Handmade Jeweler's Saw

I make my living as a professional jeweler and as such I use my saw a LOT.

After using several saws over the years I finally decided to make one for myself that would address the shortcomings of the saws I have.

The smaller saw shown is my daily driver. I like it because it's pretty rigid and it has adjustable tension for the blade. The blade tensioner however fits very loose in the frame and wobbles quite a bit unless it is fully tightened- and when it's fully tightened it twists to one side, putting a bend in the blade.

The second saw shown is typically referred to as a "German saw." These saw are formed from flat steel. The cutting depth is much greater than my daily use saw but it's nowhere near as rigid and there's no blade tension adjuster. With this type of saw you compress the frame and then tighten the blade clamps to set the blade tension, which is a less than ideal method.

I've seen a few saws on the market that have really nice rigid frame designs but they typically don't have any adjustment for blade length like my current saws. With my new saw design you can unthread the handle and raise the lower blade clamp, allowing you to use a shorter saw blade- no throwing away blades that have broken right at the end!

Let's get started!

There are a lot of different ways to make a saw like this.

Instead of brass for the blade clamps you could substitute Aluminum. You could replace the Aluminum frame with one cut from carbon fiber sheet to make it lighter and more rigid or maybe even try 3d printing the frame in a carbon reinforced material. The only thing that really matters is that the frame be reasonably stiff and light weight.

Materials:

1/4" thick 6061-T6 Aluminum sheet (4 3/4"" x 7 1/2") - used to make the saw frame.

1/2" x 1/2" x 1" 6061-T6 Aluminum blocks (2ea) - used to make the blade clamp mounts

3/8" diameter brass rod (about 5" length) - used to make the blade clamps and handle threaded section.

10-32 thread x 1 1/2" long stainless socket head shoulder cap screw (3ea) - used to make the adjuster knob studs.

10-32 thread x 2" long stainless socket head shoulder cap screw (1ea) - used to make the tension adjust screw

10-32 threaded stainless rod x 3" length (1ea) - used to make the lower blade clamp/handle adjuster.

1" diameter wood dowel x 5" length (1ea) - used to make the handle.

6-32 thread x 3/8" length stainless flat head socket screws (x4) - used to secure the blade clamp mounts to the frame. If you don't mind the screws sticking out you can use a 1/2" long button head or socket head cap screw and save yourself the trouble of recessing the screw head (but it won't look as pretty!)

6-32 thread x 3/16" long set screws - used in the blade clamps.

10-32 threaded brass thumb nuts (4ea) - used for the adjuster/blade securing knobs. You can also purchase premade threaded brass knobs.

I get my brass and Aluminum from a local metal recycler and the knobs/threaded hardware were purchased at a local hardware store -the total cost of materials was about $18

Tools:

Center drill

6-32 tap + drill bit

10-32 tap + drill bit

6-32 threading die

1/4" drill bit

#41 drill bit

Step drill bit (1/2" max hole size)

1/8" + 1/4" end mills

Center punch

Countersink bit

Dremel cut-off wheel

Deburring tool

Allen wrenches

Band saw

Drill press

Lathe

Benchtop mill

Belt sander

Red Loctite

Gorilla Glue super glue

This is pretty much everything I used. A drill press is essential but there are workarounds for the lathe, mill, belt sander, and band saw- I'll give some suggestions in each section. Also be sure to click on each photo as there are notes in the photos.

Time to cut some metal!

The 1/4" thick Aluminum spine is the heart of this saw and is what allows it to hold the blade with such high tension. Jeweler's saws (also commonly referred to as a fret saw) use pinless blades measuring 130mm (about 5 1/8") in length. I made the saw frame opening 5 9/16" long to allow room for the blade clamps and a tension distance of 3/16". The saw frame depth was set at 3 9/16", giving a total cut depth of just over 3 3/4" (the cut depth can be anything you want- only the saw frame opening length is critical to the type of saw blades you are using.)

The back of the spine is 1" wide and the front edges where the blade clamp mounts are 1/2" wide. 1/2" diameter holes were equally spaced around the frame, with the holes slightly smaller at the front of the frame. Everything was marked out on the Aluminum sheet and the holes along with the inside corners were drilled through using a step drill. A step drill tends to give much cleaner holes than a traditional drill.

