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thrust

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lmorgan100(at)charter.net
Guest

Posted: Mon Jun 24, 2013 4:52 am Post subject: thrust

Hey everyone,  

I know this subject probably has been beaten to death but here goes anyway.  

I have a 503 Rotax with a gearbox and a 60 inch three blade IVO prop. (not sure of the gear ratio.  

This is on a Twinstar MKII.  

I have it set to give me 6500 rpm on climb out.  

Is there a way to get any more thrust out of this with a prop change or am I maxed out with what I have ?  

I am trying to get off the ground quicker. (it is fine for one person, but uses a lot of runway with 2)  

Also I am still looking at landing gear issues, would the person that made spring steel gear please contact me and let me know what  

size, wall thickness, grade material and hardness he used for his.  

thanks for any responses.  

Lee,  

Twinstar MKII and CGS Hawk Classic  

       [quote][b]

rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Mon Jun 24, 2013 5:24 am Post subject: thrust

A 66 or 68 inch prop might help, if you could change to a C gearbox with the 3.47 to 1 ratio and use a 68 to 72 inch three blade you would get the most possible out of the 503. 



Dennis "Skid" Rowe

Mk3, 690L-70, Leechburg, PA



On Jun 24, 2013, at 8:51 AM, "Lee" <lmorgan100(at)charter.net> wrote:



[quote] Hey everyone,

 I know this subject probably has been beaten to death but here goes anyway

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Mon Jun 24, 2013 5:26 am Post subject: Re: thrust

Typically you get more acceleration and climb as you make the prop longer. With a 503 and a longer 3 bladed prop - say 64" or 66" - you can get to the point that you have a lot of acceleration but you are top end limited, in effect you end up with a pure climb prop. The reason for this is if you try and crank in enough pitch into a longer 3 blade for a decent cruise speed, the engine will likely not have enough torque to rev up properly, it will be constantly overloaded. A 2 blade prop should not  normally have this problem. Since the Ivo is flexible, it will be just as smooth with 2 blades as it is with 3. 



Right now I am running a 2 bladed 68" Ivo with a 582 and am very happy with the performance. Take off is prompt, climb is excellent, and top end is good. The engine will hit red line at full throttle in level flight and never lugs at any RPM.



I had to make motor mount spacers to get the engine higher for boom tube clearance. Before I made the spacers the longest prop I could use was 66". 66" was good, 68" is better. I did have a bit more top end with the 66", but not much, and since I always cruise around 65 anyway, the 68" is all good. 



If I were you, I would sell the 3 blade and get a 66" 2 blade Ivo and try that. If your engine fails to make enough torque to handle it, you can trim it down to 65" or even 64" and either way you will see quite an improvement over the 60" prop.



Can't help you on the landing gear.

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Mon Jun 24, 2013 5:51 am Post subject: thrust

This makes me want to try an old two blade 68 inch Ivo I have laying around. I currently use a 68 inch three blade Powerfin F model. Always looking for more performance. I didn't think two blades would absorb 70hp.



Dennis "Skid" Rowe

Mk3, 690L-70, Leechburg, PA



On Jun 24, 2013, at 9:26 AM, "Richard Pike" <richard(at)bcchapel.org> wrote:



 	  Quote: 	
		   

 

 Typically you get more acceleration and climb as you make the prop longer. With a 503 and a longer 3 bladed prop - say 64" or 66" - you can get to the point that you have a lot of acceleration but you are top end limited, in effect you end up with a pure climb prop. The reason for this is if you try and crank in enough pitch into a longer 3 blade for a decent cruise speed, the engine will likely not have enough torque to rev up properly, it will be constantly overloaded. A 2 blade prop should not  normally have this problem. Since the Ivo is flexible, it will be just as smooth with 2 blades as it is with 3. 

 

 Right now I am running a 2 bladed 68" Ivo with a 582 and am very happy with the performance. Take off is prompt, climb is excellent, and top end is good. The engine will hit red line at full throttle in level flight and never lugs at any RPM.

