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prkaye

Well Known Member
I got my Catto 3-blade prop today... looks beautiful! Surprisingly light.
Questions:

1) My prop didn't come with any big mounting bolts (have others gotten bolts supplied with their Catto prop?). Anybody know what bolts I'm supposed to use with this prop (O-320)?

2) on the rear side of the prop, where that metal plate is attached, the bolt holes are recessed... not sure why this would be?

3) Does anybody know where I can find a good writeup explaining the installation of this prop? I'm not sure what sequence of spinner bulkheads, spacers, extensions, crush plates etc to use with this prop (the instructions with Vans Spinner kit don't show the setup for the Catto prop).

Thanks!

Phil
 
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Some Answers

Phil,
1) While I am sure that you will get some replies from folks who know excactly what the length of the bolts (AN-6?) should be, you can figure it out on your own by calculating the grip length required.
2) The recesses in the rear face of the prop are to accept the drive bushings that are pressed into the crankshaft. Also, (and this is huge) measure the holes and you should find that one hole is larger than the others. This is to index the prop correctly. Mark that hole so it is easily identifiable, and then measure the drive bushings in the crankshaft flange and identify the one with the larger diameter.
3) Once again you will likely get all the information that you need from the Catto Prop owners in this forum!
Good Luck!

prkaye said:
I got my Catto 3-blade prop today... looks beautiful! Surprisingly light.
Questions:

1) My prop didn't come with any big mounting bolts (have others gotten bolts supplied with their Catto prop?). Anybody know what bolts I'm supposed to use with this prop (O-320)?

2) on the rear side of the prop, where that metal plate is attached, the bolt holes are recessed... not sure why this would be?

3) Does anybody know where I can find a good writeup explaining hte installation of this prop? I'm not sure what sequence of spinner bulkheads, spacers, extensions, crush plates etc to use with this prop (the instructions with Vans Spinner kit don't show the setup for the Catto prop).

Thanks!

Phil
Click to expand...
 
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jetjok said:
Also, (and this is huge) measure the holes and you should find that one hole is larger than the others. This is to index the prop correctly. Mark that hole so it is easily identifiable, and then measure the drive bushings in the crankshaft flange and identify the one with the larger diameter.
Click to expand...

Nope. The indexing lug is just for the flywheel. It is just a shoulder on the lug. The rest of the lug is the same diameter as the others.
As far as length of bolts, it will depend on your particular installation. Most 4" extensions are of the spool type and require nuts on the back side. Solid extensions will be threaded and require drilled bolt heads for safetying.
 
call this guy problems solved

here is the place for the bolts and crush plate , spacer ,everything you need
for the catto prop.. http://www.sabermfg.com/

Saber Manufacturing Inc.
3601 Nassau Ct, Granbury, TX 76049
Ph: (817) 326-6293 Fax: (817) 326-6330
E-mail: [email protected]
 
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****...

Mel said:
Nope. The indexing lug is just for the flywheel. It is just a shoulder on the lug. The rest of the lug is the same diameter as the others.
As far as length of bolts, it will depend on your particular installation. Most 4" extensions are of the spool type and require nuts on the back side. Solid extensions will be threaded and require drilled bolt heads for safetying.
Click to expand...

Mel is abosolutely correct.... I have corrected my previous posting
 
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Call the # Danny provided

They have EVERYTHING for Catto. Was five bills for me as of Nov 1st.
 
The recesses in the rear face of the prop are to accept the drive bushings that are pressed into the crankshaft
Click to expand...

hmmm... let's assume I know nothing at all (a good assumption).
I'm looking at my engine. On the "starter ring gear" (that's what it's called in Drawing C4 - it's the big round thing at the front of the engine with all those gear teeth - which i have no idea what they're for) there are 6 of those "lugs" ("bushings"? Round cylinders that are threaded on the inside, smooth on the outside) sticking out. Looking at the back of my prop, it appears these 6 lugs could fit into the 6 recessed holes on the aft face of the prop. So it appears I could just bolt the prop directly to the starter ring gear on the front of the engine. sooo....

4) why do i need a 2.25" prop extension? Is this required so the prop sticks out far enough in front of the cowl?

5) My prop (at the middle) measures about 4.25" thick. According to the note on Dwg C4 (on the diagram for wood prop assembly it shows an optional spacer and says "Prop and spacer thickness should add up to 4 3/8 In") this means I will need to add a 1/8" spacer. Is this correct?

6) Is the crush plate just protection, only needed on wood and composite props? Doesn't seem to be one shown on DWG C4 for the metal prop.

Sorry for all the naive questions! But thanks again for all the helpful replies! I've posted so many questions here over the years that one local builder here has referred to it as VansAirPhil ;)

Phil
 
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call craig

I would call craig and ask him, he will explain everything, I did need
the spacer, as the cowlings (mine) works either with cs or fp props
I think thats what makes the spacer required on the Fixed pitch
props.. vans used to have two types of cowlings, also while
fitting the cowling they showed making spacers out of pvc pipe
I think it was 2 1/4 and fine thread hardware store bolts for fitting
the cowling. most need a spacer , I think if you put the prop on
the lugs like your suggesting you would never get the cowling on
with the alternator and it would rub a whole in the cowling, its pretty
close even with the spacer..


Danny..
 
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another question - is there a trick to getting the spinner on, over the prop? I've just started playing around to see how things go together. I had craig do the spinner cutouts and drilling for me. The cutouts in the spinner for the prop blades are narrow at the back, and I'm having a hard time getting all three blade roots through the cutouts to get the spinner on. I'm worried about either marking-up the prop too much, or breaking the fiberglass spinner... any tips?

