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        Build Log AA Lidberg TA 152 #16 Free Flight to RC Flight Kitbash Contest >>Sopwith Mike<<

#1 Sopwith Mike Oct 28, 2012 12:22 PM

AA Lidberg TA 152 #16 Free Flight to RC Flight Kitbash Contest >>Sopwith Mike<<
 
Well, here goes, as if I didn't have enough to do...

I bought Al Lidberg's short kit of the TA152H some years ago, and it's been waiting in the stack until there was a good reason to start building. What better than to take part in a Kitbash?

The kit has all the laser-cut formers and ribs but you buy your own strip. I'll post a picture of what you get later on: this is just to get started.

The link to the host thread which has the list of all builders, the impressive prizes (bags I a Peter Rake Sopwith drawing!) and the rules is here

Since the 152 is one of my all time favourite aircraft, I'm really looking foward to this, and thanks to Murocflyer for initiating it.

Mike

#2 davidterrell80 Oct 30, 2012 09:33 PM

I'm in and sub'd... knock 'em out, Mike. I'm going to build a 30-inch Blackburn Skua.

#3 Sopwith Mike Nov 02, 2012 07:37 AM

4 Attachment(s)
I don't suppose it's necessary to describe the genesis of the TA152 to a group such as this: suffice it to say that it represents the pinnacle of German piston-engined fighter development during WWII and came in at least two versions; the H, with a long wing for high altitude interception, and the C which had a standard wing. The kit models the "H" version.

I have been fascinated by this plane since I was at school, and kit-bashed a Keil Kraft FW190 into the TA152H when I was about 16, but the crude prop and rubber motor didn't provide much in the way of performance!

The Al Lidberg short kit is still available, though mine is 10 years old and as I said, has been in the stack for some time. I drag the plan out every year or so and then put it back again...

The laser cut parts fall from the sheet and will form the basis of the model. Only the wing section is unsuitable, but I think that using the kit ribs as the top of the wing with some matching 1/16th to make the Clark Y profile will give sufficient rigidity to cope with the additional weight inherent in an RC conversion.

I'm not going to add detail. No retracts or flaps for me, in fact probably only aileron/elevator and SC with Litespan covering. This will keep the weight of the model as low as possible, retain its performance on a small motor and 2-cell lipo and keep it in the spirit of the kit.

I have a couple of motors to try: the first will be a 25g "Blue Wonder" with a 10A controller. These motors are great and I'm sure will provide enough power to fly. I also have a 2812 in reserve. Both run on 2 cells and drive a 9" prop. The GWS 3-blade 9x6 should look very nice.

This is my first laser-cut kit for a while...what do I say? "Pressing out parts soon?"

#4 Steve85 Nov 05, 2012 06:46 PM

Oooo...I'm subbed in! Taking a break from Depron, I see!

How big is she?

Steve

#5 Sopwith Mike Nov 06, 2012 02:57 AM

Hi Steve,

She's 40" span, so quite big for a rubber power warbird.

I'm iimpressed by the progess on your Lancaster and am looking forward to seeing that one fly.

#6 Sopwith Mike Nov 08, 2012 09:29 AM

1 Attachment(s)
I made a start this afternoon by drawing up and cutting out a dihedral brace from 1.5mm ply and glueing on the lower 1.5 sq bass spars. The scale dihedral is 2.4" per side compared with 3" for the free flight version, so not much difference there.

I'm going to make a D-box using 0.8mm sheet and, as I mentioned, increase the rib depth from the given 8% to nearly double that.

I'm using Titebond throughout (I hate CA) so there is a bit of waiting/changing mind time involved which I think is a very useful feature of ordinary glues ;)

#7 Sopwith Mike Nov 09, 2012 06:25 AM

3 Attachment(s)
On to re-profiling the ribs by adding a 1/16th strip undeneath and shaping to Clark Y. My solution is not quite so elegant as glewis's solution posted on turbojoe's Bonanza thread but pretty well as simple.

I started adding ribs to the port wing panel and so far everything fits together well bearing in mind that I have added a false LE.

#8 glewis Nov 09, 2012 11:36 AM

What is the span of this one?
Rib mod looks good, what does the final profile look like?

My vote goes to the Blue Wonder.
Just put one in my P-39 to replace the DIY motor that smoked running it on 3 cells.
It spins a GWS 8x4x3 with authority on 3 cells and should pull my model vertically with ease.
Glenn

#9 Sopwith Mike Nov 09, 2012 12:43 PM

This is a 40" span model and the final rib profile is a close to Clark Y as I could get without actually scanning each rib to the right size.