 

 I had to make motor mount spacers to get the engine higher for boom tube clearance. Before I made the spacers the longest prop I could use was 66". 66" was good, 68" is better. I did have a bit more top end with the 66", but not much, and since I always cruise around 65 anyway, the 68" is all good. 

 

 If I were you, I would sell the 3 blade and get a 66" 2 blade Ivo and try that. If your engine fails to make enough torque to handle it, you can trim it down to 65" or even 64" and either way you will see quite an improvement over the 60" prop.

 

 Can't help you on the landing gear.

 

 --------

 Richard Pike

 Kolb MKIII N420P (420ldPoops)

 richard (at) bcchapel(dot)org

 Kingsport, TN 3TN0

 Now faith is the substance of things hoped for, the evidence of things not seen. 

 Hebrews 11:1

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=403285#403285

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Mon Jun 24, 2013 6:33 am Post subject: thrust

Also I am still looking at landing gear issues, would the person that made spring steel gear please contact me and let me know what

size, wall thickness, grade material and hardness he used for his.

thanks for any responses.

Lee,

Twinstar MKII and CGS Hawk Classic 	  Quote: 	
		     Lee/Kolbers: I use .120” wall 4130, heat treated to 48 Rockwell.  I don't know what the diameter of the gear leg sockets of a MKII are.  Probably 1.125". Good idea to weld the axle socket to the gear leg, rather than use the standard "gear leg/axle socket” that bolts to the end of the gear leg.  Welding, for me, proved to be much stronger than the bolt on socket. All alignment and drilling should be done prior to heat treating. 	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4

  [quote][b]

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

gliderx5

Joined: 30 Jun 2008
Posts: 203

Posted: Mon Jun 24, 2013 8:40 am Post subject: thrust

Lee 

  

I think I had a 68" 3 blade IVO on my MKII with a 503.  Below is a link to a video showing takeoff performance. 

  

http://www.youtube.com/watch?v=wAkNU2UcADw

 

Malcolm

  From: "Lee" <lmorgan100(at)charter.net>

To: kolb-list(at)matronics.com

Sent: Monday, June 24, 2013 8:51:56 AM

Subject: thrust



      

Hey everyone, 

I know this subject probably has been beaten to death but here goes anyway. 

I have a 503 Rotax with a gearbox and a 60 inch three blade IVO prop. (not sure of the gear ratio. 

This is on a Twinstar MKII. 

I have it set to give me 6500 rpm on climb out. 

Is there a way to get any more thrust out of this with a prop change or am I maxed out with what I have ? 

I am trying to get off the ground quicker. (it is fine for one person, but uses a lot of runway with 2) 

Also I am still looking at landing gear issues, would the person that made spring steel gear please contact me and let me know what 

size, wall thickness, grade material and hardness he used for his. 

thanks for any responses. 

Lee, 

Twinstar MKII and CGS Hawk Classic

[quote]

[b]

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Tue Jun 25, 2013 6:21 am Post subject: Re: thrust

 	  gliderx5 wrote: 	
		  Lee 

  

I think I had a 68" 3 blade IVO on my MKII with a 503.  Below is a link to a video showing takeoff performance. 

  

http://www.youtube.com/watch?v=wAkNU2UcADw

 

Malcolm



 	




Nice video. It is certainly possible to run a 3 blade 68" Ivo on a 503, my only question would be  - what was your cruise speed, and what rpm were you turning at that speed? In order to get the 503 to turn 6500 rpm with that much prop, you will certainly need to take out a lot of pitch, and then your cruise speed goes to pot while the engine runs at high rpm.



Back when I had a 532 on the MKIII, I started out with a 64" 3 blade Ivo. Given that the 532 did not have as flat a torque curve as the 503, still, in order to make the engine run properly, I had to run it with the prop in fairly flat pitch and it had a great takeoff and climb, but at cruise it was turning 5800-6000 rpm with poor airspeed. Around 62 if I remember right. Took away one blade, repitched the prop, and the cruise rpm became sane, cruise speed went up, and it kept it's good takeoff and climb behavior.



