Bolly Props

Hi All,
After reading Peabody's post, and the comments, is it just me or do almost ALL Bolly props need to be checked?
I have quite a few Bollys and have yet to get a 3 blade that was the same on all blades. Maybe one two blade that was as marked on both blades. Using a Prather gauge for 12 years.
How 'bout it? Am I just lucky enough to be getting all the "bad" props? I can't believe that since they have come from several sources. It is just SOP for us to pitch, and balance, them before ever trying to use them. I did break down and specify that the prop be balanced and pitched on one three blade order, and it was. But I have had no problem balancing and pitching them. These are 11" to 13" props we're working with.
Again, are Bollys just always in need of work?
Thanks
Bill <><

YEP.....never had one that was close to ready.
NOW not to take ANYTHING from RANDY SMITH. THERE GRAT PROPS and I will never say anything BAD about the BOLLY. Just one of those things WE stunt guy's have to do.

Scott(got all of my fingers)Riese

I hope it didn't come across as if I was in any way knocking Randy, or anyone else that carries Bolly, or even Bolly them selves.
I just wondered if it is normal. I know it is for us.
Bill <><

NO you didn't. HOWEVER, with the stress in the world today we can't be sure. It's just like everything we say, or do something is wrong.

scott(define "IS" Mr Clinton)Riese:+

Mr. Bill:
Randy suggests pitching and balancing all props, unless you request that he do it.
These had been used by a local as "back-ups" for a Nat's adventure...and I suspect that the one the I labeled "Base" had, indeed, been re-pitched.

See Ya

Not only do the need to be pitch checked, there needs to be a significant amount of work on cleaning up the "shape" of the blade. If you look carefully, the LE of the props are generally "flat". I spend 2 to 3 hours a prop cleaning them up, shaping, balancing, and then pitching.

Yes, it seems like a lot of work considering the price. I think they ARE worth it. I couldn't even imagine how much time, and money I would spend to make my own carbon prop. Yes, it takes a few hours to make them work, and when finished they are reproducable and repeatable at a still reasonable price and time.

I believe the advent of carbon props have been one of the reasons the overall quality level of NAT's level flyers have improved so much. They work well and can be reproduced easily. Can't say that about wood props. In the past, there were only a few select people who had real quality props. That's not true today! Most do. Now, the same thing can be said about engines.

Yup.....Today "are" the good old days.

Props, and the care and feeding thereof, is yet another issue I will need to address as I start flying CL. In RC Pattern, I was able to get enough performance from the APC props I was using and did not engage in checking or adjusting the pitch. As long as they were in balance I used them. Reading this and other threads on props, it seems that balancing and pitching a prop is typical and expected in CL PA. Now to my questions. Is the Prather gage the one most people use? All of the discussion in this thread has been on composite props, that is heat and twist. What is the recommended procedure for wood props? In one posting I read, the flyer said he worked the forward (airfoiled) surface of the prop to make changes. I have also heard that you shouldn't ever change the forward surface, work on only the aft surface. Which is correct? I appears that I will be taking a crash course (oops, I guess I shouldn't use that phrase in this context) in prop reworking.

J Hildreth

Hi Joe:

Here is my own opinion on the prop stuff.

First, Balance every prop--and make certain it is the same length on both blades, runs true, etc.

Second, regarding altering pitch, I think today, with the supply and a range of off the shelf props available, one can go through Intermediate and never adjust pitch. I think that somewhere along the learning curve, the nuances of prop adjustment become first recognizable, and then float to the top of the priority list as other adjustments are understood and brought into your consciousness. (your "Stunt Program" if you will). Perhaps first clipping diameter a little here and there, adding a bit of pitch to tips, reshaping tips, etc.

Surely as you advance to more complex airplanes and powerplants, the ability to recognize prop differences and make pitch adjustments becomes more important.

So I guess what I'm saying is, work your way up through Intermediate using well known combinations of power, plane, and prop. And unless you just want to fiddle, use the time to fly more on the standard stuff (balanced).

BTW, I think the prather guage is most widely used but Daryl Cady offers a nice unit as well and it seems more readily available. It looks like a metal version of John Kilsdonks' Hooptee Pitch Guage--a plywood version that works just fine. I recall Brett saying he uses a set a accurately cut plywood wedges of different angles--then goes to a conversion chart that gives pitch at given station with known angle in degrees.

I've always removed material only from the front (top of foil) side. I'm pretty sure that is the advice you will get from most here.

Anyway, mostly just my opinion.

ALL props are suspect! None can be ASSUMED to be as marked. As above, all should be measured and balanced. Wood, F/G, or C/F. I've reworked more than enough to know that none can be trusted! Sure, you'll get those that measure up, as marked, but most won't. Even wood props of supposedly similar manufacture may pitch differently on each blade.

