Official Luthiers Forum!

Solely owned and operated by Lance Kragenbrink
It is currently Tue Dec 12, 2017 1:33 am


All times are UTC - 5 hours





Post new topic Reply to topic  [ 21 posts ] 
Author Message
 Post subject: CNC Fretboard fixture
PostPosted: Fri May 01, 2015 7:40 am 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Dec 27, 2004 9:42 pm
Posts: 4175
Location: Buffalo, NY
First name: Robert
Last Name: Cefalu
City: Buffalo
State: NY
Zip/Postal Code: 14217
Country: US
Looking for some suggestions on holding a fretboard blank. I want to be able to cut to size around the perimeter. radius them cut fret slots in one operation. I have a ATC so changing bits is no problem. I do too many to use double face tape so vacuum seems to be the only option. Any suggestions. TIA

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498


Top
 Profile  
 
PostPosted: Fri May 01, 2015 3:05 pm 
Offline
Cocobolo
Cocobolo

Joined: Wed Jan 08, 2014 7:58 pm
Posts: 147
First name: Leo
Last Name: Pedersen
City: Bowen Island
State: British Columbia
Zip/Postal Code: V0N 1G2
Country: Canada
Focus: Build
Status: Amateur
I've had good experiences with vacuum hold down and locator pins - one in each end of the fretboard blank.

With that scheme I've been able to radius, cut fret slots, inlays or position markers, and cut the taper down the sides, but I've been cutting the ends off by hand.

If your priority is to cut out the fretboard completely, including the ends, then perhaps tiny locator pins on the underside of the fretboard blank which don't go all the way through could work.


Top
 Profile  
 
PostPosted: Fri May 01, 2015 3:37 pm 
Offline
Koa
Koa
User avatar

Joined: Mon Nov 24, 2008 12:17 pm
Posts: 657
City: Escondido
State: CA
Zip/Postal Code: 92029
Country: USA
Focus: Build
Status: Semi-pro
I assume you have tried the obvious: double stick tape? That is what I use for radiusing, cutting fret slot, inlay, and profile (in that order usually). I admit that I have never taken the blank off the table and then tried to index it back for a second round of cutting. Is that what you are trying to do?


Top
 Profile  
 
PostPosted: Fri May 01, 2015 4:32 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Jun 12, 2008 6:59 am
Posts: 1904
Location: Rochester Michigan
I use vacuum as well and while I do have locating pins, I hardly ever use them as it takes too much time to cut them on the backs of the fretboards. Instead I use needle plates which keep them from squirming.

Full Disclosure - I also sell these needle plates on my website. I'm continually amazed because they are absolutely amazing to prevent vacuumed parts from squirming yet I've only sold a handful of them. I guess most people just don't understand

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com


Top
 Profile  
 
PostPosted: Fri May 01, 2015 6:30 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Dec 27, 2004 9:42 pm
Posts: 4175
Location: Buffalo, NY
First name: Robert
Last Name: Cefalu
City: Buffalo
State: NY
Zip/Postal Code: 14217
Country: US
rlrhett wrote:
I assume you have tried the obvious: double stick tape? That is what I use for radiusing, cutting fret slot, inlay, and profile (in that order usually). I admit that I have never taken the blank off the table and then tried to index it back for a second round of cutting. Is that what you are trying to do?

Too time consumong when you have a lot to machine.

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498


Top
 Profile  
 
PostPosted: Fri May 01, 2015 6:32 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Dec 27, 2004 9:42 pm
Posts: 4175
Location: Buffalo, NY
First name: Robert
Last Name: Cefalu
City: Buffalo
State: NY
Zip/Postal Code: 14217
Country: US
Durero wrote:
I've had good experiences with vacuum hold down and locator pins - one in each end of the fretboard blank.

With that scheme I've been able to radius, cut fret slots, inlays or position markers, and cut the taper down the sides, but I've been cutting the ends off by hand.

If your priority is to cut out the fretboard completely, including the ends, then perhaps tiny locator pins on the underside of the fretboard blank which don't go all the way through could work.

Leo what are you using for vacuum pump. Would you have any pics of your setup?

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498


Top
 Profile  
 
PostPosted: Fri May 01, 2015 10:00 pm 
Offline
Koa
Koa

Joined: Sat May 19, 2007 11:03 am
Posts: 1737
Location: Litchfield MI
Focus: Build
Status: Professional
Our blanks are prepped with counter sunk holes on center at each end, boards are then fastened to the machine bed with aluminum or brass screws. Same holes are used to locate for contour and fret slot operations.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/


Top
 Profile  
 
PostPosted: Sat May 02, 2015 3:25 am 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Dec 27, 2004 9:42 pm
Posts: 4175
Location: Buffalo, NY
First name: Robert
Last Name: Cefalu
City: Buffalo
State: NY
Zip/Postal Code: 14217
Country: US
kencierp wrote:
Our blanks are prepped with counter sunk holes on center at each end, boards are then fastened to the machine bed with aluminum or brass screws. Same holes are used to locate for contour and fret slot operations.


