Silly question about mass-loading sides.

[n~dl]

Hey everyone! This is my first post so I'll get the intro out of the way: My name's Nate, I'm just a student builder in the second year of a luthiery program invading your board from the states (though I did live in Auckland for a time). I hope to stick around a while.

Anyway. I've had the Gore/Gillet books for a few weeks and I'm enjoying hacking away at them. I'm about to experiment with mass loading the sides of an upcoming build and there's one thing I'm stumbling on. Making and fitting the mass support blocks is clear and easy enough, but, erm, what exactly are the mass blocks? Where does one get that sort of thing? Are people getting them machined someplace? I read the pertaining sections in both the Design and Build books several times but didn't see anything explicitly about the blocks themselves.

It's probably obvious to anyone who knows! Unless anyone can tell me I'll probably just wind up at the hardware store picking up random hinges and things to bolt to it.

[Jim Kirby]

I haven't gotten that far in applying the books yet, but I'm guessing that the block itself is another fabrication job like tail and head blocks. But they are mighty slim on information about what are convenient things to bolt to the blocks. Large washers would be my first guess, I think.

(I misread your post - I was talking about the mass support blocks above. Like you, I don't know what they intend to be used for masses).

[n~dl]

The Design book illustrates what appear to be some kind of lead weights with a bolt through the center, but falls short (unless I've completely overlooked something!) in disambiguating them. I might experiment layering up some mending braces, it's just that if anyone looked in the sound hole it might appear kinda ramshackle!

Looks like I'm waiting until the ozzies start waking up! (Where's the emoticon for banging together some pots and pans?)

[n~dl]

Whoops! I'm still getting my baring on this board; I didn't see there was a sub-board just for the Gore/Gillet books. If a mod needs to move the thread...

[Steve]

Hey everyone! This is my first post so I'll get the intro out of the way: My name's Nate, I'm just a student builder in the second year of a luthiery program invading your board from the states (though I did live in Auckland for a time). I hope to stick around a while.

Anyway. I've had the Gore/Gillet books for a few weeks and I'm enjoying hacking away at them. I'm about to experiment with mass loading the sides of an upcoming build and there's one thing I'm stumbling on. Making and fitting the mass support blocks is clear and easy enough, but, erm, what exactly are the mass blocks? Where does one get that sort of thing? Are people getting them machined someplace? I read the pertaining sections in both the Design and Build books several times but didn't see anything explicitly about the blocks themselves.

It's probably obvious to anyone who knows! Unless anyone can tell me I'll probably just wind up at the hardware store picking up random hinges and things to bolt to it.

G'day Nate - welcome aboard. I'm miles off applying weights yet too, but there's a bit of info here: viewtopic.php?f=33&t=4065
Steve

[n~dl]

Ah, thank you. That one didn't come up in my searches. It's about what I figured. I don't have any steel or brass around in the right dimensions, so it might be the mending braces after all.

I've still got tons to absorb in the book, too. It's a lot for a guy who just had his first algebra class in 15 years. I figure with these brackets it should be easy to add/remove them and play it by ear until I'm getting a response I like. If that's not working out, hey, just remove 'em all.

[Trevor Gore]

Check out Fig 2.3-14. I'm using 10mm by 32mm mild steel bar there. Any steel stockist will have it. Just cut it to whatever length you need to get the right mass. Brass, gold, lead, depleted uranium... all work the same. The washers in the pic were when I was experimenting with fine trim, but now I just cut the bar to the right length based on the gradient of Fig 2.3-15. When you bolt the masses in, make sure they are real tight and that your cap screw is not so long that it pierces the sides.

[woodrat]

Hi Nate...Welcome to the ANZLF....its a friendly place where all are welcome:)...Trevor and others have covered it well of course. I had some 1 1/2 x 1/8 inch brass strip hanging around from another (aborted) project that suited the purpose well. I use 2 or 3 inch strips either 1 2 or 3 as per requirements and drill a hole in the middle for my weights. Once I have determined the amount I need to get it to its target frequency I super glue the strips together so that theyare one mass and cant spin around. Remember to use a spring washer of some kind.

Regards

John

Trevor...make sure you have your lead undies on when you use depleted Uranium!

[Tom West]

I may be wrong but the weights in Trevors book looks like hot rolled steel to me. Most likely any welding shop would have some. Maybe 1/4" by 1"or so, saw to your own lenght and drill your own holes. Fine tune with washers.
Tom

[peter.coombe]

I wandered into Mitre 10 and bought an L wall bracket, biggest and thickest they had, and cut it into the appropriate sizes with an angle grinder.