|
186 Horn measurements don't add up? |
Post Reply 
|
| Author | |
dmr 
Registered User 
Joined: 30 July 2015 Status: Offline Points: 57 |
 Post Options
 Thanks(0)
 Quote Reply
 Topic: 186 Horn measurements don't add up?Posted: 06 August 2015 at 9:38pm |
|
Hi all,
I'm starting my first build; the 186 Horn plan posted on this website. Upon marking out, the front part that is 350mm (angled part sorta on the left) does not add up to the 310mm height and 195mm width using the Pythagorean theorem (its 16mm out) Do I go by the 350mm (its length), or by the height/width of where it starts and ends in relation to the side panel? In retrospect should have chosen something simpler but hey ho its a bit late now! Cheers!
Edited by dmr - 06 August 2015 at 11:04pm |
|
 |
|
|
djeddie
Old Croc 
Joined: 26 April 2004 Location: Bristol Status: Offline Points: 4124 |
Post Options
Thanks(0)
Quote Reply
Posted: 08 August 2015 at 12:42am |
|
Cut the main side panel to the exact size then 'draw' the plan on that side. You can the measure each piece as you go.
|
|
|
Chas n Dave : it's like Drum and Bass but with beards. E=mc² ±3dB
|
|
|
|
|
dmr
Registered User
Joined: 30 July 2015 Status: Offline Points: 57 |
Post Options
Thanks(0)
Quote Reply
Posted: 08 August 2015 at 10:51am |
|
Yeah that's what i'm doing, its just that if I measure 310mm in from top and 195mm in from left and place it there; the piece is no longer 350mm as specified on the plan. If I cut a 350mm piece and place it relative to the previous, it is no longer 310mm in from top and 195mm in from the left.
I continued regardless and just made a compromise half way between the two extremes, it has changed the shape of the horn slightly...
|
|
|
|
|
DMorison
Old Croc
Joined: 14 March 2007 Location: Aberdeen Status: Offline Points: 1617 |
Post Options
Thanks(0)
Quote Reply
Posted: 08 August 2015 at 12:55pm |
6mm out, not 16mm. You need to subtract the 20mm offset from the front edge of the box from the 195mm dimension before calculating  .Am still surprised it's out by that much though, would've expected it to be within a reasonable rounding error (ie nearest mm). Good luck with your build anyway, if your compromise is only a few mm I doubt it'll affect the end result - you're dealing with sounds having much longer wavelengths than that after all.
|
|
|
|
|
b grade
Young Croc 
Joined: 05 October 2012 Location: Portland OR USA Status: Offline Points: 1337 |
Post Options
Thanks(0)
Quote Reply
Posted: 08 August 2015 at 2:05pm |
|
yeah I get 356 mm mathematically too. 175 by 310 on the sides of the right triangle. I also double checked against the 1850 plans which are nearly the same. That part on the 1850 is labelled as 353 mm, which is closer, but I would have thought still about 3 mm short.
|
|
|
|
|
dmr
Registered User
Joined: 30 July 2015 Status: Offline Points: 57 |
Post Options
Thanks(0)
Quote Reply
Posted: 09 August 2015 at 8:48am |
Ahhh damn that's caught me out so many times, it doens't help that the guy at B&Q cut the side panels 10mm too short!
|
|
|
|
|
Post Reply
|
|
| Tweet |
| Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |
Topic Options
dmr wrote: