Scratch Built Toe Clamps Keep Your Work In Place

[Kevin] owns a benchtop CNC mill that has proven itself to be a capable tool, but after becoming familiar with some of its shortcomings, he has made a few modifications. In order to more efficiently hold and access workpieces on his custom fixturing table, he designed and made his own toe clamps and they look beautiful.

The usual way to secure a piece of stock to a fixturing table is to use top-down clamps, which hold the workpiece from the top and screw down into the table. However, this method limits how much of the stock can be accessed by the cutting tool, because the clamps are in the way. The most common way around this is to mount a vise to the table and clamp the workpiece in that. This leaves the top surface completely accessible. Unfortunately, [Kevin]’s benchtop Roland MDX-450 has a limited work area and he simply couldn’t spare the room. His solution was toe clamps, which screw down to the table and have little tabs that move inwards and downward. The tabs do the work of clamping and securing a piece of stock while maintaining a very low profile themselves.

The clamp bases are machined from stainless steel and the heads are brass, and the interface between the two is a set screw. Inserting a hex wrench and turning the screw moves the head forward or back, allowing a workpiece to be clamped from the sides with minimal interference. His design was done in Fusion 360 and is shared online.

Another option for when simple clamps won’t do the job is a trick from [NYC CNC], which is to use an unexpected harmony of blue painter’s tape and superglue which yields great results in the right circumstances.

15 thoughts on “Scratch Built Toe Clamps Keep Your Work In Place

  1. Very clever little design, so simple and compact! I like the process photos. Interesting that you can just tap the threads into the brass piece after cutting it, I would have thought you’d have to drill the hole, tap it, then cut it in half. For some reason, I’m not sure what my reasoning is. I’ve not done much machining of metal–yet!

    Well done!

  2. These look really well done, but still consume the side faces a bit.
    I’ve used the super glue trick for securing flat aluminum stock for machining all the way down the base without any clamps for a couple years now.
    Two flat clean surfaces, add a drop of thin super glue, wait 10 minutes. Machine away.
    Keep it cool and it can literally hold a ton. It will stand up to pretty much everything, barring fly cutting too far from the joint.
    Heat it up a little with a torch when you are done, and the part pops right off.

      1. The tape trick works fine for flat parts and 3 axis milling. In my experience, if you want to do undercutting with a 4 or 5 axis, you’ll need the extra strength that just using the glue provides. I used this to cut about a 30 degree angle into and under my parts right into the base plate and it still holds fast. The real trick then was being able to break down the glue with heat, so as to not damage your parts on removal then.

  3. Very nice! I _just_ finished trying to solve this exact problem yesterday. Don’t have a nice set of pictures to upload, but I ended up knocking off a couple 3D printed corner clamps I designed. https://cad.onshape.com/documents/c5e5cc9ba342f32452169f5f/w/763ddbd94b189f04f2de0baa/e/7e490b52fb4050cc04d68d00

    Print 2, use a #6 countersink wood screw to secure to the wood sacrifice board on my home made CNC. Was facing a heavily warped 12″ 2×8 last night.

  4. These are lovely!

    As a note, after years of doing the tape and superglue approach (an old luthier trick,) I’ve found that using sheets of adhesive shelf paper (it’s actually plastic, one piece on the table, one on the workpiece,) and spray tack glue works even better for me. The shelf paper is basically 12″ or 18″ wide heavy duty tape so it covers and adheres to broad areas, and the spray glue gives an even adhesive layer and sets really fast (and is way cheaper over time than superglue.) The bond is really strong, but will release when needed.

  5. Cool but not real original. There are tons of commercial offerings based on the same concept. Check out a company called Mitee Bite and others. They have lots of lines of fixturing hold downs and one of them looks a lot like this.

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