Matronics Email Lists :: View topic - Rotax 912 mounting options?....

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Rotax 912 mounting options?....

Matronics Email Lists Forum Index -> Pulsar-List

View previous topic :: View next topic

Author Message

mjb777

Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE

Posted: Tue May 21, 2013 1:18 am Post subject: Rotax 912 mounting options?....

Howdy again,



I have just purchased a Rotax 912 engine which I am sure will please some of you who were horrified at my plans to use an Aerovee VW in place of the Rotax 582 engine in my Pulsar!



Can the experts out there let me know what are my options regarding engine mounting? I recall seeing some pictures of conventionally (frame) mounted, and also some bed mounted 912's in pulsars???



Also, does anyone have a full set of construction manuals (.PDF would be excellent!), for the XP??



Regards,



Matt.

_________________
Pulsar 1 TD Kit.
Captain B777.
Licenced Aircraft Maintenance Engineer.

gregsmi

Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS

Posted: Tue May 21, 2013 1:53 am Post subject: Rotax 912 mounting options?....

Matt, if your Pulsar is truly a Pulsar 1, with a header tank, there is a  good possibility the fuselage and tail section are not designed to take the  extra load of a 912. Depending on the serial number, the early Pulsar kits were  manufactured for the 582. The factory used a light weight glass for the  fuselage. When the 912 was introduced in the XP, the fuel was moved to the  wings, the fuselage was manufactured with a heavier glass, and the tail section  was beefed up. I do not see anyway a early model Pulsar can be safely converted  to a 912 XP.

  

 Greg 

  

  In a message dated 5/21/2013 4:21:40 A.M. Central Daylight Time,  mattbrock777(at)gmail.com writes:

  	  Quote: 	
		  -->    Pulsar-List message posted by: "mjb777"    <mattbrock777(at)gmail.com>



Howdy again,



I have just    purchased a Rotax 912 engine which I am sure will please some of you who were    horrified at my plans to use an Aerovee VW in place of the Rotax 582 engine in    my Pulsar!



Can the experts out there let me know what are my options    regarding engine mounting? I recall seeing some pictures of conventionally    (frame) mounted, and also some bed mounted 912's in pulsars???



Also,    does anyone have a full set of construction manuals (.PDF would be    excellent!), for the    XP??



Regards,



Matt.



--------

Pulsar 1 TD    Kit.

Captain B777.

Licenced Aircraft Maintenance    Engineer.





Read this topic online    here:



http://forums.matronics.com/viewtopic.php?p=401052#401052

	


 [quote][b]

gregsmi

Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS

Posted: Tue May 21, 2013 10:29 am Post subject: Rotax 912 mounting options?....

Matt, in a private message to me, you asked for information on how to  modify the Pulsar 1 to accommodate a 912 engine. Since you started the subject  on the forum, and others have asked the same questions in the past, I thought it  best to repeat the answers for everyone. 

  

 If you want to completely rebuild the airplane, then I guess it is  possible. I will give you a few key parts that should be addressed then you can  decide if the project is worth it or you want to do it your way.

  

 1. With the extra weight of the 912, the fuel must be moved to the wings.  You do not have enough elevator to handle a landing with that much weight on the  nose and flight performance, stalls, a lot of safety issues. Dropping the nose  on at higher speeds, with all that additional weight is risking a gear  failure.

  

 2. The wood spars will not carry more than 900 pounds gross, and then, only  if they are the wood spars that had a long spar cap. If this is one of the  early 582 Pulsars with the short spar caps, the gross is much less than 900  pounds.

  

 3. The fuselage is made with 3 oz glass on the inside for the 582, The  912 Pulsar XP fuselage and tail surfaces are made with 9 oz. glass.

  

 4. The horizontal spar tubes are much stronger in the 912 Pulsar.

  

 These are just some of the differences. The 912 Pulsar was not just a 582  Pulsar with a few minor changes. The plane went through a lot of design analysis  to handle the weight and performance of the 912 engine. 

