Has Anyone Tried These?

[Juliet 15]

These sound very intriguing, really looks like a great idea. I contacted them for a brochure and info. Not cheap.



Anyone have knowledge or experience?


https://ab-marine.com/bruntons-sigmadrive/

 

[Nick F]

I am keen to hear the answers too.

 

[Marco Flamingo]

Check out the YouTube link at the bottom of the web site. Prism Reviews did a review on it for a Beta engine on a sailboat. Prism is 33 foot, so it is likely a smaller engine and shaft. He states that the flexible coupling was $500. Might be a boat buck for something that fits a Lehman 120.

 

[O C Diver]

It looks like an interesting concept. Not sure I would be happy with all thread versus the appropriate grade bolts to connect it to the transmission coupling. The coupling not having set screws into the prop shaft was also troublesome. On a sailboat, it's probably not a big deal. But on a larger propellered boat, there's a lot of force trying to pull the propeller into the rudder while in reverse.

Ted

 

[jleonard]

I didn't see any grease in there or did I miss that? Not sure I'd want a dry CV joint. Especially in a marine environment with no seal around it.
Also, I never had a problem keeping a conventional shaft in alignment.

 

[O C Diver]

I didn't see any grease in there or did I miss that? Not sure I'd want a dry CV joint. Especially in a marine environment with no seal around it.
Also, I never had a problem keeping a conventional shaft in alignment.

I watched the video, and there is a grease fitting. Like you, I've never found alignment to be all that difficult. The video mentions doing it every hundred hours, yea right. Maybe he should do it correctly the first time.

Ted

 

[syjos]

Anybody get any quotes?

Price comparison to Aquadrive?

 

[mike66]

I came across that yesterday while searching to identify whatever this is on my propshaft/coupler. Any ideas?

 

[bshanafelt]

my boat has a cummins 5.9b 210hp, with a 1 3/4" shaft.

they quote just under $2k for the unit to fit mine.

I don't seem to have alignment issues, so likely won't spend the $$ for that.

I use a 'drivesaver' disc that allegedly corrects for slight misalignment.

Mainly use it for the remote significant prop strike to 'save' the jolt to the gear

 

[Nepidae]

Shaft couplers

The only thing that I think of is whether the product posted would facilitate a prop being stopped by an object and destroying the trans as part of the damage.

I put R&D couplers (http://www.randdmarine.com/downloads/RandD_Shaft.pdf) in our boat.

 

[kremek]

We have these couplings

We have these couplings. 2-Lehman 120hp
When we purchased our boat, DeFever 49rph, she had Federal couplings from trans output flange to shaft. Few years ago headed north off NJ coast one of the Federal couplers sheared 2 of the 4 trunnion bolts. Had to cut off the shaft piece of couplings. Luckily had a spare onboard and changed it out.

Contacted Federal for a new coupling. Apparently when originally installed the shaft (50mm) was cut down to some fraction @ 1.7” and the coupler where shaft gets inserted and locked was opened up to match the new shaft dimension. This was a “not approved” configuration according to Federal and they would not sell me new couplings. On to finding new couplings.

Found the Sigma couplings. They could accommodate the 50 mm shaft size and supply a 1” extension to the transmission flange to move couplings back to the non machined portion of the shaft. As a bonus the Sigma locks the shaft with a tapered split sleeve that lockes the shaft to the coupling (I have been told it is like larger ships and boats do it). The studs holding coupling to the trans flange are a graded stud and we have never had a problem. Also the coupling is greased internally and sealed with gaskets, no need to re-grease (it can be taken apart to re-grease if you wanted to). One more thing that we are happy about, last year we replaced our old 50mm shafts and the only thing we needed on the couplings was a new tapered split sleeve and no machining of the transmission side of the shaft.

We now have over 15k miles on these and are very happy with them.
As a bonus they did get rid of a small annoying vibration we had with the Federal couplings but that may be because they were failing, don’t know.
The Sigmas fixed a problem that we has and we are glad we found them.