Return-Path: Sender: (Marvin Kaye) To: flyrotary Date: Mon, 31 Mar 2003 22:35:03 -0500 Message-ID: X-Original-Return-Path: <13brv3@mchsi.com> Received: from sccmmhc01.mchsi.com ([204.127.203.183] verified) by logan.com (CommuniGate Pro SMTP 4.1b2) with ESMTP id 2100253 for flyrotary@lancaironline.net; Mon, 31 Mar 2003 21:23:09 -0500 Received: from rad (12-218-74-116.client.mchsi.com[12.218.74.116]) by sccmmhc01.mchsi.com (sccmmhc01) with SMTP id <20030401022308mm100su8kme>; Tue, 1 Apr 2003 02:23:08 +0000 Reply-To: <13brv3@mchsi.com> From: <13brv3@mchsi.com> X-Original-To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] WARP DRIVE PROPELLERS X-Original-Date: Mon, 31 Mar 2003 20:22:56 -0600 X-Original-Message-ID: <000001c2f7f5$9ea9ede0$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C2F7C3.540F7DE0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C2F7C3.540F7DE0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable I am considering replacing my aging wood prop with a three blades carbon fiber prop from Warp Drive Inc. =20 I would appreciate a succinct evaluation of these propellers from anyone = who has practical experience with them. =20 Yvon.=20 =20 Ask me in about 3 months. I just got my 3 blade Warp Drive prop a = couple week ago, and it looks nice. The spinner is butt ugly though :-) Actually, it's nice quality, but the wrong shape to go with my cowl. I made some good notes in conversation with the Warp folks, and I'll paste them below if that helps. =20 =20 Cheers, Rusty (now officially N751RV)=20 =20 =20 Spoke with Warp Drive today about a prop. Their number is 641-357-6000. They said I would require at least 3 blades for 180-200 HP from a Mazda = with 2.178 redrive. Over about 220 HP, I'd have to go with 4 blades. A 2.85 redrive would also require a 4 blade even for 180 HP. This is to be = able to absorb the power without overstressing the blades. They said a 3 blade = prop on the Mazda would be extraordinarily smooth. Gotta like that. They recommend that I start with the standard blade, rather than the = tapered blade, because they think I'll need all the tip area I can get for the power. Once it's flying, and I give them some numbers, they can = determine if some tapering will help, and the blades can be tapered at that time. = There's really no limit to the blade angle, other than cavitation. They said 22 degrees (about 82") pitch was the limit before some cavitation = would occur. =20 Rain will erode the prop leading edge, unless you slow the prop down to = 2200 RPM or less, or unless you have the Nickel leading edge strips. They = cost $40 per blade, and are always added as the last step, so they can be = added at any time after the prop has been in service. In fact, they recommend flying the prop first to finalize the length and shape of the blades, = then having the LE strips added. It might be worth flying the prop until the rain proves to be a problem, then having the strips added if necessary. Probably won't be needed for me. =20 They recommend a max prop tip speed of 850 fps, which is about what I'll = end up with at cruise. The prop can be run faster, and 3400 rpm for a 7000 = RPM engine run should be no problem. =20 They sell fiberglass spinners as well, and have a 12" available for = about $160. It will completely cover the prop hub. =20 At this time, nobody makes a variable pitch hub for the warp blades at = this power level. =20 They did warn me that their prop will always be a bit slower on top = speed than a properly made 2-blade wood prop. He said it should be within 10 = mph though. Small price to pay for an adjustable prop.=20 ------=_NextPart_000_0001_01C2F7C3.540F7DE0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
I am considering replacing my aging = wood prop=20 with a three blades carbon fiber prop from Warp Drive Inc.
 
I would appreciate a succinct evaluation of these = propellers=20 from anyone who has practical experience with them.
 
Yvon. 
 
Ask me in=20 about 3 months.  I just got my 3 blade Warp Drive prop a = couple=20 week ago, and it looks nice.  The spinner is butt ugly = though =20 :-)    Actually, it's nice quality, but the wrong shape = to go=20 with my cowl.   I made some good notes in conversation with = the Warp=20 folks, and I'll paste them below if that = helps.  
 
Cheers,
Rusty =20 (now officially N751RV) 
 
 

Spoke with Warp=20 Drive today about a prop.  = Their=20 number is 641-357-6000.  = They said I=20 would require at least 3 blades for 180-200 HP from a Mazda with 2.178=20 redrive.  Over about 220 = HP, I’d=20 have to go with 4 blades.  = A 2.85=20 redrive would also require a 4 blade even for 180 HP.  This is to be able to absorb = the power=20 without overstressing the blades. They said=20 a 3 blade prop on the Mazda would be extraordinarily smooth.  Gotta like = that.

They = recommend=20 that I start with the standard blade, rather than the tapered blade, = because=20 they think I’ll need all the tip area I can get for the = power.  Once it’s flying, and I = give them some=20 numbers, they can determine if some tapering will help, and the blades = can be=20 tapered at that time.  =

There’s really no=20 limit to the blade angle, other than cavitation.  They said 22 degrees (about = 82”) pitch=20 was the limit before some cavitation would occur. 

Rain = will erode=20 the prop leading edge, unless you slow the prop down to 2200 RPM or = less, or=20 unless you have the Nickel leading edge strips.  They cost $40 per blade, and = are always=20 added as the last step, so they can be added at any time after the prop = has been=20 in service.  In fact, they = recommend=20 flying the prop first to finalize the length and shape of the blades, = then=20 having the LE strips added.  = It=20 might be worth flying the prop until the rain proves to be a problem, = then=20 having the strips added if necessary. =20 Probably won’t be needed for me. =20

They = recommend a=20 max prop tip speed of 850 fps, which is about what I’ll end up = with at=20 cruise.  The prop can be = run faster,=20 and 3400 rpm for a 7000 RPM engine run should be no problem. 

They = sell=20 fiberglass spinners as well, and have a 12” available for about = $160.  It will completely cover the = prop=20 hub. 

At = this time,=20 nobody makes a variable pitch hub for the warp blades at this power = level. 

They = did warn me=20 that their prop will always be a bit slower on top speed than a properly = made=20 2-blade wood prop.  He = said it=20 should be within 10 mph though. =20 Small price to pay for an adjustable prop.=20

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