  

 Matt, given the above facts, there is no way I would recommend or support  such a project. There are way too many safety concerns. Even if you found a way  to move the fuel, reinforce the fuselage, and rebuild the tail, you would be  making the plane so heavy the spars would not safely take the load. And, if you  found some way to beef up the spars, remember, the attach points in the fuselage  are still to the 3 oz fuselage skins.



 [quote][b]

mjb777

Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE

Posted: Wed May 22, 2013 5:24 pm Post subject: Re: Rotax 912 mounting options?....

Thanks for that information Greg,



I have started an analysis on wing, wing/ gear mounting and fuselage loads and reinforcement. (I commenced this a while ago using the Aerovee VW engine). Once loads are calculated, I'll be looking at reinforcing the inside surfaces of the fuselage shells with  uni-directional tape which would allow me to distribute loads more specifically and accurately, to give the same or greater strength as the additional 6 Oz of glass used in th XP, but use a lot less material and therefore result in less weight. It would look like a 2D composite version of a steel truss type structure projected onto the shells. (Same theory as the load bearing structure created by the tape used to reinforce the lower engine cowling/ mount).



the Landing gear and wing "box" structure will be reinforced accordingly after analysis and design, and the fuselage and tail analysis goes from there. It also starts at the engine mounts (bed at this stage) and load paths are also developed and combined. I have been looking into either a pure carbon or aluminium horizontal stab tube and would be interested to know the wall thickness of the XP horizontal stab aluminium tube as it would help to be able to compare my calculated required strengths and modulus to what was originally used with the XP there also.



As far as the fuel tank problem is concerned, I have a copy of the wing tank supplement and at this stage my intention is to make fully molded wing tanks which mount the same way as the XP wooden spar version, but will have less joins and fiberglass ribs to remove/ reduce the likelihood of foam rib and leakage issues. I'll also be using ethanol resistant resin. (Of course I wont bother if the C of G element of the analysis works with the "header" style tank, it's a "Plan B" thing).



I can assure you that all of my calculations will be checked by an aeronautical engineer prior to construction. Components, the entire airframe and flying surfaces will be static load tested. Standard stuff and a lot more thought and testing than most re engined/ modified homebuilt aircraft get, (Probably Pulsars included!). I'm not looking to go faster or make it aerobatic.



I have seen pictures of Pulsar 1's converted to Jabiru 2200 engines using a bed mount and with the header tank, and it has been recommended to me to use the Jabiru engine previously, it appears to have a very similar weight to the 912? I'm guessing these aircraft wouldn't have been structurally improved and probably only had the 900lb spar at maximum? (See Pictures of one example).



My AC is a Tail dragger so the nose gear failure issue isn't a concern. We will use the Grove aluminium gear. (The original fiberglass/ foam gear is still available if someone needs it, but its not worth my job trying to "sneak" it along for a ride in the 777. The guys I fly for don't have much of a sense of humor!).



Why would I bother going through this instead of disposing of my kit and doing it the easy way? I have the kit, it is a great Aircraft with loads of potential, and this is what sport aviation is all about when done properly! (.......And Sonex's don't have the curves!).



So........... do you have the XP manuals available?

5920_4_pulengine.jpg

Description:

Filesize:

48.14 KB

Viewed:

8515 Time(s)

5920_6_pulintake.jpg

Description:

Filesize:

31.66 KB

Viewed:

8515 Time(s)

_________________
Pulsar 1 TD Kit.
Captain B777.
Licenced Aircraft Maintenance Engineer.

gregsmi

Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS

Posted: Wed May 22, 2013 6:25 pm Post subject: Rotax 912 mounting options?....

Your assumption on the Jabiru weights is wrong. The 2200 Jabiru is 15  pounds heavier than the installed wet weight of the 582, making it a good swap.  Do not forget, the gross weight is limited by the wood spars. 