I'm hoping to produce a model that keeps the spirit of the original, so I think a Blue Wonder on 2 cells with a slightly larger prop (9x6?) will be fine. If I can get the plane to fly hands off for a minute or so, I reckon I will have more than succeeded!

Incidentally, how do you attach a GWS prop to the motor? Mine has a plain shaft, not the theaded type, and would really like to have a scale spinner. I plan to use a 2-blade prop for flying and a 3-blade for static display.

Mike

#10 glewis Nov 09, 2012 02:47 PM

2 Attachment(s)
I replace the shaft with a threaded one from a GWS gearbox.
The prop is mounted with a nut.
The spinners on these rubber models are usually vacu-formed. I make a ply back plate that is put on the shaft before the prop. The spinner has a balsa disk fitted into it. The disk has a hole that just a piece of fuel tubing just fits into. The tubing is glued into the front inside of the spinner and the balsa disk. The spinner mount tubing just presses onto the exposed end of the threaded shaft.
Here's a pic of my P-39 spinner for reference.

I hate prop adapters on a scale model, there's no way to hide them. You could find a prop adapter for a spinner that has the threaded hole in front.The spinner is held on with a screw that threads into that hole.

Glenn

#11 Dave K Nov 10, 2012 10:58 AM

1 Attachment(s)
I built this plane a few years ago (built mine for rubber power free flight) and found the it very difficult to get the rudder to blend into the fuselage. The best solution I could come up with was to use blue foam and sand it to shape. When the foam is roughed in a coat of light weight spackle before your final sand will fill the small imperfections

Also if I remember correctly there were some errors in the plan/parts in the rudder area so be aware as you move forward.

Looking forward to seeing this one come together one of the coolest WWII birds for sure

#12 Sopwith Mike Nov 10, 2012 11:44 AM

Thanks Dave - I noticed that the fin base is very thick as per scale. The tailplane is quite thin though!

Glen - could you talk me through changing a shaft on the Blue Wonder? I have spare GWS gearbox shafts I could use.

The port wing is pretty well "finished" and I'll be building the starboard panel over the next few days, then do the ailerons.

#13 Steve85 Nov 10, 2012 07:21 PM

Glenn, that's a pretty slick spinner mounting trick. Definitely filing that one away for future use. I'd like to see how you swap out the BW shaft for the GWS shaft too.

Steve

#14 glewis Nov 11, 2012 02:37 PM

Shaft replacement. Part 1
 
Warnings and tools required.
This is not hard to do, but, and it's a big but, you MUST have the proper tools to do it properly. You can bust the bell or magnets and ruin your motor.
Ok, with the warnings out of the way, let's get started.

Tools required:
GWS 3mm gearbox shaft
The correct hex wrench for the setscrews on the BW bell.
A set of small 1/4" drive socket wrenches.
A vice to press the shaft out/in.
Dremel tool with cut-off disk.
Hand drill.
Small file set.
Digital calipers.
Small needle nose pliers.
Scotch tape.
A pin to finish pressing the shaft out. Needs to be less than 3mm diameter and 2-3cm long. I use a short length of 3/32" music wire.
Glenn

#15 glewis Nov 11, 2012 02:50 PM

Shaft replacement. Disassembly
 
Ok, got the tools? Let's get started.
First using the needle nose pliers, remove the E clip on the back of the shaft. Remove and save the small brass spacer (if installed). I put these two parts on a piece of tape and stick them to something so they don't wander off.
Measure the shaft protrusion from the bearing surface to the end of the shaft. Write this down, you'll need this dimension later.

Pull the bell off the motor.

Put a length of tape onto the magnets to cover them. This is not necessary, but will keep ferrous swarf from getting stuck to the magnets and protects them.

Remove the two setscrews securing the bell to the shaft.

Select a small socket that just fits over the shaft to act as the receiver in the pressing procedure. The socket needs to touch the small raised portion on the inside of the bell right where the shaft hole is. The socket size is about 5 or 6mm, don't recall but it is imperative the socket is as small as possible. If not the bell aluminum will be distorted during the pressing process.

Slide the socket into the bell. It will be necessary to use a tube or another socket to make the receiver long enough.

Next, pressing the shaft out.


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