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Woodcomp Prop diameter

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Paul M 383

Joined: 19 Mar 2012
Posts: 97
Location: United Kingdom

Posted: Thu Feb 07, 2013 5:32 am Post subject: Woodcomp Prop diameter

I'm thinking of ordering a Woodcomp SR3000/3 for my 912S-powered XS Mono.



The preferred prop size seems to be 1625 mm... The factory offered 1625 or 1650, and I think 1625 is best for ground clearance reasons. Anybody got any better ideas?



I am also going for the SR3000/3 - again, unless somebody tells me I simply *must* have the 3000/3W.



All answers gratefully received...



Paul M

XS Mono 912S

christoph.both(at)acadiau
Guest

Posted: Thu Feb 07, 2013 5:47 am Post subject: Woodcomp Prop diameter

I installed the SR3000-2 blade, scimitar. It is sized 1650mm, so the

1625mm seems to make sense for the 3-blade. Saved 9 pounds weight, though

up front, with the 2 blade.

Christoph Both

#223 Wolfville, Nova Scotia, Canada

On 13-02-07 9:32 AM, "Europaul383" <europaul383(at)hotmail.com> wrote:



 	  Quote: 	
		  



I'm thinking of ordering a Woodcomp SR3000/3 for my 912S-powered XS Mono.



The preferred prop size seems to be 1625 mm... The factory offered 1625

or 1650, and I think 1625 is best for ground clearance reasons. Anybody

got any better ideas?



I am also going for the SR3000/3 - again, unless somebody tells me I

simply *must* have the 3000/3W.



All answers gratefully received...



Paul M

XS Mono 912S





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=393767#393767

frans(at)privatepilots.nl
Guest

Posted: Thu Feb 07, 2013 6:42 am Post subject: Woodcomp Prop diameter

On 02/07/2013 02:32 PM, Europaul383 wrote:



 	  Quote: 	
		   I am also going for the SR3000/3 - again, unless somebody tells me I

 simply *must* have the 3000/3W.


	


I would go for the /W, because for the Europa cruise speed the inner

portion of the blades has a much better profile. It increases

efficiency, speed, and cooling. (The latter because the inner portion of

the blades throws more air into the cooling system). I'm unaware of any

advantage of the "normal" version over the /W version. The /W version is

simply a prop better suited for the speed range of the Europa airplane.



Also I would go for the 2-blade version. This for the same reason as why

for a fast airplane a single plane wing is better than a bi-plane. With

two blades instead of three you cut down 33% of the leading edge,

blade-tip vortexes, weight, etc. The result is higher efficiency and

higher speed, lower gyroscopic effects, better glide ratio, etc. The /2W

prop has more than enough area to fully utilize the power of the Rotax

engine; you don't need more blades for this amount of power.



I have the SR3000/2W on my 914 powered Europa, and I'm very satisfied

with the performance to say the least. The only drawback of a 2-blade

prop is that it is a bit more prone to vibrations, but with the prop

properly balanced and the carburators properly tuned there are no

significant vibrations. I see it as an advantage that I immediately feel

it when the carbs are unbalanced, inviting me to investigate, rather

than to hide the imbalance to me until more serious problems develop.



Avoid the scimitar blades. They offer no advantage over the normal

blades, it is just for the looks (if it is your taste after all), but

they are asymmetrical on the variable pitch system and create strain

both mechanically as electronically.



Frans

Paul M 383

Joined: 19 Mar 2012
Posts: 97
Location: United Kingdom

Posted: Thu Feb 07, 2013 7:53 am Post subject: Re: Woodcomp Prop diameter

Thanks to both (no pun intended, Christoph!),



Christoph: I have just found our LAA limits (based on EASA CS-VLA) and it might be tricky getting 1650 approved, but now the topic has opened up to 2 vs. 3 blades and W vs. normal.



Frans: do you have any data you may have recorded during testing/touring?



Specifically, airspeed & RPM (presumably 5,500?) mapped to climb rates; and max speed at different weights.



A bit of a long shot, but have you measured any data while normally-aspirated (turbo off)? If you need an excuse to go flying, maybe you might fancy trying some normally-aspirated climbs and cruises?   



Thanks in advance,



Paul

XS Mono 912S

frans(at)privatepilots.nl
Guest

Posted: Thu Feb 07, 2013 8:18 am Post subject: Woodcomp Prop diameter

On 02/07/2013 04:53 PM, Europaul383 wrote:



 	  Quote: 	
		   Frans: do you have any data you may have recorded during

 testing/touring?

 

 Specifically, airspeed & RPM (presumably 5,500?) mapped to climb

 rates; and max speed at different weights.


	


Yes, but my ship is quite non-standard and it is impossible to attribute

the performance to the individual mods as they where there from the

beginning. I have very large wing root fairings, highly modified low

drag cooling, intercooler on the engine, a modified high top

arrangement, gap seals, modified exhaust, etc. and the /2W prop is just

one of the features. My Europa seems to be on the "fast" side when

compared to other Europa's.



 	  Quote: 	
		   A bit of a long shot, but have you measured any data while

 normally-aspirated (turbo off)?


	


I don't see how it would be possible to turn the turbo off (turning it

off is something entirely different to flipping the TCU switch) but of

course I can fly in Manifold Pressure regions that are available to

naturally aspirated engines too. In fact I usually fly with about 27 to

28" of MAP which gives me speeds around 130 IAS (at)MTOW if I recall

correctly. (Haven't been flying for a while due to weather and lack of

reachable interesting destinations).



Frans

davidjoyce(at)doctors.org
Guest

Posted: Thu Feb 07, 2013 10:35 am Post subject: Woodcomp Prop diameter

Paul, I have data comparing performance of SR 3000W 1625 

with SR 2000 1625 on a 914 and clear advantage for latter. 

Am skiing at present but when home will send you the full 

analysis. The LAA will I believe not accept 1650, and I 

suspect that Woodcomp would advise the 3 blader (but ask 

them) for a 912 S as they did for my 914, otherwise at any 

height you risk running out of propeller to take the 

power.

Regards, David Joyce, G- XSDJ

On Thu,  7 Feb 2013 07:53:03 -0800

  "Europaul383" <europaul383(at)hotmail.com> wrote:

 	  Quote: 	
		   

<europaul383(at)hotmail.com>

 

 Thanks to both (no pun intended, Christoph!),

 

 Christoph: I have just found our LAA limits (based on 

EASA CS-VLA) and it might be tricky getting 1650 

approved, but now the topic has opened up to 2 vs. 3 

blades and W vs. normal.

 

Frans: do you have any data you may have recorded during 

testing/touring?

 

 Specifically, airspeed & RPM (presumably 5,500?) mapped 

to climb rates; and max speed at different weights.

 

 A bit of a long shot, but have you measured any data 

while normally-aspirated (turbo off)? If you need an 

excuse to go flying, maybe you might fancy trying some 

normally-aspirated climbs and cruises?  [Wink] 

 

 Thanks in advance,

 

 Paul

 XS Mono 912S

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=393776#393776

 

 

 

 

 

 

 

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graeme bird

Joined: 15 Jul 2010
Posts: 434

Posted: Thu Feb 07, 2013 10:54 am Post subject: Re: Woodcomp Prop diameter

I changed last year. I guess you saw my post regarding replacement blades on the W version having to be a set. If I started again I would go for the normal ones. It has to be 1625 and 3 blades to be approved by the LAA.



having put it on, put the warp drive back, then back to woodcomp, I cant say that there was any substantial cruise performance increase except take off and more control on landing. It looks very nice though.



Kevin was very helpful.

_________________
Graeme Bird
kit4 (Wagstaff) TBD
Kit3 G-CLXU (Gregory) mono 914 xs Woodcomp
Kit2 G-PATS - (kesterton) Mono Classic 912 warpdrive
Kit 1 G-UMPY - Mono Classic/XS 912S, Woodcomp G(@)gdbmk.co.uk

frans(at)privatepilots.nl
Guest

Posted: Thu Feb 07, 2013 11:46 am Post subject: Woodcomp Prop diameter

On 02/07/2013 07:34 PM, David Joyce wrote:



 	  Quote: 	
		   I suspect that Woodcomp would advise the 3 blader (but

 ask them) for a 912 S as they did for my 914, otherwise at any height

 you risk running out of propeller to take the power.


	


With my 914 intercooler and 3000/2W I fly regularly at +FL100 but never

ran out of propeller to take the power or even close to that.



Frans

davidjoyce(at)doctors.org
Guest

Posted: Thu Feb 07, 2013 12:47 pm Post subject: Woodcomp Prop diameter

Frans, We are of course subject to LAA scrutiny & they 

require us to demonstrate climb rate of >300fpm in max 

coarse from a go around, which no doubt means that our 

coarse stop will be not so coarse as yours. I can 

overspeed the engine at 100% throttle at 10,000ft - not 

that at is of great consequence as I usually cruise at 

much lower throttle settings. Otherwise your inter cooler 

is working wonders! Regards, David Joyce



On Thu, 07 Feb 2013 20:45:50 +0100

  Frans Veldman <frans(at)privatepilots.nl> wrote:

 	  Quote: 	
		   

<frans(at)privatepilots.nl>

 

 On 02/07/2013 07:34 PM, David Joyce wrote:

 

> I suspect that Woodcomp would advise the 3 blader (but

> ask them) for a 912 S as they did for my 914, otherwise 

>at any height

> you risk running out of propeller to take the power.