Ken so you rough thickness the blanks before drilling the holes? Is your bed mdf? If so
won't the screw holes wear out and not hold after a while?

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498


Top
 Profile  
 
PostPosted: Sat May 02, 2015 5:57 am 
Offline
Cocobolo
Cocobolo
User avatar

Joined: Fri Jun 22, 2007 11:14 am
Posts: 355
Location: United States
I use a vacuum holddown with three 1/8" brass index pins that align the rough boards to the jig. The fingerboard blank is flattened on the back side, three index holes drilled about 1/8" deep. These same index holes are used for alignment to the neck later on, but at this point they lock the blank onto the clamp. Since I don't have a tool changer, I'll run several boards through a given operation, then set the next operation up and run them all again. The index pins keep everything in line over multiple operations. I surface/arch the boards, slot them, cut inlay pockets and cut to final profile on the same vacuum setup. I just use a small continuous running Gast pump for vacuum.

Dave


Top
 Profile  
 
PostPosted: Sat May 02, 2015 6:43 am 
Offline
Koa
Koa

Joined: Sat May 19, 2007 11:03 am
Posts: 1737
Location: Litchfield MI
Focus: Build
Status: Professional
Bob -- the boards are surfaced one side. For many of our parts we use job specific pallets on top of the machine bed, the pallets are interchangeable for our three machines, the pallets have threaded inserts.

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/


Top
 Profile  
 
PostPosted: Sat May 02, 2015 10:36 am 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Mon Dec 27, 2004 9:42 pm
Posts: 4175
Location: Buffalo, NY
First name: Robert
Last Name: Cefalu
City: Buffalo
State: NY
Zip/Postal Code: 14217
Country: US
ballbanjos wrote:
I use a vacuum holddown with three 1/8" brass index pins that align the rough boards to the jig. The fingerboard blank is flattened on the back side, three index holes drilled about 1/8" deep. These same index holes are used for alignment to the neck later on, but at this point they lock the blank onto the clamp. Since I don't have a tool changer, I'll run several boards through a given operation, then set the next operation up and run them all again. The index pins keep everything in line over multiple operations. I surface/arch the boards, slot them, cut inlay pockets and cut to final profile on the same vacuum setup. I just use a small continuous running Gast pump for vacuum.

Dave


Bob good ideas Ken and Dave. Dave I use the same setuo and software as you do. Right now I have been using VCarve Pro and Rhino. I do radius the fret slots so I would like to be able to drill for pin holes in one operation then cut outline, radius top, cut fret slots in Rhino. After I get done with this batch that has to go out the door on Mon. I will be back to pick your brain. bliss

_________________
Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498


Top
 Profile  
 
PostPosted: Sat May 02, 2015 3:34 pm 
Offline
Cocobolo
Cocobolo

Joined: Wed Jan 08, 2014 7:58 pm
Posts: 147
First name: Leo
Last Name: Pedersen
City: Bowen Island
State: British Columbia
Zip/Postal Code: V0N 1G2
Country: Canada
Focus: Build
Status: Amateur
Andy Birko wrote:
I use vacuum as well and while I do have locating pins, I hardly ever use them as it takes too much time to cut them on the backs of the fretboards. Instead I use needle plates which keep them from squirming.

Full Disclosure - I also sell these needle plates on my website. I'm continually amazed because they are absolutely amazing to prevent vacuumed parts from squirming yet I've only sold a handful of them. I guess most people just don't understand


:idea:
I think the lightbulb just went on for me regarding your needle plates. I've seen you post about them before but for some reason the idea just didn't stick in my head.

Now that you've mentioned them in this context it sounds like I could be saving myself from having to drill indexing holes on the back of every fretboard, flip them over and pin them back into the vacuum jig, and cut the front. Could be a significant time saver.


Do you mind sharing any photos or just the number of needle plates you use for fretboard hold-down? Is a couple at each end enough?

I'm pretty sure I'm going to have to buy some from you.


Top
 Profile  
 
PostPosted: Sun May 03, 2015 9:08 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Jun 12, 2008 6:59 am
Posts: 1904
Location: Rochester Michigan
I've never had to use more than two plates on any part I've cut, be it fretboards or whatever. For fretboards I use the .5mm plates.

Here's a shot of my fixture

Attachment:
ImageUploadedByTapatalk1430662004.566618.jpg


Attachment:
ImageUploadedByTapatalk1430662039.034067.jpg


If you need the alignment pins anyway it doesn't save time but if you don't, it's a no brainer.


Sent from my iPhone using Tapatalk


You do not have the required permissions to view the files attached to this post.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com



These users thanked the author Andy Birko for the post: Durero (Tue May 05, 2015 12:16 am)
Top
 Profile  
 
PostPosted: Tue May 05, 2015 9:22 am 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Tue May 02, 2006 9:02 am
Posts: 2347
Location: Canada
First name: Bob
Last Name: Garrish
City: Toronto
State: Ontario
Country: Canada
Status: Professional
I used to use two shallow pin holes on the backs, with 1/8" pins in them, on the vacuum fixture. As an inlay guy, I had a lot of broken off carbide micro-mills, so I drilled a few deep holes in my fixture and used them as no-drill indexing pins.