Next I cut the frame out using a bandsaw and the edges were cleaned up using a belt sander and deburring tool. Deburring tools are great for breaking sharp edges, especially around holes. If you don't have a deburring tool a small file also works to break those sharp edges. I then used a red Scotchbrite pad to rub a smooth finish on the frame.

If you don't have access to a bandsaw you can draw up the design using a free vector graphics program like Inkscape and have a service like Sendcutsend.com laser cut the frame for you. I have included both a .pdf template to print out if you want to cut it using a bandsaw as well as a .eps file for laser cutting.

The clamp mounts are made from 1/2" thick Aluminum- they measure 1/2' wide x 1/2" deep x 1" long. I cut them from some Alumiinum plate using the bandsaw.

Since the saw frame is 1/4" thick material I needed a way to attach the clamp mounts to the frame. This was done by milling a 1/4" wide slot so the mount could slide over the frame- that way I could run bolts through the mounts and frame, holding it all together. I decided to run two recessed flat head 6-32 socket head screws through each mount to secure it to the frame. I chose to have the screws fit flush as I tend to hold the saw in that area with my thumb and forefinger and I didn't want screws sticking out.

The top and bottom clamp are nearly identical - the top clamp is drilled so a 10-32 bolt can slide through it (the blade tensioner) while the bottom clamp is threaded for a 10-32 threaded rod (for the handle.) The top clamp also has a 6-32 threaded hole in one side for the tension securing knob screw.

Once the mounts are made and the necessary holes are drilled they need to be mounted to the saw frame. First the front edges of the saw frame have to be rounded over (using a belt sander or file) so the clamp mounts can fit properly. Then matching holes are drilled through the ends of the saw frame and tapped for the 6-32 screws that secure the mounts to the frame.

I milled the 1/4" wide slots using my lathe with a milling attachment (my lathe has a more powerful motor than my little benchtop mill.) If you don't have access to a lathe or mill you could make the slots by drilling a 1/4" hole (or series of holes) and then using a saw and files to clean up the slot so it can fit over the saw frame ends.

The blade clamps are made from 3/8" diameter brass rod.

The rod is held in the lathe and the hole for the blade is drilled using a center drill followed by a small drill that is slightly larger than the largest size blade you want to use (in my case this was about a .040" hole.) The center drill will leave a slight bevel on the hole, which helps guide the saw blade in. I put a slight bevel on the outer edge of the brass rod so I didn't leave a sharp edge there for my fingers to hit when trying to fit a saw blade.

Once the blade hole is drilled the rod is cut off at 1/2" length using a parting tool. The 1/2" long piece is then flipped around so a 3/16" deep 10-32 thread can be cut in the other side. The 10-32 thread is so the clamps can be threaded onto the tensioning screw and the threaded rod that attaches to the handle.

Both blade clamps require a 6-32 threaded through hole perpendicular to the blade hole. This allows for a fixed 3/16" long 6-32 set screw in one side and a blade securing knob/screw in the other to hold the saw blade in the hole when it is tensioned.

Making this part would be difficult without a lathe- but is is doable using a drill press and being careful about alignment. The trick would be making sure to drill exactly on center so the holes line up properly between the saw blade hole and the 10-32 threaded hole.

The blade tension threaded adjuster is made from a 2" long 10-32 thread stainless shoulder cap screw.

A long flat was milled in the screw using a 1/8" end mill on the benchtop micro mill. The flat section is there to keep the upper blade clamp from rotating during tensioning and to allow the adjuster knob to tighten down on the threaded adjuster without damaging the threads once the tension is set.

Once the flat is cut the screw is threaded into the upper blade clamp and tightened. Red Loctite is used to make sure it stays put. I threaded a 6-32 screw into the blade clamp to make it easier to hold onto and turn during assembly. It is super important that the flat section and the 6-32 threaded hole in the blade clamp be in alignment with each other. If they are not perfectly in line with each other the blade will twist when you tighten down the threaded adjuster securing knob.

After the upper blade clamp is secured to the tensioning screw the remaining part of the 10-32 shoulder bolt can be cut off. Be sure to clean up the edge of the screw threads at the cut so the 10-32 brass knob will thread cleanly onto the screw. There should be enough thread so you have about 3/16" length of adjustment at the end of the saw frame in order to tension the saw blade.

