Jump to content
Sign in to follow this  
Southpa

Compound radius sanding blocks

Recommended Posts

A buddy at work finally got around to making these for me.  Was about a year and a half before he could swing this little "rabbit" between company jobs (shhhh, nuff said :))   But it was well worth the wait.  The faces merge from 10" to 16" radius over a 20" length.  3" wide and the chambering was his idea to maintain ridgidity, ie. WILL NOT warp.  I made the handles out of 1/2", NC bolts, he was nice enough to drill and tap those holes, and cut up oak broom handle.  Gotta admit I work with some of the best talent in the country.  I was only looking for one but he offered to do two so...what the hey!  I can use one for coarse sanding and t'other for fine sanding.  I'm looking forward to making accurate "true" radius compound fretboards. 

HPIM3712.JPG

Share this post


Link to post
Share on other sites

Very impressive. :thumb:

Is there some kind of technique you need to employ to prevent accidentally sanding a 10" and 16" 'flat spot' in the fretboard ends while sanding? I'm having trouble envisaging how you could use these with the traditional 'scrubbing' methods and get a consistent radius taper from one end of the fretboard to the other.

Share this post


Link to post
Share on other sites

I can't see any real technique involved aside from sliding the block back and forth over the fret board.  So long as the fb is straight, pre-slotted and pre-inlaid, I can't see any issues.  Like sanding anything it should be done uniformly, ie. no excess rocking and rolling as well as using a contrasting guide coat ( eg white chalk on dark surface.  

This is simply a 20" long X 3" wide segment of a cone with radius graduating from 10" to 16". 

Share this post


Link to post
Share on other sites
1 hour ago, Southpa said:

This is simply a 20" long X 3" wide segment of a cone with radius graduating from 10" to 16". 

I guess the thing that doesn't sit right in my head is that by keeping the fretboard stationary and moving that conical segment across the length of the fretboard, the profile won't be transferred from the cone to the fretboard with the same dimensions.

The way I see it, the only way you can transfer the 10" to 16" conical shape directly to the full length of the fretboard, with a linear radius gradient from nut to 24th fret, is if the radius block and fretboard don't move but the sandpaper does, a bit like a belt sander with a bed that has the compound radius cast into it. To my thinking, sanding using the compound radius block the 'traditional' way will give you a fretboard where the first couple of inches is 10" radius, the last couple of inches are 16" radius, (depending on how much overlap you introduce scrubbing the sanding block past the extremities of the fretboard) and the area in between will be a compacted taper from 10" to 16".

Share this post


Link to post
Share on other sites

Cant see that working either! Unless it is attached to a random orbital sander which will keep the block relatively stationary with respect to the fretboard. 

Scrubbing back and forward is going to always round the board to the lowest radius in contact over the area it is in contact with

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...