What is the recommended prop clearance for flying off of grass?   E power.

Thanks

Vince

Deepends on the Grass .

If youve got those Alloy Landin Gears , with bolt on wheels /

The size of the Tyres is CHANGEABLE . Anything less than 2 inch can tend to get caught . But Huge Tyres on little aeroplanes seem a bit odd .

3 inch , you feel the bump as the tailplane goes through the wake , in square bottoms .

Nylon Prop & Trike Gear , nominal 1/2 in clearance , ridgid gear . Wore 1/4 off on concrette - touch & go , in wind .( a bit of pressure )
Wore the L E Nice & Round ( opposite to picture , same shape tho ) . Next 20 or more flights on varying lenght mainly Kaikuia Grass .

Tips were buzzing through it , if the mower hadnt been out .

ANYWAY , If you can change your wheels , youve got a fix . Nicely Mown / Rolled and Team Race ' discus ' type ( Low Drag ) wheels ,
If grounds soft , theyll dig in , So Ballon Type better .





 

That is one great photo, Matt! 

Bob Hunt

Hi Vince
I presume this is about your fabulous new E-Imitation?

Prop clearance is good, but more important see if you can make up a special grass gear that gets the wheels forward - the more the better.  From your post in the E-forum, it looks like you are using the KR system - which is designed to protect the system if it noses into the grass, but still avoiding that is a good thing! 

From your pix it looks like you have a normal CCW rotation prop.  I am using reverse pitch (CW rotation) props exclusively.  A couple years ago up at the Weak Signals contest in Detroit, I had a nose-down & prop strike in the grass, which simply loosened the prop & spinner which just fell off.  The airplane stopped, the motor continued at a now silent shaft run - same RPM just no current load.  Only thing missing was a laugh track...

 
Hi Dennis,

You are correct, it is for my Imitation.  I did make a couple of changes and we have flown the airplane successfully since.  I went to a smaller prop (11 X 5.5).  I managed to find a set of longer landing gear (not sure how because I got rid of a lot of "stuff" when we sold our house and downsized last year.  I also went with a set of 2 1/2" wheels vs. the 2" wheels that I had on there.  Those three changes gave me enough clearance to feel comfortable flying off of grass, and it turned out to be just fine with clearance.

I was going to try one of Keith's KR timers, but I already had one of Will's profile timers in my parts box, so on it went.  I've been using the FM-9 timers in all my electric planes and feel at home with them.  I have it in mind to purchase and try one of the KR timers for a future airplane. The FM-9 is working fine, no complaints. 

I feel that the 11" prop is too small for my combination.  My lap times are in the 5.4 range and the line tension, although probably adequate by most standards, could be a little stronger to suit me.  I'm only using about 50% of my TP 5S 2800 battery, so there is room for changes.  I think I'm going to put the 12 X 6 back on there and see how it feels.

This is probably as good a place as any to ask this question.  I'm now living in a small townhouse.  No work area, no workbench, no vise.  I have no way to bend 1/8" landing gear wire without killing myself.  Do any of our vendors offer custom made, pre-bent wing mounted landing gear wires?  Brodak probably does, but I get so frustrated searching for stuff on his website.  You type what you're looking for in the search window and it comes back with 35 pages of stuff you've never heard of.  Don't know what search engine he uses but it needs a new set of plugs or a tune up of some sort.

I'd like to be able to give someone the dimensions I need and just order a set.

Signing off, wife is yelling that we're under a tornado warning.  Oh boy.

Vince

You could try Allen Brickhouse's "two vice grips" method.
http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=362565&mode=full&page=6

My smaller Vice Grips, about 8inch, has smooth jaws.  It's from my Dad's work bench about 1952.  The two relatively new Chinese  10in. copies have serrations on the nose of the jaws.  The older Vice Grips is more precisely built with better alignment.  I don't know if current Vice Grips tm are still better built.