Author Topic: The Eather/Walker pitch gauge (Read 12307 times)

Bradley Walker · « **on:** October 28, 2015, 10:14:33 AM »

I was asked about a pitch gauge design. I have the fab drawings for this one if someone wants to make it.

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Brett Buck · « **Reply #1 on:** October 28, 2015, 10:56:55 AM »

Quote from: Bradley Walker on October 28, 2015, 10:14:33 AM

I was asked about a pitch gauge design. I have the fab drawings for this one if someone wants to make it.

If you have it on CAD, might consider flipping the scale around to the other side to make a CW version, too, with the scales printed on each side. You'd have to flip the scale and then flip all the numbers around forwards. The user could then put holes in the other side of the base to hold it.

Brett

Bradley Walker · « **Reply #2 on:** October 28, 2015, 10:58:08 AM »

Yup.

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Bradley Walker · « **Reply #3 on:** October 28, 2015, 10:58:33 AM »

It will do much larger props than a Prather.

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Doug Moon · « **Reply #4 on:** October 28, 2015, 03:21:14 PM »

This design has many user-freindly adaptations!!!

José Almeida · « **Reply #5 on:** October 28, 2015, 03:23:28 PM »

Hi Bradley.

Thanks for sharing the designs.
Following Brett opinion about CAD, if you have the files for sharing may be made one for CW props.
I appreciate that 👍
Regards
José

Bradley Walker · « **Reply #6 on:** October 29, 2015, 09:36:02 AM »

Quote from: Doug Moon on October 28, 2015, 03:21:14 PM

This design has many user-freindly adaptations!!!

Thank you.

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Doug Moon · « **Reply #7 on:** October 29, 2015, 01:12:55 PM »

Quote from: Bradley Walker on October 29, 2015, 09:36:02 AM

Thank you.

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You are welcome.

The items I saw right off the top are...

17 stations!
The built in clamp on the pitch arm.
The slider track that traps the slider.
The slider with the pressure balls on the bottom that keep it tight up against the slider track so the reading is the same every time yet you can slide it in small increments without having to press down on it to make sure its reading the same as the last time....(wow that is a terrible sentence)

It's a nice design, would be a great rig for sure.

Bradley Walker · « **Reply #8 on:** October 29, 2015, 01:21:56 PM »

Yes. All that.

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Eric Viglione · « **Reply #9 on:** October 29, 2015, 02:52:45 PM »

That looks awesome! Sure would fill the void for those jones'ing for the extinct Prather, and could be an upgrade for the rest that already do have one.

My Prather scale is wearing off in spots because friction from clothes-pinning the arm in place... I've had to draw it back on in spots with a Sharpie, heh heh.

If someone starts making these, I predict they will sell quick in small batches anyway. Personally, after a successful prototype, I wouldn't make the first batch more than... oh... 50 at the most... then maybe 25 at a whack... just to see when/if the market saturates and so you don't get stuck with a bunch.

Not sure if R/C guys would eat these up like we would, but its ability to pitch larger props would certainly open up the market for it.

EricV

Brett Buck · « **Reply #10 on:** October 29, 2015, 03:49:24 PM »

Quote from: Bradley Walker on October 28, 2015, 10:58:33 AM

It will do much larger props than a Prather.

I would say that was a bug instead of a feature, for stunt. Anything that keeps people from running giant props would be to their advantage. But they'll do it anyway...

Bradley Walker · « **Reply #11 on:** October 29, 2015, 03:50:11 PM »

It's not just for stunt. But yes I agree....

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Bradley Walker · « **Reply #12 on:** October 29, 2015, 03:51:08 PM »

Quote from: Eric Viglione on October 29, 2015, 02:52:45 PM

That looks awesome! Sure would fill the void for those jones'ing for the extinct Prather, and could be an upgrade for the rest that already do have one.

My Prather scale is wearing off in spots because friction from clothes-pinning the arm in place... I've had to draw it back on in spots with a Sharpie, heh heh.