  

 I am sorry Matt, I cannot support you in this endeavor. You are using a  proven design to make a new airplane. When you are done, it may look like a  Pulsar, but with all of the modifications, it will become your own design. If  you want a 912 Pulsar there are plenty of those out there and I am sure you can  find one for sale. There is one on Barnstormers.

  

 Greg

  

  In a message dated 5/22/2013 8:27:21 P.M. Central Daylight Time,  mattbrock777(at)gmail.com writes:

  	  Quote: 	
		  -->    Pulsar-List message posted by: "mjb777" mattbrock777(at)gmail.com (mattbrock777(at)gmail.com)

Thanks for    that information Greg,



I have started an analysis on wing, wing/ gear    mounting and fuselage loads and reinforcement. (I commenced this a while ago    using the Aerovee VW engine). Once loads are calculated, I'll be looking at    reinforcing the inside surfaces of the fuselage shells with     uni-directional tape which would allow me to distribute loads more    specifically and accurately, to give the same or greater strength as the    additional 6 Oz of glass used in th XP, but use a lot less material and    therefore result in less weight. It would look like a 2D composite version of    a steel truss type structure projected onto the shells. (Same theory as the    load bearing structure created by the tape used to reinforce the lower engine    cowling/ mount).



the Landing gear and wing "box" structure will be    reinforced accordingly after analysis and design, and the fuselage and tail    analysis goes from there. It also starts at the engine mounts (bed at this    stage) and load paths are also developed and combined. I have been looking    into either a pure carbon or aluminium horizontal stab tube and would be    interested to know the wall thickness of the XP horizontal stab aluminium tube    as it would help to be able to compare my calculated required strengths and    modulus to what was originally used with the XP there also.



As far as    the fuel tank problem is concerned, I have a copy of the wing tank supplement    and at this stage my intention is to make fully molded wing tanks which mount    the same way as the XP wooden spar version, but will have less joins and    fiberglass ribs to remove/ reduce the likelihood of foam rib and leakage    issues. I'll also be using ethanol resistant resin. (Of course I wont bother    if the C of G element of the analysis works with the "header" style tank, it's    a "Plan B" thing).



I can assure you that all of my calculations will be    checked by an aeronautical engineer prior to construction. Components, the    entire airframe and flying surfaces will be static load tested. Standard stuff    and a lot more thought and testing than most re engined/ modified homebuilt    aircraft get, (Probably Pulsars included!). I'm not looking to go faster or    make it aerobatic.



I have seen pictures of Pulsar 1's converted to    Jabiru 2200 engines using a bed mount and with the header tank, and it has    been recommended to me to use the Jabiru engine previously, it appears to have    a very similar weight to the 912? I'm guessing these aircraft wouldn't have    been structurally improved and probably only had the 900lb spar at maximum?    (See Pictures of one example).



My AC is a Tail dragger so the nose gear    failure issue isn't a concern. We will use the Grove aluminium gear. (The    original fiberglass/ foam gear is still available if someone needs it, but its    not worth my job trying to "sneak" it along for a ride in the 777. The guys I    fly for don't have much of a sense of humor!).



Why would I bother going    through this instead of disposing of my kit and doing it the easy way? I have    the kit, it is a great Aircraft with loads of potential, and this is what    sport aviation is all about when done properly! (.......And Sonex's don't have    the curves!).



So........... do you have the XP manuals available?     [Wink]



--------

Pulsar 1 TD Kit.

Captain B777.

Licenced    Aircraft Maintenance Engineer.





Read this topic online    here:



http://forums.matronics.com/viewtopic.php?p=401159#401159





Attachments:    



http://forums.matronics.com//files/5920_4_pulengine_162.jpg

http://forums.matronics.com//files/5920_6_pulintake_453.jpg

	


 [quote][b]

mjb777

Joined: 11 Aug 2012
Posts: 54
Location: Dubai UAE

Posted: Wed May 22, 2013 6:53 pm Post subject: Re: Rotax 912 mounting options?....

No assumptions Greg, the Rotax and Jabiru websites have the weights with exhaust etc and they are pretty much the same, so I'd like to hear your opinion on that?



