I started using bar clamps sourced from Harbor Freight to hold my material down.
Even the 36" long versions fit inside the Shapeoko Hybrid tables.
Other machines like OneFinity have T-tracks that are too small.
So, if you’re thinking about a CNC machine here is another reason to go ShapeokO.
Here’s a vid showing how I use it;
Let me know what you think.
jbc
Nice idea. I have a few, will try it out.
It’s brilliant - Shane’s Hardwood uses this inline clamp and I was thinking of getting some.
But the harbour freight ones will definitely be cheaper
2 questions-
Be careful with those Harbor Freight clamps, I’ve had many of those things not keep their tension and slip. 
I haven’t had it slip on me yet but I get your concern. Most things from HB are suspect but I love these. Their dust collectors are nice too. The clamps are a simple tool, and so dang fast.
You could go down and get a clamp from Home Depot or Lowes for $25.00 but they need to fit in the t-track.
I love that guy! A pioneer for sure.
Conceptually, you could do the exact same thing with a larger/wider clamp, just by removing the T-track.
If I get you right, you would then need to secure the clamp, and possibly in two places.
The T-track with the serrated gripper at the far end holds it to the table without needing anything else.
Using your hand to clamp your material down is so dang fast and easy.
Also interested. Which clamps are these? And it looks like you modified the far end. Care to share how & which parts?
I use bar clamps from Harbor Freight. Others should work but the bar-clamp cost from other hardware stores was 3-4x more expensive.
If you take a look at the video posted on my YouTube channel you can get more info from other vids I posted there.
Ah, ok. You’re selling the mods. Now I get it. Pretty cool idea.
Things I wouldn’t like: The handle & remaining bar hang out the front of the machine. I have an enclosure, so I’d have to leave the door open. No downward force on tightening. Looks like you have it pretty snug in the T-slot, so it shouldn’t move much. But the danger of upward movement if the cutter applies enough upward force exists.
Still clicking the “Like” button 
You can drill holes anywhere in the bar minimizing bar space out front, but the handle still takes up some space out front.
I have not had any movement in the z-axis but I might not use mine as hard as others.
Here is a video showing an option that would make sure it stays secured on the z-axis;
I agree about watching the Harbor Freight clamps. I do Corian countertops as my day job and my boss refuses to buy good clamps. He buys them from HF. I throw them away as fast as he buys them. Not only do they lose tension, but they tend to not hold very straight and I’ve even had the casting break. Do yourself a favor and get yourself some Jorgensen clamps. With the others it’s not a matter of if they are going to fail…it’s when are they going to fail. Just my experience.