Once upon a time you could buy flexible 1/4" shaft material that was comprised of a flexible section with solid 1/4" end shafts; it could be used to navigate small degree offsets; similar to the universal joint couplers but a bit more versatile. Where can you find these today?

Pete

Pete

Last time I saw something like that was in a car radio, believe from 1930's.

Try Surplus Sales of Nebraska. They have lots of stuff of that type.

http://www.surplussales.com

- Leigh

I have the "universal joint" type, not the flexi ones. Those show up in commercial or military stuff it seems.
Mark Oppat
Antique Audio

We use to use brake cable outer housing - 7mm, without the plastic sheath, will yield just over 6mm diameter. 6.32mm =1/4"

Solder or braze the ends where any set screws contact to prevent collapse. Maximum bend radius is about 80 degrees, can't quite make 90.

Some universal add-on choke cables will also work - just the housing. Like this (no affiliation..):

https://www.ebay.com/itm/Universal-Brak ... j7&vxp=mtr

remove the outer jacket at the ends, cut the inner "spring" to meet your needs, and braze or "hard" solder the ends so the set screws have bite and don't collapse the housing. You can leave the plastic sheath on any part that isn't clamped upon/inserted in the shaft ends.

I used some of these for a couple of projects years ago.
H. H. Smith had 3 and 6 inch ones but they don't show them anymore.
There is a used 4" one (manufacturer unknown) currently on Ebay. Search "capacitor 1/4" flexible shaft coupling".

Google SDP/SI.

Hobby shops have 1/4 in cable, it is used for boat driveshafts. A weed wacker may also use the same size cable.

Dave

McMasterCarr has them, but they are spendy. https://www.mcmaster.com/#shaft-couplings/=1aiew2p

Well, Surplus Sales does have them but brake cable may be worth a shot... I need to finish the mechanical layout to see what lengths are involved and associated radii.

I have done it with something as thin as a speedometer cable for short distances of only a few inches, just sleeve the end of it to fit inside a standard 1/4" shaft coupling. That seemed plenty good enough for applications where there is not a lot of torque needed to activate a switch or control.

Peter- please mention a length you need for the flex shaft. They are out there,
including in a lot of Ham junk boxes.

BTW the skinny ones with brazed-on 1/4in brass shafts could do 90 degrees
or better, as I recall...

In fact, seems to me that a longer one could do a complete 180 degree turn;
also they can be made to follow slightly zig zag courses if constrained with
strategically-placed clamps. (OK for occasional use tuning, not too good for
anything motorized- too much risk of wear/jamming)

If everything is neatly orthogonal, don't overlook plain old right angle drives with
bevel gears, they are way more plentiful.

Photos of your mechanical layout would be nice...

David

Mechanical layout is still in the works. Have you price what right angle Millen bevel gear drives are going for these days?

I found three of the springy rod types with 1/4" female ends for a good price, so I grabbed them and I should be all set. I did post a want list in the classifieds for some other odds and ends.

Pete