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What a difference an inch makes…

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What a difference an inch makes…

Post  batjac on Fri Jun 03, 2016 4:16 pm

When I was out tweaking a Medallion .049 to go on my BTC-4M, I started out with a Cox 5x3 yellow rubber ducky.  I was getting 20.3K RPM on my tach.  Then I switched to a black 6x3 Cox prop.  RPM dropped down to 13.8K.  I knew it would be lower, but 6.5K lower?  That inch makes a LOT more difference than I thought it would.

Then, just for giggles, I put on a gray Cox competition 6x3 prop.  I got 15.3K on that.  I could live with 15.3 on a 6x3 prop, but the grey competition props break so easily and they're hard to find these days.

The reason I want a 6x3 is that I’m not that interested in speed, I want pulling power to pull the planes through the pattern maneuvers.  Maybe I’ll dig around in my boxes and see if I can find an old APC 5.7x3.  Those were good props.

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Re: What a difference an inch makes…

Post  RknRusty on Fri Jun 03, 2016 5:26 pm

If you have a Master Airscrew, it might be good. They're more durable than APC too. In fact, I have more of those than I'll ever use. I have a few people I've promised to send stuff to, including New222. If I get boxing and sending this week, I'll shoot you some MA props. I'm a terrible procrastinator, so don't turn blue waiting on them. I hope New hasn't passed out waiting on his plastic hemostats. I really do feel bad but I still manage to forget. If I can't find your address I'll PM you.
Rusty the slow.

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Re: What a difference an inch makes…

Post  RknRusty on Fri Jun 03, 2016 8:02 pm

Okay Mister Inch, I got a sack o' props for you, a few new MA 6x3 and a couple of black and white Tornadoes. And I picked out New's blue bladder pinchers, so I'm gonna box 'em all up and take care of my promises... at least the ones I can remember.

EDIT: When I looked up your address there was a note that said hemostats... did I ever send those to you?

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Re: What a difference an inch makes…

Post  batjac on Fri Jun 03, 2016 10:44 pm

RknRusty wrote:Okay Mister Inch, I got a sack o' props for you, a few new MA 6x3 and a couple of black and white Tornadoes. And I picked out New's blue bladder pinchers, so I'm gonna box 'em all up and take care of my promises... at least the ones I can remember.

EDIT: When I looked up your address there was a note that said hemostats... did I ever send those to you?

Rusty, Thanks for the generous offer. I'll make a test table and compare the different props and post the data here so everyone can get an idea of different props.

Yup, you did send me the hemostats a while ago. I used them just this afternoon. I was reminded again just how clumsy I am trying to get the fuel line unclamped before the prime runs out.

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Re: What a difference an inch makes…

Post  RknRusty on Sat Jun 04, 2016 10:18 am

You either need something to hold the plane or a thumb press point like my line over the top of the fuse shown below. Underneath if aesthetics is an issue.


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