X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [65.54.250.90] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 5.0.6) with ESMTP id 921473 for flyrotary@lancaironline.net; Tue, 10 Jan 2006 21:32:12 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.250.90; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Tue, 10 Jan 2006 18:27:58 -0800 Message-ID: Received: from 4.171.114.222 by BAY115-DAV18.phx.gbl with DAV; Wed, 11 Jan 2006 02:27:57 +0000 X-Originating-IP: [4.171.114.222] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: RD-1B Service alert Date: Tue, 10 Jan 2006 21:27:54 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0106_01C6162C.B7A231B0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Tue, 10 Jan 2006 21:27:54 -0500 X-OriginalArrivalTime: 11 Jan 2006 02:27:58.0122 (UTC) FILETIME=[A2D0A8A0:01C61656] This is a multi-part message in MIME format. ------=_NextPart_000_0106_01C6162C.B7A231B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageHi Todd, Keep in mind this is all generalization but the breaking point of a = shaft is pretty much related to torque, not HP. Torque is pretty much = directly related to manifold pressure. 45" MAP is 50% higher than a NA = engine at sea level. =20 Can I predict whether your welded shaft will take the added torque? = Short answer is 'no', so all I can do is err on the side of caution. Have gotten a raft of questions from various builders regarding the = issue of why the shaft was done this or that way so I'll give a brief = thumb nail sketch of how the shaft design evolved. The first flying proof of concept prototype used a pressed together = gear/shaft assembly with an interference fit. This is a reliable method = when the interference is controller properly. This was also used on the = next production prototype but I noticed that the ID of the Ford sun = gears varied over a significant range when I got the first batch of = gears in for production. A worst case gear and shaft combination was = assembled and flown. It flew great for about 20 hours when I noticed = what sounded like an intermittent engine miss at full throttle. Turned = out to be the shaft occasionally breaking loose and friction welding = itself back together again. (Be alert for this symptom) =20 That's when the move to welded gears was made (prior to shipping any = production drives). Welding was good, fast and inexpensive (if the = proper welding rod was used) but I noticed that the better the gear was = welded, the more distortion it sustained. Engineering rock & hard spot. = A hopefully happy medium was reached and tested and all was well.=20 About the time the C drive was put into production, the drilled & pinned = method was adopted in an effort to avoid the slight distortion of the = sun gear due to welding. This was made possible by my "discovery" of = micro-grain solid carbide drill bits. Till then, I had no idea you = could drill holes in heat treated gear alloy with anything short of EDM. = Only down side is when a $35 drill bit is ruined by a chipped edge on = the very first hole : ( I had no reason to believe that the welded version posed any problem = until Dave Leonard's turbo engine broke one. Was it an abnormal = backfire that broke it? Don't know and never will since I lack NASA's = research budget to investigate it. I did examine the shaft and found = that it had weld penetration at the very bottom of the range used. = Recently, Steve Brooks turbo engine's shaft started to slip and it was = found to have welds in the middle of the weld penetration range. The = service alert was issued immediately after this observation. Why was the pinned version not used from the very beginning? Don't = know how to answer that. Same reason you find things in the last place = you look, I guess. Next rhetorical question: Are you acting as a Beta = tester for some of the stuff I build? You bet! It's the nature of this = game we choose to play. =20 Tracy Hi Tracy; I have the RD-1A on my turbo 13B which while it is not recommended = for turbo applications is rated for up to 200hp. Since my turbo is used = only for normalization purposes (mountain flying) and take off = performance (during which I use an absolute maximum of 45"MAP, but = usually <40"), I doubt that I ever see 200 hp and since the RV9 is only = rated for 160 hp I never intend to attempt to reach 200 hp. Does the RD-1A have a welded or pinned input shaft? And should I = be concerned about it?=20 Todd (too busy to put any stress on any of my airplane's parts) -------------------------------------------------------------------------= --- Service Alert on B drives=20 I will publish a service alert later today on the website = (www.rotaryaviation.com) on B drives = used on turbo charged 13Bs and 20B engines. =20 Decided to do this after reviewing Steve Brooks input shaft problem. = His input shaft was previously used for well over 100 hours on Ed = Anderson's drive (fairly early drive) with no problems. It used the = welded style sun gear attachment to the input shaft. Steve's turbo = engine apparently had enough torque to break the weld in the same way = that Dave Leonard's (another turbo) did. =20 Shortly before starting C drive production (4-23-03) we changed = over to a drilled and pinned input shaft. This service alert requests = (strongly) that any B drive used on a turbo charged 13B or 20B engine = delivered before this date be inspected for presence of a pinned input = shaft. If the sun gear is welded instead of pinned, the input shaft = should be returned to RWS to have it drilled and pinned prior to any = flight. This service will be performed for only the cost of materials = and shipping. No problems have been encountered on RD-1, RD-1A or RD-1B = drives used on normally aspirated engines but if you wish, this update = can be done for a nominal service charge ( parts & shipping + shop time = TBD). ------=_NextPart_000_0106_01C6162C.B7A231B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Hi Todd,
Keep in mind this is all generalization but the breaking point of a = shaft=20 is pretty much related to torque, not HP.   Torque is pretty = much=20 directly related to manifold pressure.  45" MAP is 50% higher than = a NA=20 engine at sea level. 
 
