VooDoo Prop Pitch Gauge - Modification to make it "right"

[Darin Jordan]

I took the plunge and purchased a VooDoo Prop Pitch gauge. Wanted something more portable and easier/quicker to read.



Well, it's all that. Seems simple to use, etc.



However, I didn't feel like it was made as precise and repeatable as it could be, and it had kind of an "unfinished" quality to it. For example, the round knob's countersunk screw protruded because the aluminum arm wasn't counterbored for it. The knob on the top of the pedestal was too small and a rounded knob, making getting it snug a bit of a task. And, it wouldn't handle 1/8" props.



So, I made some changes. Sharing in case this might help someone else out there.



1) I drilled out the brass pivot base and tapped it out to 10-32 so I could use a standard 3/6" propshaft to hold the prop.

2) I took a 3/16" stepped to 1/8" shaft for 0.0625" wire and added 10-32 threads to the 3/16" portion.

3) I used drive-dogs to hold the prop base.

4) I added a longer threaded 1/4-20 rod into the base, and got a pair of steel bushings (1/4" ID) to allow me to space the gauge up and down, depending on the prop.

5) I added a teflon screw counterbored into the base to allow me to add some slop-reducing tension on the brass pivot.



NOW, it's useful!!

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[dasboata]

Darin I measure all my props pitch at 36* I don't know if VD are set up that way But I have mine drilled special ,,makes the math much easier measure at 3 different places total and divide to get average pitch ! if you have any questions just ask !

[Darin Jordan]

Darin I measure all my props pitch at 36* I don't know if VD are set up that way But I have mine drilled special ,,makes the math much easier measure at 3 different places total and divide to get average pitch ! if you have any questions just ask !

Thanks,

On this one, I just move the decimal place over to the right one position.... re: 0.311 ~ 3.11".

[ray schrauwen]

Nice thread Darin. Maybe it's time I started some prop voodoo too!

[dasboata]

Thanks,

On this one, I just move the decimal place over to the right one position.... re: 0.311 ~ 3.11".

correct it that how it is set up at 36* ? the drive dog will just be a PITA

[Darin Jordan]

I made another very useful modification today.

Measured 10 and 20 degrees, marked off a .0625" offset to the right, and drilled/reamed 0.125" holes. Made a post from an old 1/8" propshaft.

Now the gauge is useful for measuring trailing edge pitch, etc. Just use the formula:

Pitch= (Dial reading x 360)/degrees

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[dasboata]

I made another very useful modification today.

Measured 10 and 20 degrees, marked off a .0625" offset to the right, and drilled/reamed 0.125" holes. Made a post from an old 1/8" propshaft.

Now the gauge is useful for measuring trailing edge pitch, etc. Just use the formula:

Pitch= (Dial reading x 360)/degrees

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did you use a indexing table for that Darin ! there will be some dividing also the math takes some time LOL

[Darin Jordan]

did you use a indexing table for that Darin ! there will be some dividing also the math takes some time LOL

The math is "tough" to be sure...

I used to build tooling for Boeing, so this is all just precision laid out using some of the tools I still have here laying around... I also have a Mill, which helps. Holes were drilled to 7/64" then reamed to 0.125, so that pin fits perfectly.

Seems to work well. With the smaller degrees, I'm not able to measure the trailing edge pitch, etc., which is much more informative. Using the full 36-degrees, for example, I measured one of my SAW props to be 3.15" Pitch. However, the last 10-degrees of the blade is actually 3.888".

OH, by the way, Brian Buaas should be contacting you. He wants one of your gauges as well. :)

[dasboata]

I will have 1 left , I will save it for Brian,, I will PM you over my notes on the measuring later on also works well for cupping !!! !

[Darin Jordan]

I will have 1 left , I will save it for Brian,, I will PM you over my notes on the measuring later on also works well for cupping !!! !

Excellent, Chris. I'll need them... This next SAW trip is going to be all about TINY props... 32-35mm, with very little blade area left to measure! :)

I'll have Brian contact you.