If someone starts making these, I predict they will sell quick in small batches anyway. Personally, after a successful prototype, I wouldn't make the first batch more than... oh... 50 at the most... then maybe 25 at a whack... just to see when/if the market saturates and so you don't get stuck with a bunch.

Not sure if R/C guys would eat these up like we would, but its ability to pitch larger props would certainly open up the market for it.

EricV

I have the prototype in a box in my attic.

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Gerald Arana · « **Reply #13 on:** October 29, 2015, 04:16:57 PM »

Why that looks just like mine and the one I sold Tom!

What's so unusual about it?

Just asking, Jerry

Brett Buck · « **Reply #14 on:** October 29, 2015, 04:57:38 PM »

Quote from: Bradley Walker on October 29, 2015, 03:50:11 PM

It's not just for stunt. But yes I agree....

Understood.

Brett

Motorman · « **Reply #15 on:** October 29, 2015, 08:01:40 PM »

Why does the prop holder lock into the base? I design and manufacture allot of different props and I use my pitch gauge allot and something like that would be a great inconvenience having to slide it out the end and reinsert it every time you change stations. Allot of extra machining for something that makes it worse. And the extra weight, make one that's light so you can hold it up for an extended time without distress. The Prather gauge gets heavy after a while.

MM

Bradley Walker · « **Reply #16 on:** October 30, 2015, 07:47:41 AM »

Quote from: Motorman on October 29, 2015, 08:01:40 PM

Why does the prop holder lock into the base? I design and manufacture allot of different props and I use my pitch gauge allot and something like that would be a great inconvenience having to slide it out the end and reinsert it every time you change stations. Allot of extra machining for something that makes it worse. And the extra weight, make one that's light so you can hold it up for an extended time without distress. The Prather gauge gets heavy after a while.

MM

Feel free to design your own. I give you permission.

I do not have the original inventor file. These pictures are all I have. I will try to make a page in my website where you can download the high res pics.

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Bradley Walker · « **Reply #17 on:** October 30, 2015, 09:56:35 AM »

http://www.urbanrifleman.com/2015/10/30/walker-eather-pitch-gauge/

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Bradley Walker · « **Reply #18 on:** October 30, 2015, 09:56:43 AM »

There you go.

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Gerald Arana · « **Reply #19 on:** October 30, 2015, 10:35:05 AM »

Quote from: Gerald Arana on October 29, 2015, 04:16:57 PM

Why that looks just like mine and the one I sold Tom!

What's so unusual about it?

Just asking, Jerry

Oh, now I see that it locks in?!

Sounds/looks like a PITA to operate. Oh well, I'll stick with mine. Good luck..............

Jerry

peabody · « **Reply #20 on:** October 30, 2015, 10:54:49 AM »

I like it! The Prather unit isn't as precise as it should/could be because the block that holds the prop isn't locked into place and therefore can "creep" when pitching.
Couldn't the backwards pitching requirement be solved with another print on the back side of the indicator and another mounting pivot on the other side of the unit?

If it's too much of a PITA, build a Windy gauge....no numbers, mostly eyeballing things....

Have fun!

Steve Helmick · « **Reply #21 on:** October 30, 2015, 12:57:42 PM »

Something I've thought about adding to my Prather gauge is a "foot", maybe angled a bit, bolted to the baseplate on opposite end from the gauge "flag" and indicator bar. It would be handy, I think, to not have to set it down flat on the kitchen counter while turning the prop on the slider block.

I also have some doubts about the T-slot design, based on having many years of dealing with T-slots in machinery. I suspect it might be a PITA to use, as well as manufacture. Maybe you could give it a good workout and let us know if you like it or not, from a practical standpoint? Having a longer slider seems like it would be a nice mod, helping to prevent rock & roll and also giving the eyeball more length to square the blade to?

Has B.E. been using one of these, or is yours (in the attic) the only one in existence?

