Official Luthiers Forum!
http://luthiersforum.com/forum/

Another n00bie 00psie: backward X bracing?
http://luthiersforum.com/forum/viewtopic.php?f=10101&t=31661		 Page 1 of 1
Author:  nkwak [ Mon Mar 28, 2011 11:12 pm ]
Post subject:  Another n00bie 00psie: backward X bracing?
I just looked at the plans for the OLF MJ that I'm attempting to build. I glued in the X brace last week but now that I've taken the opportunity to review the plans it looks like the X brace is backwards; the longer cut is supposed to go up by the sound hole.

Note the bevel markings of the X braces on the plans:
Image

Here's what my braces look like:
Image

Shouldn't be an issue, right? So long as there's a peak at 3" from the kerfing, right?

[uncle]
Author:  John Mayes [ Mon Mar 28, 2011 11:40 pm ]
Post subject:  Re: Another n00bie 00psie: backward X bracing?
You'll be fine, but watch out putting your face by go-bar decks without eye protection. I've seen bars fly, and it's all fun and games until....
Author:  Dave Fifield [ Tue Mar 29, 2011 2:52 am ]
Post subject:  Re: Another n00bie 00psie: backward X bracing?
What John said....watch out for those gobars! I've had one go and take out all the rest with it - it's dangerous - they fly everywhichway - almost like a small explosion!

Yours look MUCH too bent for good safety Neil! You need to increase the distance between the top of the deck and the work surface somehow. It looks like you have some wood spacers under there, so perhaps you could remove one or two or replace them with some thinner wood. In my setup, I use 3/4" plywood spacers plus a dead-flat 4" riser block that I made to get the spacing just right for any particular gluing job.

Someone on the OLF (I forget who, sorry, was it Waddy?) took the trouble to measure the downforce of gobars at various deflections and found that bending the bars more didn't excert any extra gluing force at all.
I would suggest that about 1" to 1.5" deflection of the glass fiber bars (your's look like the LMI ones, right?) is all that you need. Any more and you're making the set up unstable and unsafe.

HTH,
Dave F.
Author:  nkwak [ Tue Mar 29, 2011 7:48 am ]
Post subject:  Re: Another n00bie 00psie: backward X bracing?
Thanks, everyone. I'll just proceed as normal then.

BTW, it's my friend's go-bar deck (that's actually him in the picture) and we did have one slip (leaving a dink in the cedar) so we're aware. I'm trying to be as cautious as I can be. I measure twice and cut once. Some day I'll learn patience to measure 3-4 times instead! :)
Author:  nkwak [ Tue Mar 29, 2011 9:07 am ]
Post subject:  Re: Another n00bie 00psie: backward X bracing?
Okay, okay! I get it! :lol:

You all are just trying to ruin my fun aren't you? Using the go-bar deck was one thing I was looking forward to and FWIW the top didn't stay in there for more than a couple of hours. I haven't been over to my friend's shop since but he told me he took it out and it the tap tone is already nice and clear so I may have actually stumbled in the right direction.

I just hope he didn't launch one of those nylon bars through my cedar. beehive
Author:  WudWerkr [ Wed Mar 30, 2011 11:51 am ]
Post subject:  Re: Another n00bie 00psie: backward X bracing?
They are NEVER Mistakes [headinwall] , They are EXPERIMENTS !! laughing6-hehe
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/