The 3" long 10-32 threaded rod is fit into the lathe and a small deep hole is drilled to allow clearance for the saw blade to slide in. This hole is there for additional adjustment- it allows you to raise and lower the lower blade clamp as well as allow for odd length saw blades. If that hole wasn't there the blade could bottom out on the lower blade clamp.

The lower blade clamp is threaded onto the 10-32 threaded rod and secured using red Loctite just like the upper blade clamp. I tightened two nuts back to back on the rod in order to make it easier to tighten onto the blade clamp.

The blade clamp assemblies were then assembled with the saw frame/clamp mount assembly.

If you don't have a mill you can make the flat on the tension threaded adjuster using a file- just make the flat about 1/8" wide. The blade hole for the lower 10-32 threaded could be drilled (with careful alignment) on a drill press.

You could just buy three knobs that have a 6-32 threaded stud for this but where's the fun in that?

All three of these knobs are the same with one exception- the end on the tension adjuster securing knob needs the end to be a bit smaller diameter to fit the 1/8" slot I milled in the tension adjuster screw. If you filed a flat vs. milling a groove it doesn't matter.

To make the studs for the knobs I cut three 10-32 shoulder bolts just beyond the threaded part on the shoulder. This is so when the brass knob is threaded on it will bottom out against the end of the thread and not come off. A slot for a flat bladed screwdriver was cut in the end of the shoulder side to make tightening down the knob easier. The slot was cut using a thick Dremel cut off wheel.

The bolts were marked for the necessary length of 6-32 thread I needed to cut (about 1/4") and were placed in the lathe so they could be turned down to the proper diameter. For the tension adjuster knob a small step was cut so it would better fit the adjuster slot. Once they were turned down they were taken out of the lathe collet and flipped around and held in the tailstock chuck so they could be threaded. Threading was done by placing a 6-32 threading die into a three jaw chuck on the lathe and slowly feeding the bolt in while turning the threading die by hand. Using a lot of cutting fluid definitely helps here!

One trick I did was to thread a 10-32 nut onto the bolt before cutting the 6-32 thread. This serves as a stop for the die during threading and prevents the end of the 10-32 thread from getting messed up.

Once the studs were finished the 10-32 brass knobs were threaded on and tightened down. A bit of red Loctite helps these from coming loose later.

In the home stretch!

I made the handle using a bit of hardwood dowel leftover from when I made a Sonic Screwdriver. You can use any type of wood you like but a 1" diameter dowel will give you a good starting size without having to remove too much material.

The wood handle is glued to a threaded brass rod section that allows the internal threaded rod to be threaded up/down in the lower blade clamp mount- this means that the lower blade clamp can be raised or lowered and then the handle can be rotated to lock it into position.

In order to attach the wood handle to the 10-32 threaded rod I made a brass insert. A length of 3/8" diameter brass rod was fit into the lathe and one end was drilled and tapped for 10-32 thread about 3/4" deep. Next the rod was flipped around and was drilled through with a drill bit just large enough to slide over the 10-32 threaded rod. After this the lower section of the rod was turned down to 1/4" diameter.

The wood dowel was then chucked into the lathe, turned down to a suitable shape, and a 1/4" hole for the brass insert was drilled into the small end. After sanding and waxing the handle it was glued onto the brass insert using Gorilla Glue super glue.

Time for final assembly!

This just involved threading in the adjuster knobs and making sure everything was in alignment.

To fit a saw blade you first loosen the tension securing knob slightly and unthread the tension adjuster knob so about 3/16" thread is showing. Next fit the saw blade into the blade clamp holes. With the blade centered in the hole tighten the small set screw using an allen wrench until it just touches the saw blade. Now tighten down the blade clamp knobs. With super thin blades (size 8/0) you have to be a bit careful as you can put so much force on it that you break the end of the blade.

Once the blade is secured you can apply tension to the saw blade by turning the tension adjuster knob. Once you have the amount of tension you want tighten down the tension securing knob and you are good to go! This all sounds a bit more complex than it is in actual practice- it's really pretty easy to fit and tension blades.

It is amazing how rigid this saw is and how much tension it can apply to the blade. You can turn the tension up so much that it is possible to snap really fine saw blades. It cuts just beautifully and is an absolute pleasure to use. :)

As always if anyone has any questions please don't hesitate to ask!