3 blade Max prop vs 3 blade fixed?

[EWOL Props]

Hi TacomaSailor,

I fully agree on everything you indicated in your post.

Have you ever considered an EWOL Prop ?
Still a feathering propeller with all the advantages you indicated (reduced prop walk, increase of speed under sail, etc.)
In addition to this:
- Hi-Grade stainless steel prevents corrosion and increases strength over bronze
- Pitch setting from underwater, never the need to open the prop and no risk of setting the wrong pitch
- Ultra-fine pitch steps (0,25° every step = 50 rpm variations at each step)
- Interchangeable bearings to compensate blades play after years of working
- Dynamic balancing to prevent any type of vibrations

Look at our website: www.ewoltech.com

Originally Posted by TacomaSailor

There seems to be considerable mis-information in this thread.

I've had an 18" 3-blade Maxprop on our Caliber 40 since 1995.
We have put 2,850 engine hours on the prop. I've had the prop rebuilt the twice and changed the pitch three times.

1. I've done extensive testing of the prop under sail. I am certain that the prop feathering results in 0.4 to 0.6 knots increase in sailing speed compared to forcing it to stay full deployed. Those results have been obtained many times in winds from 6 knots apparent to 15-knots apparent on beats, reaches and runs.

2. The Maxprop innards are complicated and delicate. I sent the prop to PYI in Edmonds, WA after 2,000 hours to have them check everything and restore it to factory specifications. They found all the internal gears to be perfect. The blades needed a little fine tuning. At 2,700 hours I again had the gears checked and they were A-OK. However, the blades were pitted and eroded. A PYI approved shop in San Diego brought the blades back to as-new condition for $350.

3. Prop Walk in reverse is greatly enhanced by the MaxProp because pitch in reverse is the same as pitch in forward. That means the prop develops the same amount of thrust in reverse as forward.

4. Max Prop Walk is your friend almost all the time. You just have to plan your maneuvers to take advantage of the prop walk. I can spin Mirador 360 in about 5' more than it's length using the max prop walke.

5. It is very easy to set the pitch wrong. The internal gears are complicated and you need to be very careful when you install the prop. The first time we had the Maxprop installed resulted in a near disaster. The boat dealer installed the prop and got the pitch EXACTLY backwards. He tried to back away from the dock but the reverse lever caused the prop to go into forward and too much throttle caused the bow pulpit to strike the cribbing holding up the bow of a 50' powerboat that was towering above the dock. The boat swayed and wobbled but did not fall. Our bow pulpit was bent badly.

6. I would rank the addition of the Maxprop to our boat was the 2nd best addition, falling behind only the Raymarine autopilot.

7. I verified the thrust in Reverse by backing Mirador at 7.3 knots, just 0.2 knots slower than in Forward.

8. All that thrust in Reverse allows me to really set the anchor. My careful engineering calculations indicate that 3200 RPM in Reverse (Yanmar 4JH2E/50HP) puts the same load on the anchor as 35 knots wind from straight ahead. When I use 3000 RPM in reverse for 20-seconds and see no boat movement I know the anchor is down and digging and I sleep well at night.

Send your Maxprop to PYI and find out if it is good and then install it.

[skipgundlach]

Originally Posted by EWOL Props

Hi TacomaSailor,

I fully agree on everything you indicated in your post.

Have you ever considered an EWOL Prop ?
Still a feathering propeller with all the advantages you indicated (reduced prop walk, increase of speed under sail, etc.)
In addition to this:
- Hi-Grade stainless steel prevents corrosion and increases strength over bronze
- Pitch setting from underwater, never the need to open the prop and no risk of setting the wrong pitch
- Ultra-fine pitch steps (0,25° every step = 50 rpm variations at each step)
- Interchangeable bearings to compensate blades play after years of working
- Dynamic balancing to prevent any type of vibrations

Look at our website: www.ewoltech.com

Very interesting prop...

How do you lube it under water? I currently (as seen) have a Max Prop, which has two bungs for zerks, but I have some difficulty seeing how to lube it, unless one is supposed to remove those, insert zerks, and pump away with a gun which will turn to rust dust after it comes topsides...

I've never lubed ours other than by disassembly, cleaning, gooping, and reassembly...

And, just in case yours has some magic bullet, ours currently is 19" on a 1.25" shaft. How much would a replacement set me back?

Thanks.

[EWOL Props]

Thank you for looking at our product.

Our prop comes already greased from our factory, then you'd need to top-up grease after one or two years, when you have the occasion to haul the boat for hull preparation. It works perfectly even without grease, so no risks of jamming anyway and no need to stick precisely to one year without greasing, but surely grease helps reducing wear-out of parts.

EWOL Prop has one hole for greasing, you'll just need to remove the tap, screw in the zirc fitting, pump grease and then put back the tap.

You can find attached our maintenance booklet, see at page 10-11.

A prop 19" - 1.25" shaft comes at less than 3000 USD shipment included.

We'll be at the Annapolis boatshow Oct. 6th to 10th 2016

Best

Originally Posted by skipgundlach

Very interesting prop...

How do you lube it under water? I currently (as seen) have a Max Prop, which has two bungs for zerks, but I have some difficulty seeing how to lube it, unless one is supposed to remove those, insert zerks, and pump away with a gun which will turn to rust dust after it comes topsides...

I've never lubed ours other than by disassembly, cleaning, gooping, and reassembly...

