DIY Leg Extension Machine For Quads

DIY Leg Extension Machine

So my left knee issue has gotten worse this year and I was even having trouble doing hexbar deadlifts which only require a knee bend of 90 degrees – what most people would call 1/4 or 1/2 ROM. Anyway, I wanted to do something for quads other than biking and that left leg extensions. Trouble is, I spent weeks on amazon looking for any leg extension setup and they all had horrible problems – wobbly, back rests that fall off, tip over risk with too much weight, etc etc. Not to mention that all these take up lots of dedicated floor space, something that I dont have. My ‘gym’ is used for parking a car at night so when I am done working out, everything has to be stored.

So here is my solution! Took me about 4 hours to build out of $15 worth of OSB, 2x4s, titebond glue, and electrical conduit (for the hinges). To be very compact, it uses my Valor BD-2 stands as a base. The wooden seat simply sets on the stands.

Construction of DIY Leg Extension Machine

All construction is nailed and glued box-beam construction for incredible strength.  Cutouts were made so the sitting platform can rest upon the BD-2 stands.  The hinge is durable, low friction, and very easy to make.  First, mark all six 2x4s with the location of the hole.  Then drill the hole about 1/4″ bigger than the outer diameter of the 1″ electrical conduit pipe, that way, you dont have to worry about accuracy too much.  Now loosely assemble everything and insert the full width “hinge pin” which is a 3/4″ electrical conduit pipe – this will slip easily into the 1″ conduit.  Everything will be really loose.  To set the hinge bearings, simply apply hot glue in the spaces between the 2x4s and the 1″ conduit to lock it into exactly the right place to have the hinge perfectly aligned!  Simple, no muss, no fuss.

DIY-leg-extension-machine-bearings-1 DIY-leg-extension-machine-underside-1

DIY Leg Extension Machine In Use

DIY-leg-extension-machine-2 DIY-leg-extension-machine-3

 

Easy Storage Of Leg Extension Machine

Takes about 60 seconds to disassemble and store!

DIY-leg-extension-machine-1