RV-9A with catty prop cowl question

Was wondering how long is your nose gear leg slot on lower cowl.Having a 3 bladed catto prop I can't slide the lower cowl up and on like when I had the two bladed prop. The two blade can be placed horizontaly and the lower cowl just slips on where as on the 3 blade,,,,,two of the blades are lower thus hindering the slip on of the lower cowling so I have noticed that if I make the gear leg slot longer it would give me the wiggle room to slide the cowl up and in place.

So how long did you make your nose gear slot???

Thanks and always appreciated.

Ron in Oregon

I am just building mine right now, but plan to add what the plans say (3 and 1/8 inches) to the 2-bladed prop slot length.

catty Prop?

a little catnip and it should slide on just fine!!!

I guess it's also too late to suggest splitting the lower cowl, like it should be in the first place!

hate my cowl....and I have a 2 blade!

...just love beating the **** out of everything.... trying to get it on and off.

( and don't even start, you taildragger guys with FI, that can do it with one hand, blindfolded.)

flyboy1963 said:

a little catnip and it should slide on just fine!!!

I guess it's also too late to suggest splitting the lower cowl, like it should be in the first place!

hate my cowl....and I have a 2 blade!

...just love beating the **** out of everything.... trying to get it on and off.

( and don't even start, you taildragger guys with FI, that can do it with one hand, blindfolded.)

Click to expand...

Hands over the top edge of the cowl as it slides underneath the prop blades. Not one handed but this method has the prop rubbing the top of your hand and not the piano hinges!

I started by following the dimension Vans gave for the nose strut slot, but it was notably insufficient. I eventually ended up extending the slot by at least two more inches. What works BEST is making the slot as long as possible, only assuring that it's covered by the nose strut intersection fairing when all is assembled.

You guy are funny.a precision fitting. I just cut the slot forward of the gear leg 2 inchs for a total of 6.5"

Ron,
I made a 2 piece removable section fore and aft of the nose strut. It extends 6 inches forward of the strut. It isn't enough! The cowl will come off with the 3 blade, but it is not easy. I would probably do 2 or 3 more inches if I had to do it again.

Like so many other things in life, the longer the better.

I will probably make that slip 1 inch longer the hinge did hit the prop as I was pushing up to give an update the Ford tough skin over the instrument panel to the firewall is now installed with the help of two of my buddies Steve and tom. I never thought I would be on my back for 4 hours putting in those rivets but it's done and I gotta say 99.2% of the rivets are next to perfect 2 ok I'll pull up calling off and cut another inch into the slot and I like the idea of the filler plates should look really nice thanks guys I'll keep you updated as the day goes on. Ron in Oregonn

I feel compelled to ask why you're not rocking a Sterba prop? heehee

But seriously, I just went to Catto 3 blade on my 6A and haven't had to play with the bottom cowl YET. I'm watching with great interest to see how extending that slit works for you.

Rob you are the first one to ask me about the Sterba prop. I look forward to meeting the man of props. My decision to go to Catto prop was when Craig Catto came to our EAA chapter in Independence Oregon ( our chapter hosts Vans Hime coming) several years back and told us about the testing and development in prop design. What really made me examine my thoughts about performance was the fact that NASA came to CATTO to design multiple copies of a prop based on numbers needed by NASA engineers for their experimental aircraft. Not only did Catto meet their performance standards CATTO excided their expectations for performance by a wide margin. In my book that design performance carries a lot of weight in my decision to change to the 3 bladed prop. Another thought was ground clearance between the two and three bladed props. The Catto prop video was on You Tube. It was a hour long but separated into 4 15 minute episodes. I hope the video still exists because there was a open question session from our club members that was very informative in design. It was very interesting to learn about the blade angles as the blade changes performance every inch of the blade from the hub to the tip. Now I haven't flown with it YET but within the next 60 days. All that's left is the windshield and the glass work. Then it's engine start up! I do apolijize for grammar in last post. I used the mic on the key board to post the message. So much for auto correct. Sorry!

I'll keep you posted on Saturday on the length of the gear tube slit in the lower cowl. Today was exhausting so decided tomorrow would be my next work day on the cowl.

Enjoyed all of the posts.

Ron in Oregon

You'll not be disappointed in the Catto 3-blade. It's smooth, light , and simple. Just understand that the design point for the 68"/70 is 2800rpm, so it will twist that fast at most any altitude. Even at 8000MSL I have to run at less than full throttle to keep the R's below 2700.