Is a Bruntons Autoprop the only propeller to do what it does?

[Tim Good]

Now discovered that the Autoprop needs a shaft brake because I have a PRM gearbox - ANOTHER £1400!

Really. We got rid of our shaft brake as it was bloody liability. We now just turn off in gear and whilst the gearbox is pressurised for it locks the shaft and allows our Variprop to fold. After about 5 seconds the shaft is free to turn but it's too late as the prop has already feathered.

 

[Otter]

But he's got a ketch!

Indeed I do

No he hasn't --- anymore

Actually I have

 

[Woodlouse]

I'd recommend a featherstream. Darglow is a great company to deal with and have fantastic after sales service. When they found a design flaw with the prop they sold me they posted a replacement out to France where I was cruising, complete with torque wrench and a laminated set of instructions on how to change it, all gratis.

 

[michael_w]

I've got a 3 bladed MaxProp. Lots of grunt when required. I've also got a hydraulic PRM gearbox, just stop the boat when turning off the engine (usually by a hard burst astern) and it will feather perfectly.

 

[vyv_cox]

A shaft brake is a very expensive luxury. There are many, far cheaper ways of preventing the shaft from rotating, cheapest being a Mole wrench on the shaft but going on to somewhat more expensive and remotely controlled methods based on a bicycle brake. I find with my Bruntons that the prop will rotate until it is stopped by putting the gear in reverse. If I then put the gear back into neutral it remains stopped.

When I bought my Autoprop I was living in Holland and purchased it from a local dealer. The price then was around 2/3 that of buying in UK. I would be surprised if you could buy one in Holland with a UK address but if you have the availability of someone with a Dutch address it might well work.

 

[Otter]

That's true, I'd forgotten about the inertia issue, it takes a lot less to prevent it rotating than it does to stop it once it's spinning.

 

[ianc1200]

Is needing a brake peculiar to Autoprops? Have just had a Featherstream put on, and the gearbox is a PRM 150, so so post got me worrying. Darglow however state brake not required.

 

[vyv_cox]

Is needing a brake peculiar to Autoprops? Have just had a Featherstream put on, and the gearbox is a PRM 150, so so post got me worrying. Darglow however state brake not required.

No, I don't have one and all is well with the gear in reverse. I understood from CW's previous post that this was not an option with his gearbox.

 

[NormanS]

I don't have a shaft brake, but try to stop in astern, then move the gear / speed lever back and forward. That seems to lock the shaft. My rudder has quite a balance strip on it, and if when sailing, the prop rotates, it seems to throw water at the balance strip, making steering very difficult. The first time it happened, I thought something disastrous had happened to the rudder, but now I know better. It's happened maybe once a year, so not a problem.

 

[captainboo]

Is needing a brake peculiar to Autoprops? Have just had a Featherstream put on, and the gearbox is a PRM 150, so so post got me worrying. Darglow however state brake not required.

I have a Featherstream with an older PRM 140 hydraulic gearbox.

If you put the gearbox in neutral and then switch off the engine the propeller does not feather and continues to auto-rotate.

If however you leave the gearbox in fwd gear and just switch off the engine first the decaying hydraulic pressure is enough to keep the drive engaged long enough for the drag through the drive train to force the propeller to feather!

Just remember to engage neutral afterwards if you have a start interlock switch fitted - it can lead to a short heart stopping moment wondering why the engine won't start at a critical moment!

It is explained in the Featherstream shaft drive fitting instructions on their website here:- http://www.darglow.co.uk/product-support/Literature/index.html