Indigo Radial Winglet prop?

[Bold Rascal]

In closing, for now...

I'd like to say thanks to everyone who provided comments and feedback to my inquiry.
That being said, I have made a prop purchase, and even received a special discount. Thanks TS, Thanks MM for an awesome forum and everyone else (you too Niel) for the great feedback.

Best regards to all!

[Dave Neptune]

Go 4 it

Hey Bold, let us know how it works for you. Like I have said I do indeed love mine and I do think I am now faster with than my 3 blde phrf rating.

I am going to have mine repitched after this season unless I get a window to do it sooner.

Good luck with it.

Dave Neptune

[Chris T]

New Indigo Prop

Have installed the new Indigo 7.7 prop. Better performance than the 7.4
I had on for 7 years. Improved push and less vibration. Hull speed at 1500
rpm. E 27 sailboat.. Very much pleased with the upgrade..C Trembanis

[thatch]

"More Propwash"

All, Since the dust, or rather the propwash seems to have settled a little on this subject, I feel that the time might be right to give my input. Like many others, I started with the standard 12x7-2 blade on my Catalina 30. Wanting to increase my RPM's to a more desireable range of close to 2000, I purchased the Indigo 3 blade. Initially, I felt that it was an improvement, with an increase in RPM's and very smoothe overall performance. Over time I did seem to feel that reverse was not quite as effective as with the 2 blade and I also felt that I was experiencing slightly more propwalk. On a lark, and partly because Catalina had seen fit to use the same 2-blade on their 27's as their 30's, I decided to cut down my original 2-blade 1" and give it a try. The results were actually shocking. I now have a prop that puts my engine in the correct RPM range, has less prop walk and has a more effective reverse. I won't even begin to try to explain why this worked so well, but needless to say I am quite content with the current setup. In all fairness to Indigo, I have not had to "push" my boat in heavy seas with my new 2-blade, so I can't testify as to it's ability in those conditions. To conclude, I have a couple of other A4's, one of which will most likely see duty in a boat similar to Daniel's power skiff, which should be a good match for the Indigo 3-blade.
Tom

[sastanley]

Thatch,
You cut down what? The 12 x 7 to an 11 x 7?

[ndutton]

What was the technique/tooling you used to do it to keep it all symmetrical and balanced? Do you have a lathe?

[thatch]

Shawn and Neil,
Having a bunch of "leftover" parts from years of boatbuilding projects made this prop cutting easier. After "Dykeming" (blue dye) marking the ends of the prop I mounted it onto a spare 1" propshaft and then ran the shaft through a spare strut and then through an old stuffing box. This assembly was then bolted to a table allowing me to rotate and scribe the prop ends. After cutting on the cut lines I radiused the leading and following corners to an "almost" similar shape of the original ends. Ballancing involved attaching the propshaft to a small 1725 RPM electric motor via hoses and clamps and then Reading the ripples in a glass of water sitting on the table as the prop spun. I ran accross this ballancing method many years ago while trying to ballance a clutch in an old pickup truck. Quite accidentally I noticed that the ripples in a cup of coffee sitting on the floor of the truck decreased or increased as I added or took away "ballancing" washers installed on the pressure plate bolts. Cheap but very effictive..... I knew that my methods would raise some eyebrows.
Tom

[sastanley]

No eyebrows raised here...if it works, it works!

Fabulous process.

[tony201]

I Completely agree with Joe.

[marthur]

Tom that balancing is nicely done. But water? Wouldn't rum have provided a more nautical taste to the process?

[thatch]

"Out of ballance operator"?

Mike, Probably not a good idea to have a spinning prop, a glass of rum and me in close proximity.
Tom

[joe_db]

Wow - cool idea. You may find - if you have a way to do back-to-back testing, the three blade is faster bashing to weather and the 2 blade is faster in calm water. I think the Indigo can cavitate in reverse. I actually just noticed this recently - you do better starting out with part throttle in reverse and easing the power in. YMMV.

[Dave Neptune]

Old school Tom

Tom, balanced many ah rotating parts in my day via the extra washer and then see~repeat until satisfied. My wife wondered WTH I was doing with pieces of scotch tape and some coins because her ceiling fan was shaking. Done quite a few RC helos same way.
I do like the water trick and will certainly try it.
A long time ago I made a pitch gage which was a PIA to work, however I did rig it to mount a scribe for doing diameters. I have done many a prop that was to big for my 14" lathe, so I did the work on a pedastal grinder and a magna visor. I also played with blade shapes and area this way.
Anything up to 14" I could coax into balance on the lathe between centers and for the larger ones I'd mount it to an old Logan horizontal mill and watch the oil shaking in the ways to coax to balance.
With patience one can balance almost anything!!!

Dave Neptune

[mikeysail]

Indigo prop cavitation?

Joe_db,
I have also wondered about cavitation of the Indigo prop in reverse. After tightening up the brake band in the reversing gear and ensuring that reverse is actually engaged and not slipping, I have found that reverse at high RPM is amazingly ineffective. It does get a rise out of anyone on the dock though
Mike

[thatch]

Dave, I have also used the "coin taped to the fan blade trick". My wife likes this "fix" because she knows that I have to "dust" the fan first.
Joe and Mikey, Thank's for confirming my thoughts about the Indigo's odd reverse tendancies. I was reluctant to get too heavy handed with my comments but I firmly believe that my 2 blade slows and backs up the boat better.
Tom