Date: Mon, 08 Jan 1996 10:14:51 -0500 From: Nigel.Field@HQPSB.SSC.ssc-asc.x400.gc.ca (Field, Nigel (1416)) Subject: composite props Ron writes, >I have a friend who is planning to try an Ivo Prop on his bird. It will be interesting to see how it works out for him.> I tried a 68 inch Ivo 3 blade controllable pitch (not magnum version) on my VE last year and it damn near killed me. I got airborne OK with tons of thrust but before I reached the departure end of the runway it started to vibrate and howl. Prop RPM was rapidly increasing with airspeed thru 2650 when this occurred about 20 seconds after TO. I immediately reduced power to the minimum needed to hold 80 Kts and entered a tight downwind and was able to get it back on the runway in one piece. The blade roots were too hot to touch from flexing, split open and badly delaminated. Can't believe they all stayed on. Even before I flew it the small pitch change lead screw snapped off on the first attempt to go to fine pitch and I had to fix it. Also the blade helix (twist) is far too flat for a fast airplane. These props by design have very flexible blades to allow them to twist for pitch change. In a pusher this is bad news as they operate in the cowling and wing wake so the blade(s) see varying angles of attack through the rotational plane. This results in corresponding changes in lift (thrust) as they rotate and will produce an oscillation. The flexing at the roots creates very high stresses and heat is produced. Once the resin gets soft the fibres start to slide against each other producing lots more friction heat and the whole thing goes into thermal runaway. These are ultralight props and not good for fast airplanes, They are deadly on fast pushers. Ivo seemed quite concerned on the phone and refunded 100% when I wrote him a report. He now knows they are deadly on a VE. I sent copies of my report to Ben Owen at EAA who is compiling data on prop failures and may be a good source for advice prior to buying. As for alternatives, I certainly agree that the WD concept looks very attractive but they suffer from the same problem in that they flex too much at the root leading to failure. They are great on tractors with clean air. WD told me by phone that they definitely do not recommend them for the EZs. Apparently they are planning on a thicker version for the EZ market but as of a few months ago they had not progressed very far. At Osh 95 I saw a very nice 3 blade ground adjustable prop on a RV6 with a Mazda engine. I think it was in a recent Kitplanes article. It is all maple with thick root shanks and looks very promising. I am seriously considering one for my Cozy also the price was right at about $800. I got the guys card, Jeff Bertuleit Props Inc. Newport Oregon ph (503) 265-3032. Ron please tell your friend not to use an Ivo prop on his CP. Regards, Nigel Field Date: Mon, 08 Jan 1996 11:31:40 -0500 From: Nigel.Field@HQPSB.SSC.ssc-asc.x400.gc.ca (Field, Nigel (1416)) Subject: correction props inc. ph# The ph # for props inc should be (503)266-3032, sorry about that. Nigel Date: Wed, 10 Jan 1996 07:17:13 -0500 From: RonKidd@aol.com Subject: Re: composite props Absolutely, It makes sense. That is probably what happened to my Warp Drive Prop! I will tell my riend Rick. As a matter of fact, I will print your letter for him. Ron Date: Wed, 28 Feb 1996 06:41:19 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Fwd: Prop Spinner Advice ---- Begin Forwarded Message >Can anyone give me some advice on the advantages/disadvantages of a >spinner >versus a "Scull Cap"? >Jerry Kennel A spinner kit will be cut to fit around the prop that you chose. If you change props? Gess what, it will not fit the new blades. Cracking at the cutouts for the blades has always been a problem on most types of spinners. On a Scull cap there are no "cut outs" to crack or split. Only screws attach to the crush plate. I think the Scull Cap looks good on the 3 blade props, and not so good on 2 bladers. Jeff at AeroCad Date: Sat, 23 Mar 1996 11:13:44 -0500 (EST) From: Kenneth Brimmer Subject: Prop covering Mike, A few years ago I landed at an old airport in So. Carolina. On take-off I kicked up a rock that hit my prop. Luckily my prop has a wrap of carbon fiber so all it did was lift the fiber where the rock hit. But on take off it could have been serious. Because of that I would like to wrap my climb prop with ? ... carbon fiber? So I am going to the materials expert to see what you would advise. I know some pilots art using just glass. Other people are interested as well. I know that you will probably recomend kevlar but as it is so hard to work with unless it is the very finest I would rather not use it. Thanks- Ken Brimmer brimmer@erols.com "It's easy to build a plane that will last a life time." - Stolen Date: Thu, 25 Apr 96 08:08:31 EST From: MISTER@neesnet.com Subject: PropOPT >>Nigel Field wrote "I loaded the data into Don Bates' "Propopt" performance prediction application which has proved to be very accurate on past data that I have run. " Nigel, I'm