I fully understand the wood spar limitation and am not intending to exceed it?



At the end of the day all I am requesting is a copy of the XP manuals for reference. 



If anyone has a set that I can get a hard or electronic copy of then please let me know. I am happy to pay.



mattbrock777(at)gmail(dot)com

_________________
Pulsar 1 TD Kit.
Captain B777.
Licenced Aircraft Maintenance Engineer.

gregsmi

Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS

Posted: Wed May 22, 2013 8:08 pm Post subject: Rotax 912 mounting options?....

Matt, you are making some bad assumptions on weight. The web sights do not  give you install weight.

  

  

 In a message dated 5/22/2013 9:56:51 P.M. Central Daylight Time,  mattbrock777(at)gmail.com writes:

   	  Quote: 	
		  -->    Pulsar-List message posted by: "mjb777"    <mattbrock777(at)gmail.com>



No assumptions Greg, the Rotax and    Jabiru websites have the weights with exhaust etc and they are pretty much the    same, so I'd like to hear your opinion on that?



I fully understand the    wood spar limitation and am not intending to exceed it?



At the end of    the day all I am requesting is a copy of the XP manuals for reference.    



If anyone has a set that I can get a hard or electronic copy of then    please let me know. I am happy to    pay.



mattbrock777(at)gmail(dot)com



--------

Pulsar 1 TD    Kit.

Captain B777.

Licenced Aircraft Maintenance    Engineer.





Read this topic online    here:



http://forums.matronics.com/viewtopic.php?p=401167#401167

	


 [quote][b]

kdpalmer(at)mweb.co.za
Guest

Posted: Wed May 22, 2013 9:19 pm Post subject: Rotax 912 mounting options?....

Matt,

        The failure in an aircraft is based on it's weakest point, do you 

know where the Pulsars weakest point is based on it's current construction - 

NO



K'd





---

briana(at)xtra.co.nz
Guest

Posted: Wed May 22, 2013 9:19 pm Post subject: Rotax 912 mounting options?....

Matt,



I have a 912 in a Pulsar XP.  I also have a Jabiru in my new Flitzer. I can assure you that there is a significant difference in the installed weight.



FWIW, the installed weight that I used for determine the engine mount measurements for my Flitzer was about 140lbs, everything included. The CofG turned out to be exactly correct. The specified "ramp weight" in the manual says 134lbs. Close enough considering mine has a heavier exhaust system.



On the other hand, the manual for the Rotax 912 lists the dry weight, plus a lot of components separately, and then you have to add the oil tank, radiator, oil cooler etc etc and the fluids. By the time everything is included you will be over 160lbs.



Why are you aiming to re-engineer a perfectly good design - - - one that we know works already. Having installed the Jabiru I can't imagine how one could be fitted to a "bed" mount of the type used for the 912 in the Pulsar XP.



I can only reinforce Greg's point of view. Those of us who have built Pulsars, in accordance with the manuals, know that everything works well, and I'm sure we have a deal of admiration for the designer. The resulting performance is brilliant. There have been many changes as the design evolved over the years, all for good reasons.



Of course you are free to do whatever you want, but please don't call the result a Pulsar. It won't be. It will be a new experimental that looks like a Pulsar. Think also about the approval process for a new design. Oh, and where are the manuals that came with the kit ? The XP manuals tell you how to bold the kit. They don't give you all the dimensions and specifications for all the components.



I think that most of my fellow Pulsar builders would be horrified at what you are planning to do.



Regards,



Brian

On 23/05/2013, at 1:24 PM, mjb777 <mattbrock777(at)gmail.com> wrote:



 	  Quote: 	
		   

 

 Thanks for that information Greg,

 

 I have started an analysis on wing, wing/ gear mounting and fuselage loads and reinforcement. (I commenced this a while ago using the Aerovee VW engine). Once loads are calculated, I'll be looking at reinforcing the inside surfaces of the fuselage shells with  uni-directional tape which would allow me to distribute loads more specifically and accurately, to give the same or greater strength as the additional 6 Oz of glass used in th XP, but use a lot less material and therefore result in less weight. It would look like a 2D composite version of a steel truss type structure projected onto the shells. (Same theory as the load bearing structure created by the tape used to reinforce the lower engine cowling/ mount).