With the 582 and a 68" 2 blade, cruise speed is 65-70 at around 5500 rpm and 4 gph. Takeoff is typical Kolb - great.

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Tue Jun 25, 2013 9:47 am Post subject: thrust

Richard, do you have the light or medium Ivo blades?

Dennis "Skid" Rowe

Mk3, 690L-70, Leechburg, PA

On Jun 25, 2013, at 10:21 AM, "Richard Pike" <richard(at)bcchapel.org> wrote:

 	  Quote: 	

 gliderx5 wrote:

> Lee 

> 

> I think I had a 68" 3 blade IVO on my MKII with a 503.  Below is a link to a video showing takeoff performance. 

> 

> http://www.youtube.com/watch?v=wAkNU2UcADw (http://www.youtube.com/watch?v=wAkNU2UcADw)

> 

> Malcolm

> 

> 

 Nice video. It is certainly possible to run a 3 blade 68" Ivo on a 503, my only question would be  - what was your cruise speed, and what rpm were you turning at that speed? In order to get the 503 to turn 6500 rpm, you will need to take out a lot of pitch, and then then your cruise speed goes to pot.

 Back when I had a 532 on the MKIII, I started out with a 64" 3 blade Ivo. Given that the 532 did not have as flat a torque curve as the 503, still, in order to make the engine run properly, I had to run it with the prop in fairly flat pitch and it had a great takeoff and climb, but at cruise it was turning 5800-6000 rpm with poor airspeed. Around 62 if I remember right. Took away one blade, repitched the prop, and the cruise rpm became sane, cruise speed went up, and it kept it's good takeoff and climb behavior.

 With the 582 and a 68" 2 blade, cruise speed is 65-70 at around 5500 rpm and 4 gph. Takeoff is typical Kolb - great.

 --------

 Richard Pike

 Kolb MKIII N420P (420ldPoops)

 richard (at) bcchapel(dot)org

 Kingsport, TN 3TN0

 Now faith is the substance of things hoped for, the evidence of things not seen. 

 Hebrews 11:1

 Read this topic online here:

 http://forums.matronics.com/viewtopic.php?p=403398#403398

lmorgan100(at)charter.net
Guest

Posted: Wed Jun 26, 2013 4:02 am Post subject: thrust

Thanks everyone for the responses to the prop thrust question.  

It looks like I am in the market for a used 66 to 68 inch  IVO prop.  

keep in mind funds are low, but if anyone has one for around $200. I am interested.  

thanks,  

Lee  

       [quote][b]

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Wed Jun 26, 2013 5:07 am Post subject: Re: thrust

[quote="rowedenny"]Richard, do you have the light or medium Ivo blades?



Dennis "Skid" Rowe

Mk3, 690L-70, Leechburg, PA



[quote] 

 

Just the light ones.

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Wed Jun 26, 2013 10:32 am Post subject: thrust

This thread has me excited to try a 68 inch two blade Ivo I got from a friend several years ago and never thought it would be enough blade to absorb my 70hp. If it works, I'll buy a two blade hub for my Powerfin and give that a try.



Dennis "Skid" Rowe

Mk3, 690L-70, Leechburg, PA



On Jun 26, 2013, at 9:07 AM, "Richard Pike" <richard(at)bcchapel.org> wrote:



[quote] 

 

 [quote="rowedenny"]Richard, do you have the light or medium Ivo blades?

 

 Dennis "Skid" Rowe

 Mk3, 690L-70, Leechburg, PA

 

  	  Quote: 	
		   

 

 Just the light ones.

 

 --------

 Richard Pike

 Kolb MKIII N420P (420ldPoops)

 richard (at) bcchapel(dot)org

 Kingsport, TN 3TN0

 Now faith is the substance of things hoped for, the evidence of things not seen. 