 

 With my 914 intercooler and 3000/2W I fly regularly at 

+FL100 but never

 ran out of propeller to take the power or even close to 

that.

 

Frans

 

 

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MalcolmH

Joined: 10 May 2010
Posts: 15

Posted: Fri Feb 08, 2013 4:08 am Post subject: Re: Woodcomp Prop diameter

 	  davidjoyce(at)doctors.org wrote: 	
		  Paul, I have data comparing performance of SR 3000W 1625 

with SR 2000 1625 on a 914 and clear advantage for latter. 

Am skiing at present but when home will send you the full 

analysis. The LAA will I believe not accept 1650, and I 

suspect that Woodcomp would advise the 3 blader (but ask 

them) for a 912 S as they did for my 914, otherwise at any 

height you risk running out of propeller to take the 

power.

Regards, David Joyce, G- XSDJ

On Thu,  7 Feb 2013 07:53:03 -0800

  "Europaul383" <europaul383> wrote:

	


I'm sure David will correct me but I think he meant 'former' in his response above



Paul, I am in a similar position to yourself and indeed asked the same question on the forum and David was most helpful in the advice he gave. However then Frans suggested the 2W option. I didn't find Woodcomp particularly helpful I'm afraid. I had a little correspondence with Kevin and the factory but the bottom line seemed to be you pays your money and takes your choice.



My view is that its an awful lot of money to spend only to realize you've made a mistake and now Graeme has concluded that he would have fitted the 'normal' ones (by this I think he means 3000/3 no W suffix).



So I was erring towards the 3000/3W but not sure again after Graeme's comment.



One thing though the Smart Avionics Controller would be my option.

Paul M 383

Joined: 19 Mar 2012
Posts: 97
Location: United Kingdom

Posted: Fri Feb 08, 2013 7:44 am Post subject: Re: Woodcomp Prop diameter

As you say Malcolm, I have made up my mind I'm not sure!



I know the LAA mandate a max of 1625 mm (based on clearance calcs in CS-VLA, which is not a requirement for LAA aircraft, but that's another argument!)... they don't insist on 3 blades - Andy Draper said they have lots of 3000/2W listed for Sport Cruisers, but I guess they have the ground clearance to allow for longer blades...



I suspect 3 blades may be necessary to keep a decent blade area for 1625 diameter (with a 1650 you have more area, so can get away with 2 blades I guess).



So now it's *just* a choice of wide vs. normal:-



Data showing W is better for 914 - but does this apply equally to 912S?



or a subjective comment "If I started again I would go for the normal ones" (like you, I think that's what he means).



Decisions, decisions!

rowlandcarson(at)gmail.co
Guest

Posted: Fri Feb 08, 2013 11:10 am Post subject: Woodcomp Prop diameter

On 7 Feb 2013, at 13:32, Europaul383 wrote:



 	  Quote: 	
		   I'm thinking of ordering a Woodcomp SR3000/3 for my 912S-powered XS Mono.

 

 The preferred prop size seems to be 1625 mm... The factory offered 1625 or 1650, and I think 1625 is best for ground clearance reasons. Anybody got any better ideas?

 

 I am also going for the SR3000/3 - again, unless somebody tells me I simply *must* have the 3000/3W.

 

 All answers gratefully received...


	


Paul - for what it's worth, I have got the SR3000/3W in 1625mm diameter for my Rotax 912S, but the two have not yet been married together, and the airframe is a long way from completion yet, so I can't report on the success of the combination. The high twist of the W blade seems much better suited to the speed range of the Europa, and should not be causing negative thrust, as some lower-twist blades can, in certain speed ranges (David Joyce has done the sums on that).



in friendship



Rowland



| Rowland Carson          ... that's Rowland with a 'w' ...

| <rowlandcarson(at)gmail.com>            http://www.rowlandcarson.org.uk

| Skype, Twitter: rowland_carson      Facebook: Rowland Carson

| pictures: http://picasaweb.google.com/rowlandcarson

graeme bird

Joined: 15 Jul 2010
Posts: 434

Posted: Fri Feb 08, 2013 11:29 am Post subject: Re: Woodcomp Prop diameter

yes and the rationale was, 

a) David J had written somewhere that the twist on his 914 hadnt given him as much as expected (and I am on a 912S)

b) they are standard blades and cheaper, and a single blade can be replaced if you ding one (rather than £2000 for three). 