And, just in case yours has some magic bullet, ours currently is 19" on a 1.25" shaft. How much would a replacement set me back?

Thanks.

[skipgundlach]

Originally Posted by EWOL Props

Thank you for looking at our product.

Our prop comes already greased from our factory, then you'd need to top-up grease after one or two years, when you have the occasion to haul the boat for hull preparation. It works perfectly even without grease, so no risks of jamming anyway and no need to stick precisely to one year without greasing, but surely grease helps reducing wear-out of parts.

EWOL Prop has one hole for greasing, you'll just need to remove the tap, screw in the zirc fitting, pump grease and then put back the tap.

You can find attached our maintenance booklet, see at page 10-11.

A prop 19" - 1.25" shaft comes at less than 3000 USD shipment included.

We'll be at the Annapolis boatshow Oct. 6th to 10th 2016

Best

Thanks for the info.

But it means a haulout to grease, as I suspected. Dang. We don't haul often enough...

[EWOL Props]

If that is the problem you'll just need to use a long tube for greasing, so you can insert the end of tube on the zirc underwater but pump from the boat.....that will work.

Originally Posted by skipgundlach

Thanks for the info.

But it means a haulout to grease, as I suspected. Dang. We don't haul often enough...

[a64pilot]

I grease my Autoprop in the water, it is not good for the gun but they are cheap and surprisingly it has survived so far, but when it does succumb to rust they are only $10, compared to not greasing, that is cheap.
https://www.amazon.com/Plews-30-200-...rds=grease+gun

[a64pilot]

What kind of zinc does the EWOL use?

[EWOL Props]

EWOL props have their own specific zinc anode, fixed with 3 allen screws.
It is pure zinc.

[skipgundlach]

Originally Posted by EWOL Props

If that is the problem you'll just need to use a long tube for greasing, so you can insert the end of tube on the zirc underwater but pump from the boat.....that will work.

and

EWOL props have their own specific zinc anode, fixed with 3 allen screws.
It is pure zinc.

I'm confused. I thought this was Stainless Steel, on a stainless steel (or maybe bronze, which should present different problems) shaft, eliminating the need for zincs?

As to a hose, I can't imagine what I'd do with a hose that long, full of grease; the only other place aboard using grease is the outboards.

What grease do you recommend for your props?

[JOHNMARDALL]

Originally Posted by Davidhoy

Pleased to meet you, John, even if only virtually ;-). Apparently I just missed you at the store a couple of weeks ago.

I'm looking for the gypsy-side clutch nut. The old one literally fell apart during the pre-purchase survey. I'm probably going to replace the entire unit in the next year or two, but since I need to pay for the lightning damages to my boat first, the windlass replacement will need to wait a little while.

Thanks,
David
...............................................



......


Sent from my iPad using Cruisers Sailing Forum

Hello David

I got your message concerning the clutch nut, but if you let me have your email address I'd still like to send you the parts diagram and list. There is a part that we call the clutch nut, but it may not be what you're thinking off. A picture is worth a thousand words, and a dog is a man's best friend.

John Mardall
Vetus Maxwell Group

[skipgundlach]

This has me wondering, and I went looking at PYI's site.

Seeing it, I MIGHT even have one of those guns; I'll have to root around in my MaxProp pile. Apparently it is designed to take a tube of Lubriplate, rather than a cartridge, and looks to be mostly not-steel.

I'm thinking that I would take that under, do my thing, and then come back out, rinse thoroughly, spritz with WD40 or Corrosion Block or similar, and put it in a ziploc until next time.

I'm sure I have zerks from the last rebuild; I just need to find all that stuff, and do that the next time I intentionally ground in the Bahamas and scrub the bottom with lots of weights on (hookah, grounding and weights to keep us both immobile during my scrubbing).

https://store.pyiinc.com/products/max-prop-grease-kit

[fstbttms]

Originally Posted by EWOL Props

EWOL props have their own specific zinc anode... It is pure zinc.

Then it isn't Mil-Spec, and that isn't good.

[a64pilot]

I use a cheap gun with a rubber hose as I'm afraid of snapping off the zirc fitting, it has survived a couple of years with nothing more than being rinsed off well and put it a trash bag.
I'd like however to find some 5mm SS zircs so that I can leave them in and not be taking out the internal wrenching plugs everytime.
The grease Autoprop specifies can be found on Amazon.com, it is a type of wheel bearing grease I believe.

As far as zincs, I believe if it is metal and connected electrically to your engine, you had better have a zinc on it, SS or not.
I don't know if SS is "better" than bronze or not, but I saw on EWOL's website that they have Titanium blades available for those who feel so inclined? Would cut down on weight considerably, I believe weight on these complex props is an issue with the driveline.

[fstbttms]

Originally Posted by skipgundlach

But it means a haulout to grease, as I suspected. Dang. We don't haul often enough...

There is pretty much no maintenance or pitch change for a feathering prop (regardless of brand) that can't be performed underwater. That includes lubrication. And the relatively cheap grease gun I use to lube Max Props (6mm zerk fitting, BTW) lasts for years with zero preventative measures taken.

[Davidhoy]

Originally Posted by JOHNMARDALL

Hello David

I got your message concerning the clutch nut, but if you let me have your email address I'd still like to send you the parts diagram and list. There is a part that we call the clutch nut, but it may not be what you're thinking off. A picture is worth a thousand words, and a dog is a man's best friend.

John Mardall
Vetus Maxwell Group

Sending you a PM with my contact info.

-David