not familiar with this application, tell me more. Can it evaluate both 2 and 3 bladed configurations? Bob Misterka N342RM Date: Thu, 25 Apr 1996 15:13:22 -0400 From: Nigel Field Subject: Propopt Had a few requests for more info on the capabilities of the "Propopt" design application that I refered to yesterday, so thought I would send it to the entire group. Since the designer of the application Don Bates has already stated it very eloquently in the user manual, I have appended a direct quote from the introduction section below. I would add that my application is now 2 years old and I believe he has a later version that is more friendly and certainly cheaper. Mine cost $90.00 US but it is now advertised at $29.95 and I think well worth it if your doing any kind of engine prop development or just want to predict aircraft performance. He advertises in SA and Experimenter and Kitplanes if you wish to contact him or phone (916)622-1886 in CA. The application is math intensive requiring a minimum of a 82386 with a 287 math co-processor. On a basic 386 PC it takes several hours to converge to a solution. On my 486 66 mhz it converges in 3 to 5 seconds dependant on the number of variables. If anyone wants a copy of the user manual can forward on request as a DOS text file readable with any DOS text editor. QUOTE Follows: PROP is a constrained system optimization simulation for propeller design. The user specifies the system requirements, a feasible design starting point and the design objective to be optimized. A powerful nonlinear optimizer performs the search for the optimal design. This is the same type program used professionally in the aerospace industry. Given reasonable input parameters, it will design the best propeller for a new project or show you if your present propeller is performing optimally or redesign it to the optimum you choose. The design variables, AFDES, DIAM, RPM, REDFAC, etc. selected by the flag IOPT, are optimizable in any combination. (up to 11 simultaneous variables nigel) The desired merit function is selected by NPAYOFF, typically maximum velocity, maximum thrust or climb rate or minimum horsepower for a specified cruise. The user may either fix the number of blades or may allow the program to determine the number. (up to 4 nigel) The solution may be constrained to meet desired goals of minimum rate of climb or thrust or desired cruise speed. The user specifies limits for maximum blade activity factor, propeller diameter and engine speed and gear reduction factor. From the size and shape measurements of a propeller together with a known aircraft velocity, altitude and power setting, your equivalent flat plate drag area, ADRAG, and effective pitch can be determined by the program. These input variables calibrate the program to match its designs to your particular aircraft. This allows you to get a very accurate performance increment from your present propeller. Engine/propeller rpm gear reduction factor, REDFAC, is specified on input or may be optimized for best performance. The turbo/supercharged option allows power to be maintained up to a specified altitude. The normally aspirated model includes automatic power reduction with altitude. The program requires a maximum horsepower versus rpm curve. The input reference propeller is used to compute the initial activity factor and provide the shape to use for the final design. Start with any shape you prefer and the program will ratio it to match the optimum. The program outputs propeller design and performance data. It lists chord and chord angle versus radial station, number of blades, diameter, pitch at the 75% station, activity factor, efficiency, power required, fuel flow, thrust, thrust coefficient, power coefficient, tip speed, static performance and other miscellaneous data. (if instructed it also outputs blade airfoil template co-ordinates for nine of ten stations. nigel) The design method used in the Advanced version of the program is based directly on the test data of NACA TR 640 for the Clark Y and R.A.F. 6 airfoils and generalized design theory and data is used to extend its application to any other activity factor. Data for 2-, 3- and 4-blade propellers of both airfoils is coded into the program for the most accurate possible results. Coordinates for both the Clark Y and R.A.F. 6 airfoils are stored in the program. The R.A.F. 6 provides better takeoff and climb performance for fixed-pitch propellers due to its higher max CL and has a flat bottom which may be easier to make. END quote. There is more but this gives the overall flavor. My appologies to those who find this boring. Nigel Field Date: Fri, 03 May 96 16:30:31 EST From: MISTER@neesnet.com Subject: COZY: Propellor Stuff I am putting a 3 Bladed Performance Prop on my 3 Place Cozy. I have a Lynn Woofter prop extension on my O320 hub. Can anyone tell me what the torque on the bolts for the engine end of the prop extension and for the prop itself should be? Bob Misterka N342RM From: George Graham Subject: COZY: prop optimizer