The needle plates didn't exist for purchase back then. If I were doing it now, I'd just buy a couple of those for my fixture. They barely cost more than the little cutters I was breaking!

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services


Top
 Profile  
 
PostPosted: Thu May 07, 2015 1:35 am 
Offline
Cocobolo
Cocobolo

Joined: Fri Dec 01, 2006 6:44 pm
Posts: 437
Location: Australia
First name: Allen
Last Name: McFarlen
City: Mt. Sheridan
State: Qld.
Zip/Postal Code: 4868
Country: Australia
Focus: Build
Status: Professional
Hey Andy, what do you call the material that your vacuum jig plate is made from?

_________________
Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia


Top
 Profile  
 
PostPosted: Thu May 07, 2015 9:22 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Jun 12, 2008 6:59 am
Posts: 1904
Location: Rochester Michigan
That stuff is something called Tooling Board from General Plastics. A bunch of companies make it and the stuff is fantastic. I use the 40lb / ft^3 stuff. It's important to find a local supplier because shipping is usually pretty high.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com


Top
 Profile  
 
PostPosted: Fri May 08, 2015 4:55 pm 
Offline
Cocobolo
Cocobolo

Joined: Fri Dec 01, 2006 6:44 pm
Posts: 437
Location: Australia
First name: Allen
Last Name: McFarlen
City: Mt. Sheridan
State: Qld.
Zip/Postal Code: 4868
Country: Australia
Focus: Build
Status: Professional
Thanks. Living in the very north of Australia, nothing is local. So I'll have to look way down south in Brisbane perhaps.

_________________
Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia


Top
 Profile  
 
PostPosted: Tue Dec 01, 2015 12:06 am 
Offline
Koa
Koa

Joined: Fri Jan 25, 2008 9:55 am
Posts: 951
Location: Traverse City Michigan
Andy Birko wrote:
I've never had to use more than two plates on any part I've cut, be it fretboards or whatever. For fretboards I use the .5mm plates.

Here's a shot of my fixture

Attachment:
ImageUploadedByTapatalk1430662004.566618.jpg


Attachment:
ImageUploadedByTapatalk1430662039.034067.jpg


If you need the alignment pins anyway it doesn't save time but if you don't, it's a no brainer.


Sent from my iPhone using Tapatalk

Andy,
Can you make me one of these? for one single fingerboard only. Ship to TC MI.

I will email you.

_________________
Ken


Top
 Profile  
 
PostPosted: Wed Dec 16, 2015 9:07 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Wed Feb 20, 2008 7:15 pm
Posts: 4753
First name: Ed
Last Name: Bond
City: Vancouver
Country: Canada
Focus: Build
Status: Professional
The fixture from my past life was much like Andy's pic, but held more boards.

It was made from phenolic, and the height was a bit higher than Andy's. Basically, they were suspended 3-4" above the phenolic bed so that the spiral bit could come in and cut the taper without wrecking the platform beneath.

They were held in place with vacuum and 1/8" index pins.

They were thicknessed on the wide belt first, which just makes sense to me.

I thought that using the CNC to cut the index holes might have been a bit of a time soak. I'd have thought that a jig with drill guide bushings and a drill press could get through a pile of boards faster than having to load the machine, run, and unload. But I guess it depends on machine speed.


Top
 Profile  
 
PostPosted: Thu Dec 17, 2015 8:21 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Tue May 02, 2006 9:02 am
Posts: 2347
Location: Canada
First name: Bob
Last Name: Garrish
City: Toronto
State: Ontario
Country: Canada
Status: Professional
meddlingfool wrote:
I thought that using the CNC to cut the index holes might have been a bit of a time soak. I'd have thought that a jig with drill guide bushings and a drill press could get through a pile of boards faster than having to load the machine, run, and unload. But I guess it depends on machine speed.


I used the same fixture to drill the holes and to machine the boards, I just took the index pins out when I was cutting the backs of the boards. You can get cooking pretty fast when it takes five seconds to reload the vacuum fixture and two seconds to drill the holes. You can also hold necks on the exact same fixture plus possibly a support for the headstock.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services


Top
 Profile  
 
PostPosted: Wed Jan 13, 2016 12:08 pm 
Offline
Koa
Koa
User avatar

Joined: Fri Jan 15, 2010 3:34 pm
Posts: 1990
First name: Stuart
Last Name: Gort
Country: USA
Focus: Build
Status: Semi-pro
Another thing to keep in mind is that if you use pins to hold your fretboards down to a vacuum fixture....those same holes can be drilled into your necks in order to register the fretboard to the neck while gluing.

Doing this registers the fretboard and fret slots to the neck cad model....which can't hurt the process of achieving good intonation any.

I'll snap some pictures of my method today.

_________________
I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 21 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com