Can I predict whether your welded shaft will take the added = torque? =20 Short answer is 'no', so all I can do is err on the side of = caution.
 
Have gotten a raft of questions from various builders regarding the = issue=20 of why the shaft was done this or that way so I'll give a brief = thumb nail=20 sketch of how the shaft design evolved.
 
The first flying proof of concept prototype used a pressed together = gear/shaft assembly with an interference fit.  This is a reliable = method=20 when the interference is controller properly.  This was also = used on=20 the next production prototype but I noticed that the ID of the Ford = sun=20 gears varied over a significant range when I got the = first batch of=20 gears in for production.  A worst case gear and = shaft combination=20 was assembled and flown.  It flew great for about 20 hours when I = noticed=20 what sounded like an intermittent engine miss at full throttle.  = Turned out=20 to be the shaft occasionally breaking loose and friction welding = itself=20 back together again.  (Be alert for this symptom) 
 
That's when the move to welded gears was made (prior to shipping = any=20 production drives).  Welding was good, fast and = inexpensive (if the=20 proper welding rod was used)  but I noticed that the better the = gear was=20 welded, the more distortion it sustained.  Engineering rock & = hard=20 spot.  A hopefully happy medium was reached and tested and all was = well.=20
 
About the time the C drive was put into production, the drilled = &=20 pinned method was adopted in an effort to avoid the slight distortion of = the sun=20 gear due to welding.  This was made possible by my "discovery" of=20 micro-grain solid carbide drill bits.  Till then, I had no idea you = could=20 drill holes in heat treated gear alloy with anything short of = EDM.  =20 Only down side is when a $35 drill bit is ruined by a chipped edge =  on the=20 very first hole : (
 
I had no reason to believe that the welded version posed any = problem=20 until  Dave Leonard's turbo engine broke one.  Was it an = abnormal=20 backfire that broke it?    Don't know and never will = since I lack=20 NASA's research budget to investigate it.  I did examine the shaft = and=20 found that it had weld penetration at the very bottom of the range=20 used.   Recently, Steve Brooks turbo engine's shaft started to = slip=20 and it was found to have welds in the middle of the weld penetration=20 range.  The service alert was issued immediately = after this=20 observation.
 
 Why was the pinned version not used from the very = beginning? =20 Don't know how to answer that.  Same reason you find things in the = last=20 place you look, I guess.  Next rhetorical question:  Are you = acting as=20 a Beta tester for some of the stuff I build?  You bet!  = It's the=20 nature of this game we choose to play. 
 
Tracy
 

Hi = Tracy;
    I=20 have the RD-1A on my turbo 13B which while it is not recommended for = turbo=20 applications is rated for up to 200hp. Since my turbo is used only for = normalization purposes (mountain flying) and take off performance = (during=20 which I use an absolute maximum of 45"MAP, but usually <40"), I = doubt that=20 I ever see 200 hp and since the RV9 is only rated for 160 hp I never = intend to=20 attempt to reach 200 hp.
    Does the RD-1A have = a welded=20 or pinned input shaft? And should I be concerned about = it? 
 
Todd   =20 (too busy to put any stress on any of my airplane's = parts)

Service Alert on B drives
 
I will publish a service alert later today on the website (www.rotaryaviation.com) = on B drives=20 used on turbo charged 13Bs and 20B engines. 
 
Decided to do this after reviewing Steve Brooks input shaft=20 problem.  His input shaft was previously used for well over 100 = hours=20 on Ed Anderson's drive (fairly early drive) with no problems.  = It used=20 the welded style sun gear attachment to the input shaft.  = Steve's turbo=20 engine apparently had enough torque to break the weld in the same = way that=20 Dave Leonard's (another turbo) did. 
 
Shortly before starting C drive production (4-23-03)  we = changed=20 over to a drilled and pinned input shaft.  This service alert = requests=20 (strongly) that any B drive used on a turbo charged 13B or 20B = engine=20 delivered before this date be inspected for presence of a pinned = input=20 shaft.  If the sun gear is welded instead of pinned, the input = shaft=20 should be returned to RWS to have it drilled and pinned prior to=20 any flight.  This service will be performed for only the = cost of=20 materials and shipping.  No problems have been encountered on = RD-1,=20 RD-1A or RD-1B drives used on normally aspirated engines but if you = wish,=20 this update can be done for a nominal service charge ( parts &=20 shipping + shop time TBD).
=
 
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