program Date: Sun, 12 May 1996 12:40:55 GMT Organization: AirSep Corporation Just received Bates $35 prop program. Nigel Field thought perhaps the price had come down from the $ 90 he paid. Not really, the program I got is a "cruise" version (read tease) which does not print profiles, use the R.A.F. airfoils, or calculate flat plate areas. It was supposed to come with a book, but it will not be ready for two to three months. It takes some time to learn to use, but is very well done from what I can see. If you make your living designing props you should have it. Any questions ? George.Graham@airsep.com (716) 874-3277 Date: Sun, 16 Jun 1996 14:34:08 -0500 From: jwillis Organization: MK4 Builder Subject: COZY: WarpDrive Propeller Hi All Just a question about the WarpDrive propeller,my curiosity overwhelms me. Why does the GlassGoose,a two seater amphibian PUSHER, seem to use the WarpDrive propller with out any or very little problem? Is it because it is only using 160 hp? I remember reading earlyer in the forum about one of the builders having problems with this prop. Any takers on this question. Date: Sun, 16 Jun 1996 18:50:00 -0400 From: RonKidd@aol.com Subject: Re: COZY: WarpDrive Propeller Yes, It was on my 160 hp Cozylll. I think it was early in WD's larger prop endevours (at least I will give them the benefit of that), but, Before I ordered it, I was assured that they had "several" props used on similar apps. After two weeks of setup work and a new spinner, I tested it. I had set it up as per their specs and adjusted the pitch until I had lowered the static RPM. I took off with it and on climb out, it howled like a banshee! I throttled back and landed. Upon inspection, I found two of the blades ready to seperate from the aluminum "cores". I sent it back and was told that they had had not used the WD in an application of this HP. Luck to still be alive and the bird is still in one piece. I bought a performance props 3 blade and it has performed nicely. They hit the prop right on the money as far as cruise RPM. Please guys, no lectures as to my stupidity for trying an unapproved design, I got blasted after the first post. I would not put one of their props on my airplane if they paid me to do it! Make up your own mind. Ron Kidd Cozy N 417CZ Date: 06 Sep 96 03:48:29 EDT From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Constant Speed Props Hi to All, >Reid Siebert wrote:< >>snip<< >Invest the $12,000 in a good constant speed prop, it will help you to safely get more horses out of your engine.< We will be using a 72" diameter, 3 blade, constant speed prop that is, also, featherable and reversable (optional) produced by Whirlwind Propellers which only costs $7500 and is made in America. We feel a 3 blade is best for our pusher needs (among other benefits) for a 2 blade is blanked by the fuselage and strakes when it goes horizontal. Only one blade will be blanked on a 3 blade prop by the fuselage and strakes when it goes horizontal. This prop is carved from 68 plys of hardwood laminates by a precision duplicating machine, wrapped in carbon for even more structural strength, and 75% of the prop leading edge (from the tip) has a stainless steel leading edge bonded on to protect the prop from rain and bug erosion. The blades are then installed into a stock certified Mac Cauley hub. Whirlwind has over 10 years of experience carving custom props and testing prop airfoils at the Reno Air Races on Formual 1 racing planes - they have the best blade airfoils and the composite blade construction down to a science. Many of their props are already flying on airshow demonstration aircraft, Glasairs, etc. Whirlwind's phone #, address and Point Of Contact (POC) is: Jim Rust 1860 Joe Crosson Drive, #H El Cajon, CA 92020 (619) 562-3725 HTH. Infinity's Forever, EAA Member EAA Technical Counselor JD EAA Flight Advisor AOPA Member Test Pilot James D. Newman, President LCDR F-14 USNR INFINITY Aerospace P. O. Box 12275 El Cajon, CA 92022 (619) 448-5103 PH & FAX 72124.347@compuserve.com Home Page http://ourworld.compuserve.com/homepages/INFINITY_Aerospace Date: Fri, 6 Sep 96 17:13:00 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: COZY: CS Prop Governor? Is there room for a prop governor between the fire wall and an engine? I know this has been an issue on some Velocity installations, but I was wondering if there was more room on the Cozy or is one forced to look for an engine where the governor need to be mounted by the prop? TIA, Eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Date: Sat, 07 Sep 1996 15:04:05 From: RSiebert1@gnn.com (Reid Siebert) Subject: Re: COZY: CS Prop Governor? >Date: Fri, 6 Sep 96 17:13:00 -0800 >From: Eric_Westland@msvl.wednet.edu (Eric Westland) >Is there room for a prop governor between the fire wall and an engine? I know this has been an issue on some Velocity installations, but I was wondering if there was more room on the Cozy or is one forced to look for an engine where the governor need to be mounted by the prop? Eric, I was wrestling with this