Yes, the Prather pitch guage is the "standard". but is not always available. Pitch is relative to YOUR OWN props. Doesn't matter which guage you are using to measure each blade of your own props. It only matters when someone says "I am running a 3.75 pitch", which guage he is using. I mean, your 4" pitch on guage "A" may be equal to 3.75" on his guage "B". But you need to have all of the blades on YOUR props EQUAL! Pitch. Length. & Weight. Period!

And if you think Bolly's are expensive...You're right. But that 1 prop can be a 3.75 today, a 4.25 tomorrow, and a (true) 5.0 on Wednesday! Try that with you master air screw!

Hey Ward!
Where you been hidin'??
I remember buying a half dozen of the B-Y&O 10-5s once so that we could run the OS 32 without having to work on repitching props.
They ranged from 10-4 1/4 to 5, all different but pretty good from blade to blade on each prop! We used 4 that were in the 4 1/4 to 4 3/4 range. Still have two left, I think!
Neeed to get together soon.
Bill <><

>Yes, the Prather pitch guage is the "standard". but is not
>always available. Pitch is relative to YOUR OWN props.
>Doesn't matter which guage you are using to measure each
>blade of your own props. It only matters when someone says
>"I am running a 3.75 pitch", which guage he is using. I
>mean, your 4" pitch on guage "A" may be equal to 3.75" on
>his guage "B".

I wouldn't agree with that. If all you are doing is relative measurements and fiddling until it works, maybe. But if you are doing any sort of analysis, or want to freely swap with others and have repeatable results, you want the gauge to tell you the "real" number.

Despite what anyone might have had to say about it in the past, I found the markings on the Prather guage to be right on the money, for the most part, and at least close enough to Ted's and David's that we can swap freely with predictable results.

>And if you think Bolly's are expensive...You're right. But
>that 1 prop can be a 3.75 today, a 4.25 tomorrow, and a
>(true) 5.0 on Wednesday! Try that with you master air screw!

No disagreement there- the graphite props (Bolly and Eather) are more expensive than Rev-Ups. If you are still frequently breaking them, it matters. If you aren't they are a bargain because of the "tweakability" factor. I have managed to fly at a pretty high level for a long time, with three different engines, and I have used a total of about 10 props the entire time - and I still have 6 of those, the other 4 having been buzzed off or broken. Even if they were $50 a peice, that still only about $30 a year as a propellor bill - and that's pretty cheap.

>And if you think Bolly's are expensive...You're right. But
>that 1 prop can be a 3.75 today, a 4.25 tomorrow, and a
>(true) 5.0 on Wednesday!

And then you nose over and break it.

>I believe the advent of carbon props have been one of the
>reasons the overall quality level of NAT's level flyers have
>improved so much. They work well and can be reproduced
>easily. Can't say that about wood props. In the past, there
>were only a few select people who had real quality props.
>That's not true today! Most do. Now, the same thing can be
>said about engines.
>
>Yup.....Today "are" the good old days.

Thanks for the response , Paul!
I couldn't agree more about the availability of equipment, and the sharing of knowledge! We are indeed in a great period of Stunt history.
Bill <><

>Props, and the care and feeding thereof, is yet another issue I will >need to address as I start flying CL. In RC Pattern, I was able to get >enough performance from the APC props I was using and did not >engage in checking or adjusting the pitch.
>J Hildreth

--Big Snip--

J Hildreth,

I am enjoying your coming to grips with CL Stunt, having recently come from RC Pattern. I went through this process a few years ago, a good friend is currently doing the same. And it leads to the most interesting of discussions, many of which begin with, "You do what!? We don't do that in RC Pattern! Instead, blah, blah, blah..."

I have (slowly) been dealing with his objections, have yet to deal effectively with the idea that within a fairly wide range shifts in balance point do not effect level-flight stability, that instead the "groove" we like is much more closely related to alignment. You are predicted to be in his camp at this time.

As to APC props, it is my view that we do not take advantage of them to the near the extent we should in CL Stunt. Especially outside the ranks of the top expert-class fliers, say the upper 40 or 50 guys in the U.S.

For example, Pat Johnston has found the APC 13-4W to be his prop of choice for both the Saito 56 and ST 60, these motors being approximately equal in torque when run in Stunt tune. (Leaned out the ST 60 blows the Saito in the weeds, of course.)

Thus I think your forays into prop selection and rework might best begin with a few APC props. They are a lot cheaper. And they can be re-pitched. Find one you like, get used to it, use it as a benchmark when/if you decide to try Bolly or Eather props. (I have both, like Eather props, for whatever that is worth.)

My preferred source of APC props is Central Hobbies. Excellent stock, excellent service. But then you already know that.