Pendulum??

Hi Guys!! looking some planes on outerzone, found an tiger moth, 32" wingspan, and noticed a pendulum... i can imagine how it works.... always trying to keep the plane horizontal, and that sounds good.... BUT how effective is??

Cheers!

Pendulums !!! NOOOOOOO !

An old idea that didn't work particularly well in its day. I think Bill Dennis wrote a bit about them recently in Aeromodeller I'll see if I can dig it out but it was along similar lines to my opening statement. There was a thread on here that mentioned them too ( edit - just done a search and it is in the DH60 build thread)

With a stable design like the Tiger Moth you really don't need it.

With an elevator pendulum it makes launching very tricky as the inertia of the launch effects the pendulum and I remember reading somewhere an account of taking a pendulum to be used for the rudder up in a fullsize aircraft and in a balanced turn the pendulum does not move anyway
In the 1950's there were lots of weird and wonderful ideas for pendulums including ailerons and even throttle, often the models illustrated carried the caption 'as yet untested' which I think says it all.

I concur with Chris (Squirrelnet), avoid pendulums like the plague! You can put lifting tailplanes on scale models in the same box too - all they do is reduce the efficiency of the tailplane which, for stability, should lift DOWN rather than UP.

Absolutely - pal of mine built the APS Dart Kitten with pendulum rudder - never did anything other than spiral in - right or left, you name it. Passed the model to me. I glued the rudder in position, after which it flew fine! P.E Norman was an advocate of pendulum elevator and he somehow made them work from a hand launch - but never knew how he did it.
Mike

Yes....absolutely. With the weight factor too anything other than a medium sized model diesel powered would probably fail. As far as I know very few people have had much success with pendulums so frankly unless you have a model that is pretty unstable and are prepared to try a last resort pendulums are probably not worth the bother.

Are you looking at the Keith Laumar design - it seems he suggests pendulum is optional. I would be inclined to replace the sheet fin and tailplane with built up versions for weight saving but for my part would be favouring the Henry J Nichols design because I know that one flies well and is only slightly larger - 33ins span

Thought I would practice posting pictures and, well, show off too!!

My FF R/C assist model and the rubber powered Pacific Ace both single channel

Very nice!
Mike

The models look good Neddy, thanks for posting.

Here's a quick reminder on posting pictures, after loading the picture, you need to insert it where you want it in the text. So, after loading the picture, place the curser where you want to picture to appear, then hit the 'insert' button which will appear in the 'Attachments' line after you have 'added' the picture. I've inserted the pictures in your above post at the end of your text.

i've seen a few bolts for comp screws lately .Even got a couple myself Pendulums I tried it but with very limited success as the model has to be inherently stable anyway. Want to buy any .( Pendulums that is ) John O/T

what a lovely pair of models you have there sir.

Tony B

Thank all - and Andy - bear with me I am slow but so was the tortoise!

Neddy wrote: Thank all - and Andy - bear with me I am slow but so was the tortoise!

No probs Neddy - if you read way back in the threads, you'll see that most of us have failed to insert our pictures on our first few posts.

Pendulums certainly add a bit of excitement to free flight models. A friend built a model of the Farnham FC-1 Flycycle with a DC Wasp for motivation and pendulums on both rudder & elevator. The usual flight profile starts with a loop, which requires the person launching to dive flat on the ground as the model comes out of the loop at about 3 feet off the ground. The second loop generally runs out of energy and turns into an Immelman at the top, from which a more or less normal circling flight commences.

I must admit that when reading my ancient Aeromodeller (early 50's) magazines the descriptions of P.E. Norman's free flight adventures with his fast flying and solidly built models were quite inspirational. He was a legend and led the way so pendulums worked for him though I suspect that the crashery rate would have been high.

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