Disaster Averted

[Joe Ed Pederson]

In the last few days I was going through my collection of props and was balancing all my 7" and 8" props for testing on my Fox .15x.

Thanks be to God that I noticed that the Master Airscrew 7 x 5.5 prop I had balanced IS AN ELECTRIC PROP!  

I'm still a little spooked by the story of the recent incident of a wood prop exploding and causing great injury.  I am being more conscious of getting behind and staying behind that spinning prop.

I almost missed that the MA 7 x 5.5 is for electric motors because the letters are tiny and hard to read AND unlike some props that visually just scream, "I'm really thin! Don't put me on an IC engine," the electric Master Airscrew props look nearly identical to their IC props (at least in these diameters) and (at least to me).

Needless to say, I'm taping highly visible notes on my Master Airscrew electric props and I'm going to double check that my electric props are kept separate from my IC props.

Joe Ed Pederson

[Scott Richlen]

It is all well and good that you expelled the unwashed from amongst the chosen.  But how do you de-contaminate those exposed to possible stray ions and electrons?  How do you know if any of them have been (shudder) polarized??  Science really doesn't have the answers to this.  And then there is simple pregidous - I recall one time when I nearly had riot in my flight box because I had inadvertently mixed in some Top-Flite 10x6s with my Rev-Ups.  Later on I found the prop-nuts had loosened on some of my Rev-Ups.  I knew it was the Top-Flites, but couldn't prove anything.

Best to double-check everything now.  You could have trouble brewing!

[Joe Ed Pederson]

It is all well and good that you expelled the unwashed from amongst the chosen.  But how do you de-contaminate those exposed to possible stray ions and electrons?  How do you know if any of them have been (shudder) polarized??  Science really doesn't have the answers to this.  And then there is simple pregidous - I recall one time when I nearly had riot in my flight box because I had inadvertently mixed in some Top-Flite 10x6s with my Rev-Ups.  Later on I found the prop-nuts had loosened on some of my Rev-Ups.  I knew it was the Top-Flites, but couldn't prove anything.

Best to double-check everything now.  You could have trouble brewing!

Scott,

Thanks for making me laugh, I will keep an eye out possible conflict between the nitro side and the electron side in my shop and flight boxes.  As the old saying goes, "One can never be too careful."

Joe Ed

[Steve Helmick]

While I'm not keen on using "electric only" props on IC, I know someone who does or did. He said his reworked wood props were virtually identical to the stock "electric only" propellers, so why not?

My view is that throwing a blade in the air is almost 100% sure to screw up your model in some way, and very possibly a total. I personally won't take that chance. I had a hot K&B .40 throw a blade on a 9-6 TF Super M on the test bench, and don't really remember much about that, except I didn't like it. I don't recall how I shut it off, but probably thumb down the venturi.

On my piped .46VF, I fumbled the ignitor into the APC prop and knocked the blades off. My late & great friend Gary Letsinger was launching, and he tried to shut it off by pointing the nose down. Doesn't work with a clunk tank. I put my thumb on the open end of the rubber ducky. Burned my thumb a little, but nothing serious. The key thing is to know how to shut your engine down when chit happens. Some will throw a rag in the prop, but you could also end up with a broken prop or NV by doing that. Blocking the exhaust is THE best way, IMO. Another reason I don't like tongue mufflers! Steve