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PostPosted: Fri Dec 14, 2007 11:09 pm 
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Cocobolo
Cocobolo

Joined: Fri Jan 12, 2007 11:47 pm
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Location: United States
First name: Vincent
Last Name: Simokovich
City: Parma
State: OH
Zip/Postal Code: 44134
Country: USA
Focus: Build
Status: Amateur
I am just about finished with a fox style bender, and after the holidays I will be testing it out on a couple of orphan pieces. What I would like to know is how everyone profiles their sides to mate with the back and top. I am going to build a standard dread shape on the first few builds with a 15' radius on the back, and a 30' radius on the top. I will be using sanding dishes for both the top and back, and I will be building in a mold. Do you profile your sides prior to bending, or do you profile them after bending? Also, what tools/method do you use to profile your sides in either case?

Vince


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PostPosted: Fri Dec 14, 2007 11:29 pm 
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Old Growth Brazilian Rosewood
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Location: Ann Arbor, Michigan
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Vince I profile the back side of my sides prior to bending and leave the front side/edge of the sides straight.  I do this so that when I glue the blocks to the bent sides this can be done with the top, flat edge of the sides, down and flat on the bench.  I also do it this way so that when I place my sides in the bender I have a straight edge (the top edge of the sides) to measure the spacing from the edge of the bending stack and align the side properly in the bender.

The profiles for the sides can be captured with an ingenious little simple tool that Colin devised and posted a thread about - I think that this is in the "Tutorials" section of the OLF or perhaps someone can find the thread and post a link here for us?

The back side of the rim, once the blocks are glued in place, is sanded to final profile in the dish.  With the method that I mentioned above very little sanding is required.

For the top side of the rim I remove the majority of the excess with a small model makers plane (LMI green one) and then sand to final profile in the other dish.



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PostPosted: Fri Dec 14, 2007 11:30 pm 
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Koa
Koa

Joined: Sun Sep 23, 2007 12:39 am
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Location: United States
 I think what most do is use the dish to profile the rims after assembly of the rim  with lining  and  front and tail blocks , before you glue on top,back, and neck .. jody


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PostPosted: Fri Dec 14, 2007 11:33 pm 
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Koa
Koa

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 sorry Hesh must have been typing as I was typing ...    jody



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PostPosted: Fri Dec 14, 2007 11:33 pm 
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Old Growth Brazilian Rosewood
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Location: Ann Arbor, Michigan
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To add to what Jody just said - when dish sanding first do it without the "kerfed linings" installed.  Once the rim with out linings is profiled add the linings, slightly proud (perhaps 1/32") and then sand in the dish a second time.

This is much easier then attempting to sand through 1/4" thick kerfed linings for the majority of the profiling.



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PostPosted: Fri Dec 14, 2007 11:52 pm 
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Cocobolo
Cocobolo

Joined: Sun Mar 11, 2007 4:09 am
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Location: United States

[QUOTE=Hesh]

The profiles for the sides can be captured with an ingenious little simple tool that Colin devised and posted a thread about - I think that this is in the "Tutorials" section of the OLF or perhaps someone can find the thread and post a link here for us?



[/QUOTE]

Thanks for that Hesh.  I just looked it up and that simple method is just brilliant.  Sometimes the simplest ideas are the best.  I typically profile after bending because I never had a good way of transferring the taper that I felt comfortable with.  This method is pretty much foolproof (which is something I need every chance I can get!)




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PostPosted: Sat Dec 15, 2007 12:27 am 
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I profile after bending.
I have not always had the best of luck getting the sides to bend in the right spot, leaving either the neck end or butt end to short.
I find it less stressful to simply mark the waist and bend unprofiled. It leaves a little wiggle room that way

After that I glue the end block and neck block flush with the top edge of the sides which are dead flat front to back.
Then I tape a poster board cut out of a side template to the rim, lining it up with the top edge and then trace the radius to the side.
I use a chisel to hog off most of the wood almost to the line, leaving maybe 1/4", then I go to the sanding bowl to finish it off.

I have a nifty little set-up that makes bowl sanding a 10 minute job.
Here is a little movie file of it.
Warning, its a 6 meg file.

