SLEC Li'l Cub build

[Geoff S]

Posted by Peter Miller on 09/10/2020 08:29:41:

That looks good. Like you I am a rough and ready builder and it always works. My regular remark is "You can't see it at 50 feet"

I didn't know that SLEC did ramin dowel. Thatmight need a bit of nose weight to compensate for the extra weight but it will be stronger although mine never failed.

I can't remember if SLEC had a copy of my original drawings but there could be slight variatipons between mine and the magazine ones. IT has been known.

I'm not an expert on identifying wood types but the dowel is very hard but doesn't feel heavy. All I can say is that it looks like the ramin dowel I've used in the past. Never actually seen hard balsa dowel. Perhaps someone else with the CNC parts and wood pack can confirm.

I'm designing a working Cub-type undercarriage which will probably be heavier than the one in the drawing. Most of it will be ahead of the CoG, I think. I'm also intending to cut a large hole from F2 where the undercarriage is 'stitched' in Peter's design which will allow the battery to fit further back if I can do it without upsetting the CoG.

Geoff

[Basil]

Martin, I have just had a look around for 4mm carbon tube. There appears to be more than a single thickness. What dimensions do you reccomend please.

Bas

[Martin McIntosh]

Looking at my model I think I used 5x3 mm, not 4mm which would be too small.

[Geoff S]

I'm looking at the construction of the L/E edge slats and I'm confused.

On the drawing it says they're made up with 1x 1/32nd and 2x 1/16th sheet (so total thickness 3.75mm in metric) yet the they seem to be 7.5mm thick when measured on the drawing.

However in the instructions in the magazine it's 3x 1/32nd and 2x1/16th ( total = 5.26mm)

The instructions are closer to the drawing but still somewhat thinner.

It doesn't help that SLEC haven't provided any 1/32nd sheet and balsa that thin isn't anything I keep in stock. I can try to laminate the slats from layers of 1/16th (1.5mm) or perhaps use 1/32nd ply.

What is the required thickness? And would it be OK to laminate with all 1.5mm sheet - assuming it would curve that much.

Geoff

[Peter Miller]

Go by the instructions. My original drawings match the instructions. These things get changed when the plans are professionally redrawn and I don't always pick them up when proof checking the plans.

[Geoff S]

Thanks, Peter. As I don't have any 1/32nd balsa I'll try using laminations of 1/16th (i've got stacks of that) and see how it works.

I'm not actually there yet but I was studying ahead as I waited for glue to set

Geoff

[Martin McIntosh]

I used 1/16th soft sheet wetted and taped on layer by layer using aliphatic. Probably about four from what I can remember.

[Geoff S]

Thanks, Martin. That's what I'll do, then.

This is an unusual but interesting build. I'm struggling in places but I'll get there in the end.

I have plenty of yellow Solartex but I think I'll try and get some HK film and save the Solartex for something else which doesn't mind the weight.

Geoff

[Peter Miller]

Yes, You can use anything that gives about the right shape. To be honest the old TLAR seems to work very well.I did similar ones on my LeGrand Simon some years ago.

Hobbyking film is great. It is as near as dammit to Supershrink Polyester

[Martin McIntosh]

You certainly do not need `tex on what is supposed to be a lightweight model. I now only use the HK stuff because it is easy to apply and a fraction of the cost of Oracover.

[Geoff S]

Made a bit of progress and the outlline fuselage structure is complete and ready for undercarriage, motor mounts etc. I've been careful to make sure the rudder post is vertical (square to the wing mounts on top of the cockpit). It's a bit awkward because the fuselage doesn't have a flat bottom and the fuselage jig helps a lot (with some old batteries saved especially for their weight ).

.

Geoff

Edited By Geoff S on 14/10/2020 13:11:39

[Claes Meijer]

Hi, My small video on a scaled down build in Sweden
Its a great plane this Lil Cub design Peter

https://youtu.be/p9fsIwlY-sY

[Dwain Dibley.]

Very Nice Claes.

Hopefully Geoff will be back on this one soon.

D.D.

[Peter Miller]

Very good. Have fun

[Geoff S]

I'm afraid I haven't done much to my Li'l Cub lately. I've done a few odd jos on other models in the (vain?) of actually being able to fly again eventually. I've improved the battery hatch lid catch on my Mew Gull (it tended to come open and act as an air brake) and I'm going to fit working rigging (landing and flying wires) to my Sopwith Pup.

