshield will protect you face from serious injury, but in no way covers exposed throat or prevents the piece from snapping your neck, and even a small piece has the velocity to do that. With proper training, several hundred to a good thousand hours of actual practice, and several hundred to a few thousand more spent to include tools for smaller projects, you are ready to begin thinking about this project. Good news is you probably have an American Association of Woodturners chapter near you and there are a lot of friendly knowledgeable people who will guide your learning process. It should be able to pick out the knowledgeable for the idiots by using common sense.



6) Lastly once you have started this project expect between 18 and 36 months to finish it. Most of that will be spent not working on it because you are drying out the project so it doesn't warp or split once you do the final turning and assembly.

I hope i didn't turn you off of the notion of turning, it is a wonderful addiction, I mean hobby.
 

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Welcome to the Shack.
That would be quite a project! What diameter of a cylinder are you considering? The problem is the wood will shrink and crack unless it's treated with P.E.G. (Polyethylene glycol-1000) You can read more about it here.

http://owic.oregonstate.edu/pubs/peg.pdf

Would you be "Lumenlab" Delfins?
 
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Discussion Starter · #4 ·
Actually i have another idea, how to make cilinder - with small drill what we use in our country to take juice from birch/etc tree - it has diam. ~5cm ... so... hardly step-by-step i be able to cut out wood from inside.. then at the end i can polish inside with "DIY polisher" (sounds nice :) )... Yes, it looks pretty hard work... but for testing i am ready.. also i have (can find out) materials in my countryplace/homestead.

PS: sorry for my bad english :|

What diameter of a cylinder are you considering?
First of all - just to check how it is to make it and how its sounds - aprox 30cm...

Would you be "Lumenlab" Delfins?
Yes! (you can check my project at http://diy.delfins.id.lv/ .. also 10.6" 720p is comming)
 

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Welcome to the Shack.
That would be quite a project! What diameter of a cylinder are you considering? The problem is the wood will shrink and crack unless it's treated with P.E.G. (Polyethylene glycol-1000) You can read more about it here.

http://owic.oregonstate.edu/pubs/peg.pdf

Would you be "Lumenlab" Delfins?
Rather than pegging the log for this project i recommend using epoxy or fiberglass resin, or alternately once you start the turning project to use CA (superglue) you can buy it in pints for about $25. The reasoning for not going with a peg treatment on this is the forces of that log drying are going to require something to really hold it together. I might even go so fare as to sugge wrapping the rough turning in strips of fiberglass
 

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Rather than pegging the log for this project i recommend using epoxy or fiberglass resin, or alternately once you start the turning project to use CA (superglue) you can buy it in pints for about $25. The reasoning for not going with a peg treatment on this is the forces of that log drying are going to require something to really hold it together. I might even go so fare as to sugge wrapping the rough turning in strips of fiberglass
You lost me here, Brad. Once the cells have absorbed the PEG the log is stable. I'm not sure what you mean by " the forces of that log drying ". Could you explain?
 

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First of all - just to check how it is to make it and how its sounds - aprox 30cm...
How are you planning on mounting the speaker to the log? drilling out a log is a log harder than it sounds especially with large diameter bits. Secondly you still need a lathe to turn the outside round. Unless the outside is of equal wall thickness the resonance is going to be horrible.
 
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Discussion Starter · #8 ·
How are you planning on mounting the speaker to the log?
yep.. this is that i am thinking about every time when thinking about this project... Simple mount can be if i make plane from outside, where to mount spekear, but this will require bigger thicknes on the front "side" - or cilinder wil not be "true" cilinder, or thikness on mounting position (circle) will be more thicker.. i do not know is ot OK or bad... that is way i am posted topic... is it real to get good (not perfect) speaker from that cabinet figure (cilinder)
 

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it becomes a question of internal volume with what you are suggesting. Rather than planing the mounting surface, what I would do is remove a section with my bandsaw which can be glued back in place later I would make the mountings in this piece. This is not a technique I would reccomend for the faint of heart or inexperienced either. I have years of experience turning open hollowforms, and will tell you the slightest error will ruin this whole project and send a high velocity wooden missile, or more likely a wooden frag grenade across your shop.

Unless you really want round speakers what I would might suggest for log speakers would be as follows

1) split the log through the pith with a chainsaw and remove a wide plank from either side leaving the bark on. In the absence of an adequate chainsaw for the job, you might be able to go to a saw mill and get what you need done by purchasing a whole log.

2) plain and cut the speaker holes in the plank.

3) add a traditional box attachecd behind the plank front but hidden from view. I did something similar to this using split PVC pipe as the box.
 

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you forget most people are more interested in aesthetics rather than acoustics. I can't begin to tell you the number of times I have been asked to make "Cool" speakers at the expense of them sounding good.
 

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you forget most people are more interested in aesthetics rather than acoustics. I can't begin to tell you the number of times I have been asked to make "Cool" speakers at the expense of them sounding good.
While that surprises me at some level, I guess it really shouldn't. It's still interesting to know.

Bob
 

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While that surprises me at some level, I guess it really shouldn't. It's still interesting to know.

Bob
You want a story on how much people are will to pay for pretty, an interior decorator friend had a client who liked his theater speaker's sound. They were small infinity speakers from a box store, probably around $50 a pair. I disassembled them and slapped them in the same size box cut from curly maple (wood is free for me so these were solid maple not a veneer) I sold the 7 speakers plus the sub back to the him at $2000. After her cut and some overhead figured in that was $1700 in profits from his original speakers.
 

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I'm no expert but maybe someone can tell us what to expect from the acoustic properties of the wood.

Bob
What range are these speakers going to reproduce?

It depends on the density of the timber and the range used. If the speaker has an internal diametre of 30cm it wouldn't be unreasonable to expect a peak at 1.14Khz. unfortunately a peak at 1.14Khz would be a lot more noticable than a peak below 80Hz or above 10Khz. Of course if these are only going to be subs then it won't matter.
 
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