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Friday, November 14, 2025

T-Slot Wood Clamps for my CNC

Four clamps conspiring
This is not a new design of mine.  I've been using these wood clamps for several years.  They are sacrificial though and many have encountered spinning router bits during their lives. 

A few of the scrap wood blocks in my collection have hinted that they'd like to be clamps. As such this post is about granting that desire and replacing some previous clamps that are near death. 

My previous clamps were cut from larger boards,  A few were cut as two halves that I glued together.  A few were cut from thicker boards, then turned 90 degrees so I could cut the slot for the bolt in them.  

The length of these clamps is not critical to their usefulness and can vary. 

The first one (upper right)  I made from a dense white oak scrap.  It suffered a few broke out chips when the bottom edge was flush cut after the CNC was done. It works despite those missing bits. 

The second clamp I cut from a scrap of birch (lower left).  It also gave me some grief as I made a mistake when clamping the scrap block down. I stopped the CNC after the first pass when I realized that mistake.  It works but has a few scars from my bandsaw, drum, sand disk sanders.

The last two clamps were cut from a 5/8" thick scrap of walnut. Room enough for 4 halves that when glued together made two clamps. I added an alignment hole for a 3/4" long section of 1/4"diameter wood dowel to make it easier to clamp the halves together and aligned. 

One Scrap, Four clamp halves
Making them in halves is the most reliable method. Especially if you don't have an easy way to cut the slot after cutting out the clamp profile from the side. 

These clamps hold the work down and also prevent it from moving sideways.  Made from wood you don't have to worry if a router bit accidently encounters one. Should one or more  be ruined from such an encounters making replacements is easy. 

4D 

Saturday, November 1, 2025

Updated Wrench Handle for my Bench Vise

New handle.  Teak Oil Finish.
While there is nothing fundamentally wrong with the plywood handle I made for my garage bench vise, there are a couple of changes that could make it more useful. 
Plywood Handle
The first issue it that the handle extends above the top of the vise when vertical, and has occasionally been limited in use by objects I wants to clamp down that hang over the edge. The second issue is that it doesn't slip off easily.  If it did I could easily overcome the first issue by sliding it off and rotating it 60 or 120 degrees before slipping it back on.   I do this with the wrench handle I made for my CNC low profile vise. 

First thing needed was a CNC file and a piece of wood to make the new handle from.
Render from my Aspire software.
The wood used was a heavy and dense block of white oak.  The nut pocket, shaft hole, end hole, rounded off edges, and perimeter outline were all cut using my CNC.  The bottom side details were finished on my trim router table.  Holes for the pivot pin were drilled out on my drill press. 
When flat the new handle is the same length as the old one. The hinge allows folding the new one out to clear anything hanging over the edge of the vise.

Handle folds out.
This handle was eventually sealed with teak oil to protect the wood. It slides on and slips off easily but stays in place otherwise. 

Iteration is always a worthwhile endeavor.  The initial wrench handle worked, but use of it revealed the flaws that needed fixing.  Should the new handle reveal any new insufficiency a 3rd iteration may be needed.   Time will tell. 

4D

Wednesday, October 15, 2025

Compartmented Box for M6 Screw Assortment

I needed some flat head M6 screws for a project, and they came in a cheap subdivided plastic box. Sizes vary from 6mm to 22mm long.  The shiny stainless steel screws looked to me like they deserved a nicer box. This compartmented walnut box was made to hold them. 

Compartmented Box

The lid for the box slips onto the box easy and wedges down securely with a 3 degree tapered edge.  While I do have another piece of walnut that I could use for the top, a scrap of salvaged weathered wood with more interesting grain challenged that presumption. It was thick enough that a second use was cut into the top of it. 
Lid from a Weathered Wood Scrap
It now is a shallow tray to coral whatever small parts my current project may need. 
Parts Tray
A simple project.  Pocket toolpaths for the inner compartments. A profile toolpath for the perimeter. Another pocket for the rabbet edge on the underside of the lid.  Another profile toolpath for the outer shape of the lid.  Then the lid was flipped over to pocket cut the recess center of the tray, and round the inner edge of the recess using a profile on-the-line with a 3/8"d ball end bit.  