After my ding I would have gone from W to normal IF I hadn't done all the flight testing and been through the approval process with the W.



According to Andy Draper, 1625 is max on a mono due to ground clearance and then two short blades wont be enough.

If anyone wants two fine 3000W blades I have them - good as new.

Paul M 383

Joined: 19 Mar 2012
Posts: 97
Location: United Kingdom

Posted: Fri Feb 08, 2013 12:07 pm Post subject: Re: Woodcomp Prop diameter

Thanks Rowland and Graeme,



Great answers and both valid in their own right (dammit!) The choices seem to be:



W for the extra twist needed (although not necessarily as much as expected).

Normal for lower cost & lower replacement cost.



I'll get whatever you decide, MalcolmH!



Thanks to everybody for all the very useful input.



Paul M



XS Mono 912S

davidjoyce(at)doctors.org
Guest

Posted: Sun Feb 10, 2013 4:11 am Post subject: Woodcomp Prop diameter

Paul, Back from skiing and as promised herewith the text 

of the article I wrote comparing a 12 degree twist prop 

with a 26 degree twist prop (ie the SR3000W (The 

originalwas published in the Europa Flyer a few years 

back). The key points are:

Climb rate, Fuel consumption both improved

Top speed incvreased 4 knots at low and medium altitude - 

this is the equivalent of the engine giving an extra 7 HP!

Cooling dramatically improved./

            None of this should come as a surprise - if 

you look at any high/highish performance propeller driven 

plane from Spitfires through Red Bull racers to modern 

turboprops, they all have propellers with around 26 

degrees of twist, and given the relative diameter of their 

props their speed range demands the same sort of prop 

design as a Europa for optimal performance. At any normal 

cruise speed the central portion of a Europa 12 degree 

twist prop will be in Beta mode, effectively braking that 

central column of air and diverting it from the cooling 

intakes.

           It seems a pity to me to pick a prop on the 

basis of how much it might cost to replace if you break a 

blade

          I will contact Jiri at Woodcomp and get an 

answer as to whether they feel that a 2 bladed 3000W can 

cope with the power of a 912S

          Regards, David Joyce, G-XSDJ

On Thu,  7 Feb 2013 05:32:34 -0800

  "Europaul383" <europaul383(at)hotmail.com> wrote:

 	  Quote: 	
		   

<europaul383(at)hotmail.com>

 

 I'm thinking of ordering a Woodcomp SR3000/3 for my 

912S-powered XS Mono.

 

 The preferred prop size seems to be 1625 mm... The 

factory offered 1625 or 1650, and I think 1625 is best 

for ground clearance reasons. Anybody got any better 

ideas?

 

 I am also going for the SR3000/3 - again, unless 

somebody tells me I simply *must* have the 3000/3W.

 

 All answers gratefully received...

 

 Paul M

 XS Mono 912S

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=393767#393767

 

 

 

 

 

 

 

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Paul M 383

Joined: 19 Mar 2012
Posts: 97
Location: United Kingdom

Posted: Mon Feb 11, 2013 10:14 am Post subject: Re: Woodcomp Prop diameter

Thanks David,



I read your interesting article when it came out, but thought the improvement was between your previous SR2000 and the new SR3000 (not the SR3000 vs. SR3000/W).



Speaking to Jiri (at) Woodcomp, they simply supply "what the builder prefers", but can say historically that most Europas have 1625mm and "some" have the W blades.



What I didn't know is that the W are not just wider, but have more twist - I thought the 3000 had the same twist as the 3000/W, so it was just a choice of narrow vs. wide. Now I know different...



The factory line on blade replacement is not that the W blades have to be supplied in 3s (and the normal/narrow blades are not guaranteed to be available singly) - just that they have to be equally balanced as a set - and since the narrow blades are produced in greater numbers, there is a greater chance of finding blades that match.



In addition, most blades they produce are 1700mm, so it is less likely to find a balance match for a shorter 1625mm blade  ... even more so (statistically) for the rarer short, wide blades.



They do not want to make maintenance and replacement an expensive exercise, but they do have to find ones that balance.



I am waiting for a price on the W blades, but I suspect that is the way I shall be going.



Thanks again to everybody for very useful information.



Paul M



XS Mono 912S

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