topic just yesterday. I called a prop shop in Chicago and discussed it with the shop ownwer. He noted that the prop governor sits on an extra adapter pad, which houses the oil port for the oil line that runs to the nose of the engine case. This extra inch or so must be factored in. Then too, you must consider how the governor's input arm is configured. In our aircraft's installation you want the input arm (that tear-drop shaped piece of metal) mounted parallel with the governor's body, to avoid alot of monkey motion with the prop control cable. A Woodward governor is the shortest one on the market, and its input arm is parallel to its body, but unfortunately it is also the most expensive. Off-hand I don't know its size. Some aircraft builders install a blister in their firewall to allow extra room for the governor. I cannot do this because my battery is mounted forward of the affected firewall area (not per plans - below the spar), and not actually knowing the amount of clearance I have to work with, have budgeted to buy a three bladed, electric prop from MT-Propeller ($8000). The prop has a motor and jackscrew mounted on the hub to change the blade pitch. It weighs the same as a hydraulic prop with governor. However, no oil is involved, so it can be installed on an engine that is not configured for a hydraulic constant speed prop. This broadens engine selection by at least 17 versions of O-360. Gee, electric nose gear, electric landing flap, electric trim, electric fuel pump, electric pilot, and now electric prop. What's left? Reid Siebert Mark IV #221 Date: Sun, 08 Sep 1996 14:45:33 From: RSiebert1@gnn.com (Reid Siebert) Subject: Re: Re(2): COZY: CS Prop Governor? >Date: Sat, 7 Sep 96 21:00:08 -0800 >From: Eric_Westland@msvl.wednet.edu (Eric Westland) > I am inclined to go for the O-320 with the hydraulic CS prop. Do > you know if the O-360 set up you are doing is different than the > O-320? I understood that the prop gov. would contact the > firewall at the shear web of the main spar. I read in > your reply that yours would go through the firewall below > the spar? > Eric, I did no measuring to see how high the governor hit on the firewall, I just discounted it completely since my battery and other electrical system components were already that hogging space. I also had to leave room aft of the engine for mounting my dual electronic ignition units. If I were you I'd opt for the nose mounted governor, then you could use a cheaper governor, and have more room to adapt the control cable to the input arm. I did not consider the O-320 engine for my project, and haven't studied the type certificate data sheets for it, so I am not educated enough to provide any info on it. Sorry. Lycoming publishes a book that lists all their engines and variations. I have a copy of it at my hangar/shop and will get the pub number of it tomorrow, and pass onto you. Once you've decided on the engine variation desired, you might try to find an airplane that has it certified with it, look it over, take a few pictures, and make some drawings with measurements. The Lycoming book tells what engine variation went on what model airplane, so that will help you find the one you're looking for. Later... Reid Date: Wed, 16 Oct 1996 21:20:17 -0400 From: RonKidd@aol.com Subject: COZY: IVO Prop Does anyone have any experience with the IVO adjustable prop? A friend of mine (COZY 3) wants to install one on his flying bird and wanted me to find out if anyone had any knowledge of it? I have a Perormance 3 blade and think that is the way to go, but Ivo is only $800 (and adjustable) Ron Kidd N 417CZ Date: Wed, 16 Oct 1996 20:28:57 -0700 From: Eric Westland Subject: COZY: Prop Extensions? I have to confess to being near-ignorant on why we use prop extensions of a specific length. What are the questions to ask when determining what the best length may be? TIA eric From: "Krasa, Paul" Subject: RE: COZY: IVO Prop Date: Thu, 17 Oct 1996 06:56:28 -0400 I've been told that Danny Mahr tried an IVO Prop on one of the first Velocitys, and was unhappy with it. Can't tell you any more than that, sorry. Paul Krasa Long EZ 214LP !---*---! Date: Thu, 17 Oct 1996 07:09:42 -0400 (EDT) From: "George A. Graham" Subject: Re: COZY: IVO Prop A member of our local EAA chapter #46, Don Meyer, has a Ivo Magnum for his Velocity RG. He told me that when set at the max recommended pitch setting, it would climb very well, but his cruise was too slow, as compared to his wood two blade prop. He did not want to set it with more pitch than Ivo recommended. By the way, he likes to cruise at 200 mph. Our prop conversation took place last year. > Does anyone have any experience with the IVO adjustable prop? A friend of > mine (COZY 3) wants to install one on his flying bird and wanted me to find > out if anyone had any knowledge of it? I have a Perormance 3 blade and think > that is the way to go, but Ivo is only $800 (and adjustable) > Ron Kidd N 417CZ > George Graham Modified E-Racer # 206 Mazda Engine Installation (716) 874-3277 Date: Thu, 17 Oct 