Catto Prop installation literature

[Kenny Edwards]

Hi fellow builders
A quick request to see if anybody can direct me to the section or paragraph in the Carbon Cub manuals that deals with the installation of the kit supplied Catto Prop.Ive been thru the manuals and unable to find any info on this topic.Appreciate your early responses
Best regards
Ken Edwards

[Tom R]

Hello,

we are just nearing the completion of our build and are curious to see if there is documentation or a preferred prop to engine orientation to be used for installation.
Thanks for the info on the prop bolt size, that was helpful
Justin

[Daveembry]

Hello,

we are just nearing the completion of our build and are curious to see if there is documentation or a preferred prop to engine orientation to be used for installation.
Thanks for the info on the prop bolt size, that was helpful
Justin

Tom. There is a single page PDF in the Dropbox files called Prop and Spinner Installatiom in the miscellaneous folder. No orientation that I'm aware of but important to torque it in 2 stages and torque opposite bolts as you go around.

After you torque it, take a cardboard box and place it on the floor so when you bring the prop around by hand that one blade tip will just touch the box. Mark the box right where that blade tip touches. Then without moving the box, spin the prop around (by hand) until the other blade touches the box. It should be right on the same mark. If not then loosen and retorque the bolts gradually again and see if you can get it to match. Mine was absolutely a perfect match. Each blade tip touches the box exactly in the mark.

[jmorrical]

I am installing a Catto 3XCarbon Composite 2B 80X50 CubCrafter provided prop. Would someone please explain the intent of Notes #9,10 and 11 on this Prop and Spinner Installation page found in DropBox?

1. Note 9: Where/when is clear silicone needed and applied and for what purpose? I'm clueless.
2. Note 10: What is meant by the inboard edge of the prop? Do they mean to say the back of the hub? Do I cover the entire back of the prop hub with polyethylene tape to prevent chaffing with the carbon fiber spinner mount ring (SC52010-007)? Or just a few lines of tape across the back of the hub?
3. Note 11: Do I put polyethylene tape down over the crush plate 'edge with the radius' where the bulkhead slips into the pilot hole of the crush plate?

Screen Shot 2023-04-07 at 11.30.18 AM.jpg

[jmorrical]

Thought I should pass along what I've learned from Pete at KitSupport a couple weeks ago about Catto 80 X 50 installation. The earlier post was all I could find with any detail on installing my fixed pitch propeller. Additionally, there was the Catto Maintenance Manual in DropBox, but there is nothing about installation. That manual was only inspection procedures, damage assessment and when to return to service or the manufacturer for evaluation.

Here was Pete's response:

"This is an old drawing that is a bit outdated. Previously, before the front plate was added clear silicone was used to stabilize the backing plate to the prop. The front plate eliminated the need for this. Also, the UHMW tape was used to prevent chafing since with no front plate there was more movement. The only place we use UHMW tape any more is possibly on the opening in the front of the crush plate where the front plate indexes in, if it isn't a snug fit to keep things from moving around."

I searched the internet for this Catto Propellers Customer Operations and Maintenance Manual - Experimental Aircraft that filled in the missing information for me. Pete said he could add it to the DropBox.

https://www.cattoprops.com/wp-conten...nce-Manual.pdf

[Pete D]

The manual Jim mentioned was added to the EX1 and EX2 Dropbox folders.

Dropbox\EX1 Manuals\Reference material
Dropbox\EX2 Manuals\Service Documents

[ceslaw]

Thought I should pass along what I've learned from Pete at KitSupport a couple weeks ago about Catto 80 X 50 installation.

* * *

I searched the internet for this Catto Propellers Customer Operations and Maintenance Manual - Experimental Aircraft that filled in the missing information for me. Pete said he could add it to the DropBox.

https://www.cattoprops.com/wp-conten...nce-Manual.pdf

Thanks for posting that link. I read it and promptly headed to the hanger to reclock the prop and double check the installation. The specifics in that manual were in fact different than the instruction sheet that was provided back in 2015 when I build the first Cub. Good information!

[jmorrical]

I thought this was important enough that I should add my recent propeller bolt experience to this thread.

I received my Catto 80 X 50 composite propeller from CubCrafters in March 2020. This month I have been trying to get it installed. I mounted it with kit bolts and torqued them to specifications on the data plate. In the meantime I had been looking for more detailed instructions as to how I should install my prop. I wanted to be sure I had completed it correctly. I came across the Catto document Catto-CPZ-01 Catto Propellers Customer Operations and Maintenance Manual Experimental Aircraft with revision R-3 dtd. 30 Aug, 2019 which even had CubCrafters installation information in it. That manual now in DropBox and linked below in this 'thread' said at least three threads are to be exposed out the back of the bushings. This got my attention. My install had no exposed threads.

I found my grade 9L bolts were really 4.5" - 3/8 X 24 so I quickly learned that they were supposed to be 5" bolts. KitSupport sent a new kit of bolts. While I'm not certain of this I think bolts are actually provided by Catto Propeller. Any way, the replacement kit of 5" - 3/8 X 24 bolts came nicely shrink wrapped with washers. I did check a couple carefully, but not all six. When I got them torqued down and checked the exposed threads this time around I found one bolt had 5-7 threads exposed. What's up with that? Well, that bolt was actually a grade 5 bolt. There were differences in overall length, grip length and head depth, but I didn't notice it. Removing that bolt took more effort than the other bolts. This gave me more concern. I found it had bottomed out on the bushing and had damaged bolt threads coming out and at least a couple first threads of the bushing. Now I'm waiting for a third mailing of bolts.

In the end I determined with good level of confidence that the bushing threads were sound except for the first couple. I elected to cautiously tap to clean the first couple threads. I'm satisfied that bushing threads are sound. In exploring my issue with bolts Catto referred me to Saber Manufacturing. I had a very interesting 15 minute visit with Sam Tilleman owner of Saber Manufacturing, Inc in Granbury, TX about prop hardware, crush plates and fastener metallurgy. He gave me great technical advice about my situation, L9 and other grade bolts, prop flanges and bushings and crush plates, etc all in his area of business expertise.

Lesson relearned: Trust but verify everything.

Here are a couple photos of the second set of bolts. Notice the marked bolt head size, difference in the grip and thread length.

IMG_6669.jpg

IMG_6672.jpg

IMG_6675.jpg

[ceslaw]

Thank you for sharing that information regarding an issue that could have had serious consequences had it not been discovered and resolved.

Discretion prevents me from placing in print what I am presently thinking.

[ceslaw]

Pulled the cowl and inspected. Saw a couple of threads protruding on the prop bolts. I will sleep better tonight.

IMG_4674.jpg