I've made the leading edge slats but not the way either Peter or Martin made theirs. Mine are built-up! I cut some formers to the outliine on the drawing (I have a PDF copy, which helps) and sheeted it with 3mm balsa and covered them in glass cloth and epoxy. SLEC didn't supply the thinner balsa in the woodpack and I find cold moulding a bit of a pain. It seems to have worked OK. I'll fit the spacers and paint the whole thing before I glue them to the wings.

Most of the airframe is done. I just have to make an undercarriage, design the motor mount and battery box, make a dummy engine and cover. It's just lack of will power

Geoff

[Mark H75]

Hi all, bit late to the party. I really like the look if this model; are there any plans available as I've had a clearout and I must have thrown them away.

Mark

[Peter Miller]

Posted by Mark H75 on 20/01/2021 16:01:33:

Hi all, bit late to the party. I really like the look if this model; are there any plans available as I've had a clearout and I must have thrown them away.

Mark

I have sentyou a PM

[Geoff S]

It's a while since I posted anything about my build but I have actually been making progress, albeit in fits and starts as I found a little motivation.  I'm now at the point of glazing the cockpit.  The side glazing seems fairly straightforward but, as always the windscreen is less so.  I've made a paper template as my stock of (mostly rescued) clear acetate is limited  and I'd like to make it right first time.

 

I'm just wondering if it's better to stick the glazing on to the bare wood and then cover with film or to cover first and stick the glazing (with Zap canopy glue) to the film.  Any advice?

 

I'll post a few pictures later.  The fuselage is well on the way to completion. The wings are built but I have to mount the four servos for ailerons and flaps and attach the l/e slats and the struts so it should be finished before we're able to fly again - assuming that happens ?

 

So cover first, glazing second or vice versa?

 

Geoff

[Ron Gray]

I tend to cover first then glaze.

[Geoff S]

Thanks, Ron.  I'd more or less come to that conclusion so confirmation is helpful.

Geoff

[Ron Gray]

Easier to finish covering at edges of cockpit than to cut it into canopy, well that’s my logic!

[Peter Miller]

On 17/03/2021 at 11:26, Ron Gray said:

Easier to finish covering at edges of cockpit than to cut it into canopy, well that’s my logic!

Yes,always.

[Basil]

I am a returnee of old and am enjoying this build.However I am at rather a loss as to how to install the controls from servo to Rudder & Elevator. 'Easy' is what I can hear echoing around the forum. But for a newby or returnee unfamiliar with modern thinking and availability its a minefield. I am using mini servos from 4max and snakes/quivklink from SLEC. Firstly the holes in the servo arms are to small to fit the quick link and those items I am aware of  so after enlargment (say 2mm) not a lot of meat left. Then what do you use at the other end, whatever must connect with the 2mm plastic inner rod. What can you use to connect with the control surfaces.Once again these small scale parts have only small holes.

I expect after seeing the replies( Thats if there are any )I see its so logical I'll want the ground to open up and swallow me. I have had similar problems with the few models I have made , none have flown yet so I cant vouch for the parts used.

Bas

[Peter Miller]

I gather that you just bought SLEC snakes without the clevises.  SLEC sell 2 mm threaded rods about an inch long (Product Code: SL017-R)

These will screw into the ends of the hollow snakes and then you can screw on a metal clevis

Product Code: SL016B-R

 

If you have the solid inners to the snakes Slec sell metal ends (Product Code: SL016C-R)

snakes which can be crimped on to the snake or glued on with CA. Again the metal clevis screws on.

 

Hope this helps

[Geoff S]

I've realise that I never added to this build thread.  I have actually finished the Cub but my attempt at aviation was less than stellar.  I tried flying at our new flying site which is grass as opposed to the tarmac at our old one. As you can see from the attached photos the grass is a bit long and I suspect the flying speed was too low on take-off and it never really got sufficiently above stall speed. The return to ground required a few minor repairs which have been completed.  What with that and the pandemic I haven't actually flown for months.  Fortunately we're going to keep both sites going for the coming season so I'll have both this and the Rans Chaos to test fly in a week or two.

 

In the meantime here are a couple of pictures taken before the abortive test flight.

 

 

 

 

 

I used 3mm carbon tube, which has a 2mm dia hole which takes 2mm threaded rod epoxied in place.  I use stainless steel clevises at the control surface end and plastic ball joints at the servo.  This provided very positive control with no intermediate supports and blend well with the 'carbon' (balsa dowel) open fuslage structure.

 

Geoff