Tone in progress - "third hand" pedal...diy?

[tele_guitarist]

http://www.musictoyz.com/guitar/pedals/tip.php

Anyone ever built anything like this? It is totally mechanical-surely there is a way to diy one with a wah pedal or something similar?

[petemoore]

My buddy has a couple of similar vintage models of that device.
 Cool device.
 I would guess there are some 'plastic links' in it, like gears or whatever method theyre' driving the twisto cable with, that are easy to use once made, hard to make so that they can be used...lotsa specs...lotsa machining or ... having plastic pieces made to order.

[Mark Hammer]

It essentially does what the old E-H Hot Foot pedal used to do, only more effectively.

The Hot Foot was the same enormous wah shell that E-H used for the Queen triggered wah and other foot-treadle based products of the "golden era".  The treadle rotated a pot via a rack and pinion system, and a flexible shaft was attached to the pot shaft with a wing nut.  The other end of the shaft came out the side and could be attached to the shaft of any pot, also with a wing nut.

I had one of these (I seem to recall it cost me around $100-125 in 1979 dollars), and used it happily for a while until I had to sell a bunch of gear.  Unfortunately, it was plagued with a couple of problems, all of them stemming from pure physics.

First, the majority of knobs are top mounted on pedals, so the flexible shaft has to approach the pot shaft from above.  Because the flexible shaft came out the side of the Hot Foot, it had to first bend upwards, then downwards.  This placed an enormous amount of torque on the shaft which could only be reduced/buffered by: a) moving the to-be-controlled pedal a certain distance away (and you thought your pedal board was big NOW), b) attaching the to-be-controlled pedal to a base of some kind, or c) having a pedal which weighed a lot.  If you couldn't meet these requirements, the pedal being controlled generally got flipped over by the flexi-shaft.  In my case, I had no pedalboard, but used a couple of MXR and Univox pedals, effectively "fused" via those solid male-to-male phone plugs.  The combined weight of the pedals overcame the counterforce of the flexi-shaft (I had 4 FX pedals and a Hotfoot, and that was considered a LOT for the time - we didn't use pedal-boards), but individually the MXR pedals were easily flipped over by the flexi-shaft.  It was a stiff bugger.

The other practical problem was the space required to attach the end of the flexi-shaft.  At a time when the majority of pedals seldom had more than 2 knobs (and with E-H often no more than 1), and with the frequent size of enclosures and pot spacing, attaching a flexi-shaft end to the delay time on a Memory Man (the very first Whammy pedal, and a deliberate targetted use of the HF amongst players) or the rate pot on a Small Stone was easy.  As the number of controls grew, the chassis size shrank, and the pots themselves got smaller and more readily installed in tiny rows, Boss-style, the possibility for using a Hot Foot on such a pedal became nonexistent.  The pedal died a quick death despite how clever it was and how creative it allowed the user to be.

Quite simply, you couldn't fit it on the pot shaft, and even if you could, the pedal would flip over the moment you stepped on the HF treadle.

The Third Hand overcomes these issues by:
a) having the flexi-shaft come out the top (less torque on the shaft)
b) using a narrower gauge flexi-shaft
c) having the attachable end be narrower and more easily accommodate smaller working spaces.

In answer to the hypothetical question "Could you make one from a wah shell?", the answer is most assuredly "Yes".  But you would have to figure out how to overcome the physical problems encountered by the original Hot Foot.  It would not surprise me if a pot was used as the rotating element on the Third Hand, but to do so would require a somewhat different gear mechanism, I imagine, to be able to use it in top-mounted fashion.

[D Wagner]

It makes me think of a speedometer cable.  My commercial type Ryobi weed eater has a similar type of cable, too.  It spins in a sheathing, and must be lubricated now and again.

Derek