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Building Tips and technical articles. => 1/2 A building. => Topic started by: Fred Cronenwett on February 24, 2014, 11:25:12 AM

Title: 1/2a Propeller
Post by: Fred Cronenwett on February 24, 2014, 11:25:12 AM
Where is the best source to get propellers for the Cox black widow engines?

I found an APC prop in the right size but the hole size for the screw on the prop is way too big on the APC prop

Thanks,
Fred
Title: Re: 1/2a Propeller
Post by: Tim Wescott on February 24, 2014, 11:29:01 AM
APC claims to have adapters available.

I machined a few from aluminum.

I've heard from folks on this group that a bit of fuel tubing works well.
Title: Re: 1/2a Propeller
Post by: ray copeland on February 24, 2014, 01:48:54 PM
Fred, i still like the old cox 5x3 on a black widow. Available from the coxengines folks (google coxengines) for around $2.50 ea. sku# 5x30000 i believe. I don't care for the ones with safety tips. Also, for the apc props, i like to use tygon yellow fuel line for spacers.
Title: Re: 1/2a Propeller
Post by: Fred Cronenwett on February 24, 2014, 03:00:24 PM
thanks guys....I knew that had to be a simple answer and thought about making a spacer but fuel tubing is easier to work with

Fred
Title: Re: 1/2a Propeller
Post by: John Rist on February 25, 2014, 07:50:03 AM
I use two pieces of brass tubing. Forgot the size but one fits the prop hole ID and the other fits the shaft OD.  Cut them sightly short so that so that they don't interfere with tightening the prop.
Title: Re: 1/2a Propeller
Post by: john e. holliday on February 25, 2014, 09:57:32 AM
Contact Melvin at MBS Model Supplies.   He has the props and the adaptors.   
Title: Re: 1/2a Propeller
Post by: kenneth cook on February 27, 2014, 06:25:55 PM
           I had some input in the design of these adapters. http://www.ebay.com/itm/APC-Prop-Bushing-for-1-2-A-Props-Brass-Propeller-Bushing-Buy-5-get-the-6th-FREE-/251462760149?pt=Radio_Control_Parts_Accessories&hash=item3a8c5  They work with the APC 5x3 and for the smaller props like the 4.2x4 you will need the plastic APC bushing and this metal one will fit inside of it. Ken
Title: Re: 1/2a Propeller
Post by: Phil Krankowski on February 28, 2014, 07:39:13 PM
If you are crashing still the rubber ducky Cox props are good (they are not great though).  They are a lot less powerful than Master Airscrew, APC, and the rigid Cox competition props.  This loss is primarily due to flex, which makes them resist breaking in grass and dirt crashes.

Phil