Which reminds me....I'd like to know if folks typically do a prop one complete blade at a time or if you do all blades at a given station before progressing toward the tip? I'm voting for the last option. I've done it both ways. Started out doing one blade complete, but then decided that might not be as good.

Steve

PS: Those silver Sharpies are wonderful, aren't they?

Eric Viglione · « **Reply #22 on:** October 30, 2015, 02:24:23 PM »

Steve H -First I mount the prop in the holder, then start with a separate steel jig that aligns the prop to a true 90 Deg to the prop holder. Then I move the holder and prop to the Prather. If the prop is new, I work the station closest to the hub I can get to budge, and let the factory progress of pitch alone. If it's a used prop, I heat each blade and let it relax back to factory pitch, as most mejlik and bolly will on their own. Then, I will tweak as mentioned before, as close to the hub in the working area of the blade as I am comfortable for the given size of the prop... usually around station 8 or 9 on a big prop... and only heat and twist in that zone.

The ONLY time I mess with pitch at other stations is if I am chasing a specific issue, usually to do with drive out of a corner... pitching up the tips can help a little, but I rarely do it anymore, and just pitch as stated earlier and leave well enough alone. Once in a while, if I have 1 prop that doesn't act like my other identical props, I can usually trace it to a variance in pitch at one of the tips. Especially the old Bolly, they are so soft and easy to over-shoot with heat out at the tips, they are easy to mess up. I've seen planes left standing on their noses in hot cars mess up a single blade or tip pretty quick too. (one of many reasons I like my horizontal plane carry rack)

Back to Brads machine -As to being too much trouble, heck, unless you are doing mass production, I don't see how pulling the holder out of a slot (what, 2 extra seconds?) to pitch a prop once in a while is any big deal. I'd gladly take the extra accuracy if it is there. Doing it right the first time is a time saver in my book anyway you slice it. A clamping mechanism that doesn't drag the print off the face is a great idea too. What is not to like? I don't get some of the complaints. Maybe start eating more spinach.

EricV

Doug Moon · « **Reply #23 on:** October 30, 2015, 02:27:51 PM »

The T slot design with light pressure balls stop the Rock and Roll and help to hold in place when sliding in very small increments. It would make matching blades a snap. A few drops of food safe silicone in the groves and it would slide like a knife through butter. And you could let go of it and it stays where it is. You don't have slide back and forth 30 times trying to find your spot again. As far as sliding it all the way off to change, oh well it's worth it to get it more exact the first time instead of countless flipping back and forth.

I think it would be a great tool. But like Eric said small batches for sure. It's a one time buy so when those who would like one get one that's it.

Doug Moon · « **Reply #24 on:** October 30, 2015, 03:12:59 PM »

Quote from: Brett Buck on October 29, 2015, 03:49:24 PM

I would say that was a bug instead of a feature, for stunt. Anything that keeps people from running giant props would be to their advantage. But they'll do it anyway...

Yes using larger then 12" props for stunt is never a good idea. Just so you don't get tricked into trying it again please send me all of your larger then 12" Eather props. Everyone else can too. Thanks in advance.

Steve Helmick · « **Reply #25 on:** October 30, 2015, 06:29:50 PM »

Quote from: Eric Viglione on October 30, 2015, 02:24:23 PM

Steve H -First I mount the prop in the holder, then start with a separate steel jig that aligns the prop to a true 90 Deg to the prop holder. EricV

Eric...Thank you for your detailed response. Any chance you could post a picture of the device that aligns the prop to the 90 deg to the prop holder?

It sounds like you use a heat gun to pitch your props?

First thing I do is number the blades and put chord lines along the "blade" at the stations I'm going to change, using the silver Sharpie. After I'm done and the prop is cool and dry and I am checking the pitch at each station, I write the measured (estimated) pitch adjacent to each chord line.

