X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost03.isp.att.net ([204.127.217.103] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2720218 for flyrotary@lancaironline.net; Thu, 07 Feb 2008 19:37:48 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.217.103; envelope-from=keltro@att.net Received: from fwebmail03.isp.att.net ([207.115.11.153]) by isp.att.net (frfwmhc03) with SMTP id <20080208003707H0300i1jt1e>; Fri, 8 Feb 2008 00:37:07 +0000 X-Originating-IP: [207.115.11.153] Received: from [64.250.200.15] by fwebmail03.isp.att.net; Fri, 08 Feb 2008 00:37:06 +0000 From: "Kelly Troyer" To: "Rotary motors in aircraft" Subject: Rotor Weight Codes Date: Fri, 08 Feb 2008 00:37:06 +0000 Message-Id: <020820080037.25871.47ABA4310001D7160000650F22230647629B0A02D29B9B0EBF019D9B040A05@att.net> X-Mailer: AT&T Message Center Version 1 (Oct 30 2007) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_25871_1202431026_0" --NextPart_Webmail_9m3u9jl4l_25871_1202431026_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit George and All, Perhaps could be helpful info to know weight variance of rotors of all the different weight codes.........I do not have scales sensitive enough to tell the difference but perhaps the post office, UPS, etc scales would do it....... As time permits I will put that on my short list !!........... -- Kelly Troyer "Dyke Delta"_13B ROTARY Engine "RWS"_RD1C/EC2/EM2 "Mistral"_Backplate/Oil Manifold -------------- Original message from "George Lendich" : -------------- Kelly, Yep! your right, I was referring to the matching code. I mentioned this in case anyone would take rotors from different sources, however if they came from the same engine their likely to be matched. I don't know how the counter weight is matched, I have seen and heard of rebuilds that do all sorts of things and even balancing which is not as good as factory balancing. I believe it's to do with what's ( what weights)allowed for in the physically balancing. For those uneducated in the physical balancing process, the e-shaft is spun up with dummy weights (bolted onto the e-shaft lobes) that represent the weight of the rotor, all seal weights ( except apex seal and spring) and the oil in the rotor. The counter weights are then adjusted for best balance. Adjusting involves adding or removing metal from the counter weights. I don't believe static balancing is accurate enough fro a 2 rotor ( because of the rocking couple) but might be good enough for the single rotor. I believe that's what Richard Sohn has done to date for his single development. I think if we take parts from other engines ( as I am doing ) it would be advantageous to know the variance of the code system. I believe someone was working to identify what the difference in code represented in weight - but no final outcome to my knowledge. If we could also nail down the weight of the corresponding counter weight it would solve a lot of problems for experimental builders. Instead of matching things we could just weigh them. Is there any information you can give on different weights from your 3 sets? George ( down under) George, I presume you are making reference to the letter (A,B,C,D) weight code for rotors........Engines that have not been opened (stock) will have matched weight rotors within one letter of each other (that is AA-AB-BB-BC-CC-CD-DD)...... I have not heard of such a weight code for the counterweights but I stand to be educated if there is one.......I have managed to collect 3 sets of 89-91 rotors (9.7 to 1) with matching weight codes.........FWIW -- Kelly Troyer "Dyke Delta"_13B ROTARY Engine "RWS"_RD1C/EC2/EM2 "Mistral"_Backplate/Oil Manifold -------------- Original message from "George Lendich" : -------------- Kelly and All, Even when the weight of the rotors and the counter weight are confirmed as being compatible - one should also remember the lettering stamping system which matches a paired set, for balancing through similar weight. I have never been able to confirm what the difference in weight is exactly, which is a shame. George ( down under) --NextPart_Webmail_9m3u9jl4l_25871_1202431026_0 Content-Type: text/html Content-Transfer-Encoding: 8bit
George and All,
       Perhaps could be helpful info to know weight variance of rotors of all
the different weight codes.........I do not have scales sensitive enough to tell
the difference but perhaps the post office, UPS, etc scales would do it.......
      As time permits I will put that on my short list !!...........
--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold




-------------- Original message from "George Lendich" <lendich@optusnet.com.au>: --------------

Kelly,
Yep! your right, I was referring to the matching code. I mentioned this in case anyone would take rotors from different sources, however if they came from the same engine their likely to be matched.
 
I don't know how the counter weight is matched, I have seen and heard of rebuilds that do all sorts of things and even balancing which is not as good as factory balancing. I believe it's to do with what's ( what weights)allowed for in the physically balancing.
 
For those uneducated in the physical balancing process, the e-shaft is spun up with dummy weights (bolted onto the e-shaft lobes) that represent the weight of the rotor, all seal weights ( except apex seal and spring) and the oil in the rotor. The counter weights are then adjusted for best balance. Adjusting involves adding or removing metal from the counter weights. I don't believe static balancing is accurate enough fro a 2 rotor ( because of the rocking couple) but might be good enough for the single rotor. I believe that's what Richard Sohn has done to date for his single development.
 
I think if we take parts from other engines ( as I am doing ) it would be advantageous to know the variance of the code system. I believe someone was working to identify what the difference in code represented in weight - but no final outcome to my knowledge. If we could also nail down the weight of the corresponding counter weight it would solve a lot of problems for experimental builders. Instead of matching things we could just weigh them.
 
Is there any information you can give on different weights from your 3 sets?
 
George ( down under)
George,
    I presume you are making reference to the letter (A,B,C,D) weight code for
rotors........Engines that have not been opened (stock) will have matched weight
rotors within one letter of each other (that is AA-AB-BB-BC-CC-CD-DD)......
  I have not heard of such a weight code for the counterweights but I stand to
be educated if there is one.......I have managed to collect 3 sets of 89-91 rotors
(9.7 to 1) with matching weight codes.........FWIW
--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold




-------------- Original message from "George Lendich" <lendich@optusnet.com.au>: --------------

Kelly and All,
Even when the weight of the rotors and the counter weight are confirmed as being compatible - one should also remember the lettering stamping system which matches a paired set, for balancing through similar weight. I have never been able to confirm what the difference in weight is exactly, which is a shame.
George ( down under)
 
 
 
 
--NextPart_Webmail_9m3u9jl4l_25871_1202431026_0--