Keil Kraft Ace

Keil Kraft kits seem to be the flavour of the year.

This one is a favourite of mine after chasing the original for miles until it went bush.The kids were hanging out of the windows of the Holden giving me directions but the great god of thermals 'Hung' won that round as it disappeared vertically over the bush.

I recently built a new one, made a few mods to the design and added a viscous timer D/T.











Covering is Esaki tissue over Mylar for the fuselage, genuine pre-war (WWII) Japanese tissue on the flying surfaces, logos printed with my HP inkjet. The single prop blade has a covering of very light glass cloth with Zap Z-Poxy.

With a few loops of 3/32" Tan II rubber it flies very well and I am glad that I fitted the d/t as it wanted to join it's ancestor on it's 3rd flight after I tweaked the thrust line - took ages to finally come down.

Here are piccies, well worth building one and it also qualifies for P30 (with a plastic prop, a 9" Ikara would be good to try

).

I used my original K.K. plan but managed to find one here if somebody decides to build one outerzone.co.uk/plan_details.asp?ID=1344

* Danny *

Very nice Danny, thanks for posting...I do like the prop and wheels.

Is there any chance of a list of the mods you did to the kit, plus a description of any issues you had with the build and how you got round them. I'd also be interested in any info you have on the prop, esp the diameter and pitch.

Thanks in advance,
Andy

We were going way off topic on this one, so I've moved the discussion on lifting tails to a new thread - Model Aircraft Aerodynamics 2

Lovely little KK Ace Danny. I quite fancy having a go at outdoor rubber and it sounds like that may well prove a good first go.

Single bladed folding prop is a great addition and as Andy said more info would be great

The changes that I made were:

1. to add 1/16"x1/8" diagonals to the fuselage bays (to resist twisting due to enthusiastic winding); They really stiffened things up without adding much weight.

2. To replace the rear peg with an aluminium tube (to facilitate winding in my stooge).

3. Added a small viscous d/t timer and chamfered the front of the fin to allow the tail to tip and keyed the horizontal stabiliser for repeatability of location.

4. Laminated the nose block from 3 layers of 1/4" balsa and added a Peck Polymers nylon prop bearing. The rear of the noseblock and the face of the fuselage are faced with 1/32" ply and the front of the fuselage has a binding of Kevlar thread (to resist splitting). Added a spring to the prop shaft and a wood-screw at the rear of the noseblock to permit consistent folding at the same place with the rubber still slightly taut.

5. Laminated and carved the single blade folding prop. The folding portion of the blade is 6-1/2" long, the hub adds another 1/2", pitch is about 20". The prop is covered with 0.6oz glass cloth and Zap Z-poxy very thinly applied. Balance weight is a lead fishing sinker epoxied to the wire arm and filed to balance the opened blade.

6. Wing and horizontal stabiliser tips have small diagonal braces as my original model had a tendency to warp right there.

7. Wheels are 1-1/2" dia 1/32" ply discs with 1/16" balsa each side and aluminium bushes (left over-length to allow them to be gripped in my Dremel for sanding to profile then excess tubing trimmed off).

* Danny *

Squirrelnet wrote: Lovely little KK Ace Danny. I quite fancy having a go at outdoor rubber and it sounds like that may well prove a good first go.

Single bladed folding prop is a great addition and as Andy said more info would be great

It is an ideal model to learn the ropes but Fit a D/T!
* Danny *

Thanks Danny, that's all good info. I like the idea of a 1.5:1 pitch:diameter ratio on the prop, but I would have thought it too large for a model like this. It's nice to see that it works, however.

Next questions :

- You say you loaded a few strands of 3/32" rubber...how many strands and how long?

- What is the weight of the model without rubber?

- And what flight trim do you use for the power/glide: left/left, left right, right/left or right/right?

Again,
Many Thanks,
Andy

KK ACE was the first model I ever won a competition with.......As a 15/16 year old kid.
I did build a another about 35+ years ago, flew it and flew it and winning the prestigious Victorian Australia Garnham Trophy in 1983 by maxing out.
It did a re-cover not long ago and it was sold to a guy who just had to have it.......Enjoy, they are great of Bill Dean design.
I ran mine on 6 strands of 1/4, approx. 30 grams of it.

gossie wrote: >>>>> snip <<<<<
I ran mine on 6 strands of 1/4, approx. 30 grams of it.

Hi Howard old mate.

You must like the rocket climb. That's a decent bit of rubber for an Ace

12 strands of 3/32" Tan II is what I use in the old girl for a long lazy climb in our big paddocks with not much wind.
It turns the big single paddle enough on the initial burst to permit a 45° launch angle.
As I found with P-30's that if the model could slowly climb for a 90 sec motor run (in calm conditions) then it only had to hopefully glide for another 30 seconds for a max.

Also remember that modern rubber is usually a bit more lively than the stuff shown on the ancient plans.

* Danny *