Author Topic: reede pusher (Read 2845 times)

bob werle · « **on:** March 24, 2013, 11:04:30 AM »

If I use a Cox reed valve as a pusher do I just run it backwards with a standard prop or do I need a l/h prop?
Bob

Curare · « **Reply #1 on:** March 24, 2013, 07:43:59 PM »

You'll wear out the drive washer apparently, you reall should get one of the brass ones from cox international.

Andrew Tinsley · « **Reply #2 on:** March 25, 2013, 05:51:59 AM »

You will need a pusher prop! Again available from Cox International or Ex Model engines.

Regards,

Andrew,

Larry Renger · « **Reply #3 on:** March 25, 2013, 09:01:01 AM »

Since reed engines run either way, I don't understand the comment on the need for a pusher prop (unless that was a joke?)

Paul Smith · « **Reply #4 on:** March 25, 2013, 01:17:17 PM »

Obviously you don't need a left-handed prop unless there's an issue of using the spring starter.

I would be leary about pushing the crankpin into the reed and also the lack of a proper bearing surface with the thrust going the wrong way.

Andrew Tinsley · « **Reply #5 on:** March 25, 2013, 04:28:35 PM »

Sorry Guys,
A senior moment, you are of course correct! You don't need a pusher prop, as long as you run the reedy in the opposite direction to normal AND you put the prop on BACKWARDS to normal.
I picked up a load of ultra cheap, pusher props when Estes had their fire sale of Cox material (reedies at a few dollars each!). So when I made up some pusher, free flight delta models, I just used them , hence my unthinking incorrect advice! I must make sure that brain is engaged before putting fingers to keyboard in future!
I used the brass prop drivers plus the thrust washer that were recommended. Despite the dire warnings of premature wear, I didn't find it to be really noticeable and those deltas were flown pretty regularly over a season.

Regards,

Andrew.

Tim Wescott · « **Reply #6 on:** March 25, 2013, 04:34:12 PM »

Quote from: Paul Smith on March 25, 2013, 01:17:17 PM

I would be leary about pushing the crankpin into the reed and also the lack of a proper bearing surface with the thrust going the wrong way.

The crank pin would ride on the reed housing and not the reed, if that were an issue.

But if you look closely at your COX engine while you move the crank through its end play, you'll notice that the prop driver hits the crankcase first -- hence the advice to use a brass prop driver (because brass against aluminum is a much happier combination than aluminum against aluminum).

Do you really need a brass prop driver?

Andrew Tinsley · « **Reply #7 on:** March 26, 2013, 04:34:17 AM »

Hello Tim,
I don't know if you really need a brass prop driver or not. I had them to hand, so simply used them instead of finding out the hard way! If you use a washer behind the prop driver, then perhaps not.
The washers that I used (standard Cox items) were quite sufficient to make sure that the crank pin didn't interfer with the plastic reed housing. I suspect that it may be a bit of a none issue, but being a cheapskate, I decided why risk even a cheap Cox crankcase!

Regards,

Andrew.

bob werle · « **Reply #8 on:** March 29, 2013, 11:37:32 AM »

The motor in questionhas the oldwe style tank with the reed held in place by the spring clip. Is this still a problem? What size washer would be required to put between the thrust washer and crankcase?
Bob

Larry Renger · « **Reply #9 on:** March 29, 2013, 09:01:34 PM »

The correct washers are available through Cox. See their ad in this forum.

John Rist · « **Reply #10 on:** April 13, 2013, 01:00:59 PM »

Quote from: Larry Renger on March 29, 2013, 09:01:34 PM

The correct washers are available through Cox. See their ad in this forum.

I am running a Madallion LH crank in a pusher format. At Cox all I see is steel and fiber washers. Whitch would be best.

By the way it is in a DO-335 - the front engine provises all the cooling for both engines.

Larry Renger · « **Reply #11 on:** April 13, 2013, 06:15:34 PM »

Both types of washers work, but I would go with the metal if convenient.

Andrew Tinsley · « **Reply #12 on:** April 16, 2013, 07:07:31 AM »

Hi Motorman,
I have had great success with reedy powered canard pushers. These have been free flight and the later bigger ones have been R/C with twin Bees pushing away merrily at the rear. I have used brass prop drivers and steel washers behind the drivers as explained above. wear has been minimal (means I can't see any!).
As for overheating, well once the planes have come down they don't seem to be over hot and there are no signs of the engines sagging. Maybe it is because I run them quite rich, I peak the engines on the NV and then back off about a 1/4 turn. The sheet canards don't actually need all that much power to fly them. If you wanted peak power then maybe you would have a problem.
I suspect that over hot runs will encourage varnishing. I am quite religious when it comes to looking after my reedies. At the end of the season, they get stripped down, thoroughly cleaned and new o rings and gaskets get put in. I then use after run oil and make sure that it gets everywhere!. I also make sure there are no air leaks, the crankcase rear will get the treatment if the tank mounting screw holes are raised through over tightening and so on. After hibernation, they will start very easily in the Spring.

Andrew.

jim gilmore · « **Reply #13 on:** April 17, 2013, 09:15:37 PM »

OK, now i am confused. I distinctly remember cox selling a pusher car with a prop in the back and i think it had a babe bee as power ?

Larry Renger · « **Reply #14 on:** April 17, 2013, 09:48:58 PM »

They did indeed, but I have no idea how long the engines would last. Probably dirt did them in long before the drive washer could eat the crankcase.

RknRusty · « **Reply #15 on:** May 13, 2013, 11:03:35 AM »

I think those cars also had a thick aluminum clamp-on heat sink that fit over a special non-finned head. If it's an open air engine you could help it with a 5 fin head. That was available on Cox Texaco engines. You may find one now and then, but the 5-fin clamp ring and globee type drop-in plugs are available at Cox International and probably Ex Model Engines too. Just add extra head gaskets because they are very high compression, but they work very well. The engine may be cool enough when your plane is flying, but for bench running I would recommend running it in the direction that blows air over the engine.

John Craig · « **Reply #16 on:** May 14, 2013, 09:58:29 AM »

The car had a normal head. Once it was moving it was fine. 1/2as tend to run on the cool side.

http://www.ebay.com/itm/COX-RED-SHRIKE-RACER-12-LONG-N-R-/171036542762?pt=US_Radio_Control_Control_Line&hash=item27d292872a#ht_38wt_917

George · « **Reply #17 on:** May 14, 2013, 12:03:16 PM »

Long before the one on *bay was produced, Cox had a pusher car called the "Prop Rod" if I remember correctly. It had a normal Babe Bee in a pusher configuration. I never had one so I can't speak for how well it performed. It could be run freely or on a tether.

George

john e. holliday · « **Reply #18 on:** May 15, 2013, 08:48:11 AM »

I still have my Cox car with pusher Babe Bee .049 engine. My son and I used to take it up to the church parking lot and run it.

Larry Renger · « **Reply #19 on:** May 15, 2013, 07:32:20 PM »

Speed was impressive! But free running, they would go about 50 ft and spin out. Of course, that was WAY COOL!

mike londke · « **Reply #20 on:** May 16, 2013, 08:44:25 PM »

In response to John Rist's picture. John that is the coolest 1/2a model I have ever seen. NICE!