I've spent a lot of words trying to explain the difference between Bigfoot and other controllers, but I'm not really sure I've managed make the difference understandable to someone who hasn't tried to sew leather with a normal sewing machine.

Typical foot pedals (and typical feet) lack the finesse needed to maintain a steady sewing speed while sewing leather.

Bigfoot takes care of the finesse so that I can concentrate on the sewing.

Here's my Adler class 8 trying to sew three layers of the kind of leather I normally use in my projects.  I've programmed the Bigfoot controller to work like a normal footpedal - push harder = more power.  If you hold your foot still, the power stays the same.  When the load changes (thicker or thinner spot in the seam,) the speed changes as well.  Since low speed means low power, it has a hard time punching through leather at a speed low enough for me to keep the seams straight.

It has trouble getting started - as soon as the needle touches the leather, the motor stalls out and the needle gets stuck.  I have to reach over and turn the handwheel to get it moving again.

Once it is moving, I have to maintain a steady (fairly high) speed to keep it from getting stuck again. Of course, I'm not that good at it, so the needle gets stuck again.  I have to break my concentration and reach over and crank the handwheel to get it moving again.

On towards the end, it goes from three layers down to two, and the motor speeds up.  The faster it goes, the harder it is for me to keep the seam straight.

For comparison, here's Bigfoot with its normal software.  It monitors the speed with the tachometer and the PID control maintains the speed I've set on the foot pedal.  I push the foot pedal, and Bigfoot makes the machine go - no matter the load.

Bigfoot (with its tachometer and PID controller) has no trouble at all piercing the leather at low speed.  It maintains its speed even when transitioning from the thick, three layer part to the thinner two layer part.  The thumping on the first few stitches occur because the needle got stuck in the leather - Bigfoot merely applies power to maintain the speed and scrape the leather off the needle. 

That difference in control allows me to concentrate on making straight seams.  I don't have to worry about it going too fast or getting stuck.  Just chug along, doing my thing.

That second video is what has driven me these last few months.  I knew that typical sewing machine motors could sew leather but that the typical power regulating foot pedals were holding them back.

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Do you know how I knew that the motor could handle it?  It's because I can stick one finger through the spokes in the handwheel of the sewing machine and sew things without getting stuck.  There's no way I could exert 100watts (the rated power of the sewing machine motor) with one finger - or even 50watts if you assume the motor is only 50% efficient in converting electrical power to mechanical power.

It doesn't take massive amounts of power.  It just takes applying it correctly.

The Bigfoot controller applies the available power appropriately, and makes my sewing tasks much easier.