X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mailout2.pacific.net.au ([61.8.0.85] verified) by logan.com (CommuniGate Pro SMTP 4.3.2) with ESMTP id 964767 for flyrotary@lancaironline.net; Thu, 26 May 2005 20:22:45 -0400 Received-SPF: none receiver=logan.com; client-ip=61.8.0.85; envelope-from=peon@pacific.net.au Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86]) by mailout2.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with ESMTP id j4R0M0kG024226 for ; Fri, 27 May 2005 10:22:00 +1000 Received: from ar1 (ppp2F6A.dyn.pacific.net.au [61.8.47.106]) by mailproxy1.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with SMTP id j4R0LvqA020100 for ; Fri, 27 May 2005 10:21:58 +1000 Message-ID: <004b01c56250$c317a6a0$6a2f083d@ar1> From: "Leon" To: "Rotary motors in aircraft" Subject: Single Rotor Stuff was Date: Fri, 27 May 2005 10:12:24 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0048_01C562A4.940F81D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_0048_01C562A4.940F81D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Yo Kelly, Attached are a couple of pix of the bolt shanks and a digital Vernier = Caliper which should settle the size issues. The early 12A & 13B bolts = has a short thread, and are slightly thicker in the shank than the the = later 12A & 13B bolts, which have a MUCH longer thread. =20 The reason Mazda use an M10 x 1.0 thread is so that the thread will lock = under the light tension (27 Ft Lbs). The shank of both bolts is not = thick enough to take an M10 x1.0 thread and have sufficient depth. = Additionally, they are too thick to take a 3/8" UNF thread. =20 The only feasible alternative is to turn the bolts into studs (see pic), = and use an M 10 x 1.25 thread. It's not a full thread, but is good = enough if done in a lathe with a die holder so that the thread is square = to the shank. To make sure it locks, I put some LOW strength loctite = on the thread. I've done several thousand kms with this motor (half an = REW Cosmo engine with 9.7:1 rotor) in the RX7 Mule, and the stud method = seems to have stood up to the rigors. =20 Other single rotor motors are now in the process of being assembled, = fitted and tested in a couple of Turbocharged Sports Sedans, and Jet = Skis. However, I wouldn't think about using this threaded stud method = in an aircraft though - I'd want a FULL depth thread. I did find some cylinder head bolts of a locally (Australian) = manufactured engine that are the correct length, but are M 10 x 1.25 = thread, which do the job. However, they require the threads in the = front housing to be drilled out, tapped and helicoiled back to M10 x = 1.25 - a rather tedious and time consuming task, and I'm not convinced = that the threads will lock with only 27 Ft Lbs torque. =20 So I'm currently having some bolts made for both REW and Renesis single = rotor applications (some of the Renesis bolts are different lengths to = the REW because of the side exhaust ports, which just complicates = matters). I should have them available in about 6 weeks or so. This = all should have happened over 12 months ago, but I became exceedingly = ill and nearly "passed over" a couple of times last year. I'm just = getting back into harness now. Cheers, Leon ------=_NextPart_000_0048_01C562A4.940F81D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Yo Kelly,

Attached are a couple of pix of the = bolt shanks and=20 a digital Vernier Caliper which should settle the size issues. The = early=20 12A & 13B bolts has a short thread, and are slightly thicker = in the=20 shank than the the later 12A & 13B bolts, which have a MUCH = longer=20 thread.

The reason Mazda use an M10 x 1.0 = thread is so that=20 the thread will lock under the light tension (27 Ft Lbs). = The shank of both bolts is not thick enough to = take an M10=20 x1.0 thread and have sufficient depth. Additionally, they are = too=20 thick to take a 3/8" UNF thread.

The only feasible alternative is to = turn the bolts=20 into studs (see pic), and use an M 10 x 1.25 thread. = It's not a=20 full thread, but is good enough if done in a lathe with a die = holder so=20 that the thread is square to the shank. To make sure it = locks, I put=20 some LOW strength loctite on the thread. I've done several = thousand kms=20 with this motor (half an REW Cosmo engine with 9.7:1 rotor) in the = RX7=20 Mule, and the stud method seems to have stood up to the=20 rigors.

Other single rotor motors are = now in the=20 process of being assembled, fitted and tested in a couple of = Turbocharged=20 Sports Sedans, and Jet Skis. However, I wouldn't think = about=20 using this threaded stud method in an aircraft though - I'd want a = FULL=20 depth thread.

I did find some cylinder head bolts of = a locally=20 (Australian) manufactured engine that are the correct length, = but are=20 M 10 x 1.25 thread, which do the job. = However, they=20 require the threads in the front housing to be drilled out, = tapped and=20 helicoiled back to M10 x 1.25 - a rather tedious and time consuming = task, =20 and I'm not convinced that the threads will lock with only 27 Ft Lbs=20 torque.

So I'm currently having some bolts made = for both=20 REW and Renesis single rotor applications (some of the Renesis bolts are = different lengths to the REW because of the side exhaust ports, = which just=20 complicates matters). I should have them available in about 6 = weeks or=20 so. This all should have happened over 12 months ago, but I = became=20 exceedingly ill and nearly "passed over" a couple of times last = year. I'm=20 just getting back into harness now.

Cheers,

Leon

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