kitfox 7 propeller advice

[Dave Holl]

I am now at the point when I have to decide on the prop fror my Kitfox 7 with rotax 912ULS,
I believe that the options are warp drive,ivo prop medium both are 3 blades I have read the various threads here but are still undecided. Has anyone used the whirlwind ground adjustable 3 blade prop that kitfox use on the LSA aircraft? can we purchase this prop through kitfox? are there any other props that I should consider?
Any help would be great
Dave
PS is it worthwile going for the variable pitch option re performance verses cost?

[DanB]

Dave,
If you have read the archives of this site I believe you will come up with a strong lean towards the use of the 3 blade IVO props on the front of the Rotax 912 line. There is a reason for this...like Kitfox4 has mentioned in a thread not too long ago, there are many walls in our community that have expensive prop art for the decore. It is wise to to ask these questions and weigh the answers you get carefully. Another good question to ask is."Who can you trust?" If you start at the Kitfox factory, I can tell you they know better than anyone what works and what is wall art. They are not building Kitfox Aircraft by giving wrong information and selling stuff just to make a buck. I know some companies do, but here you are dealing with folks that love flying the product as much as they like to build it. Give John a call...he will not steer you wrong for your application. If you were to talk to Steve Kellander, he will tell you the same thing, If you talk to Phill Laker, yep, his answer would be in line with the others. Why? Because they have thousands of hours behind these engines and birds and have already blazed the trail b-4 us. Of course, you can experiment as much as you want and as deep as your pocket book will allow. As for me, I like using time tested information when I can get it.
Best wishes

[Dave Holl]

Decided to go with the IVO medium with IFA 70 inch diameter, just now have to get the Light Aircraft association to approve the installation as none have been fitted on a Kitfox here in the UK!
Dave

[HighWing]

I would like to chime in here as well as I am about ready for the prop. I few 900 hours with a warp and had zero issues with it. I am aware of all the Ivo talk and have flown with Ivo's along side me in groups and on one occasion, we had two different airplanes with Ivos request unscheduled stops because the inflight part would not cycle.

I don't like the SS leading edge, frankly it looks crappy and I have a friend that throws one on a fairly regular basis and knows immediately when it is gone when the vibration starts. I also don't like the looks of the small skull cap like spinners, I see on them.

Still, I like the reported performance benefits. I am receptive to specific details on why my concerns are non issues or alternatives to molify them.

Lowell

[Andrew G]

http://kitplanes2.com/blog/2010/09/f...nd-propellers/

Here is a vid of the company that makes the prop found in the Kitfox factory's recent model 7.

I'm impressed by the leading edge technology... does it fly well/better? John would know.

BTW... what are the advantages of the inflight adjustable? More speed? Stronger takeoff? Better fuel economy? cost diff?

If there is a thread that covers this, I'd appreciate a direction to that thread.

Thanks, Andrew

[Dave Holl]

High wing
interesting comments, the UK Light Aircraft Association who certify home built aircraft in the uk have advised against the IVO as while they say it is good on the smaller rotax engine they feel that with the 912ULS is a bit too violent for the prop as there have been a number of issues with the prop blades cracking, they have advised me that the warp would be a better prop and that there is more experience with this prop on a rotax 912uls in the uk so the story thickens!
Dave

[Av8r3400]

Wow! What a bureaucratic nightmare...

I know of several people running 912ULSs with IVO medium props without incident. The IVO Ultralight works well and is recommended for the UL (80 hp) and the 2-strokes, but the ULS (100 hp) requires the Medium prop for the reasons you have given.

[SkySteve]

I use a Warp medium square tip. I understand some have this prop "shaved" into a taper tip. What is/are the advantage(s) of the taper tip?

[Av8r3400]

A "Square Tip" 3-blade warp is too heavy for the 912 gearbox and will cause damage. Rotax will not warranty any damage to the gearbox if a square tip Warp is installed. This is also directly from LEAF and Lockwood seminars at Airventure.

Tapering the tips lessens the mass (and gyroscopic effects) sufficiently to prevent damage to the gearbox.