How to Make Handscrew Clamps
Introduction: How to Make Handscrew Clamps
I've always liked these handscrew clamps and own a pair but sometimes they are too big and a bit cumbersome. So I decided to make a smaller pair for smaller clamping jobs. Mainly I want to use these for work holding or for holding small diameter dowels when cutting them on the bandsaw.
Supplies
3/4 inch Square Hardwood
1/4 inch Brass rod
3/8 inch Brass Tube
3/8 inch Mild Steel Rod
Barrel Nuts
1/4 - 20 Right Hand Tap and Die
1/4 - 20 Left Hand Tap and Die
Table Saw
Lathe
Lathe Tools
Drill
Drill press
Drill Vice
Hacksaw or Portable Bandsaw for cutting metal
Belt Sander
Various Grit Sand Paper
25/64 inch Drill Bit
5/16 inch Drill Bit
3/8 inch Drill Bit
Bench Vice
Center Punch
Blow Torch
Brass Wire Brush
Danish Tung Oil
Step 1:
I first prepped the wood, in this case its some 3/4 inch Walnut stock that I used. I ran the pieces through my table saw to make sure they were 3/4 inch square then I marked and cut some 4" pieces. I used my belt sander to sand all four sides and make sure they were parallel to one another.
Step 2:
I have to be honest here before making these I had no real idea of how these worked so I sort of had to figure it out as I went along. They are fairly simple but I had never really put much thought in to the mechanism of their operation.
I bought some barrel nuts aka cross dowel nuts that I used to mock up their location on the wood blanks. When I found what looked about right I marked the wood for drilling. Their location isn't really crucial as long as you stay above the half way mark of the length of the wood and space them evenly. Also make sure the holes are drilled in the same location on both pieces of wood. The barrel nuts were 25/64 inch in diameter so I drilled those four holes first. Initially I thought I would be using four purchased barrel nuts for each clamp, later I realized I had to make my own for one side.
After making the holes for the barrel nuts I next transferred the lines to the adjacent side of the wood in order to drill the holes for the screw portion. I used a 5/16 inch drill bit for these holes. You can see in the last pic the eight holes drilled in each piece. 582
You will also notice that the 5/16 inch holes are elongated this is to allow for some play side to side where the threaded rods come through. To elongate the holes I just twisted the wood blank up and down while drilling. This could also be done with a router but I chose to use the side of the drill bit.
Step 3:
I cut a 12 inch brass rod in to two equal sections using my portable bandsaw table.
A little bit of a disclaimer I am skipping my mistakes and getting to what I eventually figured out after some trial and error and a little research. I wasted about 2 feet of brass rod in my experimentation, I really should have just done the research before my first attempt and saved some time and material.
Step 4:
The first picture shows you a threaded brass rod and a brass rod with some markings. In order to get these clamps to work the screw portion has to have two different thread types, one half has a right hand thread, your traditional thread righty tighty lefty loosey, and the other half has a left hand thread. The rod with the markings shows an exaggerated view of what the threading on the rod actually looks like. This threading is necessary if you want the clamps to work like the traditional ones where you can hold the handles and spin them like a bicycle crank. In order to accomplish this you need two thread cutting dies a Right Hand thread cutting die and a Left Hand cutting die. You will also need a Left Hand tap as well because a left hand threaded screw will not screw in to a right hand threaded nut.
Step 5:
I used my bench vise to hold the thread dies. I made sure to round off the ends of the brass rods so they would find the die center more easily. Next I chucked the brass rods in my hand drill and ran them through the right hand thread cutting die but only to the half way point of the brass rod. Then I removed the brass rod from the drill flipped it over end over end and chucked it back up in my hand drill and ran the brass rod through the left hand thread cutting die up to the half way point. I left a tiny section of brass rod right in the middle that was left untouched by either die. 56