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Propeller back plate simulator?

Space Cadet

Well Known Member
I'd like to fit up my cowl but don't have the prop or spinner assembly yet. I've read on other models there's instructions to simulate the backplate mounting, but anyone done it for the -10? Or did I read I could just buy the backplate or borrow a simulator somewhere? I'm tired and too frustrated to go searching right now :eek:

Thanks,
Dwight
 
Simulation

Dwight......I've done it twice and works fine. Finishing up an RV-10 right now and still don't have a prop.
Install the flywheel/ring gear. Cut 4 pieces of PVC pipe exactly 2 1/4". Square the ends. Four bolts will go through these. Borrow a spinner back plate or make something similar, aluminum or even wood. Order of assembly is forward to aft. Plate, 2 1/4" spacer, flywheel. Your cowling will fit between plate and flywheel. By the way...that spacing will fit both the Hartzell and the MT.

Wish I knew how to post photos, that set up is mounted on the engine right now. Dave Maib's RV-10 is in a hangar across from me. I'll ask him on Monday if he knows how.

Best Regards.....Joe.
 
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Got it, thanks!

Joe, thanks! Was just about to post that all I needed was the spacer dimension. I think that's the same dimension on the smaller RVs too. I'll take a picture if you figure out how to do it, just to be sure, but think I've got it. You can send via PM if you prefer.

Just for kicks- the backplate diameter's roughly 13" for standard cowls and spinners, right?

Dwight
 
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Backing Plate Fixture

I have a GREAT fixture that I stole from a friend. It uses an old prop hub and simulates the spinner in outside dimentions and 1/4" spacing to cowl. You can change spacers if you want a different gap. The beauty is that you have no prop blades in your road and you drill through the fixture into cowl to lock the top and bottom cowls in place and nothing ever moves as you work on final fit. Take the top off and keep bottom in place or visa versa. If I knew how to post a picture I would or if someone tells me where to send it I will forward the pictures to post.
 
PM sent:

Send them to me and I'll post them for you.
Here are John's pictures.
2zf0lt1.jpg
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4gitr7.jpg

8vrbj8.jpg

mw5g89.jpg
 
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Spacer sizing

Thanks for the pics John, that is a good idea.

I guess to be safe I should use the larger of the two spacer sizes listed, then I can trim up to final if needed later.

Thanks to all,
Dwight
 
Follow-up Question

Okay guys (and gals), I have the spacers and back-plate simulator, with the cowl ready to go, but I don't see how to center/align the top cowl properly with this setup. The over-sized holes in the simulator allow too much movement in height and side-to-side when being mounted, no? And that small movement in front means bigger movement of the trim line at the back of the cowl on the sides, where it shows most.

I could make the back-plate simulator round and look like the real back plate (mine is square at the moment), but I'm concerned it doesn't sit well centered with the crank/prop line still. Do I make a template to fit over the prop extension/crank behind the simulator to match up to the front of the cowl?

Or am I just over-thinking this?

Dwight
 
I had the same concerns so I made a plug to fit the crank and spinner and used the tube spacers. It wasn't a big deal for me as I own a machine shop but I would try to borrow a prop adaptor from someone if possible instead of messing around with spacers and stuff. After I made all the spacers and center plug I found out a friend had a prop adaptor to loan me.
 
Backplate from Vans

For future reference... you can buy just the backplate for the spinner assembly from Vans separately, and use it per the above posts and/or Van's suggested directions.

Don't know why I didn't think of that myself...:rolleyes:

Dwight
 
spacer distance

Anyone come up with a definite spacer distance for the simulated spinner plate? I am looking for a 3/16 gap from the spinner to the cowl. I saw on the earlier posts 1.57 and 2.25. I am at this junction and would rather wait to buy the prop.
 
might have the answer...

Not definitive, but when I spoke to the guy at LessDrag.com who has a good reputation on this forum he said it's 2.25, but there's a lip on the back plate, so if you're using a flat-plate as a simulator the space is actually 1.5"... that's 2.25 - 5/8" lip - 1/8" gap per Vans instruction. I bought the back-plate from Vans and confirmed it is a 5/8" lip. The 1.5" is close to the other posting's measurement too.

Hope that helps.
Dwight
 
Thanks Dwight. I was following Van's Construction FAQ's on the prop sim and wanted to make sure after hearing different measurements. It states 2.125 for a constant speed and 2.25 for a fixed with the spinner backlplate. I will verify with my other plate for the 1.5 without the lip.

Sean
 
Sean-

Hmm, now I'm wondering again too, and just about to cut my cowl. Think it's still safest to use the larger space (2.25" here), then trim back if it really is supposed to be 2.125.

Dwight
 
cut mine

Dwight

I called Vans. They told me that 2.125 is the spacer length for the constant speed prop and using the spinner backplate per the construction FAQ's on Van's website. This is where the hub sets the backplate and then you space off of it like it is the actual hub. I put 3/16 spacers and my top cowl is done so I hope it mates up well when I get my prop in.
 
Gents,

??? how did your Proppelor backplate Simulator SPACING work out ???

I had the prop on the bench with the backplate attached and tripple measure it. I got a spacing of 2" :confused: for a standard hartzel 2 blade [C2YR-1BFP/F8068D. 80” diameter, “blended airfoil “] between the back of the prop backplate and the flywheel.

Maybe the 2.125 spacers is to give you some extra cowl clearance? Maybe 2.125 is the actual thickness of the prop hub, so one have to deduct the thickness of the back plate. Comments and confirmations appreciated.

As you can see I have fitted the actual prop back plate, so remember the flange than turns back
spin_flyw_2.jpg


spin_flyw_1.jpg
 
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OK, I am going to answer my own question here for future reference RV10 builders.

So I made contact with Hartsell and asked them about my prop & hub STD VANS RV10 [C2YR-1BFP/F8068D. 80? diameter, ?blended airfoil ?] and spacing, I send them the Vans Drawing and they made these comments on it.
It is NOW VERY CLEAR.

prop_sim_detail.jpg


If you are using the Actual Spinner Backplate as a prop simulator then:
Your Flywheel spacers will be the distance of 2.247" MINUS the thickness of the spinner backplate material. Remember this depends if you have the doubler ring installed or not.

If you are using a flat plate then your flywheel spacers is 2.247 MINUS the skirt length of the Spinner Back Plate.

I am not home to give you those thicknesses of those items though, but at least you can calculate it perfectly.

I hope that clears it up.

Regards
Rudi
 
Rudi,

Thanks for the follow up!

I'll be tackling this step in January. That is assuming my engine actually ships this week. (Lycoming was suppose to ship on 11/1)

bob
 
I am looking at using the 3 blade Blended Airfoil Hartzell prop and it has a dedicated spinner. Does the spinner include the back plate and spacers in this case? If so I can just order that and use that to work up the cowl spacing.
 
OK, I am going to answer my own question here for future reference RV10 builders.

So I made contact with Hartsell and asked them about my prop & hub STD VANS RV10 [C2YR-1BFP/F8068D. 80? diameter, ?blended airfoil ?] and spacing, I send them the Vans Drawing and they made these comments on it.
It is NOW VERY CLEAR.

prop_sim_detail.jpg


If you are using the Actual Spinner Backplate as a prop simulator then:
Your Flywheel spacers will be the distance of 2.247" MINUS the thickness of the spinner backplate material. Remember this depends if you have the doubler ring installed or not.

If you are using a flat plate then your flywheel spacers is 2.247 MINUS the skirt length of the Spinner Back Plate.

I am not home to give you those thicknesses of those items though, but at least you can calculate it perfectly.

I hope that clears it up.

Regards
Rudi

Following up on an old, old post for clarification.

What cowl/spinner gap does this method produce?

(I've been chasing a complete summary of prop/spinner clearance for two days and cannot find one post that puts all of the pieces together.)

PS, I'm looking to net a 1/4" cowl/spinner gap.
 
Doesn't hurt to ask...

Anyone ever made a jig to fit the cowl without an engine mounted?

Or is this a risky and therefore dumb idea?

Be neat to be able to do this before the engine is purchased/hung if feasible - but I doubt it is. Too many variables, I suppose...
 
Flyboy's rents a really nice cowl installation tool that worked very well for my RV7 cowl and MT prop installation.
 
Flyboy's rents a really nice cowl installation tool that worked very well for my RV7 cowl and MT prop installation.

Great. Now all I need is a jig to affix it to the engine mount in place of the crank and case.

I guess this dilemma is what unsalvageable cases and cranks get repurposed for.
 
Two of my friends and I (the 2 Redline Pilots) bought the Flyboys cowl installation tool together for our new RV8 projects. All three of us have used this tool, and it works great - but you need to have your engine mounted. You don't need to have your prop yet (I don't), but even if you do have it, you don't use it until the cowl is finished. It takes the guess work out of positioning the front of the cowl. It holds the front end of the cowl firmly in the correct position and allows you to more precisely fit the tricky aft edges and the sides to get a really nice fit. We bought ours, but I think you can rent it from Flyboys.

http://www.flyboyaccessories.com/product-p/1502.htm
 
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