stunthanger.com

Engine basics => Engine set up tips => Topic started by: DanielGelinas on April 30, 2011, 06:36:21 PM

Title: COX engine parts?
Post by: DanielGelinas on April 30, 2011, 06:36:21 PM

Hi all,

Anyone know where I can find a crankshaft for a black widow? The propeller shaft broke off after a touching ground with engine running. >:(
This really looks like a design flaw to me.  ::)
Never had this problem years ago with my cox engines. This is a brand new black widow.

Thanks,

-Danny

Title: Re: COX engine parts?
Post by: Clint Ormosen on April 30, 2011, 07:14:26 PM

Try the Cox International folks in the vendors section. Probably your best bet for a brand new one.

Title: Re: COX engine parts?
Post by: Tim Wescott on April 30, 2011, 07:22:40 PM

You say "propeller shaft" -- do you mean the bolt that holds the prop on?  That screws into the crankshaft, but isn't part of it.

Title: Re: COX engine parts?
Post by: Mike Callas on May 01, 2011, 02:14:28 AM

http://xenalook.com/

For a crank you might look at diesel davis cranks. They are on e-bay for $20.

Title: Re: COX engine parts?
Post by: Bill Little on May 01, 2011, 03:13:54 AM

Hi Danny,

Cox International has the crankshafts and the propeller mounting screws (which are 5-40).  Very reasonable pricing, fast shipping (from Canada).  I have done multiple orders from them and absolutely no problems.  There are two others, in particular, on ebay that I also have dealt with and they are good also.  I would try Cox International in the Vendors Corner like Clint said (xenalook on ebay), they are the biggest suppliers of Cox parts right now, anywhere, and are remaking more new parts all the time.  Plus they are listed here on Stunt Hanger. ;D

I also suggest getting their piston resetting tool and their drive plate installation/removal tool for the propeller drive plates.  Makes taking them on and off real easy with no damage.

Vendors Corner:
http://stunthanger.com/smf/index.php?board=69.0 (http://stunthanger.com/smf/index.php?board=69.0)

Online Store:

http://coxengines.ca/ (http://coxengines.ca/)

Crankshaft (best for you application):

http://coxengines.ca/product.php?productid=402&cat=26&page=5 (http://coxengines.ca/product.php?productid=402&cat=26&page=5)

Prop screws:

http://coxengines.ca/product.php?productid=101&cat=26&page=7 (http://coxengines.ca/product.php?productid=101&cat=26&page=7)

Piston Setting Tool:

http://coxengines.ca/product.php?productid=280&cat=41&page=2 (http://coxengines.ca/product.php?productid=280&cat=41&page=2)

Drive plate removal tool:

http://coxengines.ca/product.php?productid=305&cat=41&page=1 (http://coxengines.ca/product.php?productid=305&cat=41&page=1)

Drive plate installation tool

http://coxengines.ca/product.php?productid=305&cat=41&page=1 (http://coxengines.ca/product.php?productid=305&cat=41&page=1)

The tools can be used over and over on all Cox .049 reed valve engines, plus they have a piston reset tool for the .020.

With running, the socket in the piston holding the connection rod loosens (flange spreads), and the setting tool tightens it back up.  Restores the power, and can keep the con rod from coming through the top of the piston if it gets really worn.  Just use a small hammer to tap the slotted rod which fits over the end of the rod and matches the socket in the piston head.  There is a hole in the provided block which holds the piston square and allows the flange of the socket to be deformed back in to the original shape and the proper clearance is set.  The socket starts to loosen up pretty quickly, but using the tool is a snap.

There is a de-varnishing brush available to remove carbon build up on the sleeve wall.  This helps performance a bunch after the engine has been run a good bit.  Very similar to a rifle barrel cleaning brush (but I do not know the caliber)

Look around the site and you will find all sorts of goodies.  Great selection of Cox props, also!

Big Bear

Title: Re: COX engine parts?
Post by: DanielGelinas on May 01, 2011, 07:53:51 AM

Thanks for all the replies  H^^ H^^

Here are some pictures  to show why I believe the design is poor using the stock spinner, supplied with the engine.
Notice that propeller screw hardly threads into the crankshaft when using the supplied metal spinner.  :(

I believe the whole crankshaft assembly needs to be changed... :( what do you think?

Thanks all!!

BTW, the crash was a light landing in grass while engine was turning. When the prop broke off, the engine continued to run at a very high RPM for a few seconds before dying.

-Danny

(http://)

Title: Re: COX engine parts?
Post by: DanielGelinas on May 01, 2011, 07:54:43 AM

another picture
(http://)

Title: Re: COX engine parts?
Post by: DanielGelinas on May 01, 2011, 07:55:45 AM

last picture

(http://)

Title: Re: COX engine parts?
Post by: DanielGelinas on May 01, 2011, 08:04:53 AM

Here is a picture of the parts list for the black widow.

Looks like I need a new crank ??? ???

A longer prop screw would be a great improvement, in my opinion. y1

-Danny  H^^

(http://)

Title: Re: COX engine parts?
Post by: John Stiles on May 01, 2011, 11:43:12 AM

I have a complete .049 Baby B, I'll send it to you just PM me your address. ~john

Title: Re: COX engine parts?
Post by: Garf on May 01, 2011, 01:07:03 PM

I have a drawer full of lower ends for this engine. Let me know.

Title: Re: COX engine parts?
Post by: Brett Buck on May 01, 2011, 05:12:53 PM

Quote from: DanielGelinas on May 01, 2011, 07:53:51 AM

Thanks for all the replies  H^^ H^^

Here are some pictures  to show why I believe the design is poor using the stock spinner, supplied with the engine.
Notice that propeller screw hardly threads into the crankshaft when using the supplied metal spinner.  :(

I believe the whole crankshaft assembly needs to be changed... :( what do you think?

    You are correct. I have to say, I have seen any number of Cox crashes and never once seen the crank break. I have had TeeDee cranks fail in flight but never from crash damage.

    Brett