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PostPosted: Mon Feb 11, 2008 12:05 am 
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Location: United States
First name: Waddy
Last Name: Thomson
City: Charlotte
State: NC
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Since I have had a number of questions about my spring loaded Go-Bars, I thought I would put a little tutorial together that shows the parts, and the way they are assembled. It isn't rocket science, and I'm sure there are lots of ways to do it. This is just my version.

First, I used 1/2" CPVC for the body of the Go-Bar, and 1/2" dowell for the inside parts.
First, I cut both the dowel and the CPVC into 18" pieces.
Attachment:
P1000572 (Large).JPG


Then, the dowel has to be sized to 15/32". I did this by making a scraper to take them down to size. Getting a 1/2 to 15/32 takes two steps. Usually the dowels are a little over size, so first, size to 1/2 then to 15/32. To make the scraper take a piece of steel bar, 3/16 thick by about 1" and about 6" long. Drill two holes about an inch apart (not important). One hole should be 1/2" the other 15/32, the flip the bar over, and from the back drill the 1/2" hole out to 17/32 or a little larger. Only drill about 3/4 of the way through. This will leave a lip that is 1/2". Then do the same thing with the 15/32 hole, with a 1/2" drill. now, file the top surface of the bar flat across the 1/2 and 15/32/ holes. This will make the edges of the holes very sharp. Then you can drive the dowel through the 1/2" hole first. This will round it up, and get it to a clean 1/2".
Attachment:
P1000323 (Large).JPG
Then drive it through the 15/32 hole.
Attachment:
P1000324 (Large).JPG
This gives you a rough 15/32 dowel. Sand it by hand to remove some of the roughness. Make sure it fits inside the CPVC pipe and slides freely.

The next step is to take a 3/16 router bit and route a slot in the CPVC. The slot should be approximately 5" from what will be the bottom end of the tube, and about 4" long, I purposely routed the slot low enough to hide the spring above the slot. When routing the slot, I used my drill press and a cross vise. I used a scrap of dowel that had been reduced, to back up the bit inside the dowel. This lets the vise grip the dowel without mashing it out of shape too much.
Attachment:
P1000569 (Large).JPG


The spring I used was an Ajax spring, Part # 54. It is 5" long, compresses to just over an inch, and at about 2 1/2" compression, it's pushing about 7 lbs. At full compression it does close to 10 lbs, so 9 is about the max you can get.
Attachment:
P1000575 (Large).JPG


As a stop for the spring, I drilled a 15/64 hole in the CPVC, about 15" from the bottom end, and I drilled a second 15/64 hole 1" up from the first one (measure holes to centers, not edges). Then I drove a 1/4" dowel in each hole. It is a very tight fit, and actually cuts the dowel down a little. Then, I flattened the ends a little to keep them from popping out.
Attachment:
P1000568 (Large).JPG
The second 1/4" dowel is to act as a stop for the spacer which I explain below..

I designed the bar to work in a deck height of about 27 1/2" clearance. For me that put the top 27 1/2" above the surface of the solera. If the deck is separate, you'd have to figure out how much clearance you would need based on how thick the item to be glued is + what it is sitting on, i.e, radius dish, etc. When gluing close to the Solera surface (top braces and fan braces), I insert a 6" spacer in the top of the Go-Bar. The spacer sticks out of the Go-Bar about 3 12". When gluing the back on the body, the spacer is removed. The 3 1/2" is a comfortable compromise of the thickness of the guitar body, based on the plans I'm using.

The layout of the parts looks like this.
Attachment:
P1000567 (Large).JPG


Continuing in the next Entry.


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PostPosted: Mon Feb 11, 2008 12:29 am 
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First name: Waddy
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State: NC
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Status: Semi-pro
Here are some close-ups of the layout, taken sequentially.
Attachment:
P1000568 (Large).JPG
Attachment:
P1000569 (Large).JPG
Attachment:
P1000570 (Large).JPG


I use a little 1/2" long piece of 15/32 dowel as a stop above the spring, so the spring will not warp or bind against the dowel driven through the hole. This little piece can also be used as an adjuster, to make all the bars the same length, in case your measuring is off a little. Mine varied anywhere from 3/8 to 5/8. Probably not all that important, but 1/2" equals about 1 lb. pressure, so you want them to be close. Then I also use a 1/8" dowel piece as a stop to keep the whole thing together. It is driven into a hole on the 15/32" dowel, and rides in the slot in the CPVC.
Attachment:
P1000577 (Large).JPG
Attachment:
P1000147 (Large).JPG
Assembled, it all looks like this.
Attachment:
P1000146 (Large).JPG


I tapered the end of the dowel down to about 1/4" to focus the pressure point. Easier to get it in the middle of something like a 3mm fan brace, when it isn't so wide.
Attachment:
P1000574 (Large).JPG


Here is a few of the bars in use. Note, here I am gluing fan braces so I have the extension in the top of the bar.
Attachment:
P1000278 (Large).JPG


To be continued in the next entry.


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PostPosted: Mon Feb 11, 2008 12:39 am 
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Joined: Mon Mar 19, 2007 7:05 am
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Location: United States
First name: Waddy
Last Name: Thomson
City: Charlotte
State: NC
Focus: Build
Status: Semi-pro
Here is a shot from the side. This is really just a dry run. No glue, but it holds a 3mm wide x 6mm high fan brace just right. When I was testing, I had not tapered the dowels.
Attachment:
P1000279 (Large).JPG


Here is a shot when I was actually gluing the fan braces in.
Attachment:
P1000358.JPG


Here are the bars gluing the back on. Here the spacer is removed. The deck top is the same height.
Attachment:
P1000549 (Large).JPG


I'll be glad to answer any questions on the process. Other ideas are also welcome. There certainly is probably a better way to do this that I didn't think of.

Thanks for looking.


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PostPosted: Mon Feb 11, 2008 10:10 am 
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That is a slick setup Waddy. Nice tutorial, very clear. Thanks for sharing.

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PostPosted: Mon Feb 11, 2008 12:29 pm 
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Koa
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Location: United States
Very interesting Waddy. Thanks for taking the time to post this. I am looking for something off the gobar deck that is a little more direct and this may fill the bill.

John


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PostPosted: Tue Feb 12, 2008 2:29 am 
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Brazilian Rosewood
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Cool Waddy!! Thanks for the tut! [clap] [clap] [clap] [clap] [clap]

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PostPosted: Mon Apr 13, 2009 3:28 am 
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Last Name: Green
City: Milford
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Zip/Postal Code: 45150
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Status: Amateur
Thank you very much for sharing, I look forward to learning here at OLF


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