Denna sida kan ses på svenska, om du vill.

How to add power to an ancient tool...
and what made me try...

To be able to use a loom, the user must have a certain amount of strength. It's just not enough being interested because of the high static load put on the user's legs. Karin - my wife - has certain problems with static load and has a great interest in weaving. Because of her light disability, the only option was to sell the loom, which she bought long before she got disabled...

She didn't want to sell it, why I couldn't resist giving it a shot.

Using electrically powered machinery is spatious and takes quite a lot of thinking and precautions before it can be done. I didn't want to put hazardeous voltage under her feet nor pay the price for the rather advanced control hardware.

I had some non-negotiable requirements stated by Karin:

The picture below show the loom from the rear, after having started the conversion.

As you can see, the cylinders are already mounted and bolted to the bottom of the loom and power to the cylinders, as well as controller hardware including pedals.

Originally, this loom has a maximum of six pedals but the electronic controller enables as many as you want, actually. I ended up with eight pedals, since more pedals are rarely used in the cloth Karin is weaving.

I haven't extended the number of shafts - six - even if it could have been done. The number of shafts has very little to do with the number of pedals.

The picture below show a closeup of the cylinder mount and the rope bend points.
The rope bend points are made from sewing machine under-thread bobbins and lead the rope from two points on top of the shafts via the cylinders to one point at the bottom of the shafts. The thin white ropes you see in the picture are the original ropes that will be replaced later.

The valves that control the air flow to the cylinders are shown in the picture below. The piping between cylinders and valves is 4mm outer diameter and 2mm inner diameter heavy duty air hose. The pipe feeding the valve mount has 6mm outer- and 4mm inner diameter. Each valve has a reduction vent of its own. It enables tuning of the cylinder speed and must be tuned to a rather
low speed. If not - the cylinders will tear the loom apart...
In the picture below, you can see the old pedal mount which has been obsoleted by the new gadgets.

The controller box - very much a working prototype - is shown in the picture below. All components are soldered to a standard vero board and no special components has been used.

The valves has a 9-pin DSUB connector and the pedals has one as well, as you can see to the left in the picture above. The connectors are keyed and can not be mistaken: female out to the pedals and male to the valves.

As you maybe can see in the picture above, 12 jumpers are already seated and the shape their placement forms can easily be seen in a standard weaving book. It's actually exactly the way each pedal connects to the shafts.

Each pedal has its own column and each valve (shaft) has its own row. You can see that column one, from left, has a jumper in row one - meaning that the leftmost pedal pulls down shaft one - the frontmost shaft in the loom.
The two rightmost columns pull three shafts each, resulting in plain weave when alternated.

The pedals were a bit tricky... They have to be made from a durable sort of wood: beechwood. The pedals trigger one microswitch each and the mount is a bit hard to adjust... See the picture below.

Part of the pedal in a picture taken from above.

Part of the air compressor showing its spec is shown below. The air outlet had to be modified since it only had a strange connector which didn't fit my needs - 6mm quick connection fitting.

The schematics for the power pedals are shown in the picture below. If you want to add some enhancements or change anything, please send me a mail on address mike @ lillhult.com