Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Engineering Techniques and Materials. => Topic started by: BreezyB on January 29, 2010, 09:35:41 pm

Title: Universal Joint
Post by: BreezyB on January 29, 2010, 09:35:41 pm

Advice Please.
I want to attach a small motor (3-6v) with a 2mm shaft to a propeller shaft also 2mm. I assume that I can use a piece of plastic/silicone tube for the job but wish to know if a particular type of tube is more suitable and should it just be a push fit or should I use an adhesive?.  {:-{ The prop is 3 bladed and is only 12mm.
Many thanks
Barrie.

Title: Re: Universal Joint
Post by: The long Build on January 29, 2010, 09:38:33 pm

I have used a standard piece of tubing taken from a mains core wire , push fit and have had no problems.

Title: Re: Universal Joint
Post by: Corposant on January 29, 2010, 11:27:58 pm

I would use silicone rubber because it's more flexible.

Mike

Title: Re: Universal Joint
Post by: chipchase on January 29, 2010, 11:42:33 pm

Barrie you will have no problem using silicone tube as a coupling as long as the rpm is not to fast. The heat generated from the shaft spinning at high rpm will soften the tube and it will just melt.

Brian

Title: Re: Universal Joint
Post by: BreezyB on January 31, 2010, 12:29:56 pm

Many thanks for your ideas, Chaps. Your input is much appreciated.

Barrie.

Title: Re: Universal Joint
Post by: Pat Matthews on January 31, 2010, 01:54:39 pm

Tubing can be ok... but if you really want a real u-joint in this size, look at the molded parts available from Northwest Shortlines (NWSL)... see the thread at:
http://www.rcgroups.com/forums/showthread.php?p=13981985#post13981985

or go directly to NWSL:
http://www.nwsl.com/hardware-parts/universal-coupling-sets

(http://www.nwsl.com/wp-content/uploads/2009/11/universal-couplings1.gif)

Title: Re: Universal Joint
Post by: allnightin on January 31, 2010, 09:36:54 pm

Barrie,

SHG models are UK based and do a set of fairly cheap universals that include 2mm shaft if you look at http://www.shgmodels.com/acatalog/ .  Their type 5500 on page 28 of the catalogue looks about right

Title: Re: Universal Joint
Post by: BreezyB on February 04, 2010, 09:51:09 pm

Many thanks to Pat and "allnightin" for the information about "engineered" couplings however in this case it is a fun project and simplicity will be OK this time.
Having said that I am most gratefull for the useful links and diagram and I will certainly save it for future reference. :-))
Thanks again for taking the trouble to help.

Barrie.