Propeller Pitch-O-Meter

[MTECHMARINE]

Hey you guys, Since this stuff was in storage for 25 years I lost the directions on how to use this thing! Anybody out there got an instruction sheet for this tool? Does the prop mount the other way??:confused::eek:

[Bill Van Steenwyk]

The wheels used on the horizonal shaft (same one the prop is on) are dependent on how many blades on the prop. Same one can be used for 2 and 4 blades, and a separate one for 3 blade. You rotate the prop toward you and place the pointed shaft on the furthest part of the trailing edge of the prop. Then "0" the vertical pointer on that pointed shaft with the 0 on the scale attached to the shaft below the pointed one. There is a little "index" pin that comes out from the left side of the tool and allows the index wheel to only move so far. The index pin has to be up against one shoulder to start, and then as you rotate the prop, the shaft will turn until the index pin stops it. When the prop is then rotated until the index pin stops the shaft, the pointed shaft is moved so it contacts the prop again. You then read the amount of distance the pointer moved from the "0" on the scale to where it is now located when it stopped.. Depending on whether the index pin has been used in the wide or narrow slot on the wheel you then read either 1/16 or 1/8 inch on the scale as 1 inch of pitch.

I had one of these that I just sold last winter, and I made a copy of the instructions so the buyer and I could discuss if he was having problems. I will see if I can find them so as to possibly help you if you can't figure it out from my brief description above.

[MTECHMARINE]

I thought it was something like that, I just couldn't remember what the scale was. There are 3 alignment wheels, one has 2 differing width for 2 blades, 2 differing for 3 blades and the third has 4 equal quadrants I assume will do a 4 blade prop. I imagine that the wider one is for general pitch and narrower one for sampling and averaging a progressive prop, yes?

Did some testing of 4 bladers for OPC way back, a great stable ride but not fast enough. Yes, A copy of the instructions would help

[Bill Van Steenwyk]

Bill:

I don't have time this evening but will look for directions tomorrow and if I can still find them will scan and post on this thread. In the meantime, after looking at the picture, you need to do the following:

1: You are correct about the wheels and which one works with which type prop, 2, 3, and 4 blades. The differing spacing between the notches in each blade is used depending on which scale you use on the measurement scale. Mine just had a piece of machinist scale glued on it. Yours looks to be the same. One notch spacing is used if you want to use 1/16th on the scale for each inch of pitch, and the other is used if you want to use the 1/8th scale. The 1/8 scale will allow for 1/4 and 1/2 inch pitch increments (easier to read).
You are also correct about the progressive pitch reading. Also sometimes one scale is better than the other depending on blade width. That is kind of a trial and error situation depending on the prop. You can also use the gauge to check and see if each blade is the same, AS LONG AS YOU DONT MOVE THE ORGINAL SETTINGS ON THE GAUGE. Just loosen the wing nut holding the prop on the shaft and slip it around to the next blade, locate the pointer IN THE SAME PLACE on the blade and remeasure that blade using the same process.

2. The vertical shaft is not normally used for storage of the wheels. As you have already probably determined, the wheels will interfere with prop rotation on the prop shaft if left on the vertical shaft during the measuring process. It is a good place to store them though.

3. Be sure and put the scale and pointer "holder" down as far on the vertical shaft as possible before starting measurment so as to just allow clearance so the wheel can barely clear the bottom of the block where the two screws that hold the shafts is located. If you don't have this in the same position each time you check pitch in a different place on the blade you will not get correct readings in relation to pitch on different parts of the blade, i.e. trailing edge, middle, etc.

4. If you were going to check the prop you have on the gauge in the picture, remove the two wheels stored on the vertical shaft, back the two measuring shafts, (pointed and one with scale on it) over to the left so the prop will clear when rotated, and then totate the prop towards you so the shaft with the pointer on it will just touch the trailing edge of the blade on the thrust face as close to the edge as possible. This can be a litte touchy at times and the diameter of the prop will determine how high on the vertical shaft the shaft with the wheel on it needs to be located so the prop will rotate without the blades hitting the base of the gauge. When you get the prop located correctly in relationship to the pointer then adjust the block with the pointer and scale shafts down so it just clears the wheel with the notches as it rotates. After these two adjustments, then push or pull the shaft with the scale on it until the vertical pointer on the shaft touching the prop lines up with either 0 or another large number such as one. I always used 0 as that allowed more movement of the scale shaft without potential of running out of measurement. VERY IMPORTANT LAST STEP BEFORE GETTING PITCH MEASUREMENT. Make sure the wheel is turned all the way, one way or another, in either the wide or narrow notch, whichever you are using, so that the "index pin" shown sticking out of the block that holds the horizonal shaft on the vertical shaft is pushed over to the left and is resting up against the stop at the end of the notch in the wheel. UNLESS THIS IS DONE YOU WILL NOT GET A CORRECT READING AS THE PROP HAS TO ROTATE THE WHOLE DISTANCE OF THE NOTCH WIDTH.

5. After you have this all lined up, scale pointer on 0, index pin in end of notch, pointer on horizonal shaft touching blade where you want to measure pitch, then rotate the wheel and prop TOWARD you and push the pointed shaft until it BARELY contacts the prop again. Now read the scale where the pointer is pointing now, and if for example you are reading on the 1/16 scale and the pointer is on the half inch marker, you have measured the prop at 8" of pitch.
Any additional 1/16'ths of an inch would be another inch of pitch each 1/16th, clear up to 16 pitch on the 1/16th scale, or a total reading of one inch.

6. Always remember that this type gauge will probably measure differently on the same prop than another type of gauge, so to try to compare a prop measured on one gauge of a different type, and then on this type, will not get you much good info. You will probably not get the same pitch reading. Rather is is like a speedometer, to be used to compare different props on the same gauge, and based on test info, speed, RPM, etc., it will certainly tell you what is happening between props of highter and lower pitch than others that are different.

Good Luck, and I will try to find the directions, but if not, you sound knowledgeable and with this short synopsis, you should figure it out OK.
Feel free to PM me if you think I can help you further.

Bill

[Bill Van Steenwyk]

Bill:

Managed to find the user instructions. Will scan and send to you at your e-mail adress later on today or this evening.

Bill


ADD: INSTRUCTIONS SENT TO YOUR E-MAIL ADRESS SEVERAL HOURS AGO. TIME NOW 7:35 PM CDT

[Roflhat]

Anyone know where I can get one of these?

[Bill Van Steenwyk]

Anyone know where I can get one of these?


Do not think they are made anymore. The one I sold was 35+ years old. Made by the fellow who mfgd the Champ Hot Rod for a time, but I do not remember his name. I bought it from him at that time. There are a number of good gauges on the market at present, but expect to spend considerably more at this time. Ron Hill could probably help you with some suggestions.