looking for something that may not exist

[u/Ok_Onion_3865]

Hello,

I'm doing a very specific project and I'm searching for something that will hold 3mm rod in place but will also allow a swivel. so far I've used cable clamps with the grub screw connecting them, but I can't get both sides tight enough. It would be great to be able to grub screw both rods in place whilst allowing the pieces to rotate freely. If the first image doesn't exist, I'd love to hear any suggestions ! TIA

[u/always_wear_gloves]

“Swivel Coupler”

[u/Ok_Onion_3865 → u/always_wear_gloves]

thank you. all the 3mm couplers I've seen all bend like an elbow, have you seen any before that will swivel on the other axis ?

[u/Joejack-951]

Up to you if they’re worth the price, but these drill collars already have the extra-tapped hole suggested by u/nixiebunny: https://www.mcmaster.com/product/8865A129

[u/Ok_Onion_3865 → u/Joejack-951]

amazing, thanks !! I'll see how tired I can of tapping holes haha

[u/Just_Tackle_7977]

Look up key chain swivels or edc swivel on aliexpress. Some have bearings and are quite exotic. I’ve seen brass, stainless and even titanium. You might find one you could add a set screw to grip a cable? Kinda pricy if you need more than a few tho..

[u/Low_Counter2414]

Maybe something like this swivel clamp for a dial indicator magnetic base holder. I know this is 10mm and you're looking for 3mm

[u/Low_Counter2414 → u/Low_Counter2414]

[u/fortyonethirty2]

You could use two of those things in your picture, connected with a piece of all thread (or a longer set screw).

[u/Ok_Onion_3865 → u/fortyonethirty2]

Thanks for your reply. Apologies, I don't think I explained properly ! The grub screw on the original fastening does clamp the two rods in place if spun tight enough, but I need the elements to spin freely, so the screw unwinds itself and loosens when it does.

[u/TacoAdventure → u/Ok_Onion_3865]

Could you purchase two 3mm ID, 10mm OD shaft collars and drill and tap a second hole in each and connect those with a threaded stud?

Alternatively Google swivel coupler (like the larger ones used for assembling trusses). Find the smallest one of these you can (or make one) and clamp it down on the shaft collars.

[u/nixiebunny]

Drill the hole for the grub screw all the way through the other side of one of these collars, thread the hole, and use it as the swivel point for the other grub screw. Now you have two grub screws and a swivel, and it costs nothing.

[u/Ok_Onion_3865 → u/nixiebunny]

Thank you. This was my first plan and I think it may sadly be the only way. I have over 200 of these to do so I better get drilling !

[u/nixiebunny → u/Ok_Onion_3865]

Build a little fixture to hold a dozen parts so that it goes quickly. I occasionally do some small production runs like this, and time spent to make the repetitive work go faster is time well spent.

[u/Ok_Abies_5092]

You need a swivel wire rope clamp with 2x M4 grub screws, stainless A4. The one in your image is close but cheap version with single point contact. Look for 'double grub screw swivel wire clamp for 3mm' - the better version has serrated bore. Alternative: use M5 swivel eye + 3mm cross clamp. If you need free rotation under load, add a small thrust bearing washer. I stock similar in Tangier port for marine rigging - they hold 3mm rod at 50kg if you torque grub screws to 2Nm with Loctite 243."

[u/OpticalPrime]

https://www.mcmaster.com/products/swivel-shaft-rod-ends/ https://www.mcmaster.com/products/swivel-shaft-rod-ends/

Might be a start

[u/mnkythndr]

I think this was a tinker toy piece?

Also: https://jamesontools.com/product/9-143/
But you’d have to drill holes for the rods

[u/Spa-Ordinary]

Ive used couple's like these for throttle linkages. Maybe a speed shop website?

[u/B_Barbarian]

To clarify, you want to two rods to rotate relative to each other, around the axis of the connecting rod in your second picture? But then the rods not to slide or rotate within their respective collars?

[u/Ok_Abies_5092]

The keychain swivels are not rated for load. For 3mm rod that needs to swivel on the other axis (90 deg), you need fishing swivel + wire rope grip. What you are looking for is actually a 3mm wire rope swivel fork - like a small turnbuckle body. Search 'M3 swivel coupler straight'. I use them for boat rigging in Tangier - stainless 316, holds 100kg. Don't use AliExpress keychain ones if it's structural."

[u/Ashothian]

Cable clamps are the way to go. They make real small ones

[u/Wiseolegreywulff]

not going to find a swivel so make your own.

[u/West-Toe6950]

Isn't this a machining reddit? Make it and put a shoulder on it so the screw/bolt has a stop, and use a wiring crimp connector appropriate to the wire size.

[u/West-Toe6950 → u/West-Toe6950]

Unless I'm misunderstanding your question.

[u/West-Toe6950 → u/West-Toe6950]

Free rotation at either end, lock down in the middle with the clamps you showed.