 

 the Landing gear and wing "box" structure will be reinforced accordingly after analysis and design, and the fuselage and tail analysis goes from there. It also starts at the engine mounts (bed at this stage) and load paths are also developed and combined. I have been looking into either a pure carbon or aluminium horizontal stab tube and would be interested to know the wall thickness of the XP horizontal stab aluminium tube as it would help to be able to compare my calculated required strengths and modulus to what was originally used with the XP there also.

 

 As far as the fuel tank problem is concerned, I have a copy of the wing tank supplement and at this stage my intention is to make fully molded wing tanks which mount the same way as the XP wooden spar version, but will have less joins and fiberglass ribs to remove/ reduce the likelihood of foam rib and leakage issues. I'll also be using ethanol resistant resin. (Of course I wont bother if the C of G element of the analysis works with the "header" style tank, it's a "Plan B" thing).

 

 I can assure you that all of my calculations will be checked by an aeronautical engineer prior to construction. Components, the entire airframe and flying surfaces will be static load tested. Standard stuff and a lot more thought and testing than most re engined/ modified homebuilt aircraft get, (Probably Pulsars included!). I'm not looking to go faster or make it aerobatic.

 

 I have seen pictures of Pulsar 1's converted to Jabiru 2200 engines using a bed mount and with the header tank, and it has been recommended to me to use the Jabiru engine previously, it appears to have a very similar weight to the 912? I'm guessing these aircraft wouldn't have been structurally improved and probably only had the 900lb spar at maximum? (See Pictures of one example).

 

 My AC is a Tail dragger so the nose gear failure issue isn't a concern. We will use the Grove aluminium gear. (The original fiberglass/ foam gear is still available if someone needs it, but its not worth my job trying to "sneak" it along for a ride in the 777. The guys I fly for don't have much of a sense of humor!).

 

 Why would I bother going through this instead of disposing of my kit and doing it the easy way? I have the kit, it is a great Aircraft with loads of potential, and this is what sport aviation is all about when done properly! (.......And Sonex's don't have the curves!).

 

 So........... do you have the XP manuals available?  [Wink]

 

 --------

 Pulsar 1 TD Kit.

 Captain B777.

 Licenced Aircraft Maintenance Engineer.

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=401159#401159

 

 

 

 

 Attachments: 

 

 http://forums.matronics.com//files/5920_4_pulengine_162.jpg

 http://forums.matronics.com//files/5920_6_pulintake_453.jpg

ccoulter(at)wavecable.com
Guest

Posted: Thu May 23, 2013 9:43 am Post subject: Rotax 912 mounting options?....

I have not seen anyone mention that the 582 Pulsars had 

blue foam ribs.  If you move the fuel to the wings the 

fuel fumes will eat up the ribs.



Clarke



On Wed, 22 May 2013 22:22:56 -0400 (EDT)

  GREGSMI(at)aol.com wrote:

 	  Quote: 	
		   Your assumption on the Jabiru weights is wrong. The 2200 

Jabiru is 15  

 pounds heavier than the installed wet weight of the 582, 

making it a good swap.  

 Do not forget, the gross weight is limited by the wood 

spars. 

 

 I am sorry Matt, I cannot support you in this endeavor. 

You are using a  

 proven design to make a new airplane. When you are done, 

it may look like a  

 Pulsar, but with all of the modifications, it will 

become your own design. If 

 you want a 912 Pulsar there are plenty of those out 

there and I am sure 

 you can  find one for sale. There is one on 

Barnstormers.