 Hebrews 11:1

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=403454#403454

rickofudall

Joined: 19 Sep 2009
Posts: 1392
Location: Udall, KS, USA

Posted: Thu Jun 27, 2013 5:55 am Post subject: thrust

Dennis, Make sure you have the prop extension for the IVO, their blades flex quite a bit more than you Power Fin.



Rick Girard

do not archive

 

On Wed, Jun 26, 2013 at 1:31 PM, Dennis Rowe <rowedenny(at)windstream.net (rowedenny(at)windstream.net)> wrote:

[quote] --> Kolb-List message posted by: Dennis Rowe <rowedenny(at)windstream.net (rowedenny(at)windstream.net)>

 

 This thread has me excited to try a 68 inch two blade Ivo I got from a friend several years ago and never thought it would be enough blade to absorb my 70hp. If it works, I'll buy a two blade hub for my Powerfin and give that a try.

  

 Dennis "Skid" Rowe

 Mk3, 690L-70, Leechburg, PA

 

 

 

 On Jun 26, 2013, at 9:07 AM, "Richard Pike" <richard(at)bcchapel.org (richard(at)bcchapel.org)> wrote:

 

 > --> Kolb-List message posted by: "Richard Pike" <richard(at)bcchapel.org (richard(at)bcchapel.org)>

 >

 > [quote="rowedenny"]Richard, do you have the light or medium Ivo blades?

 >

 > Dennis "Skid" Rowe

 > Mk3, 690L-70, Leechburg, PA

 >

 >  	  Quote: 	
		  

 >

 > Just the light ones.

 >

 > --------

 > Richard Pike

 > Kolb MKIII N420P (420ldPoops)

 > richard (at) bcchapel(dot)org

 > Kingsport, TN 3TN0

 > Now faith is the substance of things hoped for, the evidence of things not seen.

 > Hebrews 11:1

 >

 >

 >

 >

 > Read this topic online here:

 >

 > http://forums.matronics.com/viewtopic.php?p=403454#403454

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 

 

 ===========

 arget="_blank">http://www.matronics.com/Navigator?Kolb-List

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ===========

 

 

 

 	




-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

 

  [quote][b]

_________________
The smallest miracle right in front of you is enough to make you happy....

rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Thu Jun 27, 2013 11:24 am Post subject: thrust

Thanks Rick, I have 5.6 inches clearance between the front of the prop and the back of my fuselage. Just realized I didn't check the flap tube clearance to the prop, will check that and if necessary I'll steal the prop spacer off my Sport Parasol.



Dennis "Skid" Rowe

Mk3, 690L-70, Leechburg, PA



On Jun 27, 2013, at 9:54 AM, Richard Girard <aslsa.rng(at)gmail.com> wrote:



[quote] Dennis, Make sure you have the prop extension for the IVO, their blades flex quite a bit more than you Power Fin.

 

 Rick Girard

 do not archive

 

 

 On Wed, Jun 26, 2013 at 1:31 PM, Dennis Rowe <rowedenny(at)windstream.net> wrote:

> 

> 

> This thread has me excited to try a 68 inch two blade Ivo I got from a friend several years ago and never thought it would be enough blade to absorb my 70hp. If it works, I'll buy a two blade hub for my Powerfin and give that a try.

> 

> Dennis "Skid" Rowe

> Mk3, 690L-70, Leechburg, PA

> 

> 

> 

> On Jun 26, 2013, at 9:07 AM, "Richard Pike" <richard(at)bcchapel.org> wrote:

> 

> > 

> >

> > [quote="rowedenny"]Richard, do you have the light or medium Ivo blades?

> >

> > Dennis "Skid" Rowe

> > Mk3, 690L-70, Leechburg, PA

> >

> > [quote]

> >

> > Just the light ones.

> >

> > --------

> > Richard Pike

> > Kolb MKIII N420P (420ldPoops)

> > richard (at) bcchapel(dot)org

> > Kingsport, TN 3TN0

> > Now faith is the substance of things hoped for, the evidence of things not seen.

