WANTED: 72" prop for soob belt reduction pusher

[C5Engineer 1170]

My Dad is building a Soob powered hovercraft this winter . It will have a belt drive reduction so prop is spinning the same as the engine in a pusher configuration. He asked me to keep my ears open for a 72" prop for it. He has a couple of Ivo hubs if anyone has some blades laying around.

[EDMO 1078]

Joey,

      There were some Warp Drive blades and hub and prop - pushers - on ebay recently.  I need the puller blades.   Your Dad and I must think alike - I almost made a HC using the 532 engine.  I repaired a big HC too.

EdMO

Edited 16 Jan 2014 by Ed In Missouri

[lostman 198]

Is he set on having an Ivo or would he consider something else? Never know what I'll run across. Plus I custom build props from wood.

[1avidflyer 1983]

I've got a like new  74X52 Culver prop that came with my last Avid MK IV.  I think it was for a 618 Rotax, as the 74X49 Culver is what came on my first MK IV with a 582 and it was just right.  It's a left hand, not sure if that's what you need or right hand.  Jim Chuk

[akflyerbob 41]

C5

I have two sets of  iVO pusher blades

I'll measure them tomorrow and post a pic "maybe" on the pic

[C5Engineer 1170]

Thanks everyone he is not set on Ivo he's just trying to stay on the cheap and has the room to run a large diameter prop.

[EDMO 1078]

Joey,

      As an old retiree, I try to stay "on the cheap" as much as possible - If your Dad has a set of 72" tractor blades and a hub that fits a Soob, I might be interested if he wants to get rid of them.

      Otherwise, I will keep looking for some Warp Drive blades to fit my hub, or a WD prop.

EDMO

Edited 17 Jan 2014 by Ed In Missouri

[akflyer 1427]

if he is spinning in the right direction, cant you just put a tractor prop on backwards?  it would be sorta pulling, not pushing, but it shouldnt matter if rotation is correct.

 

[akflyer 1427]

and this thread is WORTHLESS without pics!  I have been thinking of a hovercraft myself.. It would be the ticket for up at the lodge as long as I could lift 600-100 pounds.. how big of one is he building?

 

[EDMO 1078]

Leni, the tractor prop cant be used as a pusher - it just don't work that way.  backwards, the leading edge becomes the trailing edge - unless they are symmetrical, and I don't know about the Ivo.

EDMO

Edited 17 Jan 2014 by Ed In Missouri

[akflyer 1427]

if its spinning the right direction it works.. or it has in the past for me in other applications.  The issue is if your trying the spin the tractor prop in a reverse direction, then of course that wont work. 

[1avidflyer 1983]

Tractor 2 stroke Rotax gear box prop is same as  belt drive Rotax 2 stroke pusher.  Both use a left hand prop. 912 Rotax turns in the opposite direction as the Rotax 2 stroke.  Not sure what direction the Suberu turns in.  My Culver prop is a left hand.  Jabiru tractor used a righthand prop, just like a Continental.   Jim Chuk

[EDMO 1078]

Soob turns right - from the pilots seat - like all "real airplane engines".  

EDMO

Edited 17 Jan 2014 by Ed In Missouri

[Av8r3400 1179]

Soob turns right - from the pilots seat - like all "real airplane engines". 

EDMO

...depending on the redrive.

[EDMO 1078]

Oh yeh - I fergot about them Eggen feller geared redrives - I was referring to belt drives like, Stratus, Ram, Reductions, RFI, etc.  U R Kerrecty, Mr.

EDMO

Edited 18 Jan 2014 by Ed In Missouri

[akflyer 1427]

sooo.. if its turning to the right in a tractor config, then it will be turning left in a pusher.  The rotax gear box prop is left hand.. Therefore, if you put a left hand TRACTOR prop on the subie in the pusher configuration with the front of the prop (same as mounted in the tractor configuration) pointed towards the front of the hover craft, wala, you have the tractor prop in the pusher installation.. Same thing Jim said, just laid out in a bit more detail.  It all comes down to the direction you are rotating the prop in the particular installation.  If it is belt drive, then the rotation will be the same as the engine.  Gear drive using 2 internal gears will reverse the prop or output rotation.  If you used a 3 gear system, it would put the prop back to spinning the same as the engine. 

 

I went through this on my electric RC planes using different gear boxes, some are 2 gear drive and driven external gears, some are 3 gear internal planetary drives.  It makes a difference and you have to reverse the wires in some cases to get the prop to turn the right direction.  in pusher installs I was able to use the gear drives and reverse the rotation on the prop to use a tractor prop in the pusher configuration.

 

Joey, we got ya confused yet

 

[EDMO 1078]

There you go Joey - Your Dad don't need a new prop - Just a new redrive that turns opposite!!!

EDMO

[akflyer 1427]

nope, your still missing the mark on it Ed... he should be able to run a tractor prop on it with the prop flipped on the hub.. if he is turning the prop to the right in a normal install with his belt drive.. 

 

[EDMO 1078]

Leni,

     I guess I spent too many years working in a prop shop - I think of props like the "real" ones - I know about model plane props, but not about Ivo blades - have never touched one - wouldn't the nickel edge be on the trailing edge if reversed?   Most "real" props have a cupped backside too.

Got me confused now!  Ha!

ED

Edited 18 Jan 2014 by Ed In Missouri

[akflyer 1427]

Leni,

     I guess I spent too many years working in a prop shop - I think of props like the "real" ones - I know about model plane props, but not about Ivo blades - have never touched one - wouldn't the nickel edge be on the trailing edge if reversed?

Got me confused now!  Ha!

ED

 

no, not if you flip the prop.. the same side of the prop will be facing the front of the hover craft as it would if the engine was in an aircraft in the tractor configuration.. think of it as the side the wind will hit in forwards motion.  all that will be different is the side if the prop that will be touching the engine.  The subbie turning right in the tractor config, will now be turning the prop to the left in a tractor install.  Therefore, the same prop will need to be used as that on a rotax 2 stroke instal using a rotax gear box.  The leading edge of the prop needs to turn to the left. 

 

In the tractor config, your sitting behind the prop and your looking at the "back" side of the prop from the cockpit looking forwards.  The "back" of the prop is bolted to the engine / gear box.  Now put that in the pusher config, still turning the prop to the left as viewed from behind.  You now have to have the "front" side of the prop bolted to the engine.  This makes that tractor prop (left hand prop from a rotax 2 stroke gear driven installation) the correct one in the pusher configuration because of the rotation you have using the belt drive. 

 

Clear as mud? 

 

[akflyer 1427]

Ed. When you worked in a prop shop, how did you guys flush out a prop that was run on an engine that had metal going through it?  as in, how did you flush it.  Or do you do a mandatory tear down and OH of said prop and there is no way to flush the old oil out?  I would think I would be able to flush it out and have it usable, but the IA is being a pain in the ass on this one..

 

[EDMO 1078]

Duh - You turn the engine around too - I never flew a pusher - Guess my HC would have flown backwards! 

I TINK I GOT IT NOW!   No I don't------If you turn engine around it turns toward left side of plane now, and it was turning toward the right side, and the prop is made to turn toward the right side, but by mounting it backward, you now have it turning left with the same blades - that just don't sound right?......

I DONT GOT IT EITHER, unless the blades are symmetrical.

Why do they sell blades as puller or pusher type if it would work either way?

EDMO

Edited 18 Jan 2014 by Ed In Missouri

[EDMO 1078]

mY "quote" still don't work - guess you eliminated it to cut down on traffic?

Leni,

     for your prop flush question - We torn down and did a O/H on all kinds of constant-speed props - VERY thorough and careful on inspections in a Certified Repair shop - The boss made decisions, I just worked on them.

     For the best answer to your flushing question, I suggest you call Jerry Alsup, owner of Dominion Propeller in Anchorage and ask him.  He is very easy to talk to.  Tell him I referred you to him.

     Sit down when you hear the price of an O/H.....You may want to put a Soob  and WD in it.....Ha!

ED Ashby

Edited 18 Jan 2014 by Ed In Missouri

[EDMO 1078]

Well heck - first you turned the Soob around so it turns left - then you swap the Soob tractor RH prop for a Rotax tractor prop which turns left, and mount it like a tractor prop backward instead of pusher  - OK.

No wonder I retired - getting too old - forgoet to take memory pills and cant find my calculater../.....

Thanks,

EDMO

Edited 18 Jan 2014 by Ed In Missouri

[lostman 198]

Is anyone else up drinking on a Friday night and laughing their ass off about this thread? I admit it's a brain twister but it is still funny to watch it unfold!

Thanks for the laugh guys!

Edited 18 Jan 2014 by lostman