1996 12:02:36 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Prop Extensions? Eric Westland wrote: >I have to confess to being near-ignorant on why we use prop >extensions of a specific length. What are the questions to ask >when determining what the best length may be? The Cowling that you use will give you that dimension. On the AeroCanard the cowl was 2" longer than the Cozy so we needed a 8" length. hope that helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com http://www.windev.com/aerocanard From: "Dewey Davis" Date: Thu, 17 Oct 1996 08:58:54 -0400 Subject: Re: COZY: Prop Extensions? On Oct 16, 20:28, Eric Westland wrote: > Subject: COZY: Prop Extensions? > I have to confess to being near-ignorant on why we use prop extensions > of a specific length. What are the questions to ask when determining > what the best length may be? > There are several tradeoffs to consider. Generally, you want the longest extension you can get in order to improve prop efficiency (get it further from the dirty air) and reduce prop noise. But the longer the extension, the larger the stress on the crank, especially if you intend to do high g maneuvers. I started with a 6 inch extension with 6 inch hub(6 x 6), just because it seemed to be the most popular choice of the Long EZ and COZY builders at the time. Later I went to a 6 x 7 extension, and now I am running an 8 x 7 extension. I wanted the bigger hub face to match the three bladed prop better. It provides more contact surface, holds torque much longer, less crush on the prop face. When I changed from 6 inch length to 8 inch length, I gained 4 knots in top speed and the airplane ran noticeably quieter. For a long time I had resisted the change to the longer extension because I was afraid of the extra stress on the crankshaft. That was true until I looked at the twins that use the same O-320 engines on 10 inch prop extensions swinging big heavy constant speed props on factory airplanes. Our wooden props have nothing near the stress on the crank those factory installations with the constant speed prop delivers. I don't believe there is any worry with eight inch extensions on O-320 EZs. A few years ago, there was a rash of failures with eight inch extensions on O-360 powered EZs. There was quite a bit of speculation about harmonic resonance at certain RPMs with that combination. There was also speculation about the manufacturing methods of the particular prop extensions that failed. Also, some suppliers used to make extensions with 6061 alum instead of 2024. Big mistake. 6061 will fatique and fail in this application. If you are going to buy an extension, I highly recommend Lynn Woofter. They make the extensions that are resold through Aircraft Spruce and other suppliers. The quality is excellent. Much better than Brock. For instance, they put in an ogee (thats the obscure term for the little smooth S transition from one diameter to the next on the inside of the prop extension), rather than a step. And if you buy direct, you can usually beat the price of the other suppliers too. I have bought three from them and every one was made with excellent craftsmanship. Dewey Davis Date: Sun, 20 Oct 1996 05:33:35 -0400 From: StetsonE@aol.com Subject: Re: COZY: Prop Extensions? In a message dated 96-10-17 12:06:28 EDT, Jeff writes: >>I have to confess to being near-ignorant on why we use prop >>extensions of a specific length. What are the questions to ask >>when determining what the best length may be? > > >The Cowling that you use will give you that dimension. On the AeroCanard >the cowl was 2" longer than the Cozy so we needed a 8" length. How much clearance should there be between the lip of the cowling and the prop? Stet Elliott stetsone@aol.com Perpetual Long-EZ builder Date: Mon, 21 Oct 96 14:46 EET From: edegov@aztec.co.za (ernie de goveia) Subject: COZY: Re cozy prop extensions --========================_19457918==_ Content-Type: text/plain; charset="us-ascii" --========================_19457918==_ Content-Type: text/plain; name="Steve"; charset="us-ascii" Content-Disposition: attachment; filename="Steve" Hi all Stet Elliot wrote >> How much clearance should there be between the lip of the cowling and >>the prop?<< Tony Bingelis in the October "Sport Aviation" says "A spinner-to-cowling clearance of 1/4" is about right for most homebuilts and store boughts." This article by Tony Bingelis gives some good ideas about fitting cowlings, even if his prop is infront,:-), it's worth checking out. Regards Ernie de Goveia Cozy 3 Ch 11 --========================_19457918==_-- Date: Tue, 22 Oct 1996 08:45:00 +0000 From: Rob Atencio Subject: Re: COZY: Prop Extensions? StetsonE@aol.com wrote: > > How much clearance should there be between the lip of the cowling and the > prop? The October issue of Sport Aviation has an article about cowling installation and mentions that "a spinner-to-cowling clearance of 1/4 inch is about right for most homebuilts and 'store boughts.'" FWIW Rob Atencio Cozy MkIV - Chpt 7 New Bern, NC ratencio@coastalnet.com