I have a very advanced technique, using our induction heating electron-burning hot water pot (made in PRC for an outfit in Ontario or Quebec, as I recall). I pour boiling hot water into a 16 oz "pounder" beer glass and drop the one blade in. If the tip hits bottom, ok fine. If not, ok fine. I let it soak for about 60 seconds. I need a timer of some sort...egg timer, maybe, doesn't need to be real accurate, but does need to be quick to set, start & shut off. After a minute, the blade is kinda rubbery and I give it a twist and then lay it into the pitch gauge. While holding it all together, I turn on the cold water in the sink (an extra elbow would be handy) and use it to cool the blade as fast as possible. After a minute or so, it should be set. The reason I like the water method is that it's pretty sure you're not going above 212 degrees.

Like you, I have a model rack that carries the plane(s) flat, with nothing mashing on the prop. It's new, and I should post some pictures, but there are a few details I still need to finish...and a few I'm still pondering. That has to wait until my bum knee gets fixed in a week or two. Meanwhile, I spend my days reading old PAMPA CD's and trying to find something interesting on TV. Bleak. We've got a "Pineapple Express" here right now. Not nice, but not as bad as you guys are having in the SE. It's pretty warm (60F at 5:30 PM), except for the bag of frozen corn on my knee.

Steve

Bradley Walker · « **Reply #26 on:** October 31, 2015, 01:38:33 PM »

Bradley Walker · « **Reply #27 on:** October 31, 2015, 01:46:37 PM »

The truth is that the Prather is a cheap piece. Easily bent, wiggles like crazy, and if anyone knows the proper way to pitch a carbon propeller they will realize while a clamping, self holding design is a way better design.

If a person didn't want a t slider it would be easy enough to make an optional old school slider.

Bradley Walker · « **Reply #28 on:** October 31, 2015, 01:49:16 PM »

It's a bit dusty.

Not bad for a prototype. Smokes any Prather ever made.

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Bradley Walker · « **Reply #29 on:** November 02, 2015, 07:47:55 AM »

As to all the comments about the t slot. It works like a charm.

As to the t slot being difficult to machine, I can assure that if the Chinese mom and pop shop could do it, I'm sure a country that can produce an entire engine made from bar stock would be capable of machining some parallel t slots.

I for one, an very satisfied with my design, as I have used it and I have hundreds and hundreds of hours on a Prather (including making all my own wood props for the Saito development program) and double that on carbon props.

And this is better. And made better.

Bradley Walker · « **Reply #30 on:** November 02, 2015, 07:49:24 AM »

The best way to pitch a carbon prop is set your pitch at station six with the clamp, slide the prop up to the bar and hit it at the hub with a heat gun. Let the prop sit against the bar until its cool.

Yer done.

The t slot makes this process even easier.

Bob Reeves · « **Reply #31 on:** November 02, 2015, 08:28:03 AM »

If someone could produce the CAD files we could probably find a Chinese company to make a bunch. Without the CAD files I don't see it as worth the effort it would take. I would love to have one setup for both prop rotations but not bad enough to try and reproduce the CAD files.

Bradley Walker · « **Reply #32 on:** November 02, 2015, 10:55:45 AM »

You can convert a pdf to Autocad.

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Bradley Walker · « **Reply #33 on:** November 02, 2015, 10:57:17 AM »

Why does it have to be a Chinese company? I don't understand that...

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Bradley Walker · « **Reply #34 on:** November 02, 2015, 11:19:07 AM »

http://www.urbanrifleman.com/2015/10/30/walker-eather-pitch-gauge/

Here is the high resolution page. You can download the high resolution pics here.

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RandySmith · « **Reply #35 on:** November 02, 2015, 11:31:50 AM »

Quote from: Doug Moon on October 30, 2015, 03:12:59 PM

Yes using larger then 12" props for stunt is never a good idea. Just so you don't get tricked into trying it again please send me all of your larger then 12" Eather props. Everyone else can too. Thanks in advance.

No send them to me ...... I don't wanna see Doug having anymore prop problems :-)

Randy

Bob Reeves · « **Reply #36 on:** November 02, 2015, 02:34:07 PM »

Quote from: Bradley Walker on November 02, 2015, 10:57:17 AM

Why does it have to be a Chinese company? I don't understand that...