Bowl Profiling Jig

Here are a few pictures









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 Post subject:
PostPosted: Sat Dec 15, 2007 12:35 am 
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Old Growth Brazilian Rosewood
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Location: Ann Arbor, Michigan
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Lance your "salad shooter" is brilliant!!!!!

Wanna make me one for Christmas?????





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 Post subject:
PostPosted: Sat Dec 15, 2007 12:40 am 
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Hesh, the inspiration goes back to my days growing up on a farm in Stockbridge Mi.
The ol' suicide knob!



By the way, one of these bolted to that dish would make it even easer.

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PostPosted: Sat Dec 15, 2007 2:42 am 
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Contributing Member
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Joined: Sat Dec 30, 2006 3:20 am
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Location: Powell River BC Canada
First name: Danny
Last Name: Vincent
Lance - that's great. It's like almost a power tool. And you have to like
those moving pictures.

Todd - That's a great time saver!

Thanks both of you and Best of the Season.

Cheers,
Danny


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PostPosted: Sat Dec 15, 2007 3:15 am 
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Location: United States
First name: Lance
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Focus: Build
Status: Semi-pro
One thing I learned the hard way was to NOT drill your hole for the handle (dowel rod) all the way through.
I did, and it sliped down through and plowed a chunk right through a cocobolo side. Luckly I was able to fix it, but that really made me want to get the "knob" fix.

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PostPosted: Sat Dec 15, 2007 3:27 am 
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Brazilian Rosewood
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Joined: Fri Dec 14, 2007 3:21 pm
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Location: Alexandria MN
I've been profiling the back before bending and leaving the top flat.  I just put a piece of tape along the edge of my half template and mark where the ends and waist are.  Then transfer it to the side.  I made a plexiglass template that is a replica of the profiled side and use it as a router template to shape the side.  Leave a little extra at each end, line the waist mark up in the bender and it's worked well.  It's close enough that I now glue the kerfed lining in before I hit it with the dish.  I use a 30' top radius so it pretty quick to sand  that in with the dish.
I kind of cheated, I called Martin a few years ago and asked them to send me a set of profiled but unbent sides for an OM and Dred.  I just copied those profiles and it worked great.  Now I'd use Colin's method.  Lance I love the suicide knob, everyone had those on their cars when I was growing up in the 50's
Terry




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 Post subject:
PostPosted: Sat Dec 15, 2007 3:29 am 
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Mahogany
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Joined: Sun Sep 02, 2007 4:52 am
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Location: United States
I would think that drilling the hole all the way through and then creating a bushing system so that the handle would rotate (making it so that it didn't spin in the user's hand) would be advantageous...




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 Post subject:
PostPosted: Sat Dec 15, 2007 3:30 am 
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Mahogany
Mahogany

Joined: Sun Sep 02, 2007 4:52 am
Posts: 74
Location: United States
hmmm....strike that...you don't need to drill all the way through to do that, in fact that would make it harder to work correctly!




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 Post subject:
PostPosted: Sat Dec 15, 2007 5:08 pm 
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Cocobolo
Cocobolo

Joined: Mon Jul 23, 2007 3:46 pm
Posts: 149
Location: United States

I just got done doing my back profile. I used a handplane for most of it.


I used a L adjustable depth square ruler thing, mark the maximum depth all around, like 4.35 inches


The neckblock which I measured and (badly) put the dish profile on. (I will have to add more wood, I was off.) So the neckblock is the 'exact' depth I want -


Tail block was trickier as I could only rough it because of the dish concavity. I was going for less 1/4 than my dred, use the L to mark a consisten maximum around the bottom end


Look at the guitar with a light through the soundhole (top was glued on) to see the uneven marks


Leaving the maximum highpoint, roughly plane it down to 1/16


Plane it to jsut above the front neckblock,


Sanding in the dish, goes pretty quick. As Lance shows, you have to keep the thing 'centered' when you sand it. You could use a plumbob to have a focal point,


My new setup will be similar but you will rotate the mold/ guitar.


 My first jig was mounted either end of the mold (like a bell) for 'easy sanding' and it made the  top and back off a bit in the sweep, because the concavity changed.  Ooops.


So I got a similar solution to constant rotation from my sculpting days using plumbing pipe for armature stands, I guess we draw on our backgrounds for lots of stuff.


I will then make top and bottom radious maps of the finished guitar for future roughcutting the sides to 1/4".


 



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