I've got a closet in my spare bedroom (storage room) that I wanted to add another clothes hanger rod to.  Among my scrap pieces I had two 1.25" diameter closet rod sections that together would be long enough, but neither was long enough on their own.  The distance to span is roughly 22". 

 

This is a CNC-cut splice joint I came up with to solve the problem.   Test cut on smaller scraps shown in the photos.  I'm calling it my radial finger joint.  

 

Finished spliced rod now loaded with clothes and seems to be able to handle the weight with no complaint.  If it does fail eventually I'll report back.

 

4D

Edited July 3, 20178 yr by 4DThinker
Correct mistakes

Looks like it will be a very strong joint.  How did you hold the work pieces when you cut them?

 

David

SLICK...

57 minutes ago, difalkner said:

Looks like it will be a very strong joint.  How did you hold the work pieces when you cut them?

I have an adjustable angle/vertical clamping jig mounted to the front rail of my Probotix Meteor. Opening below is clear to the floor.  For round stock I first clamp a vertical edge against the vertical jig, then clamp the stock against the inside corner created between the jig and edge.  Quick-grip clamps with padded faces hold the round stock firm enough to cut with the CNC. 

 

4D

Very imaginative!

Did you use the inlay toolpaths for this joint or pocket and profile toolpaths?

3 minutes ago, MEBCWD said:

Did you use the inlay toolpaths for this joint or pocket and profile toolpaths?

Profile tool paths mainly for one half.  I drew the outline of the individual fingers and made sure my 3/16" bit would fit between them. Profile cutting around each one left a small bit of wood in the center of the dowel so I added a drill toolpath with the same bit to clear the center.  

 

The other half with a solid center was all pockets inside each individual finger.   Their outlines extended outside the dowel perimeter by 1/2 the bit diameter so the bit would leave crisp square edges at the dowel edge. . 

 

4D

That's what I like about Vectric software several people can be presented with the same problem and each one can use different tools in the software to get to the same final outcome.

Very nice. I like that a lot.

1 hour ago, MEBCWD said:

That's what I like about Vectric software several people can be presented with the same problem and each one can use different tools in the software to get to the same final outcome.

I often start out creating toolpaths for a student's project, say mostly complex shaped pockets.  I'll look at the time estimate and if it seems long then I usually can find another way to toolpath the job that shortens the time it will take. Profiles, especially if you can connect all the separate vectors, are almost always quicker than pockets.  

 

I had a 3D part to cut for a student that needed to be repeated 8 times.  The first one I created 3D Rough and 3D finish tool paths for.   We cut it and it took the entire 3 hour class.  I went home that night and fairly quickly drew up 2D profile toolpaths that together would create her 3D part.  I got the cut time down to 10 minutes per part.  We cut the last 7 in one class period, with time left over to clean up the mess.    The new Moulding toolpath that vectric added in version 8.5 does automatically what I had drawn up manually to do that time. 

 

4D

One thing about the pocket tool path in Vectric's software is that it often looks like it is wasting time going back to clear out small areas that are already clear.  Lots of lifts and plunges. If the same area can be cleared out by a Profile tool path, even if it takes drawing a few extra offset lines to do it, a tremendous amount of time can be saved VS Pocket tool paths.  If you connect all the vectors used when cutting ON the line then the bit will not waste time lifting and plunging. You can turn on a Solid coloring of the area cut in the plan view for each tool path you have created.  This will show any areas in a pocket that have or haven't been cleared using profile instead.  

 

4D

Late follow up on this thread, but since coming up with this joint I've had one student use it to connect three walnut dowel sections to the ends of three red oak dowels.  The dowels were parts of her creative coat rack design.  

I also noticed that Frank Howarth used the joint to connect the top of wood mallets to the handle of the mallets he made. He used his CNC to cut the joint.   I posted a comment on his youtube video about him finding a good application for the joint, but it appears my comment was deleted from that video page: 

 

4D

Edited February 6, 20206 yr by 4DThinker
Added video link

It's still a neat joint and interesting that your comment was deleted.  Curious, even...

 

David

I had included a link to my blog page about the joint which may have been against a youtube rule, a FH personal comment policy, or simply something Frank thought might be an unnecessary distraction from his video.   No knowing though. 

 

4D 

Came across this photo of  student's project which I used the dowel splice joint on.   She bought oak dowels, but they didn't come long enough for her idea. I told her to buy a walnut dowel from the same company and we could splice walnut to the ends of the oak dowels for a nice effect/detail.

Coat rack with key tray and hook for umbrellas.  Design by Ellie Williams. Nearly every piece and connections between them were done with the CNC. 

Oak posts are split and connect through the shelf with a short length of 3/8-16 all-thread.   I embedded a square nut near the ends, and capped the slot with a CNC cut walnut plug.  There is a heavy metal plate recessed into the base. The plate and the holes for bolts in it were cut on our CNC Plasma table.  There is a leather bottom in the key tray you can see in the foreground. I used a drag knife on the CNC to cut it out to perfectly match the shape of the recess, which I'd also cut on the CNC.   A few CNC "firsts" for me were done on this project. 

4D