morris penknife
 

I need info in how to build the servo trays for the penknife. the plane is framed up without plans. I'm not sure whether to put one or two servos for ailerons. please help

morris penknife
 

I can tell you how I'm doing my servo set up on a plane this size... I'm going sheet the bottom center section of the wing with 1/16" balsa. Top will be sheeted as well with 1/32 ply hatches. On the inside of the wing I'm going to run 2 1/8" x 1/4" spruce rails between the ribs. Next I'll cut an opening for the servo and mount it from the inside of the wing...

I think it'll work pretty slick with out adding much weight. I'll take some pictures as soon as I get it done.

Wing it...
 

Sorry, bad pun...but it's true. Paul's got it right by just adding a few hardwood servo rails in each wing-based opening. The sheeting sounds like a decent idea, although I never needed reinforcement in that area of the plane (I've had several Pen Knifes...and loved them!!!).

-Juhan


for some Pen Knife action:
http://archive.ncsa.uiuc.edu/Cyberia...n_knife_2.html

morris penknife
 

no, that was a good pun

I will wing it, I just wanted to know from some of you that have experience with the plane. Usually, experience is the best teacher.

ok 2 or 1 servo for the ailerons. I am using standard servos

thanks guys

morris penknife
 

I'm going with two hs 81 micro servos'... If you're going with standard servo's, I'd only use one.

morris penknife
 

paul-would you use the bell cranks or torque rods to accommodate the single servo set up???

morris penknife
 

I have 2 standard servos in mine but it does add weight. Im just out for fun though.

morris penknife
 

If I was to use the single standard servo setup, I'd put the servo in the middle of the wing and use two push rods from a two armed servo horn..

Don Incoll sets up his Wasp's like this:
http://www.users.bigpond.com/sirexwasp/images/1ey.jpg
Wasp Site

morris penknife
 

Paul,

I got it. A picture is worth a thousand words. Thanks for all the input!!

Greg

That's nutty...
 

How do you get to the servo horn screw....through a hole drilled through the fuse (which can't be good on such a thin profile) or is it off center?

I'd also stay away from micros such as the 81. I've used 225s with good results, but you'll need to use the metal gears seeing that the control surfaces are huge and gears easily strip (on tail touches and the rudder or aileron taps the ground, etc). I've stripped three 225s on my Pen Knifes...either use standard servos or 225s (or the like) with metal gears.

Using one or two servos is completely up to you. Looks good with the one setup, although I've never tried it on the Pen Knife. (Thanks Paul for posting that pict.)

-Juhan

morris penknife
 

Juhan,

what is your set up for standard servos on your penknife??