 

 Greg

 

 

 In a message dated 5/22/2013 8:27:21 P.M. Central 

Daylight Time,  

 mattbrock777(at)gmail.com writes:

 

 

_mattbrock777(at)gmail.com_ 

 (mailto:mattbrock777(at)gmail.com) 

 Thanks for  that information Greg,

 

 I have started an analysis on wing, wing/ gear  mounting 

and fuselage loads 

 and reinforcement. (I commenced this a while ago  using 

the Aerovee VW 

 engine). Once loads are calculated, I'll be looking at 

 reinforcing the inside 

 surfaces of the fuselage shells with   uni-directional 

tape which would allow 

 me to distribute loads more  specifically and 

accurately, to give the same 

 or greater strength as the  additional 6 Oz of glass 

used in th XP, but use 

 a lot less material and  therefore result in less 

weight. It would look like 

 a 2D composite version of  a steel truss type structure 

projected onto the 

 shells. (Same theory as the  load bearing structure 

created by the tape used 

 to reinforce the lower engine  cowling/ mount).

 

 the Landing gear and wing "box" structure will be 

 reinforced accordingly 

 after analysis and design, and the fuselage and tail 

 analysis goes from 

 there. It also starts at the engine mounts (bed at this 

 stage) and load paths 

 are also developed and combined. I have been looking 

 into either a pure 

 carbon or aluminium horizontal stab tube and would be 

 interested to know the 

 wall thickness of the XP horizontal stab aluminium tube 

 as it would help to 

 be able to compare my calculated required strengths and 

 modulus to what was 

 originally used with the XP there also.

 

 As far as  the fuel tank problem is concerned, I have a 

copy of the wing 

 tank supplement  and at this stage my intention is to 

make fully molded wing 

 tanks which mount  the same way as the XP wooden spar 

version, but will have 

 less joins and  fiberglass ribs to remove/ reduce the 

likelihood of foam rib 

 and leakage  issues. I'll also be using ethanol 

resistant resin. (Of course 

 I wont bother  if the C of G element of the analysis 

works with the 

 "header" style tank, it's  a "Plan B" thing).

 

 I can assure you that all of my calculations will be 

 checked by an 

 aeronautical engineer prior to construction. Components, 

the  entire airframe and 

 flying surfaces will be static load tested. Standard 

stuff  and a lot more 

 thought and testing than most re engined/ modified 

homebuilt  aircraft get, 

 (Probably Pulsars included!). I'm not looking to go 

faster or  make it 

 aerobatic.

 

 I have seen pictures of Pulsar 1's converted to  Jabiru 

2200 engines using 

 a bed mount and with the header tank, and it has  been 

recommended to me to 

 use the Jabiru engine previously, it appears to have  a 

very similar weight 

 to the 912? I'm guessing these aircraft wouldn't have 

 been structurally 

 improved and probably only had the 900lb spar at 

maximum?  (See Pictures of one 

 example).

 

 My AC is a Tail dragger so the nose gear  failure issue 

isn't a concern. We 

 will use the Grove aluminium gear. (The  original 

fiberglass/ foam gear is 

 still available if someone needs it, but its  not worth 

my job trying to 

 "sneak" it along for a ride in the 777. The guys I  fly 

for don't have much of 

 a sense of humor!).

 

 Why would I bother going  through this instead of 

disposing of my kit and 

 doing it the easy way? I have  the kit, it is a great 

Aircraft with loads of 

 potential, and this is what  sport aviation is all about 

when done properly! 

 (.......And Sonex's don't have  the curves!).

 

 So........... do you have the XP manuals available? 

  [Wink]

 

 --------

 Pulsar 1 TD Kit.

 Captain B777.

 Licenced  Aircraft Maintenance Engineer.

 

 

 

 

 Read this topic online  here:

 

 http://forums.matronics.com/viewtopic.php?p=401159#401159

 

 

 

 

 Attachments:  

 

 http://forums.matronics.com//files/5920_4_pulengine_162.jpg

 http://forums.matronics.com//files/5920_6_pulintake_453.jpg

Display posts from previous:

	Matronics Email Lists Forum Index -> Pulsar-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum