Author Topic: Prop for OS 40VF (Read 2743 times)

Paul Raley · « **on:** June 17, 2011, 11:13:25 AM »

Any suggestions for the best currently available prop for a piped OS 40VF?

Thanks!
Paul R.

Peter Nevai · « **Reply #1 on:** June 17, 2011, 01:50:25 PM »

Quote

I would suggest trimming the prop down to 11.25 X 4, Is this a Bolly type CF prop? or does it have UC? The engine launch RPMs will be close to 11,000,(with the smaller prop) If you have pretty cool air this time of year I would also try 5% fuel with a pipe length of 18.25, pull the pipe out if you get slower RPMs. The 40 VF is happier on smaller diameter props that have less load, and it likes to turn them
The more loaded prop you put on the 40 VF the more you will have to lean it on the ground and it will unload more in the air
Randy

Something I pulled out of a old post here. I bet Randy will jump in and fill in the blanks. It is really best if you give us an Idea of what model the engine is going into, as it has a impact on the prop, pipe tuning etc.

Paul Raley · « **Reply #2 on:** June 17, 2011, 04:17:42 PM »

It is going in an Impact. I think Paul Walker suggested cutting a 11.5 x 6.5 Bolly down to 11.3 x 4.2 in the original Impact article, but (1) that is probably a task above my skill level and (2) I am thinking that Bolly props in this size may be scarce? Thanks for the advice so far!

Peter Nevai · « **Reply #3 on:** June 17, 2011, 06:00:08 PM »

By the sound of it, as you are not at the level of doing major prop mods, I'd stick with a commonly avaiable prop, like a 11 X 4 APC which puts you right into rhe hunt, You probably would not notice the subtle difference. Use the pipe length from Randy's suggestion and launch RPM. In your case fine tune by moving the pipe to work best with the chosen prop and fuel, till you get comfortable modifying props. You should be good so long as the model is not too heavy.

Steve Fitton · « **Reply #4 on:** June 17, 2011, 07:36:43 PM »

One of the Mezjlik props Randy Smith carries is a copy of the default Bolly that Paul W cites in his article. I have it downstairs but am too lazy at the moment to go down and get it to read the label. Randy knows which one it is....

RandySmith · « **Reply #5 on:** June 17, 2011, 08:42:06 PM »

Quote from: Paul Raley on June 17, 2011, 11:13:25 AM

Any suggestions for the best currently available prop for a piped OS 40VF?

Thanks!
Paul R.

Hi Paul

The magic 12.25 x 4.25 cut to 4 1/4 or 4 1/2 works as well as anything I have ever seen
The 12 x 4N 3 blade cut to 11 work well also
If you find any of the older Bolly's 11 3/4 x 4 1/4 , 12.2 x 4.2 they are excellent also

Randy

Paul Raley · « **Reply #6 on:** June 18, 2011, 05:26:41 AM »

Thanks for all the advice!

Randy, I will add one of those 12.25 x 4.25 props to my next order.

Paul R.

RandySmith · « **Reply #7 on:** June 18, 2011, 10:59:02 AM »

A quick bolt on setup might be the 11 x 4.5 Cyclone , 10% nitro fuel
I have a couple of people using this setup on an Impact

Randy

Brett Buck · « **Reply #8 on:** June 18, 2011, 11:10:10 AM »

Quote from: RandySmith on June 18, 2011, 10:59:02 AM

A quick bolt on setup might be the 11 x 4.5 Cyclone , 10% nitro fuel
I have a couple of people using this setup on an Impact

The APC 11.5-4 was designed for the 40VF, so that will work. I used one at the 94 NATs. The 12.25-3.75 was designed for the 46VF.

Brett

RandySmith · « **Reply #9 on:** June 18, 2011, 01:50:31 PM »

Quote from: Brett Buck on June 18, 2011, 11:10:10 AM

The APC 11.5-4 was designed for the 40VF, so that will work. I used one at the 94 NATs. The 12.25-3.75 was designed for the 46VF.

Brett

Hi Brett

That would be another quick inexpensive setup, I know the cyclone works well, both are cheap enough to try and see

Randy

Randy Powell · « **Reply #10 on:** June 18, 2011, 02:47:10 PM »

I've using a Thundertigre Cyclone 11 x 4.5 repitched to a bit under 4 pitch. that seems to work pretty well. I've also tried an 11x4 Bolly 3 blade I had hanging around that works pretty well. Last weekend, I was using a Steve Wilk 11.5 x 4 prop that is a copy of a Bolly that I like quite a bit. The last is a Steve Wilk prop that is an 11.5 x 4.5 "electric" prop (sort of a simitar bladed job) that is repitched to 4.

You have to get stuff in the area and just go through them until you find what works. I miss the Bolly 11.5 x 4. It sure worked well.

Peter Nevai · « **Reply #11 on:** June 18, 2011, 06:14:00 PM »

Guys, he mentioned that he can't repitch, so a off the shelf solution is what he is after.

Howard Rush · « **Reply #12 on:** June 18, 2011, 10:04:11 PM »

I found the OS .40VF to be sensitive to pitch (and not much else). I suggest finding or borrowing a Prather pitch gauge. I'll send you a pitch distribution that works with the Bolly 11.75-4.25. The magic diameter is 11.3". I would reckon that that applies to any prop you'd put on it.

Brett Buck · « **Reply #13 on:** June 19, 2011, 03:55:38 PM »

Quote from: Howard Rush on June 18, 2011, 10:04:11 PM

I'll send you a pitch distribution that works with the Bolly 11.75-4.25. The magic diameter is 12.3".

Oh, those typos!

Brett

Howard Rush · « **Reply #14 on:** June 19, 2011, 06:35:56 PM »

Thanks, Brett. I meant 11.3".

Randy Powell · « **Reply #15 on:** June 19, 2011, 08:57:55 PM »

Gee Howard, can you send it to me too?

I tried an old Gator prop on my 40VF today. It had been sitting around for years without use. It was originally something like a 13.75 x 4 narrow (really narrow) 3 blade that was binked and cut down to 11 inches. The Bolly 11 x 4 narrow three blade I was using earlier suffered a prop strike that pretty much wiped it out (there goes an irreplaceable prop) so I was scrounging around in my box for what sort of 3 blade I had that might work and came up with the Gator) Looks a bit clubby since it was cut down from a much longer unit, but it really worked well. I was surprised.

Steve Helmick · « **Reply #16 on:** June 19, 2011, 10:33:09 PM »

Steve Wilk (Eliminator Props in the Vendor's section) has Bolly 3 blade replicas in 12 x 4.25 and 13 x 4.25. They're nice props.

Steve

Joe Yau · « **Reply #17 on:** June 20, 2011, 11:43:36 AM »

Brian Eather has a 12X4 3-blade that could be cut down to 11.3". but I find that it needs to be less pitch at the tip to work. While the 11.5X4 KOI (Bolly copy narrow blade) 3-blade from Bob W (F2cracer) needs to be repitched up to 4.25 , and cut down to 11.3" to work.

Paul Raley · « **Reply #18 on:** June 21, 2011, 06:06:31 AM »

Thanks for the great advice on off the shelf props as well as some to modify. I spent some time browsing the archives and found some detailed explainations on repitching carbon props (this is a GREAT resource!) so the whole process seems less intimidating and I may buy a pitch gage and give it a try, in addition to buying a few off the shelf props to have as options.

Paul R.

Steve Helmick · « **Reply #19 on:** June 21, 2011, 01:32:17 PM »

Good luck finding a source for a pitch gauge. Since Prather went OOB, I don't know of a manufacturer. Maybe one of our laser owners would consider mowing out some Hooptee pitch gauge kits?

Steve

Randy Powell · « **Reply #20 on:** June 21, 2011, 05:15:37 PM »

Steve,

I made one of those and used it for quite awhile until I found a Prather. Got that just before they were no longer available.

Or you could go with the Dirty Dan solution.

Steve Helmick · « **Reply #21 on:** June 21, 2011, 05:54:24 PM »

Quote from: Randy Powell on June 21, 2011, 05:15:37 PM

Or you could go with the Dirty Dan solution.

Uh-oh. Should I ask? I thought the DD solution was to run an APC prop. Is there a different DD solution?

Steve