Universal Joints

[eckloss]

Anyone have a good source for 3/16" ID universal joints?

e.

[JWLaRue]

Erich,

I recommend universals from this company:

http://www.sdp-si.com/

...and specifically the "A 5Z 8-D" series found here:

http://www.sdp-si.com/PDFS/Plastic-Universal-Joints-Inch.pdf

-Jeff

p.s. for those who prefer the metric equivalent, go here: http://www.sdp-si.com/PDFS/Plastic-U...nts-Metric.pdf

[eckloss]

Thank you, Jeff. That's precisely what I'm looking for.

[s class]

Hi Erich

How many do you want drop me an email Bob OTW

[tommydeen]

How much are those u joints
I think the black delrin ones are being
Made again. Sdpi has good customer service i wish i could say the same for
WM Berg

[JWLaRue]

You can check pricing here for inch-based universal joints: https://shop.sdp-si.com/catalog/?cid=p545 For metric you can find them here: https://shop.sdp-si.com/catalog/?cid=p546

-Jeff

[Guest]

My favourite type of coupling is two small pieces of turned round plastic that press fit onto either shaft, with a small length of silicone tubing sleeved other each part. I size the shaft holes about 0.1mm smaller, four thou in old money. Gives a maintenance free solution that's totally silent, can easily be adapted for any size of boat and works for most power levels a model submarine requires. Cost is pennies, as tubing and plastic rod is fairly cheap, and you only use a small bit for each coupling. You do need a lathe, or at least access to one to make them though.

[salmon]

Andy,
I am intrigued, do you have any photos?
Peace,
Tom

[Ralph --- SSBN 598]

Tom, you have seen my GW.
It runs with a short piece of fuel tubing between the motor and propeller shaft.
Nothing else, just slipped on.
It it a tight fit.
The GW has it's share of issues but the tubing connecting the motor and propeller shaft has never been one of them.
The two shafts are only 1/8" apart.

[Guest]

Recently made one for a small speedboat refurb.

This was made using some nylon rod (acetal/delrin would also be suitable). I make the plastic rod diameter about 25-30% larger than the inside diameter of the tubing. I've used silicone tubing here, you can also use polyurethane tubing or other rubber pipe. Some will be stiffer than others, I find for low power electric use (e.g. 100watts or less), the softer the better.

The motor shaft is 3mm diameter, and I drilled the hole 2.9mm for a nice interference push fit- no grub screws required. The other end was a threaded shaft, I just used the shaft to tap into the plastic, as the thread didn't seem to match any of my tools, having drilled it out prior to tapping.

I have a set of finely graded drills for this sort of work. Not particularly cheap, but very useful. Model engineering suppliers are useful for that kind of thing.



None of this is particularly new. Here is a page from a 1956 publication for boat modellers by Vic Smeed.



Back then items weren't so readily available commercially, so modellers had to make parts themselves, or go without. So publications showed you how to make things using bits and bobs or items you could pick up at a hardware shop.

[crueby]

I have taken to using flex shaft cable like the gas boats use rather than u joints. Quiet and easy to make, cable gets held with loctite 603 in brass blocks grub screwed to the shaft ends. You can buy them custom made, or make your own, a coil of the cable cost about the same as a premade unit.

[salmon]

Thank you!

[Guest]

Earlier post updated.

[salmon]

Again, Thank you! The pictures helped.

[bigdave]

You can also make the fuel tubing U joint in removable form.
Using two wheel collars and some brass tubing.
I drew up a example. This one is for 1/8" shafts.
The collar set screw passes through the brass tubing and tightens on the shaft.
The silicone fuel tubs pushes over the 3/32 brass tube.
I have done this for years. BD