PDA

View Full Version : propeller pitch fixture



herman pahls
11-19-2018, 04:04 PM
At 9:30 of Trent Palmers Cub Killer part 3 video, it shows for a few seconds what appears to be a prop pitch fixture they are using to set the pitch.
It rests against the prop hub and extends about 12" to an aluminum plate that is contoured to fit the blade.
It appears to be "homemade" and seems like a great idea to quickly get all 2 or 3 blades at the same pitch with out using a protractor or smart level.
Is this method common practice that I am out of the loop on?
Does someone sell a similar product.
I do not enjoy setting prop pitch and am looking for an easier method.

avidflyer
11-19-2018, 08:25 PM
I built a jig that would hold a laser and it clamps to the prop blade. The way it's made, it ends up in the same place on each blade. It will shine a light on the wall of the hangar. Mark where that blade gets the spot, and then adjust the pitch on the other blades to hit the same spot. Very accurate, and easier to read then a Warp Drive protractor. Although they are pretty accurate also. Can't find the pictures right now.... JImChuk

PS thought I had posted them here at one time.
www.teamkitfox.com/Forums/showthread.php?t=6559&highlight=lazer+prop+adjuster

herman pahls
11-27-2018, 11:38 PM
I received a 2 blade Luga prop today and it came with the prop pitch fixture that I noticed on the Cub Killer video.
I am clueless how to post a photo.
Is there an easy way to post a photo from an I-phone?
If so please advise and I will demo the fixture
Thanks

avidflyer
11-28-2018, 07:51 AM
Hi Herman, I just figured out how to downsize pictures to fit this site a couple of days ago, so if you want to send them to my email address, I will give a try at posting them to here. If you no longer have my address, it's avidflyer6014 at g mail. JImChuk

Wheels
11-29-2018, 11:36 PM
I want to see the pic too. pleeeeees.

bbs428
12-03-2018, 08:03 PM
I'm also interested in your Luga prop specs, engine, etc.
I'm thinking of buying a two blade Luga myself.

Go, go gadget iPhone pic's. lol. :D

herman pahls
12-03-2018, 10:33 PM
Yesterday was supposed to be the 72" Luga 2 blade prop test day and photos showing the "propeller pitch fixture" in action.
It was a beautiful day here on the southern Oregon coast.
My plan was to get full throttle static, climb and straight and level RPM readings before removing the 75" 3 blade Whirlwind and weigh each prop with out spinners.
I found out that the drive lugs on my 912S prop flange were too long for the Luga hub and will need to be replaced or shortened, I will need shorter bolts and the prop pitch fixture was not intended for this particular prop.
Once I get these issues resolved I will post photos with help from Avidflyer.

The good news is the the Luga prop assembly weighs 7.5 pounds, which is 4 pounds less than the Whirlwind at 11.5 pounds.
Less prop inertia which will be kinder to the 912 gearbox and sprague clutch.

I was disappointed that this prop fixture concept will not work on my Whirlwind prop set up because the Whirlwind prop hub does not have a flat surface and center hole like the Warp Drive or Luga hubs do.
I did learn that Whirlwind blades can be used in a Warp Drive hub which if I keep the Whirlwind would make setting the pitch much easier with this fixture.

The Luga props have a graduated scale on the blade root that lines up with the part line of the Hub.
Hal Stockton says some Luga owners set their pitch with the scale only and not using fixtures , protractors or smart levels.

The fixture consists of a 10" inch long, 3/8's inch diameter aluminum that is threaded on each end.
On one end there is a small aluminum flat plate (2" x 1-1/2") that screws to one end of the rod, that is cut so that it rests against the flat prop hub and is captured by the center hole in the prop hub.
The other end has a plate that is shaped to hook and rest against the trailing edge and make contact with the airfoil ~4" towards the leading edge.
It does not need to be airfoil shaped, just make contact with the prop in a consistent location on each blade
That plate consists of 2 pieces that are riveted with one rivet to allow adjusting the angle of the device.
Just move the fixture to each blade to match pitch.
Of course you will need to use something to set the first blades pitch in relation to the hub at initial set up and when reducing or adding pitch.

This device could easily be made in an hour.
The angle of the device could be adjusted at one end by the screw that holds a plate on instead of a 2 piece plate.

photos to follow, hopefully