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Cost, it's the American way these days isn't it.

PDF files are not much good, would have to be redrawn in a format that can be converted to CNC machine code. Making them one-off from the drawings would be extremely expensive.

Bradley Walker · « **Reply #37 on:** November 02, 2015, 02:51:30 PM »

No it wouldn't. There's hardly any cnc in this design.

The base would require a single cut on an offset. The t cut would be a tool. You could cut it by hand on a mill. I would cut six feet of material at a time then separate the pieces. The flag would be die cut. The slider is crazy simple.... Etc etc etc

I keep hearing about cost. I hadn't noticed people in rc or stunt have any problems spending crazy money for stuff... I mean the average guy who goes to the Nats has a drawer with five thousand dollars worth of engines and crap...

I think you could make a pitch gauge in the United States. This isn't an ipod. Every mom and pop machine shop in the Midwest is making AR 15 parts. I think they could handle this.

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john e. holliday · « **Reply #38 on:** November 02, 2015, 09:00:49 PM »

So why haven't you went into production, even though I wouldn't buy one as I now fly for fun.

Doug Moon · « **Reply #39 on:** November 03, 2015, 09:25:34 AM »

Quote from: RandySmith on November 02, 2015, 11:31:50 AM

No send them to me ...... I don't wanna see Doug having anymore prop problems :-)

Randy

NO don't send them to Randy. He has plenty of props, and then some. I need all the prop problems I can handle.

Bradley Walker · « **Reply #40 on:** November 03, 2015, 09:30:19 AM »

You could easily make this out of plywood using a laser cutter.

Assemble it with CA and screws.... Apply a vinyl sticker for the face.

Done.

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Bradley Walker · « **Reply #41 on:** November 03, 2015, 10:20:28 AM »

Brian's version is wood.

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john ohnimus · « **Reply #42 on:** November 04, 2015, 12:45:45 PM »

Nice looking stuff Brad!!!

Done a little "F" class shooting myself.

Could you give any more info on your stunt plane "The Zone" I have found the plans for it and it looks fantastic! just looking for some general stuff, how it handles the wind,etc.

Thanks,

Tony O

Bradley Walker · « **Reply #43 on:** November 10, 2015, 07:17:51 AM »

It's based on the time machine. Which is based on a Patternmaster. Can't really go wrong there.

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Bradley Walker · « **Reply #44 on:** May 02, 2016, 03:27:17 PM »

I have a direct link to the PDF for the pitch gauge plans.

Bradley Walker · « **Reply #45 on:** May 02, 2016, 03:29:00 PM »

PDF file:

https://drive.google.com/file/d/0Bze88XvZ7f52d29HQ2lobVM2UDg/view?usp=sharing

frank williams · « **Reply #46 on:** May 02, 2016, 04:27:12 PM »

I've always thought that Goran Olson's pitch gauge was pretty neat.

Brian Gardner · « **Reply #47 on:** May 02, 2016, 04:38:25 PM »

Looks magic Brad

Motorman · « **Reply #48 on:** May 02, 2016, 08:56:51 PM »

What does the short leg on the indicator arm do?

MM

Geoff Goodworth · « **Reply #49 on:** May 02, 2016, 09:52:50 PM »

Guys, it would have been nice to see most of this discussion take place on the CAD forum but this is OK.

First, there is a simple conversion process available—free!

Import the PDF into Inkscape and save it as a DXF file.

This works so long as the PDF is generated from the vector diagram using a good PDF writer.

Also, if anybody wants to reverse the gauge for use with clockwise rotating props, I think you will need both the pointer and the scale reversed. AutoCAD does this while regognising text and keeping it reading the correct way. I haven't done it for a while and I can't remember whether the text moves when the drawing is rversed.

PS I've just tried the above process. It didn't work this time but I'm sure that it is exactly the same as I converted a drawing successfully late last year. Maybe I've forgotten something, but I don't have time to try again and trouble shoot.