> > Hebrews 11:1

> >

> >

> >

> >

> > Read this topic online here:

> >

> > http://forums.matronics.com/viewtopic.php?p=403454#403454

> >

> >

> >

> >

> >

> >

> >

> >

> >

> >

> 

> 

> ===========

> arget="_blank">http://www.matronics.com/Navigator?Kolb-List

> ===========

> http://forums.matronics.com

> ===========

> le, List Admin.

> ="_blank">http://www.matronics.com/contribution

> ===========

 

 

 

 -- 

 Zulu Delta

 Mk IIIC

 Thanks, Homer GBYM

 

 It isn't necessary to have relatives in Kansas City in order to be unhappy

gajindra(at)sbcglobal.net
Guest

Posted: Thu Jun 27, 2013 1:08 pm Post subject: thrust

On the Mark 3 IVO requires a 4 inch extension due  to the flexing. There blades do truly move a lot

Gary Jindra

Mark 3

582 115 hours

912 ul 20 hours

   From: Dennis Rowe <rowedenny(at)windstream.net>

 To: "kolb-list(at)matronics.com" <kolb-list(at)matronics.com> 

 Sent: Thursday, June 27, 2013 3:23 PM

 Subject: Re: Re: thrust

 Thanks Rick, I have 5.6 inches clearance between the front of the prop and the back of my fuselage. Just realized I didn't check the flap tube clearance to the prop, will check that and if necessary I'll steal the prop spacer off my Sport Parasol.

Dennis "Skid" RoweMk3, 690L-70, Leechburg, PA

On Jun 27, 2013, at 9:54 AM, Richard Girard <aslsa.rng(at)gmail.com (aslsa.rng(at)gmail.com)> wrote:

[quote]Dennis, Make sure you have the prop extension for the IVO, their blades flex quite a bit more than you Power Fin.

Rick Girard

do not archive

On Wed, Jun 26, 2013 at 1:31 PM, Dennis Rowe <rowedenny(at)windstream.net (rowedenny(at)windstream.net)> wrote:

[quote] --> Kolb-List message posted by: Dennis Rowe <rowedenny(at)windstream.net (rowedenny(at)windstream.net)>

 This thread has me excited to try a 68 inch two blade Ivo I got from a friend several years ago and never thought it would be enough blade to absorb my 70hp. If it works, I'll buy a two blade hub for my Powerfin and give that a try.

 Dennis "Skid" Rowe

 Mk3, 690L-70, Leechburg, PA

 On Jun 26, 2013, at 9:07 AM, "Richard Pike" <richard(at)bcchapel.org (richard(at)bcchapel.org)> wrote:

 > --> Kolb-List message posted by: "Richard Pike" <richard(at)bcchapel.org (richard(at)bcchapel.org)>

 >

 > [quote="rowedenny"]Richard, do you have the light or medium Ivo blades?

 >

 > Dennis "Skid" Rowe

 > Mk3, 690L-70, Leechburg, PA

 >

 >  	  Quote: 	

 >

 > Just the light ones.

 >

 > --------

 > Richard Pike

 > Kolb MKIII N420P (420ldPoops)

 > richard (at) bcchapel(dot)org

 > Kingsport, TN 3TN0

 > Now faith is the substance of things hoped for, the evidence of things not seen.

 > Hebrews 11:1

 >

 >

 >

 >

 > Read this topic online here:

 >

 > http://forums.matronics.com/viewtopic.php?p=403454#403454

 >

 >

 >

 >

 >

 >

 >

 >

 >

 >

 ===========

 arget="_blank">http://www.matronics.com/Navigator?Kolb-List

 ===========

 http://forums.matronics.com

 ===========

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ===========

-- 

Zulu Delta

Mk IIIC

Thanks, Homer GBYM

It isn't necessary to have relatives in Kansas City in order to be unhappy.

   - Groucho Marx

   	  Quote: 	

http://www.matronics.com/contribution[b]

Richard Pike

Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee

Posted: Fri Jun 28, 2013 6:29 am Post subject: Re: thrust

If anybody needs an Ivo prop spacer, let me know, I've got one.

_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0

Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.

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