Flexible drive shaft

I agree with John. I've utilized various sizes of tubing for flexible couplings. Shrink tubing can even be used if you have a light duty application or are able to find thick walled shrink tubing.

Erector sets used a flex shaft like the spring you mentioned. I'm not sure what your application is but an old set may provide just the parts you need!

Rubber tubes and lines, etc., work pretty well for this, as long as it is light duty: I'm looking for a source of metal ones made for this purpose but have not found it. 

 

If you use rubber tubes on Superstreets cars or with other real high RPM motors you have a vibration problem I've noticed - not due to the rubber hose, but just because of the slightly misalignment of shoaft.  I've used rubber tubes to extend from the back 1/8 inch shaft out of SS vehcile motors to a custom-built frame behind the motor that holds a flywheel -- makes them run much more smoothly.  But it takes a lot of fiddling and shimming and adjustment to get the vibration shake worked out of the alighnment.

HO engines from the 1950's used them...especially when the motor was in the tender. The flexible shaft connected the tender motor to the gear box shaft in the boiler section. These were the compressed coil type...rubber or plastic tubing is not stable enough.

I'm thinking a hobby shop that deals in race cars or airplanes might be a source.

I've tried searching on-line with the key words: flexible drive shaft...flexible coupling...spring shaft...flexible linkage...but nothing small enough for O gauge usage.  Also tried McMaster-Carr.

If you willing to spend money, these folks call them "bellows couplings":

http://www.rw-america.com/prod...ature_couplings/mk2/

 

This is closer to what I think we want - made for model boats: the site has a search engine and words like 'coupling' and 'connector' 'flexible drive shaft' and such bring up dozens of items to look through.

http://www.rcplanet.com/AquaCr...upler_p/aqub7854.htm

There's also this, which looks like it has potential, with the above, for somethings

http://www.rcplanet.com/AquaCr..._Vega_p/aqub7868.htm

Lee,
Not sure if it'll help but I saw some drive shaft universals in the micro mark catalog.
I know the ones your talking about made from speedometer cable material but haven't seen any in a while. Coarse that is an option. get a speedometer cable and 2 set screw shaft couplings and make your own.

David

Just a thought: would the "Old type of Auto, or whatever" speedometer cables work? You may have to also use the cable housing to act as a "Keeper" for the coil spring as it spins.  Dennis M.

 

David, sorry, you type faster than I. Dennis

I use Model Airplane fuel line.   It is almost indestructible and comes in 2-3 grades of flexibility and ID.   And it is relatively cheap - a couple of bucks a foot at the most.   Most applications use a couple inches.

No problem Dennis.
If the cable is short it won't need a housing because it won't be able to double back on itself. Not hard to get the cables still alot of cars out there that need them and you may find one for free in a junk yard
Thanks for the compliment Dennis . I finally found someone who thinks I type fast.
My wife and daughters say I type slower than grandma moses but when they do it it's a wonder the keyboard doesn't catch fire. Me I always use the tried and true method called "Hunt and peck"
David

Lee check this out . They just may have what you need . I think you'll be looking for a bellows coupler.

http://www.sdp-si.com/estore/CoverPg/Couplings.htm

David

These indeed fill the bill (at least the msllest one), and at $49 are expensive, but problem worth it if you need the torque rating.  they are rated to 20K RPM, too, which is very good. 

I have seen the felxible rubber drive shafts that allow some movement.

 

But if you have the length you can use the Weaver drive line; P&D sells the parts link below to the parts page;

http://pdhobbyshop.com/show_products.php?category=Trains&sub_category=%26quot%3BO%26quot%3B%20Scale%202%20Rail&sub_sub_category=Drive%20Components&manufacturer=P%26amp%3BD%20Weaver

 

If you look further down there are individual parts you can buy.

There is one shaft that has 2 U joints so allows it to flex and has a sliding drive shaft that allows the trucks to move and the drive shaft to slide in and out.

 

I think I can help.  2-rail O Scale has used rubber hose coupling in high power applications for 3/4 of a century.  Rubber is not what it used to be, and as of now the only hose that will do for high torque motors on large models is the Toyota #0 vacuum line.

 

To use hose like this, you need to have the alignment of motor shaft and worm shaft such that no "S" curve is necessary - that is, the  enter lines extended must intersect in the exact middle of the gap.

 

For steam models, you need as long a worm shaft as possible to reduce torque wrap-up.

 

I have used speedometer cable between front and rear engines of Mallets and articulateds.  There is not enough room for the Toyota hose, and a slip joint is absolutely necessary.

 

I have miniature automotive style U- joints, but prefer combinations of hose and horney balls on Diesels and tender-drive locomotives.

 

Of course, this is just my opinion.

Make that center lines.  Why is this thread so wide?

Found it...it's called a "flexible spring coupling". Our above forum member DPC has the supplier link: Stock Drive Products/Sterling Instruments. Alas...its been discontinued!!! BUT...at least I now know the name of the part I'm looking for...its a coupler, not a shaft.

I use this for bending small diameter tube. maybe you could try this.

 

http://www.google.com/products...&ved=0CH8Q8wIwAg

A  look at small universal joints.
Turntable drive.