Comments encouraged!

4D

Saturday, October 11, 2025

Nesting Boxes.

 As my collection of wood scraps vary in length, width, and thickness, it occurred to me that a series of boxes that nest together might be a fun project to make.  Open the largest one to find a slightly smaller one inside.  Open that box to find an even smaller box inside it. Open that smallest box and there may be a surprise to find inside it. 

This story is not yet complete, but it starts with one box.

One Box. 2.625" x 1.75" x 1.5: tall.

Open the lid to find the lid of another smaller box.

Something inside.

Remove it to discover that lid covers another box.

Box #2. 2.25"x 1.375" x 1" tall.
Open the lid of box #2....
To find Box #3.
Box #3 is missing a lid.  The lid will have a dovetailed edge that slides in from the side.  That lid is yet to come. 
Three nesting boxes. 
With a range of router bits available, and a range of scraps in varying thicknesses available, CNC cut boxes can be made in a range of sizes.  The smallest box is 1.75" x 15/16" x 7/16" thick. It was cut with a 1/8" diameter bit.  An even smaller box may come, as I do have a 1/16" diameter bit.  Larger purely CNC cut boxes are limited by the length of the available bits and the Z axis range of my CNC. A constructed box with 4 sides, a bottom, and a lid may yet encase these nested CNC cut boxes.  Time and the available wood scraps I have will tell. 

4D

  

Friday, October 10, 2025

Table Saw Throat Plate Fix

My table saw's throat plate is unsupported at the end next to the blade slot. It will flex down when I'm cutting thin strip and cause them to catch on the lip of the table top. This is a solution for that design flaw.
Throat plate unsupported here.
Three inches or so below that area is the top edge of the blade housing. I carefully measured how thick the housing was, how far it was below the table saw bed, and how thick the throat plate was at that spot.
1" Dowel to Support the Throat Plate
I cut a slot in the bottom end of a 1" dowel to slip snuggly over the blade housing.  The dowel now stands up to support the throat plate. 

A simple solution for a nasty design flaw.  I only wish I'd gotten around to solving this 10 years ago. 

4D


 

Sunday, October 5, 2025

A Small Maple Box with a Contoured Lid.

This little box was cut from 4 corner scraps left over from a previous project.  The 4 corners were glued together to make a board with enough area for this 3" x 3" box. 

The lid was made from a scrap of Walnut wood I found in my scrap bin. The walnut was a bit thicker than I liked, so I cut the top to taper down to a thinner edge. 

Contoured Top
The bottom has a rabbet edge with a 3 degree slope for a fit that slips on easy but wedges tight.
Rabbeted edge
The lid overhangs the box by 1/16" to make it easier to pop the lid off. 
Overhanging Edge
The contrast between lid and box wasn't my original intent.  I started with a scrap of beech for the top but it worked loose while being cut and was ruined. A constant potential of using the CNC for making small parts.  I may darken the box with a walnut stain to lessen the contrast between box and lid. 

4D

 

Friday, October 3, 2025

Low Angle Dovetail Joint

I found this joint sample hiding in a box of CNC-cut joinery samples I made for students to consider when designing their project. 

For Low Angle Corners

One half slides into the other half.

Not quite as simple as it looks to cut
I endeavored to figure out how to connect wood pieces at any angle with a CNC-cut joint while I was teaching.  This is an extreme sample that I don't remember ever using for a student project.  The left half in the photo above is the complicated one to cut.  The sides taper in as the bottom of the dovetail is narrower than the top.  

This sample will return to the box I found it in to wait hopefully for the day when it can come out to inspire a real corner connection on an actual project. 

4D