Also... DWG C4 seems to suggest 6 long bolts that go through the prop and the extension and into the engine. But another thread I was just reading seemed to suggest that there are 12 seperate bolts: 6 bolts to attach the extension to the engine, and then 6 other bolts to attach the prop to the extension. Which is correct?
 
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Call Sabre..

All installation questions should be answered. Ask him for an installation sketch, I bet he'll gladly help out!
Spinner requires some effect. Tape up the blades til you get it figured out or you'll have some messed up blsdes. Fit two of the slots onto two of the blades, then carefully separate the last cutout til it kinda twists into place. You'll get better at doing it as time goes on, but you'll need to use the tape or you'll definitely scar the blades.
Good luck!
 
OK thanks guys. Will call Sabre tomorrow. I'll tape up my prop blades for putting the spinner on, maybe grease up the tape to help them to slip on... how much twisting will that fiberglass spinner take before it cracks?
 
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prkaye said:
OK thanks guys. Will call Sabre tomorrow. I'll tape up my prop blades for putting the spinner on, maybe grease up the tape to help them to slip on... how much twisting will that fiberglass spinner take before it cracks?
Click to expand...

It's very flexible and robust. It somehow slipped out of my hands (mold release got wet) when I was making cuts. The thing jumped from backyard deck, slammed the patio floor, bounced couple times and left only tiny bruise which perfectly marked the center. No cracks no chips.
 
prkaye said:
Also... DWG C4 seems to suggest 6 long bolts that go through the prop and the extension and into the engine. But another thread I was just reading seemed to suggest that there are 12 seperate bolts: 6 bolts to attach the extension to the engine, and then 6 other bolts to attach the prop to the extension. Which is correct?
Click to expand...
It depends on which spacer you use. Van's spacer utilizes six VERY long bolts that go through both the prop and spacer. The Saber spacer uses six bolts to attach the spacer to the hub and another six to attach the prop to hub. Even though the Saber spacer requires 12 bolts, they are a lot shorter than the very expensive very long bolts required for the Van's spacer.

Since the bolts on my O-290 are only 3/8" diameter, I elected to go with the shorter bolts and the Saber spacer. The Saber spacer is a quality product and they are great guys to deal with.
 
Crush Plate

When you call, he will want to discuss the crush plate size and weight. Yes, the prop is only 18lbs... I think my crush plate ended up at 22lbs to keep CG calculations in line.
 
This thread has a lot of confusing information on a relatively simple problem - mounting the Catto prop to a the 0320 engine (or 0360).

The 2.25" extension is required for a wood prop install with the "short" cowl Van's invented some time ago. The extension comes in 2 versions, a cheap one and a slightly more expensive one. One has bolts through the prop and extension to the engine flange. It is not recommended because the extension should be torqued to the engine flange at 50-55 foot pounds (metal to metal), but the Catto should not be torqued over 40 (or whatever is on the prop data plate). The recommended more expensive extension has 12 holes, 6 to mount it to the engine flange at the proper metal to metal torque, and 6 for the prop to mount metal to wood (composit). In both cases, the crush plane must be used in front of the prop. The O360 uses a 7" plate but the 0320 may get away with a 6", check with Saber on this.

The 0360 always uses 1/2" bolts, the 0320 may use 7/16" or 3/8".

I don't know what is going on with your spinner cut outs and the prop. You should check with Craig Catto on this.
 
My O-360, Catto three blade prop and what I ASSUME is a standard cowl does not have an extension thingie.

The order...engine forward is as follows (Don't assume yours is the same)

Engine flange
Aft spinner bulkhead
Prop
Forward spinner bulkhead
1/8 inch crush plate like spacer (may be unique to my installation)
Real...approx 1/2 inch thick crush plate
Bolts through all that
 
Ron Lee said:
My O-360, Catto three blade prop and what I ASSUME is a standard cowl does not have an extension thingie.

The order...engine forward is as follows (Don't assume yours is the same)

Engine flange
Aft spinner bulkhead
Prop
Forward spinner bulkhead
1/8 inch crush plate like spacer (may be unique to my installation)
Real...approx 1/2 inch thick crush plate
Bolts through all that
Click to expand...

Well, that's interesting. Goes to show how much I know, don't hang your hat on this old fence post. :)

What I do know is if I did not have the 2.25" extension, the prop would be back into the cowl about 2 inches. This is with the standard RV-7 IO360 cowl, a standard dynafocal engine mount and IO360 180HP.
 
No problem David. Hopefully I caveated my setup adequately. The front of my cowl is just behind the crankshaft prop flange (right term?). Since my spinner is off, I will take a picture tomorrow morning and post it, plus verify that I did not lie in my previous post.

The original poster needs to make sure that he does it right, including proper bolts of the correct length. I don't recall if anyone mentioned what he needs to do to get the right length.

I do know that when I put on the Catto prop I measured very carefully to make sure that the bolts did not bottom out (run out of threads) in the flange as I was torquing the bolts. This is one area (of many) that you don't want to do it wrong.
 
info from Sabre

I emailed Sabre last night and had a reply with an invoice including everything I will need this morning. I had also emailed Craig at Catto, and he also referred me to Sabre. The quote for the extension and all bolts and stuff was about 500 bucks. Ouch... didn't know I'd need to add that to the cost of my prop! Anyway, was very impressed by the prompt and detailed response from Sabre... apparently the stuff will come with instructions. So I'll be ordering their stuff after the holidays.
 
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